Equipment of boiler plants and the principle of their operation. Hydraulic calculation of the heating network. Construction of a piezometric graph. Requirements for a gas boiler room

Purpose of boiler rooms.

Heating Boiler houses are designed to generate heat used for heating and hot water supply of residential, public and industrial structures and buildings.

The productivity of the installations is determined as the sum of the maximum hourly heat consumption for the specified purposes at the design temperature of the outside air and the heat consumption for own needs.

Heating and production Boiler houses are designed to generate heat used for heating and hot water supply for residential, public and industrial buildings and structures, as well as to supply the enterprise with steam used for technological needs.

Production Boiler houses are designed to generate heat for technological purposes. They have productivity, which is determined by the maximum daily schedule, taking into account losses and their own needs.

The most widespread are heating and heating-industrial boiler houses.

Boilers installed in industrial heating systems are produced with a capacity of 4; 6.5; 10; 20; 30; 50; 100 and 180 Gcal/h.

Boiler brands:

· Gas and oil

PTVM – modernized direct-flow cogeneration water-tube boiler;

KVGM – gas-oil water tube boiler.

· Solid fuel

KVTK – solid fuel water tube boiler with chamber fuel combustion;

KVTS is a solid fuel water tube boiler with layer combustion of fuel.

In hot water boilers, steam formation is not allowed to avoid the formation of scale and water hammer. To do this, it is necessary to maintain a constant speed of water in the system, i.e. hot water boilers operate at a constant flow rate. To avoid low-temperature corrosion on the boiler tail surfaces, the water temperature is maintained above the dew point temperature. The dew point temperature when burning gas is 54-57°C, when burning low-sulfur fuel oil 60°C, when burning high-sulfur fuel oil – 90°C.

The choice of the type of boiler house is carried out on the basis of technical and economic calculations. The quantity and unit power of equipment is determined based on the results of thermal loss diagrams; when choosing equipment, one should strive to enlarge the unit productivity.

In boiler houses for heating purposes, backup boilers are not installed; in industrial and industrial heating boiler houses, the issue of reserving steam boilers is determined by the requirements external consumers, if the consumer does not allow interruptions in the steam supply, then reserve ones are installed in the boiler room steam boilers.

Replenishment of water losses in the network is carried out with chemically purified water, therefore the boiler room is equipped with chemical water treatment 9 and a deaerator 6. Deaerator vacuum type, the pressure in it can be from 0.07 to 0.6 kg/cm 2. Typically the deaerator is adjusted to a pressure of 0.6 kg/cm2. Deaerators can operate with or without heating. When operating without heating, the water temperature at the inlet to the deaerator should be 5-10°C higher than the pressure saturation temperature in the deaerator. When operating with heating, the water temperature at the inlet to the deaerator is 5-7°C lower than the pressure saturation temperature in the deaerator.

In this case, the chemically purified water is heated with network water from the boiler; to heat the water to the required temperature, a chemically purified water heater 4 is installed in front of the deaerator 6. normal operation water treatment 9, the temperature before it should be 25-40°C, therefore, before 9, the water must be heated with hot network water from boiler 2 in water-water raw water heaters 5. After water treatment, the water temperature becomes 5°C lower than the temperature before it.

Rice. Thermal diagram of a hot water boiler house. 1 – network pump; 2 – hot water boilers; 3 – recirculation pump; 4 – heater of chemically purified water; 5 – raw water heater; 6 – vacuum-type heating network make-up deaerator; 7 – heating network feed pump; 8 – raw water pump; 9 – chemical water treatment; 10 – vapor cooler; 11 – water jet ejector; 12 – ejector supply tank; 13 – ejector pump.

Raw water is supplied from the main water pipeline using raw water pump 8. After the deaerator 6, deaerated water is supplied to the return heating network using the heating network make-up pump 7 to the suction of network pumps 1 to replenish water leaks in the network and maintain pressure in the return line.

To recover heat from the vapor of the deaerator 6, a vapor cooler 10 is installed, where the steam-water mixture gives up its heat to chemically purified water, which enters the deaerator 6. The condensate from the vapor cooler 10 is pumped out using water jet ejector 11.

To maintain the set temperature and flow rate, a recirculation unit is installed in front of the boiler with the boiler exiting to the inlet using a recirculation pump 3.

To maintain a constant water flow in the boiler and the temperature at the inlet from the boiler, a bypass unit is provided, i.e. some of the water passes by the boiler.

PREFACE

“Gas is safe only with technically competent operation

gas boiler room equipment.

The operator's training manual provides basic information about a hot water boiler house operating on gaseous (liquid) fuel, and examines the schematic diagrams of boiler houses and heat supply systems industrial facilities. The manual also includes:

• basic information from heat engineering, hydraulics, aerodynamics is presented;
• provides information about energy fuels and the organization of their combustion;
• issues of water preparation for hot water boilers and heating networks are covered;
• the design of hot water boilers and auxiliary equipment of gasified boiler houses was considered;
• Gas supply diagrams for boiler houses are presented;
• a description of a number of instrumentation and circuits is given automatic regulation and security automation;
• great attention is paid to the operation of boiler units and auxiliary equipment;
• issues on preventing accidents of boilers and auxiliary equipment, providing first aid to victims of an accident were considered;
• Basic information on organizing the efficient use of heat and power resources is provided.

This operator’s training manual is intended for retraining, training in related professions and advanced training of gas boiler house operators, and can also be useful: for students and students in the specialty “Heat and Gas Supply” and operational dispatch personnel when organizing a dispatch service for the operation of automated boiler houses. To a greater extent, the material is presented for hot water boiler houses with a capacity of up to 5 Gcal with gas-tube boilers of the “Turboterm” type.

Preface	2
Introduction	5
CHAPTER 1. Schematic diagrams of boiler houses and heat supply systems	8
1.3. Methods for connecting consumers to the heating network 1.4. Temperature chart quality regulation heating load 1.5. Piezometric graph
CHAPTER 2. Basic information from thermal engineering, hydraulics and aerodynamics	18
2.1. The concept of coolant and its parameters 2.2. Water, water vapor and their properties 2.3. The main methods of heat transfer: radiation, thermal conductivity, convection. Heat transfer coefficient, factors influencing it
CHAPTER 3. Properties energy fuel and its combustion	24
3.1. General characteristics energy fuel 3.2. Combustion of gaseous and liquid (diesel) fuels 3.3. Gas burner devices 3.4. Conditions for stable operation of burners 3.5. Requirements of the “Rules for Device and safe operation steam and hot water boilers" to burner devices
CHAPTER 4. Water treatment and water chemical regimes of the boiler unit and heating networks	39
4.1. Quality standards for feed, make-up and network water 4.2. Physico-chemical characteristics of natural water 4.3. Corrosion of boiler heating surfaces 4.4. Water treatment methods and schemes 4.5. Deaeration of softened water 4.6. Complex-metric (trilometric) method for determining water hardness 4.7. Malfunctions in the operation of water treatment equipment and methods for eliminating them 4.8. Graphic interpretation of the sodium cationization process
CHAPTER 5. Construction of steam and hot water boilers. Auxiliary equipment boiler room	49
5.1. Design and principle of operation of steam and hot water boilers 5.2. Steel water-heating fire-tube-smoke boilers for burning gaseous fuels 5.3. Air supply and combustion product removal schemes 5.4. Boiler valves (shut-off, control, safety) 5.5. Auxiliary equipment for steam and hot water boilers 5.6. Set of steam and hot water boilers 5.7. Internal and external cleaning heating surfaces of steam and hot water boilers, water economizers 5.8. Instrumentation and boiler safety automation
CHAPTER 6. Gas pipelines and gas equipment boiler rooms	69
6.1. Classification of gas pipelines by purpose and pressure 6.2. Gas supply schemes for boiler houses 6.3. Gas control points of hydraulic fracturing (GRU), purpose and main elements 6.4. Operation gas control points GRP (GRU) boiler houses 6.5. Requirements of the “Safety Rules in the Gas Industry”
CHAPTER 7. Boiler room automation	85
7.1. Automatic measurements and control 7.2. Automatic (technological) alarm 7.3. Automatic control 7.4. Automatic control of hot water boilers 7.5. Automatic protection 7.6. Control kit KSU-1-G
CHAPTER 8. Operation of boiler plants	103
8.1. Organization of operator work 8.2. Operational diagram of pipelines of a transportable boiler house 8.3. Regime card operation of a Turbotherm type hot water boiler equipped with a Weishaupt type burner 8.4. Operating instructions for a transportable boiler room (TC) with “Turboterm” type boilers 8.5. Requirement of the “Rules for the design and safe operation of steam and hot water boilers”
CHAPTER 9. Accidents in boiler rooms. Actions of personnel to prevent boiler accidents	124
9.1. General provisions. Causes of accidents in boiler rooms 9.2. Operator action in emergency situations 9.3. Gas hazardous work. Work according to the permit and approved instructions 9.4. Fire safety requirement 9.5. Personal protective equipment 9.6.Providing first aid to victims of an accident
CHAPTER 10. Organization of efficient use of heat and power resources	140
10.1. Heat balance and boiler efficiency. Boiler operating map 10.2. Fuel consumption rationing 10.3. Determination of the cost of generated (supplied) heat
References	144

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INTRODUCTION

Modern boiler technology of small and medium productivity is developing in the following directions:

• increasing energy efficiency by comprehensively reducing heat losses and making the most of the energy potential of fuel;
• reducing the size of the boiler unit due to intensification of the fuel combustion process and heat exchange in the firebox and heating surfaces;
• reduction of harmful toxic emissions (CO, NOx, SOv);
• increasing the reliability of the boiler unit.

New combustion technology is implemented, for example, in boilers with pulsating combustion. The combustion chamber of such a boiler is sound system With high degree turbulization flue gases. IN combustion chamber Boilers with pulsating combustion do not have burners, and therefore no torch. The supply of gas and air is carried out intermittently at a frequency of approximately 50 times per second through special pulsating valves, and the combustion process occurs throughout the entire combustion volume. When fuel is burned in the furnace, the pressure increases, the speed of combustion products increases, which leads to a significant intensification of the heat exchange process, the possibility of reducing the size and weight of the boiler, and the absence of the need for bulky and expensive chimneys. The operation of such boilers is characterized by low CO and N0 x emissions. Coefficient useful action There are 96 such boilers %.

A vacuum water heating boiler from the Japanese company Takuma is a sealed container filled with a certain amount of well-purified water. The boiler firebox is a fire tube located below the liquid level. Above the water level in the steam space, two heat exchangers are installed, one of which is included in the heating circuit, and the other operates in the hot water supply system. Thanks to a small vacuum automatically maintained inside the boiler, the water boils in it at a temperature below 100 o C. Having evaporated, it condenses on the heat exchangers and then flows back. Purified water is not discharged anywhere from the unit, and it is not difficult to provide the required amount. Thus, the problem of chemical preparation of boiler water, the quality of which is an indispensable condition for reliable and long-term operation of the boiler unit, was eliminated.

Heating boilers from the American company Teledyne Laars are water-tube installations with a horizontal heat exchanger made of finned copper pipes. A feature of such boilers, called hydronic, is the ability to use them with untreated network water. These boilers provide for a high speed of water flow through the heat exchanger (more than 2 m/s). Thus, if water causes corrosion of equipment, the resulting particles will be deposited anywhere but in the boiler heat exchanger. If you use hard water, fast flow will reduce or prevent scale formation. The need for high speed led the developers to the decision to minimize the volume of the water part of the boiler. Otherwise, you need a circulation pump that is too powerful and consumes a large amount of electricity. IN lately on Russian market products appeared large number foreign firms and joint foreign and Russian enterprises, developing a wide variety of boiler equipment.

Fig.1. Water heating boiler of the Unitat brand of the international company LOOS

1 – burner; 2 – door; 3 – peeping contest; 4 – thermal insulation; 5 – gas-pipe heating surface; 6 – hatch into the water space of the boiler; 7- flame tube (furnace); 8 – pipe for supplying water to the boiler; 9 – outlet pipe hot water; 10 – exhaust gas duct; 11 – viewing window; 12 – drainage pipeline; 13 – support frame

Modern hot water and steam boilers of small and medium power often performed by fire tube or fire gas tube. These boilers are characterized by high efficiency, low emissions of toxic gases, compactness, high degree of automation, ease of operation and reliability. In Fig. Figure 1 shows a combined fire-gas-tube water-heating boiler of the Unimat brand of the international company LOOS. The boiler has a firebox made in the form of a flame tube 7, washed from the sides with water. At the front end of the flame tube there is a hinged door 2 with two-layer thermal insulation 4. A burner 1 is installed in the door. Combustion products from the flame tube enter the convective gas-tube surface 5, in which they make a two-pass movement, and then leave the boiler through the gas duct 10. Water is supplied to the boiler through pipe 8, and hot water is discharged through pipe 9. The outer surfaces of the boiler have thermal insulation 4. To observe the torch, a peephole is installed in the door 3. Inspection of the condition of the outer part of the gas-tube surface can be done through hatch 6, and the end part of the body through inspection window 11. A drainage pipeline 12 is provided to drain water from the boiler. The boiler is installed on a support frame 13.

In order to assess the efficient use of energy resources and reduce consumer costs for fuel and energy supply, the Law “On Energy Saving” provides for the conduct of energy surveys. Based on the results of these surveys, measures are being developed to improve the heat and power facilities of the enterprise. These activities are as follows:

• replacement of thermal power equipment (boilers) with more modern ones;
• hydraulic calculation of the heating network;
• adjustment of hydraulic modes of heat consumption facilities;
• regulation of heat consumption;
• elimination of defects in enclosing structures and introduction of energy-efficient structures;
• retraining, advanced training and financial incentives for personnel efficient use TER.

For enterprises that have their own heat sources, the training of qualified boiler room operators is necessary. Persons who are trained, certified and have a certificate for the right to service boilers may be allowed to service boilers. This operator's training manual is precisely used to solve these problems.

CHAPTER 1. PRINCIPAL DIAGRAMS OF BOILERS AND HEAT SUPPLY SYSTEMS

1.1. Fundamental thermal diagram hot water boiler house running on gas fuel

In Fig. Figure 1.1 shows a schematic thermal diagram of a hot water boiler house operating on a closed hot water supply system. The main advantage of this scheme is the relatively low productivity of the water treatment plant and make-up pumps, the disadvantage is the increased cost of equipment for hot water supply subscriber units (the need to install heat exchangers in which heat is transferred from network water to water used for hot water supply needs). Hot water boilers operate reliably only when maintaining a constant flow rate of water passing through them within specified limits, regardless of fluctuations in the consumer’s heat load. Therefore, the thermal circuits of hot water boiler houses provide for regulation of the supply of thermal energy to the network according to quality graphics, i.e. by changing the temperature of the water leaving the boiler.

To ensure the calculated water temperature at the entrance to the heating network, the scheme provides for the possibility of mixing the required amount of return network water (G per) to the water leaving the boilers through the bypass line. To eliminate low-temperature corrosion of the tail surfaces of the boiler heating to the return network water at its temperature less than 60 ° C when operating at natural gas and less than 70-90 °C when operating on low and high sulfur fuel oil, a recirculation pump is used to mix the hot water leaving the boiler to the return network water.

Figure 1.1. Schematic thermal diagram of the boiler room. Single-circuit, dependent with recirculation pumps

1 – hot water boiler; 2-5 - network, recirculation, raw and make-up water pumps; 6- make-up water tank; 7, 8 – heaters of raw and chemically purified water; 9, 11 – make-up water and vapor coolers; 10 – deaerator; 12 – installation chemical cleaning water.

Fig.1.2. Schematic thermal diagram of the boiler room. Double-circuit, dependent with hydraulic adapter

1 – hot water boiler; 2-boiler circulation pump; 3- network heating pump; 4- network ventilation pump; 5-pump DHW internal contour; 6- pump DHW circulation; 7-water-water DHW heater; 8-dirt filter; 9-reagent water treatment; 10-hydraulic adapter; 11-membrane tank.

1.2. Schematic diagrams of heating networks. Open and closed heating networks

Water heating systems are divided into closed and open. In closed systems, water circulating in the heating network is used only as a coolant, but is not taken from the network. IN open systems ah, the water circulating in the heating network is used as a coolant and is partially or completely taken from the network for hot water supply and technological purposes.

The main advantages and disadvantages of closed water heating systems:

• stable quality of hot water supplied to subscriber installations, not different from the quality tap water;
• ease of sanitary control of local hot water supply installations and control of the density of the heating system;

• complexity of equipment and operation of hot water supply user inputs;
• corrosion of local hot water supply installations due to the entry of non-deaerated tap water into them;
• scale formation in water-water heaters and pipelines of local hot water supply installations during tap water with increased carbonate (temporary) hardness (Fc ≥ 5 mEq/kg);
• With a certain quality of tap water, in closed heating systems it is necessary to take measures to increase the anti-corrosion resistance of local hot water supply installations or to install special devices at customer inputs for deoxygenation or stabilization of tap water and for protection against contamination.

The main advantages and disadvantages of open water heating systems:

• the possibility of using low-potential (at temperatures below 30-40 o C) industrial thermal resources for hot water supply;
• simplifying and reducing the cost of subscriber inputs and increasing the durability of local hot water supply installations;
• the possibility of using single-pipe lines for transit heat;

• increasing complexity and cost of station equipment due to the need to construct water treatment plants and make-up devices designed to compensate for water costs for hot water supply;
• water treatment must ensure clarification, softening, deaeration and bacteriological treatment of water;
• instability of the water supplied to the water supply, according to sanitary indicators;
• complication of sanitary control over the heat supply system;
• complication of control of the tightness of the heat supply system.

1.3. Temperature graph of high-quality heating load regulation

There are four methods for regulating the heating load: qualitative, quantitative, qualitative-quantitative and intermittent (bypass). Qualitative regulation consists in regulating heat supply by changing the temperature of hot water while maintaining constant quantity(consumption) of water; quantitative – in the regulation of heat supply by changing the water flow rate at a constant temperature at the entrance to the controlled installation; qualitative-quantitative - in regulating heat supply by simultaneously changing water flow and temperature; intermittent, or, as it is commonly called, regulation by passes - in the regulation of heat supply by periodically disconnecting heating installations from the heating network. Temperature graph for high-quality regulation of heat supply for heating systems equipped heating devices convective-radiative action and connected to the heating network via elevator scheme, is calculated based on the formulas:

T 3 = t vn.r + 0.5 (T 3p – T 2p) * (t vn.r – t n)/ (t vn.r – t n.r)+ 0.5 * (T 3p + T 2p -2 * t vn.r) * [ (t vn.r – t n)/ (t vn.r – t n.r)] 0.8 . T 2 = T 3 - (T 3p – T 2p) * (t ext – t n)/ (t ext – t n.r). Т 1 = (1+ u) * Т 3 – u * Т 2

where T 1 is the temperature of the network water in the supply line (hot water), o C; T 2 – temperature of water entering the heating network from the heating system ( return water), o C; T 3 – temperature of water entering heating system, o C; t n – outside air temperature, o C; t in – internal air temperature, o C; u – mixing coefficient; the same designations with the index “p” refer to the design conditions. For heating systems equipped with convective-radiative heating devices and connected directly to the heating network, without an elevator, u = 0 and T 3 = T 1 should be taken. The temperature graph of qualitative regulation of heat load for the city of Tomsk is shown in Fig. 1.3.

Regardless of the adopted central control method, the water temperature in the supply pipeline of the heating network must not be lower than the level determined by the hot water supply conditions: for closed heating systems - not lower than 70 o C, for open heating systems - not lower than 60 o C. Water temperature in the supply pipeline on the graph looks like a broken line. At low temperatures tn< t н.и (где t н.и – наружная температура, соответствующая излому температурного графика) Т 1 определяется по законам принятого метода центрального регулирования. При t н >t n.and the water temperature in the supply pipeline is constant (T 1 = T 1i = const), and the regulation of heating installations can be carried out either quantitatively or intermittently (local skips) using the method. The number of hours of daily operation of heating installations (systems) at this range of outside air temperatures is determined by the formula:

n = 24 * (t vn.r – t n) / (t vn.r – t n.i)

Example: Definition of temperatures T 1 and T 2 to construct a temperature graph

T 1 = T 3 = 20 + 0.5 (95- 70) * (20 – (-11) / (20 – (-40) + 0.5 (95+ 70 -2 * 20) * [(20 – (-11) / (20 – (-40)] 0.8 = 63.1 o C. T 2 = 63.1 – (95-70) * (95-70) * (20 – (-11) = 49.7 o C

Example: Determining the number of hours of daily operation of heating installations (systems) at the outside air temperature range t n > t n.i. The outside air temperature is t n = -5 o C. In this case, per day heating installation should work

n = 24 * (20 – (-5) / (20 – (-11) = 19.4 hours/day.

1.4. Piezometric graph of a heating network

Pressures at various points of the heating supply system are determined using water pressure graphs (piezometric graphs), which take into account the mutual influence of various factors:

• geodetic profile of the heating main;
• network pressure losses;
• height of the heat consumption system, etc.

The hydraulic operating modes of the heating network are divided into dynamic (when the coolant circulates) and static (when the coolant is at rest). In static mode, the pressure in the system is set 5 m above the highest water position in it and is depicted by a horizontal line. There is one static pressure line for the supply and return pipelines. The pressures in both pipelines are equalized, since the pipelines are connected using heat consumption systems and mixing jumpers in the elevator units. The pressure lines in dynamic mode for the supply and return pipelines are different. The slopes of the pressure lines are always directed along the flow of the coolant and characterize the pressure losses in the pipelines, determined for each section according to the hydraulic calculation of the heating network pipelines. The position of the piezometric graph is selected based on the following conditions:

• the pressure at any point in the return line should not be higher than the permissible operating pressure in the local systems. (no more than 6 kgf/cm 2);
• the pressure in the return pipeline should ensure that the upper appliances of local heating systems are flooded;
• the pressure in the return line, in order to avoid the formation of a vacuum, should not be lower than 5-10 m.w.c.;
• suction side pressure network pump should not be lower than 5 m.water column;
• the pressure at any point in the supply pipeline must be higher than the boiling pressure at the maximum (design) temperature of the coolant;
• the available pressure at the end point of the network must be equal to or greater than the calculated pressure loss at the subscriber input for the calculated coolant flow.

In most cases, when moving the piezometer up or down, it is not possible to establish such a hydraulic mode in which all connected local heating systems could be connected according to the simplest dependent circuit. In this case, you should focus on installing pressure regulators, pumps on the jumper, on the return or supply input lines at the consumer inputs, or choose connection according to an independent scheme with the installation of heating water-water heaters (boilers) at the consumers. The piezometric graph of the heating network operation is shown in Fig. 1.4 CHECK QUESTIONS AND TASKS:

1. Name the main measures to improve the thermal power system. What are you doing in this direction?
2. List the main elements of the heat supply system. Define open and closed heating networks, name the advantages and disadvantages of these networks.
3. Write down on a separate sheet the main equipment of your boiler room and its characteristics.
4. What kind of heating networks do you know by design? What temperature schedule does your heating network follow?
5. What purpose does a temperature graph serve? How is the break point of a temperature graph determined?
6. What purpose does a piezometric graph serve? What role do elevators, if you have them, play in thermal units?
7. On a separate sheet, list the operating features of each element of the heat supply system (boiler, heating network, heat consumer). Always take these features into account in your work! Tutorial operator, together with a set of test tasks, should become a reference book for an operator who respects his work.

A set of educational and methodological materials for the Boiler House Operator costs 760 RUR.He tested in training centers when training boiler room operators, the reviews are the best, both from students and teachers of Special Technologies. BUY

A boiler plant (boiler room) is a structure in which the working fluid (coolant) (usually water) is heated for a heating or steam supply system, located in one technical room. Boiler houses are connected to consumers using heating mains and/or steam pipelines. The main device of a boiler room is a steam, fire tube and/or hot water boiler. Boiler houses are used for centralized heat and steam supply or local heat supply to buildings.

A boiler plant is a complex of devices located in special rooms and serving to convert the chemical energy of fuel into thermal energy steam or hot water. Its main elements are a boiler, a combustion device (furnace), feeding and draft devices. In general, a boiler installation is a combination of boiler(s) and equipment, including following devices: fuel supply and combustion; purification, chemical preparation and deaeration of water; heat exchangers for various purposes; source (raw) water pumps, network or circulation - for circulating water in the heating system, make-up - to replace water consumed by the consumer and leaks in networks, feed pumps for supplying water to steam boilers, recirculation (mixing); nutrient tanks, condensation tanks, hot water storage tanks; blower fans and air duct; smoke exhausters, gas path and chimney; ventilation devices; systems for automatic regulation and safety of fuel combustion; heat shield or control panel.

A boiler is a heat exchange device in which heat from the hot combustion products of fuel is transferred to water. As a result, water is converted into steam in steam boilers, and heated to the required temperature in hot water boilers.

The combustion device is used to burn fuel and convert its chemical energy into heat of heated gases.

Feeding devices (pumps, injectors) are designed to supply water to the boiler.

The draft device consists of blower fans, a gas-air duct system, smoke exhausters and a chimney, which ensures the supply required quantity air into the furnace and the movement of combustion products through the boiler flues, as well as their removal into the atmosphere. Combustion products, moving through flues and coming into contact with the heating surface, transfer heat to water.

To ensure more economical operation, modern boiler systems have auxiliary elements: water economizer and air heater, which serve to heat water and air, respectively; devices for fuel supply and ash removal, for cleaning flue gases and feed water; thermal control devices and automation equipment that ensure normal and uninterrupted operation of all parts of the boiler room.

Depending on the use of their heat, boiler houses are divided into energy, heating and industrial and heating.

Energy boiler houses supply steam steam power plants, generating electricity, and are usually included in the complex power station. Heating and industrial boiler houses are found in industrial enterprises and provide heat for heating and ventilation systems, hot water supply of buildings and technological processes production. Heating boiler houses solve the same problems, but serve residential and public buildings. They are divided into free-standing, interlocking, i.e. adjacent to other buildings, and built into buildings. Recently, more and more often, separate enlarged boiler houses are being built with the expectation of servicing a group of buildings, a residential area, or a microdistrict.

The installation of boiler rooms built into residential and public buildings is currently permitted only with appropriate justification and agreement with the sanitary inspection authorities.

Low-power boiler houses (individual and small group) usually consist of boilers, circulation and feed pumps and draft devices. Depending on this equipment, the dimensions of the boiler room are mainly determined.

2. Classification of boiler installations

Boiler installations, depending on the nature of consumers, are divided into energy, production and heating and heating. Based on the type of coolant produced, they are divided into steam (for generating steam) and hot water (for producing hot water).

Power boiler plants produce steam for steam turbines at thermal power plants. Such boiler houses are usually equipped with high- and medium-power boiler units that produce steam with increased parameters.

Industrial heating boiler systems (usually steam) produce steam not only for industrial needs, but also for heating, ventilation and hot water supply.

Heating boiler systems (mainly hot water, but they can also be steam) are designed to service heating systems for industrial and residential premises.

Depending on the scale of heat supply, heating boiler houses are local (individual), group and district.

Local boiler houses are usually equipped with hot water boilers that heat water to a temperature of no more than 115 °C or steam boilers with an operating pressure of up to 70 kPa. Such boiler houses are designed to supply heat to one or more buildings.

Group boiler systems provide heat to groups of buildings, residential areas or small neighborhoods. They are equipped with both steam and hot water boilers with higher heating capacity than boilers for local boiler houses. These boiler rooms are usually located in specially constructed separate buildings.

District heating boiler houses are used to supply heat to large residential areas: they are equipped with relatively powerful hot water or steam boilers.

Rice. 1.

Rice. 2.

Rice. 3.

Rice. 4.

Individual elements It is customary to conventionally show a schematic diagram of a boiler installation in the form of rectangles, circles, etc. and connect them to each other with lines (solid, dotted), indicating a pipeline, steam lines, etc. B circuit diagrams There are significant differences between steam and hot water boiler plants. A steam boiler plant (Fig. 4, a) consisting of two steam boilers 1, equipped with individual water 4 and air 5 economizers, includes a group ash collector 11, to which the flue gases are approached through a collection hog 12. For suction of flue gases in the area between the ash collector 11 and smoke exhausters 7 with electric motors 8 are installed in the chimney 9. To operate the boiler room without smoke exhausters, dampers 10 are installed.

Steam from the boilers through separate steam lines 19 enters the common steam line 18 and through it to the consumer 17. Having given up heat, the steam condenses and returns through the condensate line 16 to the boiler room in the collecting condensation tank 14. Through pipeline 15, additional water from the water supply or chemical water treatment is supplied to the condensation tank (to compensate for the volume not returned from consumers).

In the case when part of the condensate is lost from the consumer, a mixture of condensate and additional water is supplied from the condensation tank by pumps 13 through the supply pipeline 2, first into the economizer 4, and then into the boiler 1. The air required for combustion is sucked in by centrifugal blower fans 6 partially from the room boiler room, partly from the outside and through air ducts 3, it is supplied first to air heaters 5, and then to the boiler furnaces.

The water heating boiler installation (Fig. 4, b) consists of two water heating boilers 1, one group water economizer 5, serving both boilers. Flue gases leaving the economizer through a common collection duct 3 enter directly into the chimney 4. Water heated in the boilers enters the common pipeline 8, from where it is supplied to the consumer 7. Having given off heat, the cooled water through the return pipeline 2 is sent first to the economizer 5 , and then again into the boilers. Water by closed loop(boiler, consumer, economizer, boiler) is moved by circulation pumps 6.

Rice. 5. : 1 - circulation pump; 2 - firebox; 3 - steam superheater; 4 - upper drum; 5 - water heater; 6 - air heater; 7 - chimney; 8 - centrifugal fan (smoke exhauster); 9 - fan for supplying air to the air heater

In Fig. Figure 6 shows a diagram of a boiler unit with a steam boiler having an upper drum 12. At the bottom of the boiler there is a firebox 3. To burn liquid or gaseous fuel, nozzles or burners 4 are used, through which the fuel together with air is supplied to the firebox. Boiler limited brick walls- lining 7.

When fuel is burned, the heat released heats water to boiling in pipe screens 2 installed on inner surface furnace 3, and ensures its transformation into water vapor.

Fig 6.

Flue gases from the furnace enter the boiler flues, formed by lining and special partitions installed in the pipe bundles. When moving, the gases wash the bundles of pipes of the boiler and superheater 11, pass through the economizer 5 and the air heater 6, where they are also cooled due to the transfer of heat to the water entering the boiler and the air supplied to the firebox. Then, the significantly cooled flue gases are removed through the chimney 19 into the atmosphere using a smoke exhauster 17. Flue gases can be removed from the boiler without a smoke exhauster under the influence of natural draft created by the chimney.

Water from the water supply source through the supply pipeline is supplied by pump 16 to the water economizer 5, from where, after heating, it enters the upper drum of the boiler 12. Filling of the boiler drum with water is controlled by a water indicator glass installed on the drum. In this case, the water evaporates, and the resulting steam is collected in the upper part of the upper drum 12. Then the steam enters the superheater 11, where due to the heat of the flue gases it is completely dried and its temperature rises.

From the superheater 11, steam enters the main steam line 13 and from there to the consumer, and after use it is condensed and returned to the boiler room in the form of hot water (condensate).

Losses of condensate from the consumer are replenished with water from the water supply or from other water supply sources. Before entering the boiler, water is subjected to appropriate treatment.

The air required for fuel combustion is taken, as a rule, from the top of the boiler room and supplied by fan 18 to air heater 6, where it is heated and then sent to the furnace. In boiler houses of small capacity, there are usually no air heaters, and cold air is supplied to the firebox either by a fan or due to the vacuum in the firebox created by the chimney. Boiler installations are equipped with water treatment devices (not shown in the diagram), control and measuring instruments and appropriate automation equipment, which ensures their uninterrupted and reliable operation.

Rice. 7.

For proper installation of all elements of the boiler room, use a wiring diagram, an example of which is shown in Fig. 9.

Rice. 9.

Hot water boiler systems are designed to produce hot water used for heating, hot water supply and other purposes.

To ensure normal operation, boiler rooms with hot water boilers are equipped with the necessary fittings, instrumentation and automation equipment.

A hot water boiler house has one coolant - water, in contrast to a steam boiler house, which has two coolants - water and steam. In this regard, the steam boiler room must have separate pipelines for steam and water, as well as tanks for collecting condensate. However, this does not mean that the circuits of hot water boiler houses are simpler than steam ones. Water heating and steam boiler houses vary in complexity depending on the type of fuel used, the design of the boilers, furnaces, etc. Both steam and water heating boiler systems usually include several boiler units, but not less than two and no more than four or five . All of them are connected by common communications - pipelines, gas pipelines, etc.

The design of lower power boilers is shown below in paragraph 4 of this topic. To better understand the structure and principles of operation of boilers of different power, it is advisable to compare the structure of these less powerful boilers with the structure of the higher power boilers described above, and find in them the main elements that perform the same functions, as well as understand the main reasons for the differences in designs.

3. Classification of boiler units

Boilers as technical devices for the production of steam or hot water are distinguished by a variety of design forms, principles of operation, types of fuel used and production indicators. But according to the method of organizing the movement of water and steam-water mixture, all boilers can be divided into the following two groups:

Boilers with natural circulation;

Boilers with forced movement of coolant (water, steam-water mixture).

In modern heating and heating-industrial boiler houses, boilers with natural circulation are mainly used to produce steam, and boilers with forced movement of coolant operating on the direct-flow principle are used to produce hot water.

Modern natural circulation steam boilers are made of vertical pipes located between two collectors (upper and lower drums). Their device is shown in the drawing in Fig. 10, photograph of the upper and lower drum with the pipes connecting them - in Fig. 11, and placement in the boiler room is shown in Fig. 12. One part of the pipes, called heated “riser pipes,” is heated by the torch and combustion products, and the other, usually unheated part of the pipes, is located outside the boiler unit and is called “descent pipes.” In heated lifting pipes, water is heated to a boil, partially evaporates and enters the boiler drum in the form of a steam-water mixture, where it is separated into steam and water. Through lowering unheated pipes, water from the upper drum enters the lower collector (drum).

The movement of the coolant in boilers with natural circulation is carried out due to the driving pressure created by the difference in the weights of the water column in the lowering pipes and the column of steam-water mixture in the rising pipes.

Rice. 10.

Rice. 11.

Rice. 12.

In steam boilers with multiple forced circulation, the heating surfaces are made in the form of coils that form circulation circuits. The movement of water and steam-water mixture in such circuits is carried out using a circulation pump.

In direct-flow steam boilers, the circulation ratio is unity, i.e. feed water, heating up, it successively turns into a steam-water mixture, saturated and superheated steam.

In hot water boilers, water moving along the circulation circuit is heated in one revolution from the initial to the final temperature.

Based on the type of coolant, boilers are divided into hot water and steam boilers. The main indicators of a hot water boiler are thermal power, that is, heating output, and water temperature; The main indicators of a steam boiler are steam output, pressure and temperature.

Hot water boilers, the purpose of which is to produce hot water of specified parameters, are used to supply heat to heating and ventilation systems, household and technological consumers. Hot water boilers, usually operating on the direct-flow principle with constant flow water are installed not only at thermal power plants, but also in district heating, as well as heating and industrial boiler houses as the main source of heat supply.

Rice. 13.

Rice. 14.

Based on the relative movement of heat exchange media (flue gases, water and steam), steam boilers (steam generators) can be divided into two groups: water tube boilers and fire tube boilers. In water-tube steam generators, water and a steam-water mixture move inside the pipes, and flue gases wash the outside of the pipes. In Russia in the 20th century, Shukhov water-tube boilers were mainly used. In fire tubes, on the contrary, flue gases move inside the pipes, and water washes the pipes outside.

Based on the principle of movement of water and steam-water mixture, steam generators are divided into units with natural circulation and with forced circulation. The latter are divided into direct-flow and multiple-forced circulation.

Examples of placement of boilers of different capacities and purposes, as well as other equipment, in boiler rooms are shown in Fig. 14-16.

Rice. 15.

Rice. 16. Examples of placement of domestic boilers and other equipment

The gas boiler unit is the most popular in its class. Since, having connected to the gas supply line, you do not need to worry about the delivery and storage of fuel. It should be said that gas is a class of fuel that is explosive and fire hazardous, and if used incorrectly, it can be released into the room. That is why it is necessary to carefully follow all the design standards for a gas boiler house (calculations, gas supply and flue duct standards, etc.), which are specified in SNiP in order to avoid danger.

Gas installations with a license of this class provide heating and hot water for industrial facilities, residential buildings, cottages and villages, as well as agricultural facilities.

Advantages and disadvantages of gas equipment

The main advantages of gas boiler room equipment include:

• Economical. A gas boiler house with a license will use fuel economically, and at the same time, generate a sufficient amount of thermal energy (automation does all the calculations). With proper design of the circuit, this installation is very profitable to operate;
• Environmentally friendly fuel. Today it's very important factor. Manufacturers are trying to produce equipment with the maximum level of emission purification. It should also be noted that CO2 emissions when operating a device with a license of this class are minimal;
• High efficiency rate. Gas equipment produces the highest coefficient, the rate of which reaches up to 95%. And accordingly, during operation, high-quality heating of the premises is obtained;
• The equipment of a gas boiler room has smaller dimensions than in installations of other classes;
• Mobility. This only applies to modular installations on gas. They are designed at the factory and produced with a license;
• For ease of operation, you can install GSM control of boilers (this way you can carry out all calculations and enter parameters, monitor emissions).

Designing gas boiler houses with an automated circuit allows reducing operator control.

The disadvantages of operating gas installations of this class are:

• It is necessary to carry out licensed boiler room maintenance before starting heating season, since this equipment is a source of danger and gas emissions are possible during operation;
• Connecting to the central gas main (obtaining a license) is expensive and a long process (if it does not exist);
• The operation of gas units directly depends on the calculation of pressure in the line;
• This equipment is volatile, but this problem can be corrected if uninterruptible power supply is provided in the circuit;
• To obtain a license for installation on gas (natural or liquefied), you must comply with strict licensing standards of inspection inspections in accordance with SNiP.

Turnkey gas installation design

Designing gas boiler houses with a license consists of drawing up and calculating a heating scheme, gas supply and flue ducts. To do this, be sure to familiarize yourself with the SNiP “Gas Boiler Houses” standards and take into account the characteristics when installing heating units and gas ducts.

The design of a gas boiler room must occur in a certain sequence and in accordance with the following points (standards):

• Architectural and construction diagrams and drawings are carried out in accordance with SNiP standards. Also at this stage, the customer’s wishes are taken into account (in calculations).
• The gas boiler room is calculated, that is, the amount of thermal energy required for heating and hot water supply is calculated. In other words, the power of the boilers that will be installed for operation, as well as their emissions.
• Location of the boiler room. This is an important point in the design of gas boiler houses, since all working units are located according to the standards in one room with a certain calculation. This room can be in the form of an extension or a separate building, it can be inside a heated object, or on the roof. It all depends on the purpose of the object and its design.
• Development of diagrams and plans that help gas boiler equipment function. The automation class and heat supply system should be taken into account. All gas supply circuits for the boiler room must be arranged in accordance with SNiP standards. Do not forget that these installations are quite dangerous and proper design is very important. Development must be carried out by qualified turnkey specialists who are licensed to do so.
• It is necessary to check the object for safety through a special examination.

If the design of gas boiler houses is incorrect and not licensed, you can incur large financial costs (fines) and also be exposed to danger during operation. It is better to entrust the installation of equipment of this class to companies that perform turnkey installation of gas boiler houses. Companies are licensed to carry out this work, and this guarantees long-term operation of the gas installation and compliance with all SNiP standards.

Principle (diagram) of operation of a gas installation

The operation of equipment of this class does not include complex processes and diagrams (calculations). The boiler room flues provide gas supply, that is, they supply fuel (natural or liquefied gas) to the burner in the boiler or boilers (if the installation has several gas units according to the license). Next, the fuel burns in the combustion chamber, as a result of which the coolant heats up. The coolant circulates in the heat exchanger.

Boiler systems with gas supply have a distribution manifold. This structural element calculates and distributes the coolant throughout established circuits(depending on the gas boiler room layout). For example, these could be heating radiators, boilers, heated floors, etc. The coolant releases its thermal energy and returns to the boiler in reverse. Thus, circulation occurs. The distribution manifold consists of a system of equipment through which the coolant circulates and its temperature is controlled.

The release of fuel combustion products (natural or liquefied gas) occurs through a chimney, which must be designed according to all the characteristics of SNiP in order to prevent dangerous situation.

Installations with gas supply are controlled automatically, which minimizes operator intervention in the operating process. Automation in gas equipment has multi-level protection. That is, it stops boilers in dangerous emergency situations, calculates all parameters and emissions, etc. Modern automated systems can notify the operator even via SMS.

Rice. 1

Species

The following classification of licensed gas boiler houses can be distinguished according to installation method:

• Roof installation. At production facilities, heating equipment is often mounted on the roof;
• Transportable installation. Boiler houses of this type are emergency and are produced from the factory fully equipped. They can be transported by first installing them on a trailer, chassis, etc. These installations are completely safe;
• Block-modular gas boiler room. This class of installations is mounted together with the room using special modules. Transported by any type of transport. And it is assembled by the manufacturer on a turnkey basis. The manufacturer is also involved permitting documentation(license);
• Built-in boiler room. Gas units are installed indoors inside the building.

Rice. 2

For built-in boiler houses with a license, there are certain SNiP standards that must be adhered to to ensure safety and prevent gas emissions. A boiler room of this class must have direct access to the street.

The design of such boiler houses with gas supply is prohibited:

• V apartment buildings, hospitals, kindergartens, schools, sanatoriums, etc.
• above and below premises where there are more than 50 people, warehouses and hazardous production facilities A, B categories(fire hazard, explosion hazard).

Liquefied gas installations

Boiler houses using liquefied gas have their advantages, for example, there are no problems with pressure in gas lines, there is no need to worry about increasing heating costs, and you can also set your own standards and limits. This class of equipment is also autonomous.

But when designing and installing a liquefied gas boiler room, additional financial investments should be spent on the design (circuit). Since the design requires the installation of a special fuel tank. This is a so-called gas holder, which can have a volume of 5-50 m2. Additional boiler room gas ducts are installed here, that is, those through which liquefied gas enters the boiler plant. This class of gas supply looks like a separate pipeline (gas duct). Reservoir filling frequency liquefied gas depends on its volume, this can happen from 1 to 4 times a year.

Refilling of such equipment with liquefied gas is carried out by companies that have a license to carry out turnkey work of this class. Their licensing also allows for technical inspection of gas ducts and gas tanks. It is imperative to hire craftsmen who have permits and a license, since this is work with high level danger.

The liquefied gas design is no different from the one running on natural gas. This class of equipment also includes radiators, shut-off valves, pumps, valves, automation, etc.

A gas holder with liquefied fuel can be installed in 2 options (schemes):

• Above ground;
• Underground.

The design of both options must be carried out in compliance with certain conditions and calculations, which are also indicated in SNiP. A tank for liquefied fuel, which is located above the ground, must be surrounded by a fence (from 1.6 m). The fence should be installed at a distance of 1 meter from the tank along the entire perimeter. This is necessary for better air circulation during operation.

There are also other standards for the design and location of a ground-based gas tank (to avoid danger) - this is the calculation of the distance from various objects:

• At least 20 meters from residential buildings;
• At least 10 meters from roads;
• At least 5 meters from various kinds structures and communications.

Rice. 3

As for designing an underground tank, all of the above standards are reduced by 2 times. But there is a calculation of the immersion depth of the liquefied gas tank and the gas duct. These design standards must be calculated individually according to the volume of the container and its design.

Rice. 4

But equipment of this class also has its drawbacks during operation, since if the quality of the gas is poor, then the boiler room will not function in the specified mode. Refilling the tank must be done by a company with all permits and licenses.

Safety standards for operation

The operation of gas boiler houses has many advantages, but do not forget about a significant disadvantage - the danger of this equipment. This is due to the use of highly flammable substances and combustible substances, which pose all the danger.

So we can say that such installations are