Photo from Google Maps
I recently asked on my Facebook page if anyone knows what they do in the heating network when the hot water is turned off for a month.
And I was lucky: one of the senior employees KP "Kharkov Heating Networks" agreed to give an interview on condition of complete anonymity.
I think that after reading his answers to my questions, you will understand why he preferred not only his last name, but also his first name not to be mentioned anywhere.
So, I present to your attention a shocking interview with an employee of Kharkov Heating Networks about their work. In particular, about what they are actually doing in heating networks when every year they turn off our hot water “for preventive maintenance.”
- Good afternoon! How long have you been working at Kharkov Heating Networks?
- Kind. In total - about 15 years.
– So what do they do at Kharkov Heating Networks when our hot water is turned off? What kind of work is being done? What equipment is being changed or updated?
- Most often - nothing. They don't change or update anything! :))))
- How is this?!
– Conducted hydraulic tests– and based on their results, defects are eliminated, but not in a timely manner and in minimal quantities (due to a lack of materials, equipment and personnel). Volume planned work V recent years absolutely minuscule. But let me first tell you about the structure of CTS and where it comes from hot water in your homes.
- Let's!
– So, Kharkov Heating Networks have a branch in every district of the city. Each branch, in turn, is divided into several thermal districts. Each heating district has two (or more) sections, which are managed by foremen, a staff of mechanics, welders and other employees. They are the ones responsible for the repair of one or another segment (a section of intra-block and intra-house heating networks).
– Are there enough employees at the stations?
– There are only a few areas where the staff is fully staffed. In most areas it is often large number places remain vacant. For example, there should be 5 mechanics, but in fact there are only one or two...
- Wow! Why is that?!
– Very low wages, which, moreover, are paid with delays, irregularly, in parts, often for 200-300 UAH. A 5th category mechanic receives an average of 3,500 UAH. If he has additional payments for experience/professionalism, etc., then 4,000 UAH. Locksmiths of the 6th category receive a little more. Plus everything in the year before and last year summer period the enterprise switched to a four-day operating mode. Salaries were cut accordingly, and even then they were paid irregularly. It was then that a significant part of the qualified personnel left. Well, working conditions are also often terrible...
– What about technology?
- Sadly. Almost all the equipment at the branches is from the USSR era, the lion's share is in very poor condition, many units are not operational most of the time. Sometimes, out of four excavators, it is difficult to repair and put one or two on line so that they can work half-heartedly. IN winter time often impossible to carry out emergency work without special vehicles with heating, and not only due to labor protection rules, but also because when during an accident people work in a pit where it is wet and steamy, they crawl out into the cold completely wet. We need cars with potbelly stoves in which you can warm up and dry out. So, in some branches such machines are not running at all – since last year. Excavators and other equipment, as I already said, are from the times of the USSR. Most of it is inoperative.
- Holy shit... Really? new technology no at all?
– There are practically none at the branches. We have now purchased some new equipment, in particular excavators, but they are in transport branch(on Stoletova Street), and they go to this or that work at the request of the districts, through half the city they get to the place of work - and back...
- Tell me about hot water.
– On the territory of each site there are usually several heating points, central and individual. On every heating point The heat exchangers are something like this...
This is roughly what the heat exchangers that are installed at heating points look like:
One of the heating points of the Moscow branch of HTS. It is in such heating points that cold water becomes hot.
– These heat exchangers are used to produce hot water from cold water.
– That is, hot water does not come to our houses from a thermal power plant, but is heated “on site”?!
- Absolutely right. The heating station receives coolant from the thermal power plant, the same “water” that is used for heating, as well as plain water, which is supplied by Kharkovvodokanal. Passing through the heat exchanger, “heating water” heats cold water, which then enters the house.
– What happens when our hot water is turned off? What equipment is being replaced? After all, judging by the picture, the heat exchanger is a fairly simple device.
– Almost no equipment is changed unless it is lucky enough to be included in the annual work plan or some targeted modernization/reconstruction program. Often, in recent years, for almost this entire period, only simple routine maintenance (maintenance and maintenance) is carried out, which does not require any serious costs or the purchase of expensive materials.
- How so?!
– When hot water is turned off in this area, hydraulic tests are carried out and the pipes are checked with a test pressure. They raise the pressure in a certain area, usually up to 16 atmospheres. At the same time, weak points “shoot out”, break through rotten pipes, valves that have served their purpose crack... Then these defects are eliminated - that’s all “prevention”.
- I'm shocked! I was always sure that during this month they would change something complex equipment, installing new...
- Lord, no, of course not! 🙂 Where does so much money come from for new equipment? Almost all of the city's heating networks are badly worn out. What's the replacement? Usually, a section of the damaged pipe is cut out (down to the “live”) or a valve - and a new one is welded. Basically, we are not talking about any large-scale replacements at all. There is nothing alive on some highways. Entire sections need to either be torn up and rebuilt in a new way, or pipes must be laid over the surface. But in fact they simply fix leaks...
- Hmmm... But why did it take so long then? Due to lack of people? There has been no hot water in the center for more than 2 months...
– After the tests, the repair personnel determined the defects and the materials necessary to eliminate them, and made applications for their purchase. Some parts are eliminated using available resources, others are only dismantled and/or excavated... And that’s all! Since then (June-July) nothing more has been done...
- But why?!
– Yes, because many areas were not given the materials and equipment necessary to carry out repairs. But every day they call each site and ask: “What, have they eliminated it?” And what can they answer if there is no equipment and materials necessary for repairs?!
– But this is just some kind of idiocy on the verge of sabotage! And this situation happens every year?
– Every year it gets worse and worse. Previously, by the end of August they began to move more or less seriously, then by the end of September...
– So, this year we can’t expect hot water before October?
– I find it difficult to answer.
- Fine. Although, of course, nothing good. But if the materials are issued, then it will probably still take time for repairs? The same month that everyone just sat waiting for them?
- Of course, it will take some time. But the deadlines will be very tight, “as of yesterday,” so repairs will be carried out to the minimum extent necessary to get back into work as quickly as possible.
- Okay, what if you don’t take it? complex cases, how long will it take to complete repairs, if any? necessary materials?
- On different areas- differently. It depends on the amount of work, how staffed, and the allocation of the necessary equipment.
– Why not provide the necessary materials to the sites? Don't have money to buy them? Or is there money, but it hasn’t been purchased? Why anyway?
- No idea. The reasons are not stated.
- Pfft... Can I ask again? It turns out that all these weeks and months we have been sitting without hot water only because KP HTS, after testing and establishing a list of breakthroughs, simply does not allocate or release from the warehouse the materials necessary to eliminate and repair them? And because of this (lack of materials), the workers at the sites simply cannot fix all these leaks in order to turn on the hot water?
–Alas, yes. In most cases, this is precisely why. Plus there are problems with equipment and fuel... And it’s still good if the tests still passed...
- How is this? It turns out that they may not be carried out at all?
- Not quite like that. Look here. For example, distribution networks from highways are tested together with them. At the same time, pipes in areas where there are weak points break. But today the mains are so worn out that very often it is the main that breaks first, and not the pipes on the site. Naturally, in this case, the test is stopped and the “shot” line is repaired. In this case, the matter may not reach a full test of the entire section.
- So what then?
– Then he will probably “shoot” in the fall/winter. And it’s good if it’s a plot distribution network, and not the highway itself. After all, after the distribution networks pass the tests, they are turned off - and the main line itself is checked with a little more pressure. How can you check it under high pressure if she vomits at a pressure just above working pressure?
– I simply have no words... But what about the annual reports on winter readiness, the signing of acts...
– In the last couple of years, many areas have not issued certificates of preparedness for the network at all (or they have registered the networks as not ready for the season). How can you take responsibility and sign if full tests have not been completed? To sign this is to take responsibility and “expose yourself” at the first serious accident. And the authorities, of course, report. They can’t come to the City Council and say: “The city is not ready for winter (from the word “at all”)” - they will simply have their heads taken off.
– Have there already been cases when highways burst in winter - and entire areas of the city could freeze?
- Yes. Last season, there were at least two quite serious accidents in the city, when highways burst in the middle of winter. Fortunately, they were eliminated quickly enough so that the consequences did not become irreversible. But whether this will continue to be the case is unknown.
– You said that large-scale repairs and relocation large plots no pipes are produced. But I myself have seen how in some areas quite large pieces are changed...
– Most likely, this replacement is due to the fact that the city is repairing intra-block roads and sidewalks. Before laying asphalt, we and the water utility must check our pipes, and if they run under these roads, sidewalks and require repair, replace them. These are the works you saw. But in fact, this is even less than a drop in the ocean. And this work is mostly not carried out by CTS.
– Why not HTS? Who then?
– Private contractors. Previously, such work (overhauls) was done by the KT KP itself, so to speak, “in a self-employed manner.” But now they have been given to private owners. Why – I personally don’t understand.
– Maybe private traders do better and faster?
– I observed several such repairs... They carried out the installation of pipes with violations of technology, they used equipment that was not entirely suitable. They didn't have their own excavator either. According to their director, they hire somewhere for cash. As for the speed, again, if we talk about the objects that I saw, then with the appropriate equipment and qualifications, it could be done 2 times faster. The quality of the work itself, if we talk about it, is average.
- It's clear. Maybe you can tell me something else interesting?
- Hmm... Yes, I’ve already told you about two dismissals if my name becomes known. 🙂
– Bgggg... 🙂 It’s tough on you. Okay, thank you very much for such an interesting interview.
– You’re welcome... 🙂
A short story about subsidies -
from me personally (and some interesting numbers)
In the spring, KP HTS became embroiled in a scandal involving subsidies and sudden debts. Suddenly (out of thin air!) people had a debt of 260 million hryvnia.
I think you all understand that heating subsidies are not provided for 100% of the payment, but only for some part. For example, you need to pay 1,500 UAH for heating, of which 1,100 is a subsidy, and the rest is a mandatory payment that the person pays himself.
This year, for some reason, the accrual of this mandatory payment was not reflected in the receipts (why this is so is still not entirely clear).
According to KP HTS, people had to find out this amount from the subsidies department - and pay on their own. But many did not. And as a result, they did not make mandatory payments throughout the heating season, since they saw overpayments in the receipts.
In May 2017, after the end of the season, the amounts were recalculated and the excess subsidies received were returned to the budget.
At the same time, of course, debts emerged for unpaid mandatory payments. Their total amount, as I already said, was 260 million. This is for approximately 115 thousand apartments - on average 2.3 thousand UAH per apartment (for some it is 300–500 UAH, and for others it is 5–6 thousand UAH).
And now - dry numbers from financial statements KP "Kharkov Heating Networks" for the period from 2013 to 2016 inclusive.
So, according to the financial report, average number KP employees amounted to 6,722 people in 2013, 6,727 people in 2014, 6,549 people in 2015, and 6,493 people in 2016, which confirms the words about a fairly strong outflow of personnel.
However, according to the KP employee who gave an interview, the figure for 2016 is questionable, since, according to him, During this period, about 1,000 people quit. Perhaps this is " average temperature in the ward” or just a number from the ceiling.
Further - more interesting.
Thus, as of July 1, 2016, the uncovered losses of KP HTS amounted to UAH 585.6 million, while the lion’s share of them, namely UAH 349.5 million, were received in the first half of 2016.
At the same time, the debt of consumers for CP services as of July 1, 2016 is 1 billion 706 million hryvnia!!!
How can an enterprise exist in such conditions?
Very simply, KP HTS itself has a debt to suppliers of much larger size– as much as 2 billion 581 million hryvnia.
Heat network - a system of pipeline communications through which the coolant (steam or hot water) transfers heat from the source (heat generator - boiler) to consumers and returns back: through the same system of communications-heat pipelines, called the system district heating. Construction in this area is one of the most responsible and technically complex work, since the laying of elements pipeline system in urban and suburban farms makes their repair and emergency restoration very labor-intensive, which forces them to place increased demands on quality capital construction. High temperatures and pressure require at least high reliability and guarantees for the safety of heating networks (heating mains).
According to the fundamental type of device, the circuits of main heating networks are conventionally divided into ring and radial (dead-end). Jumper connections are usually provided between remote main networks: so that in the event of an emergency there are no excessive interruptions in the heat supply. If the main heating network is very long, an additional unit is installed in it - a booster pumping substation. For this purpose, underground (where heating networks usually pass, as well as branch points), special chambers are equipped in which gland compensators and pipeline fittings (shut-off and control structures) are located.
It is the main heating networks that have the greatest extent, as they can be several kilometers or even more away from the heat source. When constructing main heating mains, pipelines made of special steels are used (for high-temperature working environments); the diameter of such pipes can reach 1400 mm. In situations where the coolant is supplied by several generating enterprises, the so-called. loops. Essentially, uniting all these enterprises into one heating network. This solution allows us to significantly increase the level of reliability of supply to heating points and, accordingly, the reliability of heat supply to the end consumer.
In case of accidents that occur from time to time on highways and in boiler houses, heat supply to the emergency section of the heating network is handled by one of the neighboring boiler houses of this heating network. In some cases, a planned redistribution of load between heat generating enterprises is arranged. Water prepared in a special way, with specified indicators of carbonate hardness, oxygen and iron content, is used as a coolant for main networks. Ordinary tap water (“hard”) water should not enter the main heating network, since it chemical composition at high temperatures leads to accelerated corrosion wear of the pipeline. In particular, to prevent this, heating network projects provide for such a special design as a heating point. Such a heating point should normally be no more than a kilometer away from consumers. And within the city limits, this distance reaches an average length of about two blocks.
Heating networks for auxiliary purposes, which are usually called secondary, are usually small in total length. The pipelines used in the construction of such networks have relatively small diameters: from 50 to 150 millimeters. In addition, such a heat conductor can be made not only of steel, but also of polymers. The most convenient and durable for heating systems of similar design, on at the moment, polymer pipelines are considered.
V.G. Semenov , general manager JSC "Association VNIPIenergoprom", President of the NP "Energy Efficient City", editor-in-chief magazine "ENERGOSOVET", Moscow
There were no serious problems with determining the cost of hot water before, during the absence of metering devices. Typically, two standards were used - specific water consumption per inhabitant and thermal energy consumption per cubic meter of water. Residents consumed water without thinking about saving, and heat supply organizations were satisfied with the standard.
But the time has come for instrumentation, and the unsolved centralized task of determining what hot water is is now being forced to be resolved in numerous courts, since with any standard one of the parties ends up losing. To understand the problem and create an energy efficient model economic relations With hot water needs to be seriously addressed.
Hot water as a commodity consists of two goods: source water and thermal energy contained in the water (used to heat it). A hot water meter is an ordinary water meter installed at the entrance to the apartment. The main problem with a water meter is that it does not measure heat content. Even if you install a heat calculator and a temperature sensor, this will not be enough to correctly measure the amount of heat spent on heating, because it is necessary to measure the temperature of the source cold water. And this can be done with different schemes connections to different points: in the basement of a house, at a central heating point, or even at a heat source. Therefore, the average temperature of the source water is widely used - in winter +5, and in summer +15 degrees, which corresponds to heat consumption of 0.055 and 0.045 Gcal / cubic meter. meter (at a hot water temperature of 60 degrees). This understanding of hot water does not depend on the type of heating system, the type of heating point, and coincides with the understanding of a resident who is interested in what flows from his tap.
But in many houses circulation systems function normally DHW systems and thermal energy in this case is needed not only to ensure the parameters of hot water pouring out of the tap, but also to compensate for losses in heated towel rails, risers and rapidly spreading systems heated floors, which are often connected to the DHW circulation circuit. It has long been customary to attribute these costs of thermal energy to hot water, by introducing increased standards for heating a cubic meter of water. So another, already third, component appeared in the hot water. The right to establish standards was given to municipalities, which, despite the presence methodological instructions The Ministry of Regional Development of the Russian Federation sometimes began to set a standard even lower than the original one, which does not take into account circulation.
The situation became even more aggravated due to the requirement of the Sanitary and Epidemiological Supervision Authority to increase the temperature of hot water to 60 degrees (SNiP required no more than 55 degrees) - the heat content in a cubic meter of water increased, and the volume of its sales, on the contrary, decreased. It was necessary to introduce a compensatory increase in the standard, but this, in turn, led to an increase in the tariff for hot water, which was not politically welcomed.
The massive installation of metering devices and the use of modern water taps further aggravated the situation - people reduced their hot water consumption, while circulation losses remained unchanged and began to account for up to half of the heat consumption for heating directly consumed hot water. IN major cities disagreements began to amount to hundreds of millions of rubles.
Let's consider options for different connection schemes.
Option 1 - individual heating point (IHP)
Thermal energy metering device is installed, as a rule, only at the entrance to the building up to the heating point and cannot separately show the amount of thermal energy spent on heating tap water and for heating.
In rare cases, usually when the ITP belongs to the heat supply organization, metering devices are installed after the ITP, separately for heating and hot water, or only for hot water, and heating is calculated based on the difference.
In a simple case, the owners of a separate non-residential building purchase:
- with an open system - thermal energy and coolant. The coolant used for hot water supply and to compensate for leaks in the building is not allocated.
- with a closed system - tap water, thermal energy for heating it and coolant to compensate for leaks in the building’s heating system. The method of distributing payments for thermal energy between persons using individual parts of the building is not regulated by the state.
In an apartment building (MKD), the same goods are purchased from the water utility and heat supply organization, but problems arise when distributing payment for them among residents.
Put additional devices metering thermal energy separately for hot water after ITP does not make sense for the following reasons:
- These devices are very expensive;
- their error, related not to the flow of water circulating in the building, but to the flow of water pouring out of the taps, is very large;
- the heat contained in the hot water is also used to heat the building DHW risers, heated towel rails and heated floors.
It is easier to introduce a simple formula, universal for the entire country, for the standard consumption of thermal energy contained in water pouring out of a tap:
q=(T 1 -T 2)/1000[Gcal/m3];
WhereT 1 - hot water temperature, i.e. 60 degrees,T 2 - average temperature of tap water.
The tariff for hot water will be stable and undeniable, since all the features of variable circulation heat losses in a particular building will be considered outside of this tariff. There is no need to introduce a separate tariff for heating hot water, which is variable and incomprehensible to the resident, or, even worse, a variable tariff per cubic meter of hot water, calculated according to monthly meter readings.
Heat consumption in the system Building DHW to water taps (for circulation) is better attributed to general house needs and distributed not by the number of residents, but by square meters, as well as for heating. Even if no one is registered in the apartment, the owner will pay his share of this expense, which is fair (another more accurate option is distribution by the number of bathrooms).
Thus, if there is a heat meter in the ITP located in the apartment building, the heat in the hot water is taken according to the universal standard for cubic meter consumed hot water (according to the water meter after ITP), the rest of the heat is used for heating and is distributed in proportion to the area of the apartments. Residents will take the variability of heat consumption for circulation calmly, since heating payments, calculated per square meter, are also variable.
When the temperature of hot water increases, residents regulate its temperature by mixing it with cold water, so heat consumption from hot water will practically not increase, but heat consumption with circulation may increase due to hotter pipes of heated towel rails or risers; this heat will be taken into account by the general house meter and, accordingly, allocated to heating .
When the temperature of hot water decreases, the heat consumption taken into account by the heat meter is automatically reduced, therefore the undersupply of thermal energy to maintain the standard DHW temperature will be automatically taken into account in the heating component (heat costs with circulation acquire negative values) and the proposed approach only significantly simplifies the calculations and makes them quite transparent.
The heat supply organization does not care how the heat spent on heating hot water is distributed among residents or square meters. But for the residents themselves there is a fundamental difference - if they regulate water consumption themselves, then the management company must regulate the circulation. With low water consumption, the payment for circulation losses may exceed the payment for hot water. Taking this fact into account fundamentally changes the approach to energy saving in terms of hot water - you need to save not only in the apartment, but throughout the entire house (temperature control, circulation regulation, insulation of pipework, installation of jumpers and taps on heated towel rails).
In the variant under consideration, the product - hot water - appears directly at the water tap during the provision of hot water supply services.
The costs of maintaining and operating the heating point are borne by the owner, if this heat supply organization, then they are taken into account in the tariff for thermal energy.
Option 2 - central heating point
Thermal energy metering devices are installed at the entrance to the building, one for heating, the other for hot water.
At open circuit- the design is not fundamentally different from the case with ITP. The difference is that the coolant for hot water supply is not delivered to the house via common pipe, but separately.
The thermal energy meter at the entrance to the house shows the flow rate of the coolant entering the house, but the device cannot show the amount of thermal energy spent by the heat supply organization on heating it, it does not have a signal from the temperature sensor of the original water supply or artesian water. You have to manually enter a certain average temperature in at least two options - for the heating and non-heating periods.
But the same device calculates the consumption of thermal energy to ensure circulation without any problems. The circulation flow is equal to the flow in return pipeline, and the temperature difference is measured right there.
This begs the question simple circuit similar to the option with ITP. The heat content of hot water is set fixed (possible with two variations - summer/winter) and is calculated using the simplest formula. Heat consumption for circulation relates to general house needs and is distributed in proportion to the number of square meters and is added to it during the heating payment period.
If the heat supply organization that owns the central heating station increases the temperature above the agreed upon one, then the consumer does not pay for the excess. Periods of temperature decrease below SanPiN requirements are recorded in the heat meter archive, and this is enough to impose penalties. But even without presenting fines, you can easily “sew” a program into the heat calculator of the metering device to reduce the calculated heat consumption for circulation in proportion to the underheating of hot water.
At closed scheme heated at the central heating station for hot water supply purposes tap water. According to the design of the law “On Heat Supply,” central heating stations are part of the heating network, and heating networks are designed to transfer coolant. Replacing this design with another would require making huge, unjustified changes to the law.
At the same time, the introduction of the concept of “hot water as a coolant used in DHW needs"turned out to be unjustified, since hot water in the house would also become a coolant and regulatory documents regulating relations with hot water inside the house were broadcast to heating supply organizations. There would also be a methodological difficulty in classifying the entire volume of coolant in an open heating system as hot water, since most of it will sooner or later be used for the needs of hot heating.
So what circulates in heating networks after central heating stations, to which hot water supply systems for consumers (heat DHW networks)? This is not water from a cold water supply system, since its composition (content of bacteria, iron, etc.) and temperature have changed. At the same time, this is not a coolant from the main heating networks, but some other coolant that corresponds to all its functions (transfer of thermal energy, losses in networks, possibility of direct use). It seems that this fork can be overcome by introducing the concept of circulating water.
Circulating water is actually an analogue of the coolant in an open heat supply scheme, which can be produced not only at the central heating station, but also at the heat source (small thermal power plants or boiler houses) with four-pipe heating networks. It also circulates through closed loop in heating networks and is also used both directly for DHW purposes and for transferring heat to consumers through their heat-consuming installations- heated towel rails and heated floors.
Circulating water is a type of coolant in closed heating systems, used in heating networks after central heating points to provide hot water supply load.
In this case, the system of relations with the consumer connected to the central heating point will be exactly the same as with an open circuit. To simplify calculations, the cost circulating water is assumed to be equal to the cost of tap water, the costs of its production are taken into account as part of the tariffs for thermal energy.
Hot water is generated directly in the house and its cost consists of the cost of circulating water (according to the cold water tariff) and the cost of the regulated amount of heat for heating it (according to the thermal energy tariff).
The cooling of circulating water in the building is taken into account by the meter and distributed among residents by square meters as thermal energy consumption for general house needs (according to the thermal energy tariff). Losses in DHW heating networks remain with the heat supply or heating network organization.
Option 3 - no hot water circulation in the house
With this option, there is no heat loss due to circulation, but this does not mean that the water in the pipework does not cool down. Since the heat supply organization is not responsible for the absence of circulation pipelines, calculations for hot water should be based on its actual temperature. It is impossible to record the amount of heat in a cubic meter of water, since it is impossible to measure heat losses in piping.
For such cases, the thermal insulation of risers is of particular importance, since this helps not only to reduce losses, but also prevents massive discharges of cooled water.
The option of direct removal of coolant from heating batteries can be considered as a leak on intra-house networks, with a distribution of the coolant and thermal energy measured by the metering device by square meters of apartment area.
Perhaps everyone knows that the huge boiler-cooling towers and striped chimneys emitting smoke, which are visible from anywhere in the city, belong to the thermal power plant. Moreover, many people know that these colossuses provide our homes with light, heating and hot water. But what exactly is the process of heat generation and how cooling tower columns are involved in it is a rather confusing question.
Consumables
The entire process of CHP operation begins with water preparation. Since it is used here as the main coolant, it requires preliminary cleaning before entering the steam boiler, where the main metamorphoses will occur with it. To prevent scale on the walls of boilers, the water is first softened - its hardness sometimes needs to be reduced by 4000 times, and it also needs to be removed from various impurities and suspensions.
As a rule, gas, coal or peat are used as fuel for heating water boilers at various power plants. The combustion of these materials releases thermal energy, which is used at the station to operate the entire power unit. Coal is ground before use, and the incoming gas is purified from mechanical impurities, hydrogen sulfide and carbon dioxide.
Steam production
The huge steam boiler in the turbine hall - the height of a 9-story building is not the limit - can be called the heart of the thermal power plant. It is fed by prepared fuel, releasing huge amount energy. Under its force, the water in the boiler turns into steam with an outlet temperature of almost 600 degrees. Under the pressure of this steam, the generator blades rotate, resulting in the creation of electricity.
The thermal power plant also produces thermal energy intended for heating and hot water supply to the region and city. For this purpose, there are selections on the turbine that remove part of the heated steam before it reaches the condenser. The exhausted steam is transferred to a network heater, which acts as a heat exchanger.
Heat networks
Once in the tubes of network heaters, the water is heated and transmitted through underground pipelines further into heating network due to pumps driving water through pipes. Heating networks, as a rule, carry water at 70-150 degrees - it all depends on the temperature outside: the lower the degree outside, the hotter the coolant.
The central heating point (CHS) becomes the transfer point for the coolant. It serves an entire system of buildings, an enterprise or a microdistrict at once. This is a kind of intermediary between the object that creates heat and the direct consumer. If water in a boiler room is heated due to fuel combustion, then the central heating station works with an already heated coolant.
Hot water recipe
The supply of coolant ends at the entrance to the central heating substation or ITP (individual heating substation) - so, the coolant is transferred to further actions in the hands of the HOA or other management company. It is at the heating point that the hot water that we are used to dealing with is created - the water coming here from the thermal power plant heats clean cold water from the water intakes in the heat exchanger and turns it into the very hot water that flows in our taps.
After heating the building and room, this water gradually cools, its temperature drops to 40-70 degrees. Part like this water is coming for mixing with the coolant and supplied to our hot water taps. The road to the other part is back to the station, here the cooled water will be warmed by network heat exchangers.
What are cooling towers for?
The majestic and massive towers, called cooling towers, are not the reactors and centers of action in a thermal power plant and actually play a supporting role. Surprisingly, they are used in heating plants to cool water. But why let water that is constantly heated cool?
Cooling towers use the second part of the “return”, which has gone through a heating-cooling cycle. But its temperature is still quite high: 50 degrees for further application- too high a figure. The water that has been in cooling towers is used to cool the condensers of steam turbines. This is necessary so that the steam passing through steam turbine, was able to get into the condenser and condense on the cold pipes inside it. These pipes are precisely cooled by the water that has passed through the cooling tower, the temperature of which is now about 20 degrees. If they are not cooled, then there will be no steam flow through the turbine, and then it will not be able to work. The condenser will again turn the steam into water, which will be recirculated.
A common way to obtain hot water supply (DHW) today is to use the heating network. Two types of heat extraction are used - open and closed. The heated water is delivered to the end consumer through a circular and dead-end pipeline.
You can get hot water from a centralized source or an individual one. In the first case, the heated water enters residential buildings and organizations along the heating main, and in the second, personal water heaters are used for the entrance, private house or separate apartment.
The heat source for heating main water is thermal stations, boiler rooms. In this way, large volumes of water can be pumped, so a centralized pipeline is used to supply apartment buildings and entire neighborhoods. Based on the method of extracting heat from the mains, DHW systems are divided into open and closed.
Open heating system
You can see pipes on city streets large diameter, wrapped in a heat insulator - this is the heating network. Hot water flows through them, heated at a thermal station. To everyone, for example, residential building, from such a pipe a branch passes through the substation (central heating station). This is how water enters the system. central heating- batteries. In an open system DHW hot The water in the faucet in the kitchen or bathroom comes from the same source as in the battery. The temperature in the DHW system can vary from +50˚С to +75˚С. But in the highway it is usually much higher, so it can be mixed with cold water. Such a procedure is not always technically possible, so often, especially cold winter, the temperature of hot water from the tap is close to critical.
The open method of obtaining hot water is considered the simplest: there is no need for additional elements heating At the same time, to comply sanitary standards It is often necessary to purify water from contaminants. Their presence is clearly noticeable when the test heating is turned on for the first time: water in hot tap comes the same as that passed through oxidized after summer downtime batteries. The quality of the resulting water directly depends on wear heating equipment and the presence of filter elements. Despite this, open system quite common due to its mass use during Soviet times.
Closed heating system
This method also uses a heat pipe, like the one described above. The difference lies in the heating method: if in open water is heated at the thermal power plant and directly enters the house, then when closed it has a separate, dedicated circuit. Purified cold water is pumped into it, which passes through heating heat exchangers. They, in turn, take heat from the main water heated by the thermal power plant. The same one that is directly supplied when open method DHW. Other heat sources are possible, but the most common is convection, heat transfer from an open-type hot water supply.
With this method, the quality of the water does not depend in any way on the central heating pipes. The closed method requires the presence of heat exchangers and additional pumps, which increases the cost when switching from open to closed type. But subsequent savings are also possible due to the stability of the specified temperature conditions: V open type It is often necessary to unnecessarily heat main water due to its division for heating and domestic purposes. Also wins closed system according to organoleptic and bacteriological indicators. The water temperature in the house is always stable and does not depend on the air temperature in winter, as in open method receiving hot water supply. However, it is not enough to prepare hot water; it must be delivered to houses or apartments without loss. Today there are two feeding options - circular and dead-end.
Circular feeding method
In it, the heated liquid constantly circulates through a closed circle of a thermal power plant or boiler room, a main line, a substation, a water supply system and back. This was done for a number of reasons, including a large number of subscribers, heat loss when the water is idle. In practice, this method allows you to get hot water from the tap instantly. It's always on the go and ready to use. When it stops, cooling will occur, which is fraught with large losses. IN high-rise buildings For this purpose, the riser is divided into blocks or additional pumps.
Small difficulties are also possible with the circular method: all owners of heated towel rails in the bathroom know about the impossibility of reducing their heat in summer time year: heated water circulates in them around the clock and all year round. The only way The temperature of this device will be adjusted by installing a regulator tap and inserting additional pipe, through which the liquid will flow when the tap on the heated towel rail is closed.
Dead-end delivery method
Here the hot water supply system works less efficiently: the consumer has a complete, dead-end water supply system. It contains only water supply pipes without a return circuit. The heated liquid moves when the mixer tap is opened, and when it is closed, the water in the pipe stops and gradually cools. In practice, this means that if the mixer is left inactive for a long time, particularly at night, cool water will flow from the tap first and only then hot water. The dead-end supply method is usually used in private houses connected to the water supply. IN lately It was the dead-end connection method that became popular due to the spread of individual heaters - boilers.
Local hot water systems
A hot water boiler is an alternative to any hot water system in the absence of one or a backup option in case of a traditional summer shutdown. The source of thermal energy is gas or electricity. Boilers are also divided into flow-through and storage. In the first case, cold water from the tap is passed through the heater and immediately discharged outside. The second is more thorough, and in it heated water to the desired temperature is stored in a tank with a capacity of up to 200 liters. It is drained through a regular mixer, which is connected through a lockable splitter to the boiler and the main hot water supply.
Local hot water systems can be used throughout apartment building on an individual basis. This is sometimes used in new buildings that are equipped with an autonomous heating unit. Essentially this is one large boiler for the whole house. Such independent system allows you to save on transporting hot water long highway and practically excludes traditional summer blackouts for routine maintenance.
Whatever hot water system is used, each of them has pros and cons. The quality of hot water can be affected not only by the presence/absence of a dead-end water supply, but also by the pressure of cold water in the main. When it increases and the mixer performs poorly, it is sometimes difficult to achieve an ideal balance of cold and hot water at the outlet. If there are frequent hot water outages in the house, then it is worth purchasing and installing a boiler: its presence will help you comfortably survive the time of repair of the heating main.