GOSGORTECHNADZOR Guiding documents CFR
RUSSIA Gosgortekhnadzor RD-03-29-93
several types
METHODOLOGICAL INSTRUCTIONS
ON CONDUCT
TECHNICAL INSPECTION OF STEAM AND HOT WATER BOILERS, PRESSURE VESSELS, STEAM AND HOT WATER PIPELINES
EDITORIAL TEAM:
1. GENERAL PROVISIONS
1.1. These Guidelines determine the procedure for conducting technical inspection of steam and hot water boilers, pressure vessels, and steam and steam pipelines. hot water, which are subject to the requirements of the Device Rules and safe operation steam and hot water boilers, Rules for the design and safe operation of pressure vessels, Rules for the design and safe operation of steam and hot water pipelines.
1.2. The guidelines were developed to develop the requirements of section 6.3 of the Rules for the design and safe operation of pressure vessels, section 10.2 of the Rules for the design and safe operation of steam and hot water boilers, section 5.3 of the Rules for the design and safe operation of steam and hot water pipelines.
1.3. The guidelines can be used when conducting technical examinations both by the inspectors of the Gosgortekhnadzor bodies and specialists of organizations that have permission (licenses) to conduct technical examinations, and by departmental supervision services of enterprises.
1.4. The purpose of the technical examination is to check the technical condition of the facility, its compliance with the Boiler Inspection Rules * and determine the possibility of further operation.
1.5. Boilers, pressure vessels, steam and hot water pipelines are subject to technical inspection by an inspector of Gosgortekhnadzor before commissioning (initial) and ahead of schedule in cases provided for by the Rules. Specialists of organizations that have permission from the Gosgortekhnadzor authorities to conduct technical inspections carry out periodic inspections of these objects and are responsible for the quality of its implementation.
1.6. The enterprise administration is obliged to notify the Gosgortekhnadzor inspector or a specialist from an organization that has a permit about the upcoming survey. spend tion technical examinations, no later than 5 days before it is carried out.
1.7. Instrumentation, instruments and others required for technical examination technical means, as well as special clothing must be provided to the person conducting the technical examination by the enterprise administration.
1.8. All work to determine the condition of equipment during its design service life, related to the control of metal and welds, must be carried out in accordance with the requirements of the manufacturers' instructions and regulatory documents before the start of technical examination.
1.9. Technical diagnostics of boilers, vessels, steam and hot water pipelines that have exhausted their design service life must be carried out according to programs drawn up on the basis of the requirements of the Rules and methods agreed with the State Technical Supervision Authority of Russia.
The list of regulatory and technical documentation for technical examination and diagnostics is given in the appendix.
1.10. When technically inspecting boilers, vessels and pipelines in the chemical industries, one should also be guided by the requirements of the General Rules explosion-proof For explosive and fire hazardous chemical, petrochemical and oil refining industries and other regulatory documents from the list given in the appendix.
2. TECHNICAL INSPECTION OF BOILERS
2.1. General requirements
2.1.1. Before technical inspection, the boiler must be cooled, turned off and cleaned in accordance with the requirements of the Rules. Internal devices of the drum, if they interfere with inspection, should be removed.
In the event that the boiler is not prepared in a timely manner for internal inspection or hydraulic testing, it should be required to re-submit it for inspection and impose a penalty on the persons responsible for this.
2.1.2. Primary technical examination of newly installed boilers (with the exception of boilers that underwent technical examination at the manufacturer and arrived at the installation site assembled) is carried out after their installation and registration. Inspection of boilers with brickwork or insulation work is carried out during installation, it is recommended to carry out before complete nia these works. In this case, the inspection of the boiler is carried out before its registration.
2.1.3. During a periodic or early technical inspection, the person conducting the inspection has the right to demand the opening of the lining or removal of insulation in whole or in part, and in boilers with smoke pipes - complete or partial removal of the pipes.
The need for complete or partial removal of pipes, lining or insulation is determined depending on the technical condition of the boiler based on the results of the previous inspection or technical diagnosis, the duration of operation of the boiler since its manufacture and the last inspection with the removal of pipes, as well as the quality of the repairs performed.
For riveted boilers, it is necessary to remove the lining and thoroughly clean the rivet seams of the drums, mud traps and other elements of the boiler, as well as remove the lining and insulation from the pipes of the drain, purge and feed lines at the places where they are connected to the boiler.
2.1.4. Technical inspection of the boiler is carried out in the following sequence:
checking technical documentation;
external and internal inspection;
hydraulic test.
2.2. Checking technical documentation
2.2.1. During the initial technical examination, it is necessary to familiarize yourself with the design features of the boiler and make sure that the manufacture and installation of the boiler, equipping it with fittings, instrumentation, automation and alarm equipment and its auxiliary equipment comply with the requirements of the Rules, the project and the documents submitted during registration. The compliance of the factory and registration numbers of the boiler with the numbers written in the passport is also checked.
2.2.2. Before periodic or early technical inspection, it is necessary to familiarize yourself with the previously made entries in the boiler passport and the repair log. If the boiler has been repaired, you should check from the documents whether the requirements of the Rules were fully complied with when performing repair work (quality of materials used for welded joints, etc.).
Before periodically inspecting high-pressure boilers at thermal power plants, it is necessary to familiarize yourself with the results of checks and surveys carried out in accordance with the instructions of the Rules and documents issued by the ministries jointly with the Gosgortechnadzor of Russia or agreed with it (control of boiler metal, inspection of drums, bends unheated pipes, inspection of boilers that have worked beyond their design life).
2.3. External and internal inspection
2.3.1. Before inspecting the boiler, you should check the reliability of its disconnection from existing boilers and the implementation of other safety measures (presence of low-voltage lighting, ventilation of the combustion chamber and flues, deslagging combustion chamber, etc.).
2.3.2. In the drums, the internal surfaces are inspected, as well as welded and riveted seams, ends rolled or welded pipes and fittings.
In most cases, the internal surfaces of collectors, chambers and mud pans are accessible for inspection only through hatches or holes.
2.3.12. In horizontal water-tube boilers, due to overheating, cracks may form in the cylindrical part of the heads of the tube bundles, in the welded or riveted seams of the tube sheet, as well as deformation of the pipe walls. For these boilers, it is necessary to check the protection of the heads from overheating, the absence of bending of the tube sheets and sagging of the pipes.
Typical damage to boilers
2.3.27. When inspecting the bottoms of the drums, you need to pay attention to the welding zones of the corner gussets, anchor ties and adjacent smoke pipes, as well as the bridge between the holes.
2.3.28. A thorough visual inspection of the external surface should be carried out smoke pipes available for inspection, as well as bends pipelines within the waste heat boiler and feedwater and steam input pipes.
2.4. Hydraulic test
2.4.1. A hydraulic test of the boiler is carried out only if the internal inspection results are satisfactory.
Together with the boiler, its fittings are tested: safety valves, water level indicators, shut-off devices. If it is necessary to install plugs, they are placed behind the shut-off bodies.
external and internal inspection;
hydraulic test.
When inspecting a vessel, it is necessary to pay attention to possible deviations from geometric shapes (ovality exceeding acceptable, deflections, dents, otdulids, misalignment etc.), as well as the presence of hatches required by the Rules, the correct location of the welds, and the reliability of fastening the covers. In vessels intended for tipping operation, the presence of devices to prevent self-tipping should also be checked.
3.3.3. During periodic inspection, you should ensure that there is no damage or wear to the vessel elements that occurs during its operation. The most typical vascular injuries are:
cracks, most often occurring at bends, flanges, in rivet seams and in places where supports and stiffening rings are welded; corrosion damage to the internal as well as external surfaces of the vessel, especially in the lower part and in places of support. Surface cracks in vessel elements can be detected by direct inspection using a magnifying glass with preliminary grinding and etching of the inspection areas;
mechanical (erosive) wear, more often observed in vessels equipped with internal rotating devices, as well as in places where the working medium moves at high speeds;
wear of locking devices of covers with cap bolts;
residual deformations arising due to metal creep in vessel elements operating at a wall temperature exceeding 450° C.
3.3.5. When inspecting sulfite digesters and hydrolysis apparatuses with internal acid-resistant lining, you should familiarize yourself with the results of ultrasonic testing of their metal walls, carried out in accordance with Art. 6.3.2 Rules for vessels.
3.3.6. Internal inspection of autoclaves should be carried out after performing periodic technical diagnostics in accordance with the Regulations on the system of technical diagnostics of autoclaves. When inspecting, special attention should be paid to internal surfaces in places where condensation may accumulate. In this area it is possible to form intergranular cracks caused by the presence of alkaline environment and increased stresses in the metal. When inspecting autoclaves that have reached the end of their safe operation life, you should familiarize yourself with the results of expert technical diagnosing these autoclaves.
4.3.3. When inspecting heating networks, they also check compliance with the requirements of the Rules for underground and above-ground laying of pipelines; in this case, special attention should be paid to compliance with the requirements for joint laying steam and hot water pipelines with product pipelines, correct location of fittings (ease of maintenance and repair), presence and correct placement of hatches in chambers and tunnels, protection of pipelines and load-bearing metal structures from corrosion.
4.4. Hydraulic test
4.4.1. Hydraulic testing of pipelines is carried out only after completion of all welding and heat treatment, as well as after installation and final fastening of supports and hangers. In this case, documents confirming the quality of the work performed must be submitted.
4.4.2. For hydraulic testing, water with a temperature of not lower than 5° C and not higher than 40° C should be used.
Hydraulic testing of pipelines must be carried out at positive ambient temperatures. During hydraulic testing of steam pipelines operating at a pressure of 10 MPa (100 kgf/cm 2) and higher, the temperature of their walls must be at least 10 ° C.
4.4.3. The pressure in the pipeline should be increased gradually. The rate of pressure rise must be indicated in the design documentation.
The use of compressed air to increase pressure is not permitted.
4.4.4. The test pressure should be monitored by two pressure gauges. Pressure gauges must be of the same type, with the same accuracy class, measurement limit and division value.
The holding time of the pipeline and its elements under test pressure must be at least 10 minutes.
After the test pressure has been reduced to operating pressure, a thorough inspection of the pipeline along its entire length is carried out.
4.4.5. The results of the hydraulic test are considered satisfactory if the following is not found:
leaks, “tears” and “sweating” in the base metal and welded joints;
visible residual deformations.
4.4.6. If defects are identified by the person conducting the inspection, depending on their nature, a decision may be made to prohibit the operation of the pipeline, to put it into temporary operation, to shorten the period of the next inspection, to conduct more frequent inspections of the pipeline by the enterprise administration, to reduce operating parameters, etc.
4.4.7. When carrying out a technical inspection of a pipeline after repair using welding, it is necessary to check using documents whether the requirements of the Rules were fully complied with when performing repair work (quality of materials used, quality of welding, etc.), and carefully inspect the sections of pipelines that were repaired.
4.4.8. During a technical inspection of a pipeline that has been out of service for more than two years, in addition to following the above instructions, the following is checked:
monitoring compliance with the conservation regime (according to documents);
selectively the condition of the internal surfaces of the pipeline (by disassembling flange connections, removing valves, cutting out individual sections, etc.)
state of thermal insulation.
The person who carried out the technical examination, if doubts arise regarding the condition of the walls or welds of the pipelines, may require partial or complete removal of the insulation.
5. REGISTRATION OF THE RESULTS OF TECHNICAL INSPECTION OR DIAGNOSIS
5.1. The results of technical examination or diagnostics are entered into the object’s passport by the person who carried out them *.
* During technical inspection of boilers, vessels and pipelines in the chemical industries, it is also necessary to comply with the requirements of Section 10 (pp. 10.1-10.13) General rules explosion-proof For explosive and fire hazardous chemical, petrochemical and oil refineries production
If defects are found during inspection or diagnosis of an object, they must be recorded indicating their location and size.
5.2. When carrying out additional tests and studies during the inspection process, the person who performed the technical inspection must write down in the object passport the reasons that necessitated their conduct, and the results of these tests and studies, indicating the sampling locations.
The results of additional tests and studies need not be recorded in the passport if it makes reference to the relevant protocols and forms, which in this case are attached to the passport.
5.3. Having made an entry in the passport, the person who carried out the examination or diagnosis must sign and indicate his position and the date of the examination.
5.4. A permit to operate the facility after a technical examination or diagnosis, indicating the permitted operating parameters and the timing of the next technical examination or diagnosis, is issued by the person who performed it, which is recorded in the passport.
5.5. If, as a result of a technical examination or diagnosis, it becomes necessary to prohibit the operation of an object or reduce operating parameters, a corresponding motivated entry must be made in the passport.
From 12/29/91 and from 04/02/92)
4. Rules for the design and safe operation of electrode boilers and electric boiler houses. Approved Gosgortekhnadzor of Russia 06.23.92
5. Rules for the design and safe operation of steam boilers and air tanks of steam locomotives of industrial enterprises. Approved Gosgortekhnadzor of the USSR 12/31/57
6. Rules for certification of welders. Approved Gosgortekhnadzor of Russia 03/16/93
7. Rules for certification of non-destructive testing specialists. Approved Gosgortekhnadzor of Russia 08/18/92
8. Rules for the design and safe operation of steam boilers with a steam pressure of no more than 0.07 MPa (0,7 kgf/cm 2), hot water boilers and water heaters with a water heating temperature not higher than 388 K (115° C). I agree. with Gosgortekhnadzor of Russia 03.06.92
For technical diagnostics
35. Regulations on the system of technical diagnostics of steam and hot water boilers for industrial energy. Developed by: MGP TsKTI, gas processing production Approved Gospromatnadzor USSR 11/20/91
49. Methodology for determining the residual life of chemical production equipment. Developed by: GIAP. I agree. with Gospromatnadzor of the USSR.
50. Methodology for assessing the residual service life of process equipment in oil refining, petrochemical and chemical industries. Developed by: VNIKTIneftekhimoborudovanie. Approved Gosgortekhnadzor of Russia 10/29/92
54. Regulations on the procedure for establishing acceptable periods of further operation technological equipment explosive and fire hazardous enterprise production "Agrokhima". Approved "Agro chemist" 02.12.91
55. Regulations on the procedure for establishing acceptable periods for further operation of boilers of railway tank cars for the transportation of liquid ammonia operated at enterprises "Agrokhima".
56. Regulations on assessing the technical condition of vessels and pipelines operating under pressure at enterprises of the State Agrochemical Association using the acoustic emission method. I agree. with Gosgortekhnadzor of Russia 11.25.91
* As of 08/01/93
1. General Provisions
2. Technical examination of boilers
2.1. General requirements
2.2. Checking technical documentation
2.3. External and internal inspection
2.4. Hydraulic test
3. Technical examination of vessels
3.1. General requirements
3.2. Checking technical documentation
3.3. External and internal inspection
3.4. Hydraulic test
4. Technical inspection of steam pipelines
and hot water
4.1. General requirements
4.2. Checking technical documentation
4.3. External inspection
4.4. Hydraulic test
5. Registration of the results of technical examination or diagnostics
Application. List of normative and technical documentation for technical examination and diagnostics of boilers, vessels, steam and hot water pipelines
MINISTRY OF ENERGY AND ELECTRIFICATION OF THE USSRPRODUCTION ASSOCIATION FOR SETTING UP, IMPROVING TECHNOLOGY AND OPERATION OF POWER PLANTS AND NETWORKS "SOYUZTEKHENERGO" METHODOLOGICAL INSTRUCTIONS FOR TESTING HYDRAULIC STABILITY STI OF DIRECT FLOW ENERGY AND WATER HEATING BOILERS
SOYUZTEKHENERGO
Moscow 1989 Contents DEVELOPED by the Moscow head enterprise of the Production Association for setting up, improving technology and operating power plants and networks "Soyuztechenergo" CONTRACTORS V.M. LEVINSON, I.M. GIPSHMAN APPROVED BY "Soyuztechenergo" 04/05/88 Chief engineer K.V. SHAHSUVAROV Validity period set
from 01/01/89
until 01/01/94. These Guidelines apply to stationary once-through steam power boilers and hot water boilers with absolute pressure from 1.0 to 25.0 MPa (from 10 to 255 kgf/cm2). Guidelines do not apply to boilers: with natural circulation; steam-water-heating; locomotive units; waste heat boilers; energy-technological, as well as other boilers for special purposes. Based on the experience accumulated in Soyuztekhenergo and related organizations, methods for testing boilers in stationary and transient modes are specified and described in detail in order to check the conditions hydraulic stability of steam-generating heating surfaces of direct-flow steam boilers or screen and convective heating surfaces of hot water boilers. Hydraulic stability tests are carried out both for newly created (head) boilers and for those in operation. Tests make it possible to check the compliance of hydraulic characteristics with the calculated ones, assess the influence of operational factors and determine the boundaries of hydraulic stability. The guidelines are intended for the production departments of the Soyuztechenergo PA conducting tests of boiler equipment according to clause 1.1.1.06 of the “Price list for experimental adjustment and improvement work technology and operation of power plants and networks", approved by Order of the Minister of Energy and Electrification of the USSR No.
313 dated October 3, 1983. The guidelines can also be used by other commissioning organizations performing tests of the hydraulic stability of once-through boilers.
1. KEY INDICATORS
1.1. Determination of hydraulic stability: 1.1.1. The following indicators of hydraulic stability are subject to determination: thermal-hydraulic sweep; aperiodic stability; pulsation stability; stagnation of movement. 1.1.2. Thermal-hydraulic testing is determined by the difference between the flow rates of the medium in individual parallel elements of the circuit and the outlet temperatures in the same elements compared to the average values in the circuit. 1.1.3. Violation of aperiodic stability associated with the ambiguity of hydraulic characteristics is determined by: an abrupt decrease in the flow rate of the medium in individual elements of the circuit (at a rate of 10%/min or more) with a simultaneous increase in the outlet temperature in the same elements compared to the average values in the circuit; or when reversing the movement by changing the sign of the flow rate of the medium in individual elements to the opposite, with an increase in the temperature at the inlet to these elements. On boilers operating with subcritical pressure in the circuit, an increase in temperature at the outlet of the elements may not be observed. 1.1.4. Violation of pulsation stability is determined by pulsations of medium flow (as well as temperatures) in parallel elements of the circuit with a constant period (10 s or more) regardless of the amplitude of the pulsations. Flow pulsations are accompanied by pulsations in the temperature of the pipe metal in the heated zone and the temperature at the outlet of the elements (at subcritical pressure the latter may not be observed). 1.1.5. Stagnation of movement is determined by a decrease in the flow rate of the medium (or the pressure drop on the flow measuring devices) in individual elements of the circuit to zero or to values close to zero (less than 30% of the average flow rate). 1.1.6. It is allowed in cases provided for by the standard method of hydraulic calculation [1], when violations of hydraulic stability of one type or another are obviously impossible, not to determine the corresponding indicators. For example, there is no need to check aperiodic stability for purely lifting motion in a circuit. Checking pulsation stability is not required at supercritical pressure, in the absence of subcooling to boiling at the inlet circuit, as well as for hot water boilers. At supercritical pressure, most circuits do not require a check for stagnation, with the exception of certain cases (heavily slagging firebox risers, shadowed corner pipes, etc.). 1.1.7. The following indicators required to assess the conditions and boundaries of hydraulic stability are also subject to determination: flow rate and average mass velocity of the medium in the circuit, G kg/s and wr kg/(m 2 × s); temperature of the medium at the inlet and outlet of the circuit, tVx And tYoux ° C; Maximum temperature at the exit from contour elements, ° C; subheat to boiling, D tunder ° C (for hot water boilers); medium pressure at the outlet of the circuit (or at the inlet to the circuit, or at the end of the evaporative part of the steam boiler), for hot water boilers - at the inlet and outlet of the boiler, R MPa; flow rate and mass velocity of the medium in the circuit elements, Gel kg/s and ( wr)el kg/(m 2 × s); heat perception (enthalpy increment) in the circuit, D i kDk/kg; metal temperature of individual pipes in the heated zone, t vtn ° C. 1.1.8. When determining individual (from among those specified in clause 1.1.1) indicators of hydraulic stability or during tests of a research nature, additional indicators can also serve as: pressure drop in the circuit (from inlet to outlet), D R k kPa; temperature at the inlet to the circuit elements, tel° C; thermal scanning coefficients, rq; hydraulic reaming, rq; uneven heat perception, hT. 1.2. In necessary cases (for new or reconstructed circuits, during a preliminary assessment of stability, to clarify the type, nature and causes of identified violations, etc.), the hydraulic characteristics of the corresponding circuits are calculated or the reliability margins are assessed based on factory calculations. The calculation of hydraulic characteristics is carried out on a computer (using programs developed at Soyuztechenergo) or manually according to [1]. Based on the calculated data and preliminary assessment of the hydraulic stability of individual circuits, the least reliable of them are more fully equipped with measuring instruments, the tasks and test program are specified.2. ACCURACY INDICATORS OF DETERMINED PARAMETERS
Indicators of the thermal and hydraulic performance of the circuit are determined by measuring temperature, flow and pressure in the circuit and its elements. The error of these indicators obtained as a result of processing measurement data should not exceed the values indicated in table. 1. Table 1|
Name |
Error |
Steam boilers |
Hot water boilers |
Flow rate and average mass velocity of the medium in the circuit, % | Temperature at the inlet and outlet of the circuit, °C | Temperature at the inlet and outlet of the circuit elements, °C | Subheating to boiling, °C | Pressure at the inlet and outlet of the circuit, % | Pressure drop in the circuit (from inlet to outlet), % | Note. The flow rate of the medium in the circuit elements, the enthalpy increment, as well as the coefficients of thermal and hydraulic expansion and unevenness of heat perception are determined without standardization of accuracy. The temperature of the metal in the heated zone is determined without standardization of accuracy in accordance with methodological instructions for departmental full-scale tests temperature regime heating screen surfaces of steam and hot water boilers. |
3. TEST METHOD
3.1. Available regulatory materials, primarily [1], make it possible to perform an approximate calculation of the main indicators of the hydraulic stability of the boiler. Calculations include, however, a number of parameters and coefficients that can be established with the required accuracy only experimentally, including: actual temperatures environment along the tract; enthalpy increment in the circuit, pressure, pressure drop (circuit resistance); temperature distribution among elements; values of parameter deviations in dynamic modes of real operation; coefficients of thermal, hydraulic testing and unevenness of heat absorption, etc. On the other hand, calculation methods cannot cover the entire variety of specific design solutions used in boilers, especially newly created ones. In view of this, carrying out full-scale industrial tests serves as the main method for determining the hydraulic stability of steam and hot water boilers boilers 3.2. Depending on the purpose of the work and the required volume of measurements, tests according to the Price List for experimental adjustment work and work to improve the technology and operation of power plants and networks are carried out in two categories of complexity: 1 - checking an existing or newly developed calculation and testing methodology; or identifying operating conditions for new hydraulic circuits that have not yet been tested in practice; or checking the boiler heating surfaces on a prototype sample; 2 - tests of one heating surface of the boiler. 3.3. Tests are carried out in stationary and transient modes; in the operational or extended range of boiler loads; if necessary, also in kindling modes. In addition to planned experiments, observations are carried out in operating modes. 3.4. Hydraulic stability indicators are determined for the following types of boiler hydraulic circuits: pipe packages and panels with parallel-connected heated pipes, inlet and outlet manifolds; heating surfaces with parallel-connected pipe packages or panels, inlet and outlet pipelines, inlet and outlet common manifolds; complex circuits with parallel connected subflows, which include heating surfaces, connecting pipelines, transverse bridges and other elements. 3.5. In double-flow boilers, subject to a symmetrical design, it is allowed to perform tests only for one controlled flow with monitoring of operating parameters for both flows and for the boiler as a whole.4. MEASUREMENT SCHEME
4.1. The experimental control scheme includes special experimental measurements that provide experimental values of temperatures, flow rates, pressures, pressure drops in accordance with the test objectives. Experimental control measuring instruments are installed on both or one controlled flow of the boiler (see clause 3.5). Standard control measuring instruments are also used. 4.2. The scope of experimental control includes measurements of the following main parameters: - medium temperatures along the steam-water path (for both flows), at the inlet and outlet of all sequentially connected heating surfaces in the economizer-evaporation part of the path (before the built-in valve, separator, etc.), as well as in the steam superheating part and in the reheating path (before and after injections and at the outlet of the boiler). For this purpose, submersible thermoelectric converters (thermocouples) for experimental control are installed, or standard measuring instruments are used. Measuring instruments for experimental control are installed on the surface under test. The boiler is equally equipped with measuring instruments along the steam-water path even if the tests cover only one or two heating surfaces. Without this, it is impossible to properly determine the influence of regime factors; - temperature of the medium at the outlet (and in necessary cases- also at the entrance) of subflows and individual panels in the studied contour (surface). Measuring instruments are installed in outlet pipes (submersible thermocouples; the use of surface thermocouples is allowed if their installation sites are carefully insulated). They cover all parallel elements. At large number It is allowed to equip some of them with parallel panels, including the middle ones and the most non-identical ones (in design and heating); - temperatures at the outlet of the coils (heated pipes) of the test surfaces; in necessary cases (if there is a danger of overturning, traffic stagnation) - also at the entrance. This is the most widespread type of measurement in terms of quantity. Measuring instruments are installed in the unheated zone of the coils (surface thermocouples); as a rule, in the same panels where outlet temperature measurements are provided. In multi-pipe panels, thermocouples are installed in “middle” pipes evenly in width (in increments of several pipes) and in pipes with thermal and structural non-identity (extreme and adjacent to them; enveloping burners; differing in connection to collectors, etc.). In the absence in the coils of the test surface of the unheated zone (as is the case, for example, on hot water boilers, according to their design), to directly measure the temperature, submersible thermocouples are installed at the outlet of these coils; - feed water flow along the streams of the steam-water path (allowed for one stream if experimental control is installed on one stream). The measuring device is usually a standard standard diaphragm in the supply line, to which, in parallel to the standard water meter, an experimental control sensor is connected; - flow rate and mass velocity of the medium at the entrance to the subflows of the circuit (in each) and in the panel (selectively). TsKTI or VTI pressure tubes are installed on the supply pipes in panels, which, according to a preliminary assessment, are the most dangerous in case of hydrodynamic disturbances, and in coordination with the installation of thermocouples; - flow rate and mass velocity of the medium at the inlet to the coils. Installed on entrance areas pipes in the unheated zone, pressure tubes TsKTI or VTI. The number and placement of measuring instruments is determined by specific conditions, including “average” and most dangerous coils, in accordance with the installation of thermocouples at the outlet of the coils, as well as temperature inserts (i.e. on the same coils). Means for measuring flow rates in the elements of the circuit must be placed in such a way that they, in total, with the minimum possible number, reflect all the instability of stability in the circuit expected according to a preliminary assessment; - pressure in the steam-water path. Selecting devices for measuring pressure are installed at characteristic points of the tract, including at the outlet of the test surface, at the end of the evaporation part (before the built-in valve); for a hot water boiler - at the boiler outlet (as well as at the inlet); - pressure drop (hydraulic resistance) of the subflow, or heating surface, or a separate section of the circuit under test. Selected devices for measuring pressure drop are installed in special cases: during research tests, when checking the compliance of calculated data with actual data, when there are difficulties in classifying instability, etc.; - temperature of the pipe metal in the heated zone. Temperature or radiometric inserts for measuring metal temperature are installed in the test surfaces, mostly in the flow, where most of the measurements are taken, but also control inserts for other flows. Inserts are placed around the perimeter and height of the firebox in the area of maximum thermal stress and expected highest metal temperatures. The choice of pipes for installing inserts should be linked to the installation of temperature and flow measurements across the coils. 4.3. The experimental control measuring instruments according to clause 4.2 apply to purely direct-flow boiler circuits. In the complex branched hydraulic circuits inherent in modern boilers, other necessary measuring instruments are installed in accordance with the specific design features. For example: a circuit with parallel subflows and a transverse hydrodynamic jumper - temperature measurement before and behind the insertion of the jumper on both subflows; flow measurement via jumper; measuring the pressure difference at the ends of the jumper; a boiler with medium recirculation through a screen system (pumping or non-pumping) - measuring the temperature of the medium in the selections of the recirculation circuit upstream and downstream of the mixer; measurement of medium flow in the recirculation circuit selections and through the screen system (behind the mixer); measurement of pressures (pressure differences) at nodal points of the circuit, etc. 4.4. Indicators of the boiler operation as a whole, indicators of the combustion mode, as well as general unit indicators are recorded using standard control devices. 4.5. The volume, as well as the features of the measurement scheme, are determined by the goals and objectives of the tests, the category of complexity, the steam output and parameters of the boiler, the design of the boiler and the circuit under test (radiation or convective surfaces, all-welded and smooth-tube screens, type of fuel, etc.). For example, when testing NRF on a gas-oil boiler of a 300 MW monoblock, the measurement scheme may include from 100 to 200 temperature measurements in an unheated zone, 10-20 temperature inserts, approximately 10 measurements of flow rates and pressures; when testing a hot water boiler - from 50 to 75 temperature measurements, 5-8 temperature inserts, approximately 5 flow and pressure measurements. 4.6. All experimental control measurements must be submitted for registration using self-recording secondary instruments. Secondary devices will be placed on the experimental control panel. 4.7. A list of measurements, their locations in the boiler and a breakdown by instrument are given in the documentation for the measurement scheme. The documentation also includes an instrument switching diagram, a sketch of the panel, a diagram of the placement of temperature inserts, etc. Approximate measurement diagrams, in relation to testing the NRF boiler TGMP-314 and testing the water heating boiler KVGM-100, are shown in Fig. 12.
Rice. 1. Scheme of experimental control of the NRF boiler TGMP-314: 1-3 - panel numbers; I-IV - numbers of moves; - immersion thermocouple; - surface thermocouple; - temperature insert; - pressure tube TsKTI; - pressure selection; - differential pressure selection.
Number of surface thermocouples: at the input of the front half-flow coils A: I stroke - 16; 2nd turn - 12; III move - 18; the same for rear half-flow A: I stroke - 12; 2nd move - 8; III - move - 8; IV move - 8 pcs.; on jumper A - 6 pcs.; on jumper B - 4 pcs. . Notes: 1. The diagram shows measurements along flow A. Submersible thermocouples are installed along flow B similar to flow A. 2. Measurements along flow B are similar to flow A. 3. Numbering of panels and coils is from the boiler axes. 4. Measurements of temperatures and flow rates along the steam-water path are carried out in accordance with the boiler instrumentation and control diagram.
Rice. 2. Scheme of experimental control of the KVGM-100 water heating boiler: - upper collector; - lower collector; - surface thermocouples on pipelines; - the same on pipes and risers; - immersion thermocouples in envelope coils; - temperature inserts at the level of the upper tier of burners; - differential pressure selection;
1 - rear screen of the convective part: 2 - side screen of the convective part; 3 - screens of the convective part; 4 - package I; 5 - packages II, III; 6 - intermediate firebox screen; 7 - firebox side screen; 8 - front screen
5. TESTING MEANS
5.1. During testing, standardized measuring instruments must be used, metrologically ensured in accordance with GOST 8.002-86 and GOST 8.513-84. Types and characteristics of measuring instruments are selected in each specific case depending on the equipment being tested, the required accuracy, installation and installation conditions, ambient temperature and from other external influencing factors. Measuring instruments used during testing must have valid verification marks and technical documentation, indicating their suitability, and ensure the required accuracy. 5.2. Requirements for measurement accuracy: 5.2.1. The permissible error in measuring the initial values, ensuring the required accuracy of the determined indicators (see Section 2), should not exceed for: temperature of water, steam, metal in an unheated zone: steam boiler - 10 ° C; hot water boiler - 5 ° C; water flow and steam - 5%; water and steam pressure - 2%. 5.2.2. The requirements specified in this section refer to type tests of boilers. When conducting tests on experimental, or modernized, or fundamentally new equipment, or when checking new test methods, the test program must stipulate additional requirements for measuring instruments and accuracy characteristics. 5.3. To measure parameters that do not require accuracy standards during testing (see Section 2), indicators can be used. The specific types of indicators used are specified in the test program. 5.4. Temperature measurement: 5.4.1. Temperature is measured using thermoelectric converters (thermocouples). When making measurements at relatively low temperatures that require high accuracy, thermoelectric thermometers (resistance thermometers) in accordance with GOST 6651-84 can also be used. Depending on the range of measured temperatures, XA thermocouples are used (at the upper limit of measured temperatures 600-800 ° C) or XK (400-600°C) wire diameter 1.2 or 0.7 mm. It is recommended to insulate thermionic wires with silica or quartz filament by double winding. Detailed characteristics of thermocouples are contained in the specialized literature [2, etc.]. 5.4.2. To directly measure the temperature of water and steam, standard immersion thermocouples of the TXA type are used. Submersible thermocouples are installed on a straight section of the pipeline in a sleeve welded into the pipeline. The length of the element is selected depending on the diameter of the pipeline based on the location of the working end of the element thermocouple along the flow axis. The minimum length of a standard element is 120 mm. Submersible thermocouples can be installed in small diameter pipelines non-standard production, but in compliance with the installation rules (for example, when testing hot water boilers, see paragraph 4.2.3). 5.4.3. Surface thermocouples are installed outside the heating zone on the outlet (or inlet) sections of the coils, near the collector, as well as on the outlet (or inlet) pipes of the panels. The connection to the metal of the pipe (the working end of the thermocouple) is recommended to be made by caulking the thermoelectrodes into a metal boss (separately in two holes), which in turn is welded to the pipe. The working end of the thermocouple can also be made by caulking the thermocouple into the body of the pipe. The initial section of the insulated surface thermocouple, at least 50-100 mm long from its working end, must be tightly pressed to the pipe. The thermocouple installation site and the pipeline in this area must be carefully covered with thermal insulation. 5.4.4. Measurement of pipe metal temperatures in the heated zone (using Soyuztekhenergo temperature inserts with a thermocouple cable KTMS or XA thermocouples, or radiometric inserts TsKTI with XA thermocouples) should be carried out in accordance with the “Methodological instructions for departmental full-scale tests of the temperature regime of screen heating surfaces of steam and hot water boilers.” Inserts are not standardized measuring instruments and serve as indicators when testing hydraulic stability (see clause 5.3). 5.4.5. As secondary devices when measuring temperature using thermocouples, self-recording electronic multipoint potentiometers with analog, digital or other form of recording (continuous or with a recording frequency of no more than 120 s) are used. In particular, KSP-4 devices of accuracy class 0.5 by 12 points are used (with a cycle of 4 s and a recommended tape drawing speed of 600 mm/h). Multi-channel measuring devices with access to digital printing and punching devices are also used. As secondary devices for measuring temperature using resistance thermometers using measuring bridges direct current. 5.5. Measuring water and steam flow: 5.5.1. Flow is measured using flow meters with orifices (measuring diaphragms, nozzles) in accordance with the “Rules for measuring the flow of gases and liquids using standard orifices” RD 50-213-80. Flow meters with restriction devices are installed on pipelines with a single-phase medium with an internal diameter of at least 50 mm. The flow metering device, its installation and connecting (pulse) lines must comply with the specified rules. 5.5.2. In cases where additional pressure losses are not allowed, as well as on pipelines with an internal diameter of less than 50 mm, flow meters with pressure tubes (Pitot tubes) designed by TsKTI or VTI are installed as a flow indicator [2]. TsKTI rod tubes, like round VTI tubes, have a small non-recoverable pressure loss. Pressure tubes are suitable only for the flow of a single-phase medium. The design of pressure tubes TsKTI and VTI with a description and flow coefficients is given in Appendix 1 and in Fig. 3, 4.
Rice. 3. Designs of pressure tubes for measuring water circulation rates 
Rice. 4. Values of flow coefficients for rod and cylindrical tubes 5.5.3. Differential pressure gauges (GOST 22520-85) are used as primary transducers (sensors) when measuring flow rates. Connecting lines are laid from the measuring device to the sensor in accordance with the rules of RD 50-213-80. 5.6. Selection of signals based on static pressure is carried out through holes (fittings) in pipelines or manifolds of the heating surface outside the heating zone. Sampling devices should be installed in places protected from the dynamic effects of the work flow. Pressure gauges with an electrical output (GOST 22520-85) are used as sensors. 5.7. The pressure difference is measured using static pressure taps at the beginning and end of the measured section of the circuit, which are carried out according to the type of pressure measurement. Differential pressure gauges are used as sensors. 5.8. The type and accuracy class of sensors and secondary instruments used in measuring flow, differential pressure and pressure are given in Table. 2. Table 2 Note. To measure flow, instead of DME and Sapphire 22-DC sensors, which provide a linear differential pressure signal, DMER and Sapphire 22-DC sensors with NIR (with an extraction unit) can be used square root and transition to the consumption scale). Since testing scales are usually non-standard and must be suitable for various conditions, sets with a linear scale of differences (with further recalculation during processing) often turn out to be more convenient. 5.9. Choice
sensors according to the pressure differential measurement range is made from a number of values in accordance with GOST 22520-85. Approximately used values: feed water consumption - 63; 100; 160 kPa (0.63; 1.0; 1.6 kgf/cm2);
water flow (speed) in panels and coils - 1.6; 2.5; 4.0; 6.3 kPa (160; 250; 400; 630 kgf/cm2); for boilers SKD-40 MPa (400 kgf/cm 2), for boilers VD-16; 25 MPa (160; 250 kgf/cm2); for hot water boilers - 1.6; 2.5 MPa (16; 25 kgf/cm2). 5.10. The lower guaranteed limit of measurement for flow sensors (LMED) is 30% of the upper limit. In cases where during testing it is necessary to cover a large range of flow rates (or pressures), including small and starting loads of the boiler, two sensors are connected in parallel to the measuring device at different measurement limits, each with its own secondary instrument. 5.11. To record the main values of flow and pressure, single-point secondary devices with continuous recording are usually used (with a recommended tape pulling speed of 600 mm/h). Continuous recording is necessary due to the high speed of hydrodynamic processes, especially in case of instability. If there is a large number of the same type of hydraulic sensors in the circuit (for example, for measuring velocities in panels and coils), some of them can be transferred to multi-point secondary instruments indicated in Table. 2 (for 6 or 12 points with a cycle of no more than 4 s). 5.12. The experimental control panel is mounted near the main control room (preferably), or in the boiler shop room (at the service level if there is good communication with the main control room). The panel is equipped with electrical power, lighting, and locks. 5.13. Materials: 5.13.1. The quantity and range of materials required for the installation of connecting electrical and pipe wiring, as well as electrical and thermal insulating materials, are determined in the test work program or in the order specification, depending on the steam or heat output of the boiler, its design and the volume of measurements. 5.13.2. The primary switching of temperature measuring instruments to prefabricated boxes (SC) is carried out: from submersible thermocouples and temperature inserts with a compensation wire (copper-constantan for XA thermocouples, chromel-copel for XK thermocouples); from surface thermocouples with a thermocouple wire. Secondary switching from the SC to the experimental control panel is performed with a multi-core cable (preferably a compensation cable, if this is not available - copper or aluminum). In the latter case, to compensate the temperature of the free end of the measuring thermocouples, a so-called compensation thermocouple is inserted from the SC to the device. 5.13.3. Switching of flow and pressure signals from the sampling point to the sensor is carried out by connecting tubes (made of steel 20 or 12Х1МФ) with shut-off valves d y
10 mm for the corresponding pressure. The electrical connection between the sensor and the panel is made with a four-core cable (in case of danger of interference, shielded). 6. TEST CONDITIONS
6.1. Tests are carried out in stationary boiler modes, in transient modes (during mode disturbances, decrease and increase in load), and also, if necessary, in firing modes. 6.2. When carrying out tests in stationary modes, the values indicated in the table must be maintained. 3 maximum deviations from the average operational values of boiler operating parameters, which are monitored using verified standard instruments. Table 3|
Name |
Steam boilers steam capacity, t/h |
Hot water boilers |
Steam capacity | Feed water consumption | Pressure | Temperature of superheated steam (primary and intermediate) | Water temperature (at the inlet and outlet of the boiler) |
7. PREPARATION FOR TESTS
7.1. The scope of work to prepare for testing includes: familiarization with technical documentation for the boiler and power unit, equipment condition, operating modes; drawing up and approval of a test program; development of an experimental control scheme and technical documentation for it; technical supervision of the installation of an experimental control scheme; adjustment of the scheme experimental control and its implementation. 7.2. The technical documentation that requires familiarization includes, first of all: drawings of the boiler and its elements; diagrams of steam-water and gas-air paths, instrumentation and automation; boiler calculations: thermal, hydraulic, thermomechanical, wall temperature, hydraulic characteristics (if any); boiler operating instructions, operating map; documentation on damage to pipes, etc. On-site familiarization with the equipment of the boiler and dust preparation system, with the power unit as a whole, and with standard instrumentation is carried out. The operational features of the equipment to be tested are identified. 7.3. A test program is drawn up, which must indicate the purpose, conditions and organization of the experiments, requirements for the condition of the boiler, the necessary parameters of the boiler operation, the number and main characteristics of the experiments, their duration, and calendar dates. The non-standardized measuring instruments used are indicated. The program is coordinated with the heads of the relevant departments of the thermal power plant (KGC, Central Research Institute, TsTAI) and approved by the chief engineer of the thermal power plant or REU. The procedure for the development, coordination and approval of the test program must comply with the “Regulations on the procedure for the development, coordination and approval of test programs at thermal, hydraulic and nuclear power plants , in energy systems, thermal and electrical networks", approved by the USSR Ministry of Energy on August 14, 1986. 7.4. The contents of the experimental control scheme are given in Section. 4. In some cases, when large volume tests are being compiled technical task for a draft experimental control scheme, according to which a specialized organization or division is developing a scheme. If the volume is small, the diagram is drawn up directly by the team conducting the tests. 7.5. Based on the experimental control scheme, documentation on preparatory work for testing is compiled and transferred to the customer: list preparatory work(in which it is advisable to indicate the scope of installation work performed directly on the boiler); specification for the necessary devices and materials supplied by the customer; sketches of devices requiring manufacturing (temperature inserts, bosses, panel panels, etc.). A specification for devices and materials is also drawn up , supplied by Soyuztekhenergo. Appendix 2 gives sample samples the specified documentation. 7.6. Installation supervision: 7.6.1. Before installation begins, the locations for installing measuring devices are marked, as well as the locations for the monitoring system, switchboard, and sensor stands are selected. The marking must be treated with special attention, as an operation that determines the quality of subsequent measurements. When installing test equipment, it is necessary to check the correct installation of the measuring devices and compliance with the drawings. 7.6.2. Welding of surface thermocouple bosses is carried out under the direct supervision of team representatives. The main thing is to prevent the wire from burning out (welding with 2-3 mm electrodes, minimum current), and in case of a burnout, restore it again. It is recommended to check the presence of the chain immediately after welding. 7.6.3. The thermocouple and compensation wires are laid to the SC in protective pipes. Open wiring with a harness is allowed in some cases on a short time, but not recommended. Laying should be done with a single wire, avoiding intermediate connections. Particular attention should be paid to possible places where the insulation of wires is damaged (kinks, turns, fastenings, entrances to protective pipes, etc.), protecting them with additional reinforced insulation. To eliminate possible EMF interference, compensation wires and cables should not intersect with power cable routes. 7.6.4. Pressure tubes are installed on straight sections of pipes, away from bends and manifolds. The straight section of flow stabilization in front of the tube should be (20 ¸ 30) D (D - internal diameter of the pipe), but not less than 5 D. Pressure tube immersion is 1/2 or 1/3 D. The tube must be welded with signal-perceiving holes strictly along the center line of the pipe; select fittings are located horizontally. Main valves must be accessible for maintenance. 7.6.5. The laying of connecting lines for flow and pressure measurements must meet the requirements of RD 50-213-80. When laying connecting pipes, one-sided slope or horizontal lines must be strictly observed; Do not allow connecting pipes to pass in places with high temperatures to avoid boiling or heating of still water in them. 7.6.6. Sensors for measuring flow rates and differential pressures are installed below (or at the level of) the measuring devices, usually at the zero mark and at the service mark. The sensors are mounted on group stands. For normal maintenance, devices are provided for purging the sensors (two shut-off valves are installed on each purge line to avoid leaks). The complete set for one sensor consists of 9 shut-off valves (main valves, in front of the sensor, purge valves and one equalizing valve). 7.6.7. Before installing the sensors on the stand, they should be carefully checked by the metrological service of the thermal power plant and calibrated. After installation on the stands, it is necessary to check the position of the “zeros” and the maximum values of the differences. For sensors designed to measure water flow rates in panels and coils, it is advisable to shift the “zero” on the scale of the secondary device by 10-20% to the right (in case zero or negative values in non-stationary modes). In any special cases, when flow movement in both directions is possible, the “zero” of the device is set to 50%, i.e. to the middle of the scale (for example, flow reversal, strong pulsation, hydrodynamic jumper tests, etc.). When the zero is shifted, the device is used as an indicator. 7.7. Upon completion of the preparatory installation work, the experimental control circuit is adjusted (switching continuity, crimping and trial activation of sensors, activation and debugging of secondary devices, identification and elimination of defects). 7.8. Before testing, the readiness of the boiler and its elements for testing must be checked (gas tightness, internal and external contamination of heating surfaces, density and serviceability of fittings, etc.). Particular attention is paid to standard instrumentation: the serviceability of the measuring instruments required for testing, the correctness of their readings, the presence of valid verification marks (for water meters and other devices), the compliance of experimental and standard instruments. The power plant is provided with a list of works to eliminate shortcomings in equipment and instrumentation1 that impede testing. The condition of the boiler must meet the requirements specified in the test program.8. TESTING
8.1. Work program of experiments: 8.1.1. Before the start of testing, on the basis of the approved test program, working experimental programs are drawn up and agreed with the management of the thermal power plant. The work program is drawn up for a single experiment or a series of experiments. It contains instructions for organizing the experiment, the state of the equipment involved in the experiment, the values of the main parameters and the permissible limits of their deviations, and a description of the sequence of operations performed. 8.1.2. The work program is approved by the chief engineer of the thermal power plant and is mandatory for personnel. 8.1.3. For the duration of the experiment, a responsible representative from the TPP must be allocated, who will provide operational management of the experiment. The test manager from Soyuztechenergo provides technical guidance. The watch personnel performs all their actions during the experiment according to the instructions (or with the knowledge) of the test manager, transmitted through the responsible representative of the thermal power plant. Appendix 3 provides an approximate work program for the experiments. 8.2. During the entire period of the experiment, compliance with the work program of the following values must be ensured: excess air; recycling shares flue gases; fuel consumption; feed water flow and temperature; medium pressure behind the boiler; steam consumption (only for steam boiler); temperature of fresh steam (or water) behind the boiler; combustion mode; operating mode of the dust preparation system. 8.3. If the boiler operating parameters do not comply with the requirements established in section. 6 and in the work program, the experiment stops. The experiment also ends in the event of an emergency at the power unit (or power plant). In case of reaching the limit values of the temperature of the medium and metal specified in the program, or the cessation (or sharp decrease) of the medium flow in individual elements of the boiler, or the appearance of other violations of hydrodynamics according to experimental control devices, the boiler is transferred to a mode easier for the equipment (previously entered disturbances or necessary decisions are made). If the violations do not pose an immediate danger, the experiment can continue without further tightening the regime being tested. 8.4. Tests begin with preliminary experiments. During preliminary experiments, familiarization is made with the operation of the equipment and its features. operating modes, final debugging of the measurement scheme, working out the organizational routine in the team and relationships with the watch personnel. 8.5. Stationary modes: 8.5.1. Tests in stationary modes include experiments: at the rated load of the boiler; two or three intermediate loads (usually at loads of 70 and 50% as corresponding to factory calculations, as well as at the load prevailing under operating conditions); minimum load (established in operation or agreed upon for testing). For steam boilers, experiments are also carried out with a reduced temperature of the feed water (with the HPH turned off). Experiments are also carried out for hot water boilers: with different temperatures inlet water; with minimal outlet pressure; with the minimum permissible water flow. The static characteristics (dependence on the boiler load) of temperatures and pressures along the path are determined; indicators of hydraulic stability of the tested circuits in stationary modes; permissible range of boiler loads according to these indicators. 8.5.2. In stationary experiments, the operating mode is taken as a basis. regime map. The influence of the main operating factors is also checked (excess air, DRG loading, various combinations of operating burners or mills, fuel oil illumination, feed water temperature, boiler slagging, etc.). 8.5.3. On boilers operating on two types of fuel, experiments are carried out on both types (on reserve fuel and on a mixture of fuels, a reduced volume is allowed). Experiments on dust and gas boilers natural gas due to contamination of the screens, they should be carried out after a sufficiently long continuous campaign on gas. If necessary, experiments on slag fuels are carried out at the beginning and at the end of campaigns, on a “clean” and on a slagged boiler. 8.5.4. For SKD boilers operating at sliding pressure, hydraulic stability tests should be carried out taking into account the guidelines for testing once-through boilers in unloading modes at sliding pressure of the medium. 8.5.5. At a given boiler load, in order to obtain more reliable experimental materials, two duplicate experiments should be carried out, and not on the same day (preferably with a time gap). If necessary, additional control experiments are carried out. 8.5.6. Tests in stationary conditions must precede experiments with disturbances. 8.6. Transitional modes: 8.6.1. The most unfavorable in terms of hydraulic stability of boiler circuits are, as a rule, non-stationary conditions associated with regime disturbances and certain deviations of parameters from normal (average) conditions. In experiments in transient modes, the hydraulic stability of the tested circuits is determined in experimental conditions close to emergency ones, when the water-fuel ratio is unbalanced and when there are thermal imbalances. Maximum reductions in flow rates and increases in temperatures in circuit elements are monitored, the discrepancy between separate elements, as well as the nature of the restoration of the original values after the disturbance is removed. 8.6.2. For steam boilers, the following mode disturbances are checked: a sharp increase in fuel consumption; a sharp decrease in feed water consumption; turning off individual burners while maintaining the total fuel consumption (the effect of thermal distortion across the width and depth of the furnace); turning off (or reducing the load) of the DRG; reducing the pressure of the medium, as well as other actions based on local circumstances (turning on blowers, switching to another fuel, etc.). Depending on the circuit diagram, sometimes it may also be necessary to check the combination of unbalance with skew (for example, water discharge when the burners are turned off). For hot water boilers, mode disturbances are checked a sharp decrease in feed water consumption and a decrease in medium pressure, etc. 8.6.3. The value and duration of disturbances are not standardized and are established on the basis of existing experience and actual operating conditions, depending on the design of the boiler, its dynamic characteristics, type of fuel, etc. Thus, for a gas-oil boiler of a 300 MW monoblock, we can recommend disturbances for water and fuel with a value of approximately 15 % and lasting 10 minutes (i.e., according to existing experience, almost until the parameters along the path stabilize). With large disturbances (20-30%), under the condition of maintaining the superheat temperature, the duration is usually less than 3-5 minutes without stabilization of parameters, which does not give confidence in identifying all the features of the hydrodynamics of the circuit. Disturbances of less than 15% have a relatively weak effect on the steam-water path. 8.6.4. Disturbances can be made along both or only one controlled flow of the steam-water path (or one side of the boiler) for which the tests are performed. 8.6.5. Before applying disturbances, the boiler must operate in a stationary mode for at least 0.5-1.0 hours until the parameters stabilize. 8.6.6. Experiments with regime disturbances are carried out at two or three boiler loads (including the minimum). Usually they are combined with experiments at the required load in a stationary mode and are carried out at the end of it. 8.7. If necessary (for example new technology kindling, damage during start-up modes, causing concern results of preliminary calculations, etc.) the hydraulic stability of the tested circuit is checked in boiler firing modes. Kindling is carried out in accordance with the operating instructions and work program. 8.8. During the experiment, continuous monitoring of the operation of the boiler and its elements is carried out using standard and experimental control devices. It is necessary to constantly monitor experimental control measurements and promptly detect certain violations of hydrodynamics. Detection of hydrodynamic disturbances is the main task of testing. 8.9. An operational log is kept recording the progress of the experiment, operations performed by the watch personnel, main indicators of the regime and disturbances. Regular entries are made in observation logs of boiler parameters using standard instruments. The recording frequency is 10-15 minutes in stationary modes, 2 minutes during disturbances. Excess air is monitored (using oxygen meters or Orsa devices). It is necessary to monitor the combustion mode by inspecting the firebox. 8.10. Careful supervision is carried out over the serviceability of experimental control devices, including: the “zero” position, the position and pulling of the tape, the clarity of the readings on the tape, the correctness of the readings of instruments and individual points. Malfunctions must be corrected immediately. The correspondence of the readings of experimental and standard instruments according to similar parameters is verified*. Before each experiment, the flow and pressure sensors are registered and zeroed. At the end of the experiment, the registration of “zeros” is repeated. * The difference in readings should not exceed , where And 1 and And 2 - instrument accuracy classes. 8.11. Regularly at the beginning, end and throughout the experiment, to synchronize the instrument readings, a simultaneous time stamp is made on all tapes. The mark is made manually or with a large number of devices using a special electrical time marking circuit (simultaneous short-circuiting of the device circuits). 8.12. It is recommended, if possible, to subject the resulting experimental material to express processing immediately after the experiments. A preliminary analysis of the results of previously conducted experiments allows for more targeted subsequent experiments with timely adjustment of the test program if necessary. 8.13. During the testing period, in addition to planned experiments, observations of the operating conditions of the boiler are carried out using standard and experimental control devices. The purpose of the observations is to obtain confirmation of the representativeness and completeness of the experimental modes, data on the stability or instability of boiler parameters over time (which is especially important for pulverized coal boilers), as well as to obtain current information on the status of standard control measurements in preparation for the next experiments. The observation results are used as auxiliary material.9. PROCESSING OF TEST RESULTS
9.1. Test results are processed using the following formulas
G el
= (wr)el × F el; D i = iout - iinput ; 
h T = rq × rr × hk,Where F- internal cross-section of the pipeline, m 2 ; t us - saturation temperature by medium pressure at the outlet of the circuit, °C; a- flow coefficient of the measuring tube; D R measurement - pressure drop across the measuring tube, kgf/m2; v- specific volume of the medium, m 3 /kg; F el- internal cross-section of the element, m 2 ; i in,i out- enthalpy of the medium at the inlet and outlet of the circuit, kJ/kg (kcal/kg), taken from thermodynamic tables, i =
f(t,P),
pressure is taken at the inlet and outlet of the circuit; hk- coefficient of structural non-identity of an element (individual pipe), taken from design data according to [1]. Explanations for the rest letter designations see paragraphs. 1.1.7 and 1.1.8.9.2. Errors in determining indicators based on measurement results are determined as follows: d (wr) = d (G); D ( tinput) = D ( t); D ( tout) = D ( t); D ( tel) = D ( t); d(D R k)
= d(D R).Absolute error D( t us)
is found from thermodynamic tables and is equal to half the unit digit of the last significant digit. The permissible absolute error in temperature measurement is determined by the formula where D TP- permissible error of thermocouples; D hp - communication line error caused by deviation of the thermo-EMF of the extension wires; D etc- basic error of the device; D¶ i- additional instrument error from i th influencing environmental factor; p pr- the number of factors influencing the device. The permissible relative error in measuring flow rate, differential pressure and pressure is determined by the formulas: 
Where dsu -
permissible relative error of the restriction device; d ¶
- permissible relative error of the sensor; detc
- basic relative error of the device; d ¶ i ,
detci
- additional relative errors of the sensor and device from i th external influencing factor; P ¶ -
number of influencing factors on the sensor. 9.3. Before the start of processing, the time intervals of the experiments are specified and time markings are made on the chart tapes of the recorders (for stationary modes - at intervals of 5-10 minutes, for modes with disturbances - after 1 minute or every clear). The timing of the tapes of all devices is checked. Readings from the tapes are taken using special scales, which are calibrated according to standard scales or according to individual calibrations of instruments and sensors. Unrepresentative measurement results are excluded from processing. 9.4. The results of measurements in stationary modes are averaged over time during the experiment: boiler parameters according to entries in observation logs, other indicators according to recorder tapes according to the markings. Particular attention is required to processing the results of measurements of temperatures and pressures of the medium along the steam-water path, since enthalpy is determined from them and enthalpy increments in heating surfaces are calculated, which is the basis of a large part of the processing. One should take into account the possibility of significant errors in determining enthalpy during SCD in the zone of high heat capacities (at subcritical pressure - in the evaporation part). The pressure at intermediate points in the duct is determined by interpolation, taking into account direct measurements and hydraulic calculations of the boiler. The average processing results are entered into tables and presented in the form of graphs (distribution of temperatures and enthalpies of the medium along the path, temperature and hydraulic measurements, dependence of the thermal and hydraulic performance of the circuit on the boiler load and on operating factors, etc.). 9.5. The task of testing in transient modes is to determine deviations of flow rates and temperatures in circuit elements from the initial stationary values (in terms of magnitude and rate of change). In view of this, the processing results are not averaged and are presented in the form of graphs depending on time. It is advisable to display areas with stability violations on separate graphs with an increased time scale or provide photocopies of the tapes. Kindling modes are also processed in the form of time graphs. 9.6. When processing hydraulic measurements, individual scales are used that correspond to the calibration of the sensor. The counting is made from the “zeros” marked on the tape during the experiments. For stationary modes when measuring flow, the pressure drop readings on the measuring device taken from the tape are recalculated into flow or mass velocity values. Recalculation is carried out using the formulas given in clause 9.1, or using auxiliary dependencies ( wr),
G from D R measurement, constructed on the basis of the specified formulas (for the operating range of temperatures and pressures of the medium). For transient modes when constructing a time graph, it is allowed not to recalculate the flow measurement in the circuit elements and to build the resulting graph in D values R measurement(showing approximate flow rates using the second scale on the graph). 9.7. The measured pressure values are corrected for the height of the water column in the connecting line (from the sampling point to the sensor); on the measured pressure difference - correction for the difference in height of the water column between the sampling points. 9.8. The most important part of processing test results is the comparison, analysis and interpretation of the obtained materials, assessment of their reliability and sufficiency. Preliminary analysis is carried out at intermediate stages of processing, which allows you to make the necessary adjustments along the way. In some more complex cases (for example, when results are obtained that differ from those expected, to assess the limits of stability outside the experimental data, etc.), it is advisable to perform additional calculations of hydraulic stability taking into account the experimental material. 10. PREPARATION OF A TECHNICAL REPORT
10.1. Based on the test results, a technical report is drawn up, which is approved by the chief engineer of the enterprise or his deputy. The report should contain test materials, analysis of materials and conclusions on the work with an assessment of the hydraulic stability of the boiler, conditions and limits of stability, as well as, if necessary, recommendations for increasing stability. The report must be prepared in accordance with STP 7010000302-82 (or GOST 7.32-81). 10.2. The report consists of the following sections: “Abstract”, “Introduction”, “Brief description of the boiler and the tested circuit”, “Test methods”, “Test results and their analysis”, “Conclusions and recommendations”. The introduction formulates the goals and objectives of the tests, the fundamental approach to their implementation and the scope of work are determined. The description of the boiler must include design characteristics, equipment, and the necessary data from factory calculations. The section “Test Methodology” provides information on the experimental control scheme, measurement technique and test procedure. The section “Test Results” and their analysis" covers the operating conditions of the boiler during the testing period, provides detailed results of measurements and their processing, as well as an assessment of the measurement error; an analysis of the results is given, the obtained indicators of hydraulic stability are considered, compared with existing calculations, the results are compared with known results from other tests of similar equipment, stability assessments and proposed recommendations are substantiated. Conclusions should contain an assessment of hydraulic stability (for individual indicators and in general) depending on boiler load, other operating factors and from the influence of non-stationary processes. If insufficient stability is identified, recommendations are given to improve operational reliability (operational and reconstructive). 10.3. Graphic material includes: drawings (or sketches) of the boiler and its components, a hydraulic diagram of the circuit under test, a measurement diagram (with the necessary components), drawings of non-standard measuring devices, graphs of the results of calculations, graphs of measurement results (primary material and generalizing dependencies), sketches of proposals on reconstruction (if any). The graphic material must be sufficiently complete and convincing so that the reader (customer) can get a clear understanding of all existing aspects of the tests carried out and the validity of the conclusions and recommendations made. 10.4. The report also provides a list of references and a list of illustrations. The annex to the report includes summary tables of test and calculation data and copies necessary documents(acts, protocols).11. SAFETY REQUIREMENTS
Persons participating in testing must know and comply with the requirements set out in [3] and have an entry in the knowledge test certificate.Annex 1
DESIGN OF PRESSURE PIPES
When choosing a particular design of measuring pressure tubes (Pitot tubes), one should be guided by the required pressure drop, the flow area of the pipes, take into account the complexity of manufacturing a particular tube design, as well as the ease of their installation. The designs of pressure tubes for measuring circulation and water velocities are shown in Fig. . 3. TsKTI rod tube (see Fig. 3, a) is usually installed at a depth of 1/3 D, which is significant for small-diameter pipes. In Fig. Figure 3b shows the design of a cylindrical VTI tube. For screen pipes with an internal diameter of 50-70 mm, the diameter of the measuring tube is taken to be 8-10 mm, they are installed to a depth of 1/2 of the internal diameter of the pipe. The disadvantages of cylindrical tubes compared to rod ones include their greater cluttering of the internal cross-section, and the advantages are their simpler manufacture and lower flow coefficient, which leads to an increase in the pressure drop of the sensor at the same water flow. Along with the above designs of pressure tubes for measurement cylindrical through tubes are also used in circuits (see Fig. 3, c), which are easy to manufacture - only turning and drilling of channels. The flow coefficient of these tubes is the same as that of cylindrical VTI tubes. The specified measuring tube can be made of a simplified design - from two pieces of small diameter pipes (see Fig. 3d). Parts of the tubes are welded in the middle with a partition installed between them, so that there is no communication between the left and right cavities of the tube. Pressure signal sampling holes are drilled near the partition as close to each other as possible. After welding the tubes, the welding site should be thoroughly cleaned. To weld a tube into a screen or bypass pipe, it is welded to the fittings. To correctly install measuring tubes of any design along the water flow, marks should be made on the outer part of the end of the cylinder or fittings. In Fig. 4a shows the results of calibration of rod tubes with a length of the measuring part equal to 1/2, 1/3, 1/6 D(D- internal diameter of the pipe). As the length of the measuring part decreases, the value of the tube flow coefficient increases. For pipe with h = 1/6D the flow coefficient approaches unity. As the internal diameter of the pipe increases, the flow coefficient decreases for all lengths of the active part of the meter. From Fig. 4a it can be seen that the lowest flow coefficient, and therefore the highest pressure drop, have tubes with a measuring part length equal to 1/2 D. When using them, the influence of the internal diameter of the pipeline is significantly reduced. In Fig. 4, b the results of calibration of VTI tubes with a diameter of 10 mm with the measuring part set to 1/2 are presented D. Dependence of flow coefficient a the ratio of the diameter of the measuring tube to the internal diameter of the pipe in which it is installed is given in Fig. 4,c. The given flow coefficients are valid when measuring tubes are installed in screen pipes, i.e. for numbers Re, located at the level of 10 3, and acquire constant values for the TsKTI tubes at numbers Re³ (35 ¸40) ×10 3, and for VTI tubes at Re³ 20 ×10 3. In Fig. 4d shows the flow coefficient for a through cylindrical tube with a diameter of 20 mm depending on the length of the stabilizing section L pipes with an internal diameter of 145 mm. In Fig. 4, d shows the dependence of the flow coefficient and correction factor on the ratio of the diameters of the measuring tube and the pipe in which it is installed. The actual flow coefficient in this case will be: a f= a × TO Where TO - coefficient that takes into account other factors. Correct installation of pressure tubes increases the accuracy of determining velocities. The holes in the tube that receive the pressure signal must be located strictly along the axis of the pipe in which it is installed. Possible distortions in the tube readings if it is not installed accurately, obtained on the stand, are shown in Fig. 4f. Comparison of pressure tubes designed by TsKTI and VTI with an active length of the measuring part equal to 1/2 D shows that the pressure drop created at the same flow rate for VTI tubes for screen pipes with an internal diameter of 50 and 76 mm, respectively, is 1.3 and 1.2 times greater than for CNTI tubes. This ensures greater measurement accuracy, especially at low water velocities. Therefore, when the obstruction of the internal section of the pipe by the measuring tube is not of decisive importance (for pipelines of relatively large diameter), then VTI tubes should be used to measure water velocities. TsKTI tubes are most often used on coils of small internal diameter (up to 20 mm). Measuring water velocities less than 0.3 m/s, even with VTI tubes, is not recommended, since in this case the pressure drop is less than 70-90 Pa (7 -9 kgf/m 2), which is less than the lower guaranteed measurement limit for sensors used in flow measurement.Appendix 2
PREPARATORY WORK FOR TESTING THE SCREENS OF THE TGMP-314 BOILER OF THE KOstroma GRES
|
Name |
Quantity, pcs. |
Manufacturing of temperature inserts | Insertion of temperature inserts into the NRF and SRF | Opening of insulation on collectors and pipelines (NRCh, SRCh, VRC) |
25 plots |
Installation and welding of surface thermocouples | Switching thermocouples and inserts to junction boxes (JB) | Installation SK-24 | Laying compensation cable KMTB-14 | Installation of pressure pipes (with drilling in supply pipes and NRF coils) | Installation for pressure signal selection | Installation for selecting signals for ignition feedwater flow (from a standard diaphragm) | Laying connecting (impulse) pipes | Installation of flow sensors | Manufacturing and installation of a panel for 20 devices | Installation of secondary devices (KSP, KSU, KSD) | Preparing the work area | Technical inspection (audit) of standard measurement systems for the steam-water path | Installation of sewn lighting. |
|
Name |
Quantity, pcs. |
Differential pressure sensor DM, 0.4 kgf/cm 2 (at 400 kg/cm 2) | Pressure sensor DER 0-400 kgf/cm 2 | Differential pressure sensor DME, 0-250 kgf/cm 2 (at 400 kgf/cm 2) | Single-point KSD device | KSU single-point device | Device KSP-4, 0-600°, HA, 12-point | Compensation wire MK | XA thermoelectrode wire | Fiberglass | Silica tape (glass) | Insulation tape | Chart tape for KSP, 0-600°, HA | Chart tape for KSU (KSD), 0-100%, | Flat batteries | Round batteries |
Appendix 3
I affirm:Chief Engineer of State District Power Plant
WORK PROGRAM FOR EXPERIMENTAL TESTING OF HYDRAULIC STABILITY OF NRF AND SRCH-1 OF BOILER No. 1 (with HPH)
1. Experiment 1. Set the following mode: power unit load - 290-300 MW, fuel - dust (without backlighting with fuel oil), excess air - 1.2 (3-3.5% oxygen), feed water temperature - 260°C ,in the operation of the 2nd and 3rd injections (30-40 t/h per flow). The remaining parameters are maintained in accordance with the regime map and the current instructions. During the experiment, if possible, do not make any changes in the regime. All operating automation is in operation. Duration of experiment - 2 hours. Experience 1 a. The influence of the water-fuel imbalance on the stability of hydrodynamics is checked. Set the same mode as in experiment 1. Turn off the fuel regulator. Sharply reduce the feed water consumption along stream “A” by 80 t/h without changing the fuel consumption. After 10 minutes, in agreement with the representative of Soyuztechenergo, restore the original water flow. During the experiment, temperature control along the boiler path should be carried out by injection. The permissible limits of short-term deviation of the fresh steam temperature are 525-560°C (no more than 3 minutes), the temperature of the medium along the boiler path is ±50°C from the calculated ones (no more than 5 minutes, see paragraph 4 of this appendix). Duration of the experiment is 1 Part 2. Experiment 2. Set the following mode: power unit load - 250-260 MW, fuel - dust (without backlighting with fuel oil), excess air - 1.2-1.25 (3.5-4% oxygen), temperature feed water - 240-245°C, in operation of the 2nd and 3rd injections (25-30 t/h per flow). The remaining parameters are maintained in accordance with the regime map and the current instructions. During the experiment, if possible, do not make any changes in the regime. All operating automation is in operation. Duration of experiment - 2 hours. Experiment 2a. The effect of misalignment on the burners is checked. Set the same mode as in experiment 2, but on 13 dust feeders (dust feeders No. 9, 10, 11 are turned off). Duration of the experiment is 1.5 hours. Experiment 2b. The influence of the water-fuel imbalance is checked. Set the same mode as in experiment 2a. Turn off the fuel regulator. Sharply reduce the feed water flow along stream “A” by 70 t/h without changing fuel consumption. After 10 minutes, in agreement with the representative of Soyuztekhenergo, restore the initial water flow. During the experiment, temperature control along the boiler path should be carried out by injection. Permissible limits of short-term deviation of fresh steam temperature 525-560°C (no more than 3 minutes), medium temperature along the boiler path ±50°C from the calculated one (no more than 5 minutes, see clause 4 of this appendix). Duration of the experiment - 1 hour .3. Experiment 3. Set the following mode: power unit load 225-230 MW, fuel - dust (at least 13 dust feeders in operation, without fuel oil illumination), excess air - 1.25 (4-4.5% oxygen), feed water temperature - 235-240°C, in operation of the 2nd and 3rd injections (20-25 t/h per flow). The remaining parameters are maintained in accordance with the regime map and the current instructions. During the experiment, if possible, do not make any changes in the regime. All operating automation is in operation. Duration of experiment - 2 hours. Experiment 3a. The influence of the water-fuel imbalance and the inclusion of burners is checked. Set the same mode as in experiment 3. Increase the excess air to 1.4 (6-6.5% oxygen). Disable the fuel regulator. Dramatically increase fuel consumption by increasing the rotation speed of the dust feeders by 200-250 rpm without changing the water flow through the streams. After 10 minutes, in agreement with the representative of Soyuztekhenergo, restore the original speed. Stabilize the regime. Sharply increase fuel consumption by simultaneously turning on two dust feeders in the left half-furnace without changing the water flow along the streams. After 10 minutes, in agreement with the representative of Soyuztekhenergo, restore the original fuel consumption. During the experiment, temperature control along the boiler path should be carried out by injection. The permissible limits of short-term deviation of the overheating temperature are 525-560°C (no more than 3 minutes), the temperature of the medium along the boiler path is ±50°C from the calculated ones (no more than 5 minutes, see paragraph 4 of this appendix). Duration of the experiment is 2 hours. Notes: 1. KTC appoints a responsible representative for each experiment. 2. All operational actions during the experiment are carried out by the watch personnel on the instructions (or with the knowledge and agreement) of the responsible representative of Soyuztechenergo. 3. In the event of emergency situations, the experiment is terminated and the watch personnel act in accordance with the relevant instructions. 4. Limit short-term ambient temperatures along the boiler path, ° C: for SRCh-P 470 to VZ 500 behind screens - I 530 behind screens - II 570. Signature: _________________________________________________ (test manager from Soyuztekhenergo) Agreed by: _____________________________________________ (heads of GRES workshops)
List of used literature
1. Hydraulic calculation of boiler units (standard method). M.: "Energy", 1978, - 255 p. 2. Kemelman D.N., Eskin N.B., Davidov A.A. Setting up boiler units (handbook). M.: "Energy", 1976. 342 p. 3. Safety rules for the operation of thermal mechanical equipment of power plants and heating networks. M.: Energoatomizdat, 1985, 232 p.16.1 A hydraulic test of the boiler for strength with a pressure of 1.5 from a worker is appointed by the Register inspector after major repairs have been carried out on the boiler body associated with a change in the strength of parts.
The strength test is usually carried out with the fittings dismantled and plugs installed in their place.
In places of welds, welding defects and other places, as directed by the Register inspector, thermal insulation must be removed.
16.2 Hydraulic testing of the boiler for density with a pressure of 1.25 from the worker is carried out during inspection of the boiler within the period established by the Rules Register, as well as after routine repairs, replacement of pipes, coils, when the boiler is allowed to operate after a long break in operation of more than 1 year, etc.
Utilization water-tube boilers that are not available for internal inspection are subject to hydraulic testing at each regular inspection.
A hydraulic test for tightness is carried out with the fittings installed, while the safety valve plates must be pressed to the seats using special clamps; If this is not possible, the safety valves must be removed.
16.3 Hydraulic tests for strength and density are carried out in the presence of a Register inspector.
16.4 Hydraulic testing of the boiler with working pressure is carried out according to the decision of the STM in the following cases:
After killing pipes or coils;
After welding fistulas on pipes or coils;
After pipe rolling;
To determine leaks and leaks;
If the boiler is put into operation after prolonged snoring or chemical cleaning.
16.5 Superheaters, desuperheaters, economizers, separate sections of the recovery boiler and the steam separator, where possible, may be tested separately from the boiler.
16.6 V winter time The hydraulic test must be carried out at an air temperature in the engine room of at least +5°C.
The temperature difference between water and outside air should exclude the possibility of sweating.
16.7 Hydraulic tests for strength and density should be carried out using a hand pump.
16.8 In addition to the pressure gauge on the pump, two tested pressure gauges must be installed on the boiler for the test period.
16.9 Filling the boiler (section) with water must be done in such a way that complete removal of air from the pipe system and collectors is ensured. Air valves should close only after water comes out of them without air bubbles
16.10 Hydraulic testing for strength and density must be carried out in the following order:
a) gradual increase in pressure to working pressure within 5-10 minutes;
b) preliminary inspection of the boiler under operating pressure;
c) raising the pressure to test pressure;
d) exposure and inspection under test pressure with the pump turned off for 5-10 minutes;
e) reducing the pressure to working pressure and inspection at working pressure;
e) a gradual, uniform decrease in pressure over time.
16.11 There should be no pressure drop during exposure to test pressure.
16.12 During exposure to working pressure, all new welds and places where defects are welded must be subjected to uniform tapping with light blows using a copper or lead hammer weighing no more than 1 kg with a handle no more than 300 mm long.
16.13 The boiler is considered to have passed the test if, during inspection, no leaks, local bulges, residual deformations, cracks or signs of damage to the integrity of any parts and connections are detected. Drops that do not drain during testing pressure in the rolling joints are not considered a leak. The appearance of these signs in welds is not allowed.
16.14 Correction of defects discovered during hydraulic testing may be carried out after draining the water from the boiler.
Correcting leaks in welds by caulking is prohibited.
Inspection of the boiler by the classification society
17.1 All steam boilers with an operating pressure of more than 0.07 MPa (0.7 kgf/cm2) and hot water boilers with a water heating temperature of more than 115°C are operated under the supervision of the Register or another classification society.
17.2 The boiler must be presented to the Register inspector:
a) for verification in operation - during the annual survey;
6) for internal inspection:
Water tube boilers - every two years, starting from the second year of operation of the vessel;
Fire tube boilers - every two years during the first eight years of operation, then annually;
The boiler must also undergo an internal inspection after repair of the boiler before putting it into operation; after damage to the casing or boiler accident;
c) for hydraulic testing for density - through one next classification survey, starting from the second;
and also after boiler repair. For boilers that are not available for internal inspection, a hydraulic density test is carried out at each regular inspection;
d) for hydraulic strength testing - after boiler repairs associated with changes in the strength of the boiler body.
17.3 The STM must ensure that the boiler is presented for external and internal inspection by the Register within the prescribed time frame.
17.4 The boiler must be prepared for inspection in accordance with the requirements of [I].
17.5 During the annual inspection of the boiler in operation, safety valves, alarm and protection systems, upper and lower blowing, VUP, nutrients, emergency drives of the main steam stop valve and BZKT must be in operation.
All listed tools must be adjusted, configured and prepared for testing.
For instructions on setting safety valves, see 11.4.
17.7 The safety valves of the recovery boiler may be checked with compressed air on site or on a bench, followed by sealing.
17.8 The boiler must be presented for internal inspection after cleaning both the water side and the gas side, with manholes, hatches and shields opened.
During an internal inspection of a fire tube boiler, the Register inspector must be provided with measurements of the diameters of the fire tubes of the boiler.
17.9 Boiler repairs must be carried out under the supervision of the Register. Before the start of work, the boiler is presented to the Register inspector for internal inspection, and a defect inspection report, a list of planned repairs and the scope of presentation of the quality of work performed during the repair process are agreed upon.
Repair of water tube boiler manifolds and fire tube boiler bodies, as well as other complex renovation work must be carried out in accordance with the documentation approved by the Register.
After repair, the boiler must be presented to the Register inspector for internal examination and hydraulic testing. At the same time, documentation must be submitted confirming the quality of the work performed.
Typical malfunctions and damage to boilers, their causes and solutions
Table A.1 - Changes in steam parameters (at a constant boiler load)
| Malfunction | Cause of malfunction | |||
| 1. The pressure in the boiler drops | a) The evaporation or smoke pipe in the boiler has burst (the pressure drops quickly, at the same time the water level leaves the water indicator, there may be a pop in the firebox; steam comes out of the firebox, chimney) b) Fistula in the pipe c) The automatic regulator is faulty d) The pulse valve is closed or the pipeline to the steam pressure regulator is clogged | Take the boiler out of operation immediately. After the boiler has cooled down, plug the burst pipe or replace it. Take the boiler out of operation, plug the damaged pipe or replace it. Check the operation. automatic regulators and fix the problem Go to manual control combustion and eliminate the malfunction | ||
| 2. The pressure in the boiler increases | a) Cause specified in point 1, items c and d b) Safety valve is faulty | See point 1, items c and d Adjust the safety valve or take the boiler out of operation to eliminate the malfunction | ||
| 3. The temperature of the superheated steam has decreased | a) The normal operation of the superheated steam temperature regulator has been disrupted b) The desuperheater is leaking (fistula) c) The humidity of the saturated steam has increased due to a high water level and (or) high concentration of salts in the boiler d) The humidity of the saturated steam has increased due to a malfunction of the steam separation device e) The heating surface of the superheater covered with soot | Eliminate the malfunction of the regulator Turn off the desuperheater and continue to operate the boiler or take the boiler out of operation and eliminate the damage Reduce the water level in the boiler, bring the salinity content of the boiler water to normal by blowing out Take the boiler out of operation, open the steam-water manifold and eliminate the malfunction Blow off the superheater; When the boiler stops operating, inspect the superheater and clean it | ||
| 4. The temperature of the superheated steam has increased | a) The reason specified in paragraph 3, item a b) Large excess of air in the furnace c) The heating surface of the convective beam is covered with soot d) Fuel atomization is unsatisfactory, leading to fuel burning out in the flues e) The temperature of the feed water has decreased | See point 3, item a Reduce air pressure. Check the tightness of the sheathing. Fix leaks immediately or, if this is not possible, upon arrival at the port. Blow off soot. The next time the boiler goes out of operation, clean the external heating surfaces of the boiler. Find out the reasons and take the measures indicated in Table A.4, paragraph 4. Increase the temperature of the feed water to the specification | ||
Note: If the measures taken are not enough and the superheated steam temperature is higher than normal, reduce the boiler load.
Table A.2 Change in water level
| Malfunction | Cause of malfunction | Recommended troubleshooting method |
| 1. The water level in the water indicator increases or decreases | a) The water indicator shows the wrong level b) The normal operation of the power regulator is disrupted c) The normal operation of the feed pump is disrupted | Blow out the water indicator Switch to manual control, eliminate the malfunction Strengthen monitoring of the level Start the second pump, adjust or stop the faulty one, eliminate the malfunction immediately |
| 2. The water level in the water indicator is not visible. | a) Water has been lost from the boiler (when blowing through the device, water does not appear) b) The boiler is overfed (when blowing, the level appears, but quickly goes up beyond the water level of the device) | Take the measures specified in 11.2 of the RND text. Reduce combustion, close stop valves, reduce boiler power (do not close the feed valve completely); find out and eliminate the cause of boiler overfeeding |
| 3. The water level in the water indicator fluctuates sharply | a) The channels in the water indicator device are clogged or the gaskets are installed incorrectly b) The channels to the water indicator device are clogged c) Boiling and foaming of water in the steam-water drum due to increased salinity | Blow out the device; if this does not give results, replace the device with a spare one. Remove the device, clean the channels up to the cutting valves. If necessary, take the boiler out of operation. Strengthen the top blowing |
Note - If the boiler is significantly oversaturated, the presence of water in the water indicator device is difficult to determine even by blowing it through. There is doubt about the presence of water in the device. In this case, you need to close the secant valves to the device from the steam and water spaces of the boiler and open the device purge valve. If there is water in the device, the level will slowly drop under the influence of pressure and its own weight and will be clearly visible.
Table A.3 Changes in water parameters behind the economizer
| Malfunction | Cause of malfunction | Recommended troubleshooting method | |
| 1. The water temperature behind the economizer has increased | a) The heating surfaces of the boiler are covered with soot b) The temperature of the feed water has increased c) The fuel atomization is unsatisfactory, leading to burning out of the fuel in the flue | See Table A. 1, paragraph 4, listing in Bring the feed water temperature to the required level Find out the reasons and take the measures indicated in Table A. 4, paragraph 4 | |
| 2. The water temperature behind the economizer has decreased | a) The outer heating surfaces of the economizer are covered with soot or there are scale deposits on internal surfaces pipes b) The feed water temperature has decreased | Blow off soot. When the boiler stops operating, if necessary, carry out internal flushing or chemical cleaning of the economizer heating surface Bring the feed water temperature to the required | |
| 3. Water pressure in front of the economizer has increased | a) The non-return shut-off valve between the economizer and the boiler is not fully open b) The feed turbopump regulator is faulty or incorrectly adjusted c) The feed pipe in the steam-water manifold is contaminated with slag or foreign objects d) Slag or scale deposits in the pipes | Check the opening of the valve Adjust the operation of the feed pump regulator After the boiler stops operating, inspect and clean the pipe After the boiler stops operating, flush the economizer pipes | |
Table A.4 Changes in gas-air parameters and combustion problems
| Malfunction | Cause of malfunction | Recommended troubleshooting method | ||
| 1. The air temperature behind the air heater has increased | The reason indicated in Table A. 1, paragraph 4, listed in | See table A.1, paragraph 4, listing in | ||
| 2. The air temperature behind the air heater has decreased | The heating surfaces of the air heater are covered with soot | Blow soot out of the air heater | ||
| 3. The air pressure behind the air heater has decreased | Leaks in air heater pipes and air guide devices | Increase air supply. During the next repair, eliminate leaks | ||
| 4. Fuel atomization is unsatisfactory (for symptoms see table A.1, paragraph 4, table A.3, paragraph 1, table A.4, paragraphs 5,7,8, 11 and 12) | a) The fuel heating temperature is low b) The fuel pressure is low c) The injector fuel channels are clogged d) The steam channels are clogged or condensation has accumulated in the steam line in front of the injectors (for steam-mechanical injectors) e) The injector nozzles are worn out, the heads are coked f) Poor mixing of fuel with air due to incorrect installation or deformation of air guide devices | Increase the fuel temperature Raise the fuel pressure to normal Blow out steam or disassemble the injector and clean it Blow out the steam line in front of the injectors and steam channels, increasing the steam pressure, or change the injector Check the nozzles for compliance with the drawings, replace worn parts Check the installation of air guide devices, eliminate defects or replace defective parts | ||
| g) The nozzles or diffuser are not installed correctly along the tuyere axis h) There are leaks and leaks of fuel due to improper assembly of the nozzles | Move the nozzle or diffuser (center the nozzle) Change the nozzle. Check the condition and fit of the surfaces of the nozzle parts | |||
| 5. Black smoke coming out of the chimney | a) Lack of air b) Fuel atomization is unsatisfactory c) Air supply has stopped (the fan is faulty or has stopped) | Check the position of the diffusers and air guide dampers. Raise air pressure. Eliminate possible leaks in the air channels. Find out the reasons and take the measures specified in point 4. Reduce the boiler load. If necessary, stop fuel supply. Take action to resolve fan faults | ||
| 6. White smoke coming out of the chimney | a) Water gets into the fuel b) The reason indicated in Table A.1, paragraph 1, items a and b, paragraph 4, item b | Take the measures specified in 8.4.11 of the text of the RND See table A.1, paragraph 1, items a and b, paragraph 4, item b | ||
| c) Fuel overheating | Bring fuel temperature to normal | |||
| 7. Throwing sparks out of the pipe | a) Excessive boost of the boiler b) Accumulation of soot in the flue c) Ignition of soot in the boiler or flue | Reduce the load Clean the flue duct See 11.5. RND text | ||
| 8. Black streaks in the torch, smoke in the firebox, flame strikes on the masonry and walls of the firebox | Reasons specified in paragraphs 4 and 5, item a | See paragraph 4 and paragraph 5, item a | ||
| 9. Pulsation and popping of the torch, vibration of the boiler front | a) Increased amount of water in the fuel b) Reasons specified in paragraph 4, item 5, item a c) Fluctuations in fuel pressure | Take the measures specified in 8.4.11 of the RND text. See paragraph 4, item g and paragraph 5, item a. Check the operation of the fuel pressure regulator. Troubleshoot fuel pump | ||
| 10. Hissing and fading of the torch | a) Water getting into the fuel b) Increased content of mechanical impurities in the fuel | Take the measures specified in 8.4.11 of the RND text. Check the serviceability and cleanliness of fuel filters and injectors. Switch to receiving fuel from another tank | ||
| 11. Coking of tuyeres | a) The reasons specified in paragraph 4, items f and g | See paragraph 4, items f and g | ||
| b) The geometry of the tuyere is broken | Restore the geometry of the tuyere in accordance with the drawing | |||
| 12. Formation of coke on the walls of the furnace and evaporation pipes (especially when burning waxy fuel oils) | a) Reasons specified in paragraph 4 | See point 4 | ||
| 13. General darkening of the flame and its ejection from the firebox | a) The reason specified in paragraph 5, item a b) Entrainment of the gas path | See paragraph 5, item a. Take the measures specified in Table A.1, paragraph 4, item c. | ||
| 14. The appearance of a ragged flame with sparks in the firebox | a) The reason specified in paragraph 10, item b b) Excessive heating of the fuel in front of the injectors | See point 10, item b Bring the fuel heating temperature to normal | ||
| 15. Torch separation or extinction when working at low loads | a) Significant overheating of the fuel b) Increased or decreased steam pressure (for steam-mechanical injectors) | Reduce fuel heating temperature Adjust steam pressure | ||
Table A.5 Safety valve malfunctions
| Malfunction | Cause of malfunction | Recommended troubleshooting method |
| 1. Safety valve misses | a) Dirt or scale has gotten under the valve b) The supporting surfaces have nicks or are corroded c) There are leaks between the seat and the valve body | Put the boiler out of operation, turn it off and drain it. Clean the valve Same. Thoroughly wipe and grind the valve seat together with the valve plate and then grind in. The same. Eliminate leaks between the seat and the valve body. |
| 2. Valve closing pressure after detonation is lower than required | a) The valve stem in the guide is stuck b) The quality of the valve spring is unsatisfactory | Correct the misalignment between the guide and the valve stem. Check the stiffness of the spring, replace it if necessary. |
Table A.6 Miscellaneous faults
| Malfunction | Cause of malfunction | Recommended troubleshooting method |
| 1. Overheating of the boiler casing | a) Fuel burns out in the gas ducts b) The brickwork has collapsed, the masonry has burned out | Find out the cause and take the measures indicated in Table A.4, paragraph 4. If there is significant destruction of the masonry, remove the boiler from operation. Repair defects in brickwork and insulation |
| 2. Powerful sound boom with the release of flue gases from the furnace | Gas explosion in the furnace | Stop fuel supply. Extinguish the flame. Ventilate the firebox for 10 minutes; inspect the boiler and flues. If there is no damage, relight the injector |
| 3. Fire in an air heater, economizer, convection beam, detected by a sharp increase in the temperature of the casing, air or flue gases | a) Intensive soot deposition at low loads and its ignition during the subsequent transition to normal load due to untimely soot blowing b) Air leaks into the gas side due to subsidence or weakening of pipes in the tube sheets of air heaters, the presence of cracks in the tube sheets (on jumpers), damage to the pipes themselves | Take the measures specified in 11.5 of the RND text. The same. As soon as possible, eliminate air leaks into the gas side of the air heater. |
Table A.7 Typical damage to boilers and measures to prevent them
| Malfunction | Cause of malfunction | Recommended troubleshooting method | ||
| 1. Deformation of flame tubes, fire chambers, drums, collectors | a) Local overheating of the walls due to a significant layer of scale b) The ingress of oil products onto the heating surface from the steam-water side c) An unacceptable decrease in the water level in the boiler (water loss) d) The presence of foreign objects in the boiler e) The nozzle is not centered - the torch is directed to the side | Observe the established water regime of the boiler; When scale appears, carefully clean the heating surfaces. Follow the operating instructions for the condensate feed system. If oil products enter the boiler, take it out of operation and perform leaching. Carefully monitor the water level and technical condition water indicating devices Open the manholes, check the cleanliness of the pipes. Carefully inspect the boiler before closing the openings and openings. Do not allow the boiler to operate with an uncentered nozzle. | ||
| 2. Bulging, deformation, ruptures and burns of evaporator pipes due to their overheating | a) Reasons specified in paragraph 1 b) Partial or complete blockage of pipes c) Significant thermal distortions on the gas side | See point 1 See point 1, items a and d Carefully regulate the combustion process, carry out timely cleaning of gas ducts | ||
| d) Thinning of pipes as a result of wear and burning e) Disruption (“overturning”) of circulation in water-tube boilers f) Lack of steam flow through the superheater when the boiler is running | Carry out timely wear monitoring and replacement of pipes Follow the instructions regarding bottom blowing, especially screen collectors Follow the operating instructions regarding blowing the superheater | |||
| 3. Leaks of water or steam at the ends of boiler pipes, in rivet seams and connections (detected by salt streaks in the places of leaks) | a) Weakening of rolling joints and rivet seams under the influence of sudden changes in temperature b) The appearance of fistulas and corrosion due to the accumulation of soot at the ends (roots) of pipes c) Violation of pipe rolling technology | Maintain time standards for commissioning and decommissioning of the boiler in accordance with the operating instructions. Monitor the correct operation of soot blowers; when taking the boiler out of operation, completely clean the boiler of soot and other deposits. Follow the rolling technology, avoiding cutting the pipes | ||
| 4. Corrosion of drums and evaporator pipes from the inside, flame and smoke pipes from the outside | a) Accumulation of dirt and sludge in the water space; sub-sludge corrosion | Observe the boiler blowing modes and water mode; promptly remove iron and copper oxides from the boiler and carry out chemical cleaning | ||
| b) The effect of acids, salts, dissolved oxygen on the metal, carbon dioxide c) Moisture on steam-water surfaces during long-term “dry” storage d) Storing a boiler partially filled with water | Comply with water regulations. After chemical cleaning, when putting the boiler into storage, thoroughly rinse it. Follow the rules for storing boilers. Store the boiler in accordance with section 12 of the RND text. | |||
| 5. Pipe corrosion on the outside | a) Moisture ingress into pipes covered with soot b) Failure to dry the boiler from moisture after washing or insufficient drying | When storing the boiler, protect the pipes from moisture. Rinse the boiler from soot immediately before putting it into operation, or dry it by lighting the nozzle | ||
| 6. Cracks in the lining, damage brickwork | a) Unacceptably rapid rise of steam in the boiler or sudden cooling during cooling b) Soaking the lining with water when washing the boiler c) long length torch | Follow the instructions for the time of steam rise and shutdown of the boiler. See 14.2.4 of the RND text. Adjust the flame length | ||
Appendix B (for reference)
Table B.1
| Water | Level of quality | Unit change | Main, auxiliary and recovery boilers | Main boilers (water tube) pressure | |||||||||
| gas pipes with pressure up to 2 MPa (20 kgf/cm 2) | gas-tube and water-tube pressure up to 2 MPa (20 kgf/cm 2) | over 2 to 4 MPa (20-40 kgf/cm 2) | over 4 to 6 MPa (40-60 kgf/cm 2) | over 6 to 9 MPa (60-90 kgf/cm 2) | |||||||||
| Nutritious | Overall hardness | mEq/l | no more than 0.5 | no more than 0.3 | no more than 0.02 | no more than 0.002 | no more than 0.001 | ||||||
| Content of oil and petroleum products | mg/l | no more than 3 | no more than 3 | absence | absence | absence | |||||||
| Oxygen content O 2 | mg/l | no more than 0.1 | no more than 0.1 | no more than 0.05 | no more than 0.03 | no more than 0.02 | |||||||
| Iron compounds | µg/kg | – | – | – | no more than 100 | no more than 100 | |||||||
| Copper connections | µg/kg | – | – | – | no more than 50 | no more than 50 | |||||||
| Condensate | Chlorides C1 | mg/l | no more than 50 | no more than 10 | no more than 2 | no more than 0.2 | no more than 0.1 | ||||||
| Distillate or chemically treated water | Overall hardness | mEq/l | – | no more than 0.5 | no more than 0.02 | no more than 0.001 | no more than 0.001 | ||||||
| Fresh | Overall hardness | mEq/l | no more than 8 | no more than 5 | – | – | – | ||||||
| Boiler room | Total salt content | mg/l | no more than 13000 | no more than 3000 | no more than 2000 | no more than 300 | no more than 250 | ||||||
| Chlorides C1- | mg/l | ||||||||||||
| Base number, NaOH | mg/l | 150-200 | 150-200 | 100-150 | 10-30 | 10-15 | |||||||
| Phosphate number, PO | mg/l" | 10-30* | 10-30* | 20-40 | 30-50 | 10-20 | |||||||
| Nitrate number, NaNO | mg/l | 75-100* | 75-100* | 50-75 | 5-15 | – | |||||||
| Residual hardness | mEq/l | no more than 0.4 | no more than 0.2 | no more than 0.05 | no more than 0.02 | no more than 0.02 | |||||||
| * For boilers switched to phosphate-nitrate mode Notes: 1. Lower alkalinity limits correspond to lower total salinity content of boiler water. 2. Nitrate numbers should be 50% of the actual base number. | |||||||||||||
Appendix B (for reference)
Table B.1
Notes
1. Intra-boiler water treatment is carried out in accordance with approved instructions.
2. When using the phosphate-alkaline regime to prevent intergranular corrosion of metal in places of possible steaming through leaks, the relative alkalinity of the boiler water should be no higher than 20%, i.e. the value of the total salt content of the boiler water should not fall below a value equal to five times the value of the established alkalinity number.
In the case of using sodium-cotioned additional water with high alkalinity in the feed water composition, in order to reduce the excess alkalinity number of the boiler water, the composition of the latter must be adjusted by introducing sodium ion phosphate.
Appendix D (for reference)
Table E.1
| Water | Controlled indicators | Note |
| For boilers in all tanks Distillate and chemically treated Condensate of main and auxiliary condensers Feeder for gas-tube boilers The same, for gas-tube and water-tube boilers up to 2 MPa (20 kgf/cm2) The same, for water-tube boilers up to 6 MPa (up to 60 kgf/cm2) cm 2) The same, for water-tube boilers over 6 MPa (60 kgf/cm 2) Boiler water for boilers operating in phosphate-alkaline mode The same, for boilers operating in phosphate-nitrate mode The same, for boilers operating in phosphate regime | Chlorides (chlorine ion) Chlorides, total hardness Chlorides, oil Total hardness, chlorides, oil Total hardness, chlorides, oil, oxygen The same Total hardness, chlorides, oil, oxygen, iron, copper compounds Base number, chlorides Base number, chlorides , phosphate number, nitrate number, hardness Base number, chlorides, phosphate number | Compare the results with the analysis of the initially received water Determine during the water preparation process – – – – – At least once every 2-3 days, check the residual hardness The same The same |
Appendix E (for reference)
Table E.1 "Wet" storage method
Table E.2 "Dry" storage method
Notes
1. Before using calcium chloride, take a sample for analysis. In the presence of free chlorine, it is prohibited to use calcium chloride as a desiccant.
2. Before use, ignite silica gel for 3-4 hours at a temperature of 150-170°C.
Ministry of Transport of Ukraine
State Department of Marine and river transport
Regulatory document maritime transport of Ukraine
Thermal testing of the boiler is carried out in order to establish compliance of its characteristics with the technical specifications for delivery (customer requirements), that is, to determine the suitability of the tested boiler for the ship's power plant. Tests are carried out at full, maximum, minimum and partial loads with manual and automatic control.
During testing, the following is determined:
– boiler specifications – fuel consumption, steam output, parameters of the steam produced by the boiler, saturated steam humidity, efficiency, gas-air resistance, excess air coefficient, as well as thermochemical characteristics of the boiler (salinity of boiler water, superheated steam, purge mode, etc. .);
– reliability of operation of the boiler as a whole and all its elements, which is judged by the temperature conditions of the elements, the strength of the boiler structure, the density of the fittings and cladding, the quality of the brickwork and insulation, the stability of the combustion process and maintaining the water level in the steam-water collector, etc.;
– maneuverability characteristics of the boiler – duration of wiring, lifting and unloading, stability of steam parameters;
– operational features of the boiler – convenience, accessibility and duration of disassembly and assembly of individual parts of the boiler (necks, manhole valves, internal parts of the steam-water manifold, PP manifold, etc.) accessibility of cleaning and inspection, maintainability (convenience of plugging failed tubes, repairing boiler parts , PP, VE, VP), efficiency of soot blowers, ease of monitoring the operation of the boiler.
Thermal testing is carried out in two stages:
1) commissioning - at the manufacturer’s stand, during which all control and protection systems are tested, the combustion process and water regime are adjusted, the obtained characteristics are checked for compliance with the design ones, and the boiler is prepared for acceptance tests;
2) warranty and delivery - in conditions where the operating features of the ship's power plant (SPP) for which the boiler under test is intended are comprehensively taken into account; These tests are performed at nominal and maximum loads, as well as at fractional modes corresponding to 25, 50, 75 and 100% fuel consumption loads. Thermotechnical tests of recovery boilers are carried out during testing of the control system.
Commissioning tests are preceded by detailed inspections of the boiler and its servicing systems, as well as a steam test. Its purpose is to check the density and strength of the boiler and its individual parts, as well as the deformation of the boiler elements during gradual heating. Based on the results of the steam test, safety valves are adjusted.
Before the start of acceptance tests, the boiler must operate without cleaning for at least 50 hours. Based on the results of acceptance tests, all characteristics of the boiler are finally established and the documentation is adjusted; technical specifications for delivery, technical data sheet, description and operating instructions.
The diagram of the bench installation for conducting thermal and thermochemical tests is shown in Fig. 8.1.
Steam from the boiler steam-water header 1 enters through a throttle-moistening device 2 to the capacitor 6 , where the condensate pump comes from 7 directs condensate to measuring tanks 9 . Usually one tank is filled and the other is pumped 10 the boiler is powered. Arrow 5 The boiler is fed with additional water. To make it possible to change the chemical composition of the boiler water, measuring tanks are available 5 , which are filled with solutions of various chemical reagents. Reagents can also be supplied directly to the boiler using special dispensers.
To provide the boiler with fuel and measure its consumption, there are measuring fuel tanks 13 , one of which is filled with fuel, and from the other fuel is supplied through filters 15 pump 14 to the nozzle. When the boiler operates on fuel oil and motor fuels, a fuel heater and a recirculation system are used to preheat the fuel to a temperature of 65–75°C. Air enters the boiler from a fan 18 .
A steam sampling device is installed on the main steam line, from which a steam sample is sent to the condenser 3 . The resulting condensate goes directly into the salinity meter or into the flask 4 and then to the laboratory for chemical analysis. The results of the analysis allow us to determine the moisture content of the steam. Boiler water sampling is carried out through the refrigerator 17 , from which cooled water is drained into a vessel 16 for further chemical analysis. The composition of combustion products is determined using a gas analyzer. These data are used to calculate the excess air coefficient. Water removed from the boiler by upper and lower blowing through the refrigerator 12 enters the measuring container 11 . Parameters of steam, feed water, air, products
Symbols of devices
<жиннь/й монометр для замера (г) давлений пара р } топлива р?л
TJ~ shaped nanometer For measuring ^2 static pressures in the air box b. in Vtopka. D) Vdymna-
®еь, А Thermometers (thermocouples) for is a measure of air temperatures tr B j7ion/lu-va t 7 fi, flue gases й^ x.
Rice. 8.1. Schematic diagram of a stand for conducting thermal and thermochemical tests of boilers
combustion is measured using instruments, some of which have devices for automatically recording readings. In order to determine the thermal and operational characteristics of the boiler over a wide range of loads, its balance tests are carried out under stationary operating conditions.
The steam output of the boiler is determined by the flow of feed water at a constant water level in the steam-water manifold and tightly closed upper and lower blowing valves, under these conditions 
.
Feedwater and fuel flow rates are measured using pre-tared measuring tanks. To do this, it is necessary to measure the change in level 
water (fuel) in the tank during 
.
Then the consumption of feedwater (fuel) can be calculated using the formula
Steam flow is also determined using flow metering diaphragms installed on the main steam line. The temperature of water, fuel, air is measured with technical mercury thermometers, and the temperature of exhaust gases is measured with thermocouples; pressure of steam, feed water and fuel - with spring pressure gauges, and pressure in the gas-air path - with U-shaped water pressure gauges. The readings of all stand instruments are recorded using a common signal after 10–15 minutes. The duration of reaching the stationary mode is 2 hours. The mode is considered stationary (steady) if the readings of the instruments measuring the main parameters do not go beyond the permissible deviations from the average value. During measurements, deviations are allowed: steam pressure ±0.02 MPa, gas and air pressure ±20 Pa; temperature of feed water and flue gases ±5°С. The average values of instrument readings over time are found as the arithmetic average over the test period. Values that differ from the more acceptable average are not taken into account. If the number of such readings exceeds 17% of the total number of measurements taken, then the experiment is repeated.
The efficiency of the boiler is determined by formulas (3.13) and (3.14), heat losses with flue gases 
and from chemical underburning 
formulas (3.3), (3.24), (3.26) and (3.27), and losses to the environment 
, calculated using the heat balance equation
To calculate the excess air coefficient a, gas analysis data and calculated dependencies (2.35)–(2.41) are used. Based on the test results, graphs are drawn (Fig. 8.2), which represent dependences on fuel consumption IN. This full scope of testing is intended for newly developed boilers. For serial samples, the volume of testing can be reduced, which is provided for by special programs.
Highly economical and safe operation of a boiler on a ship can be ensured provided that all requirements of the USSR Register, which supervises their implementation, are met. This supervision begins with the consideration of technical documentation, drawings, calculations, technological maps, etc. All main, auxiliary and recovery boilers, their superheaters, economizers with an operating pressure of 0.07 MPa or more are subject to supervision.
Representatives of the USSR Register subject boilers to inspection, which may coincide in time with the inspection of the vessel as a whole or be carried out independently. They are initial, regular and annual.
Initial the survey is carried out in order to establish the possibility of assigning a class to the vessel (the technical condition and year of construction of the vessel, mechanisms, including boilers, are taken into account), another, – to renew the class of the vessel and check the compliance of the technical condition of mechanical equipment and boilers with the requirements of the USSR Register; annual inspection is necessary to control the operation of mechanisms and boilers. After repair or accident, the ship undergoes an extraordinary survey. During surveys, a representative of the Register may carry out internal and external inspections, hydraulic tests of boilers, adjustment and testing for operation of safety valves; inspection of means for preparing and supplying feed water, fuel and air, fittings, instrumentation, automation systems; checking protection operation, etc.
Hydraulic test test pressures are usually 
, but no less than 
MPa ( 
working pressure). For superheaters and their elements 
if they operate at a temperature 
, equal to 350°C and above.
|
|
0.1 0.2 0.3 V,kg/s
Rice. 8.2. Boiler characteristics
The steam boiler and its elements (PP, VE and PO) are maintained at test pressure for 10 minutes, then the pressure is reduced to operating pressure and the inspection of the boiler and its fittings continues. Hydraulic tests are considered successful if the test pressure does not decrease within 10 minutes, and upon inspection no leaks, visible changes in shape or residual deformation of the boiler parts are detected.
The safety valves must be adjusted to the following opening pressures: for 
MPa; 
For 
MPa.Maximum pressure when the safety valve operates 
.
During the inspection, external inspections of boilers are carried out along with pipelines, fittings, mechanisms and systems at operating steam pressure.
The results of the survey are entered into the register book of the steam boiler and the main steam pipeline, which is issued by the inspector of the USSR Register during the initial survey of each boiler.
To check the strength of the structure and the quality of its workmanship, all elements of the boiler, and then the boiler assembly, are subjected to hydraulic tests with test pressure R etc. Hydraulic tests are carried out after completion of all welding work, when insulation and protective coatings are still missing. The strength and density of welded and rolling joints of elements is checked by test pressure R pr = 1.5 R r, but not less R p + 0.1 MPa ( R p – operating pressure in the boiler).
Dimensions of elements tested under test pressure R p + 0.1 MPa, as well as elements tested at a test pressure higher than indicated above, must be subject to a test calculation for this pressure. In this case, stresses should not exceed 0.9 of the yield strength of the material σ t s, MPa.
After final assembly and installation of fittings, the boiler undergoes a final hydraulic pressure test R pr = 1.25 R r, but not less R p + 0.1 MPa.
During hydraulic tests, the boiler is filled with water and the operating water pressure is brought to the test pressure R with a special pump. Test results are determined by visual inspection of the boiler. And also by the rate of pressure drop.
The boiler is considered to have passed the test if the pressure in it does not drop and upon inspection no leaks, local bulges, visible changes in shape or residual deformations are detected. Sweating and the appearance of small droplets of water at the rolling joints are not considered a leak. However, the appearance of dew and tears at the welds is not allowed.
Steam boilers, after installation on a ship, must be subjected to a steam test at operating pressure, which consists of putting the boiler into operational condition and testing it in operation at operating pressure.
The gas cavities of recovery boilers are tested with air at a pressure of 10 kPa. Gas ducts of auxiliary and combined PCs are not tested.
4. External inspection of boilers under steam.
External inspection of boilers complete with apparatus, equipment, service mechanisms and heat exchangers, systems and pipelines is carried out under steam at operating pressure and, if possible, combined with a check of the operation of ship mechanisms.
During the inspection, it is necessary to make sure that all water indicating devices are in good condition (water gauge glasses, test taps, remote water level indicators, etc.), as well as that the upper and lower blowing of the boiler is working properly.
The condition of the equipment, the proper operation of the drives, the absence of steam, water and fuel leaks in the seals, flanges and other connections must be checked.
Safety valves must be tested for operation. The valves must be adjusted to the following pressures:
valve opening pressure
R open ≤ 1.05 R slave for R slave ≤ 10 kgf/cm 2 ;
R open ≤ 1.03 R slave for R slave > 10 kgf/cm 2 ;
Maximum permissible pressure when the safety valve is in operation R max ≤ 1.1 R slave.
Superheater safety valves should be adjusted to operate somewhat ahead of the boiler valves.
Manual actuators for releasing safety valves must be tested in operation.
If the results of the external inspection and operational testing are positive, one of the boiler safety valves must be sealed by the inspector.
If checking the safety valves on recovery boilers while moored is not possible due to the need for long-term operation of the main engine or the impossibility of supplying steam from an auxiliary fuel-burning boiler, then the adjustment check and sealing of the safety valves can be carried out by the shipowner during the voyage with the execution of the appropriate report.
During the inspection, the operation of the automatic control systems of the boiler installation must be checked.
At the same time, you should make sure that the alarm, protection and blocking devices work flawlessly and are triggered in a timely manner, in particular when the water level in the boiler drops below the permissible level, when the air supply to the furnace is cut off, when the torch in the furnace is extinguished and in other cases provided for by the automation system.
You should also check the operation of the boiler installation when switching from automatic to manual control and vice versa.
If, during an external inspection, defects are discovered, the cause of which cannot be established by this inspection, the inspector may require an internal examination or hydraulic test.