General information about boiler installations, types of boilers for building heat supply. Classification of boiler rooms

Boiler house - a structure in which the working fuel is heated (mainly water) for heating systems, steam supply and hot water supply, located in one technical room. Consumers are connected to the boiler house with the help of steam pipelines and heating mains. The most important device in a boiler room is a steam and/or hot water boiler. The boiler house is used for district heating and steam supply or for local use, if this boiler house is of local use (one house or a closely spaced group of houses).

Classification of boiler rooms

By type of accommodation:

Built-in (in a building for another purpose, in a specially equipped place);

Separately located (in a separate building);

Rooftop (on the roof of a building in a specially equipped facility);

Frame (large nodal assembly without construction);

B local (modular) execution(container, in a transportable structure, etc.);

Attached (a specially equipped structure attached to another building).

By type of fuel used:

Liquid fuel (diesel fuel, waste oil, fuel oil);

Solid fuel (firewood, peat, coal);

Gas;

Combined.

According to the type of boilers used:

Steam;

fire tube;

Water heating;

Mixed.

By type of heat load:

Industrial (hot process water, industrial steam);

Heating (Ventilation, heating, hot water supply);

Combined.

Boilers can operate on various fuels, for example, on natural or liquefied gas, coal, wood, fuel oil, diesel fuel and various production wastes. Therefore, in connection with this, all boiler houses are divided according to the type of working fuel: gas, liquid fuel, solid fuel and combined. Gas boilers are one of the most popular types of boilers. Gas is one of the most environmentally friendly and cheapest types of fuel. But when installing this equipment, the only problem of a complex process may arise - obtaining permission to use gas for heating and hot water supply. Gas boilers are also classified and can be: built-in, attached, freestanding, and rooftop. The thermal power of the boiler room depends on the power of the boiler (boiler unit), which is selected depending on the area of ​​​​the heated object: the larger the heated object, the more powerful the boiler should be.

Oil-fired boilers mostly run on diesel fuel, but are more expensive than natural gas. But in exceptional cases, this type of boiler plant is preferable to the use of natural gas. In addition to diesel fuel, fuel oil, petroleum and waste oil can be used. No special permissions are required to install them.

Solid fuel boilers, on the other hand, run on solid fuels such as coal, compressed wood and wood waste. One of the main advantages of these boilers is the complete absence of the use of both gas and electricity, while if you use wood waste, the boiler pays for itself very quickly, despite the fact that its cost is much higher than others.

The operation of combined types of equipment is based on the use of two types of fuel: one is the main one, and the other is used as a backup or emergency. In this case, there must be at least two boilers, which are equipped with combined gas-diesel burners operating on both gas and diesel fuel. Natural gas is most often the main fuel. In the event that the supply of the main fuel is interrupted, the boiler room automatically starts using the backup, which means that hot water supply and heating will be supplied uninterruptedly to all consumers.

Each individual situation and the choice of one or another type of boiler house is considered individually, in accordance with which the most optimal option is selected.

Introduction

General information and the concept of boiler plants

1 Classification of boiler plants

Types of heating boilers for heat supply of buildings

1 Gas boilers

2 Electric boilers

3 Solid fuel boilers

Types of boilers for heat supply of buildings

1 Gas-tube boilers

2 Water tube boilers

Conclusion

Bibliography

Introduction

Living in temperate latitudes, where the main part of the year is cold, it is necessary to provide heat supply to buildings: residential buildings, offices and other premises. Heat supply provides comfortable living if it is an apartment or a house, productive work if it is an office or a warehouse.

First, let's figure out what is meant by the term "Heat supply". Heat supply is the supply of building heating systems hot water or by ferry. The usual source of heat supply is CHP and boiler houses. There are two types of heat supply for buildings: centralized and local. With a centralized supply, certain areas (industrial or residential) are supplied. For the efficient operation of a centralized heating network, it is built by dividing it into levels, the work of each element is to perform one task. With each level, the task of the element decreases. Local heat supply - the supply of heat to one or more houses. District heating networks have a number of advantages: reduced fuel consumption and cost reduction, use of low-grade fuel, improved sanitation of residential areas. The district heating system includes a source of thermal energy (CHP), a heat network and heat-consuming installations. CHP plants produce heat and energy in combination. Sources of local heat supply are stoves, boilers, water heaters.

My goal is to get acquainted with general information and the concept of boiler plants, which boilers are used to heat buildings.

1. General information and concepts about boiler plants

A boiler plant is a complex of devices located in special rooms and serving to convert the chemical energy of fuel into thermal energy of steam or hot water. The main elements of the boiler plant are the boiler, the combustion device (furnace), feed and draft devices.

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

The combustion device serves 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 blowers, a system of gas ducts, smoke exhausters and a chimney, with the help of which the supply of required amount air into the furnace and the movement of combustion products through the gas ducts of the boiler, as well as their removal into the atmosphere. Combustion products, moving through the gas ducts and in contact with the heating surface, transfer heat to the water.

To ensure more economical operation, modern boiler plants have auxiliary elements: a water economizer and an 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 the normal and uninterrupted operation of all parts of the boiler room.

Depending on the purpose for which thermal energy is used, boiler houses are divided into energy, heating and production and heating.

Power boilers supply steam to power plants that generate electricity and are usually part of a power plant complex. Heating and production boiler houses are built at industrial enterprises and provide thermal energy for heating and ventilation systems, hot water supply of buildings and technological production processes. Heating boiler rooms are intended for the same purposes, but serve residential and public buildings. They are divided into separate, interlocked, i.e. adjacent to other buildings, and built into buildings. IN Lately more and more often stand-alone enlarged boiler houses are being built with the expectation of serving a group of buildings, a residential quarter, a microdistrict. The installation of boiler houses built into residential and public buildings is currently allowed only with appropriate justification and coordination with the sanitary supervision authorities. Low-power boiler houses (individual and small group ones) usually consist of boilers, circulation and make-up pumps and draft devices. Depending on this equipment, the dimensions of the boiler room are mainly determined. Boilers of medium and high power - 3.5 MW and above - are distinguished by the complexity of the equipment and the composition of service and amenity premises. The space-planning solutions of these boiler houses must meet the requirements of the Sanitary Design Standards for Industrial Enterprises.

1.1 Classification of boiler plants

Boiler plants, depending on the nature of consumers, are divided into energy, production and heating and heating. According to the type of heat carrier produced, they are divided into steam (for generating steam) and hot water (for generating hot water).

Power boiler plants produce steam for steam turbines at thermal power plants. Such boiler houses are equipped, as a rule, with boiler units of large and medium power, which produce steam with increased parameters.

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

Heating boiler plants (mainly water-heating, 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 divided into local (individual), group and district.

Local boiler houses are usually equipped with hot water boilers with water heating up to a temperature of not 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 plants provide heat to groups of buildings, residential areas or small neighborhoods. Such boiler houses are equipped with both steam and hot water boilers, as a rule, with higher heat output than boilers for local boiler houses. These boiler houses 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.

2. Types of heating boilers

.1 Gas boilers

If the main gas is connected to the site, then, in the vast majority of cases, it is optimal to heat the house using a gas boiler, since you will not find cheaper fuel. There are many manufacturers and models of gas boilers. In order to make it easier to understand this diversity, we divide all gas boilers into two groups: floor boilers and wall-mounted ones. Wall and floor boilers have a different design and equipment.

The floor boiler is a traditional, conservative thing that has not undergone major changes over many decades. The heat exchanger of floor boilers is usually made of cast iron or steel. There are different opinions about which material is better. On the one hand, cast iron is less susceptible to corrosion, a cast iron heat exchanger is usually made thicker, which can positively affect its service life. At the same time, the cast-iron heat exchanger has its drawbacks. It is more fragile, and, therefore, there is a risk of microcracks during transportation and loading and unloading. In addition, during the operation of cast-iron boilers when using hard water, due to the design features of cast-iron heat exchangers, and the properties of cast iron itself, over time, they are destroyed as a result of local overheating. If we talk about steel boilers, they are lighter, they are not very afraid of bumps during transportation. At the same time, if used incorrectly, the steel heat exchanger can corrode. But, it is not very difficult to create normal operating conditions for a steel boiler. It is important that the temperature in the boiler does not fall below the "dew point" temperature. A good designer will always be able to create a system that will maximize the life of the boiler. In turn, all floor gas boilers can be divided into two main groups: with atmospheric and pressurized (sometimes called replaceable, fan, hinged) burners. The first ones are simpler, cheaper and at the same time work quieter. Boilers with pressurized burners are more efficient and are much more expensive (including the cost of the burner). Boilers for work with pressurized burners have the possibility of installing burners operating either on gas or on liquid fuel. The power of outdoor gas boilers with an atmospheric burner, in most cases, ranges from 10 to 80 kW (but there are companies that produce more powerful boilers of this type), while models with interchangeable air

burners can reach a power of several thousand kW. In our conditions, one more parameter of a gas boiler is very important - the dependence of its automation on electricity. After all, in our country there are often cases of problems with electricity - somewhere it is supplied intermittently, and in some places it is completely absent. Most modern gas boilers with atmospheric burners operate regardless of the availability of power. As for imported boilers, it is clear that such problems in Western countries are absent, and the question often arises, are there good imported gas boilers that operate autonomously from electricity? Yes, they exist. This autonomy can be achieved in two ways. The first is to simplify the boiler control system as much as possible and, due to the almost complete absence of automation, achieve independence from electricity (this also applies to domestic boilers). In this case, the boiler can only maintain the set temperature of the coolant, and will not be guided by the air temperature in your room. The second method, more advanced, is using a heat generator, which generates electricity from the heat necessary for the operation of the boiler automation. These boilers can be used with remote room thermostats that will control the boiler and maintain the room temperature you set.

Gas boilers can be single-stage (operate only at one power level) and two-stage (2 power levels), as well as with modulation (smooth control) of power, since the full power of the boiler requires approximately 15-20% of the heating season, and 80-85% time it is unnecessary, it is clear that it is more economical to use a boiler with two power levels or power modulation. The main advantages of a two-stage boiler are: an increase in the life of the boiler, due to a decrease in the frequency of burner on / off, operation at the 1st stage with reduced power and a decrease in the number of burner on / off, saving gas, and, consequently, money.

Wall-mounted boilers have appeared relatively recently, but even in this relatively short time period they have won a lot of supporters around the world. One of the most accurate and capacious definitions of these devices is "mini boiler room". This term appeared not by chance, because in a small case there is not only a burner, a heat exchanger and a control device, but also, in most models, one or two circulation pumps, an expansion tank, a system that ensures the safe operation of the boiler, a pressure gauge, a thermometer, and many others. elements without which the operation of a normal boiler room is indispensable. Despite the fact that the most advanced technical developments in the field of heating were realized in wall-mounted boilers, the cost of "wall-mounted boilers" is often 1.5-2 times lower than that of their floor counterparts. Another significant advantage is ease of installation. Often, buyers believe that ease of installation is a virtue that only installers should be concerned about. This is not entirely true, because the amount that a real consumer will have to pay for installing a wall-mounted boiler or for installing a boiler room, where the boiler, boiler, pumps, expansion tank and much more are installed separately, differs very significantly. Compactness and the ability to fit a wall-mounted boiler into almost any interior is another plus of this class of boilers.

Despite the fact that the most advanced technical developments in the field of heating were realized in wall-mounted boilers, the cost of "wall-mounted boilers" is often 1.5-2 times lower than that of their floor counterparts. Another significant advantage is ease of installation. Often, buyers believe that ease of installation is a virtue that only installers should be concerned about. This is not entirely true, because the amount that a real consumer will have to pay for installing a wall-mounted boiler or for installing a boiler room, where the boiler, boiler, pumps, expansion tank and much more are installed separately, differs very significantly. Compactness and the ability to fit a wall-mounted boiler into almost any interior is another plus of this class of boilers.

According to the method of removing exhaust gases, all gas boilers can be divided into models with natural draft (exhaust gases are removed due to the draft created in the chimney) and forced draft (using a fan built into the boiler). Most companies producing wall-mounted gas boilers produce models with both natural draft and forced draft. Natural draft boilers are well known to many and the chimney above the roof does not surprise anyone. Boilers with forced draft appeared quite recently and have a lot of advantages during installation and operation. As mentioned above, the exhaust gases from these boilers are removed using a fan built into them. Such models are ideal for rooms without a traditional chimney, since the combustion products in this case are discharged through a special coaxial chimney, for which it is enough to make only a hole in the wall. A coaxial chimney is also often called a "pipe in a pipe". Through the inner pipe of such a chimney, the products of combustion are brought out into the street with the help of a fan, and air enters through the outer pipe. In addition, these boilers do not burn oxygen from the room, do not require an additional inflow of cold air into the building from the street to maintain the combustion process, and allow you to reduce capital investments during installation, because. there is no need to make an expensive traditional chimney, instead of which a short and inexpensive coaxial chimney is successfully used. Forced draft boilers are also used when there is a traditional chimney, but the intake of combustion air from the room is undesirable.

According to the type of ignition, wall-mounted gas boilers can be with electric or piezo ignition. Boilers with electric ignition are more economical, since there is no igniter with a constantly burning flame. Due to the absence of a constantly burning wick, the use of boilers with electric ignition can significantly reduce gas consumption, which is most important when using liquefied gas. Saving liquefied gas in this case can reach 100 kg per year. There is another plus of boilers with electric ignition - in the event of a temporary power outage, the boiler will automatically turn on when the power supply is restored, and the model with piezo ignition will have to be turned on manually.

According to the type of burner, wall-mounted boilers can be divided into two types: with a conventional burner and with a modulating burner. The modulating burner provides the most economical mode of operation, as the boiler automatically adjusts its output depending on the heat demand. In addition, the modulating burner also provides maximum comfort in DHW mode, allowing you to maintain the temperature of hot water at a constant, set level.

Most wall-mounted boilers are equipped with devices that ensure their safe operation. So the flame presence sensor turns off the gas supply when the flame goes out, the blocking thermostat turns off the boiler in case of an emergency increase in the temperature of the boiler water, a special device turns off the boiler in the event of a power failure, another device blocks the boiler when the gas is turned off. There is also a boiler shutdown device when the coolant volume drops below normal and a draft control sensor.

2.2 Electric boilers

There are several main reasons that limit the distribution of electric boilers: not all areas have the ability to allocate the electrical power required for heating a house (for example, a house of 200 sq. M. requires about 20 kW), very high cost of electricity, power outages. The advantages of electric boilers, indeed, are many. Among them: relatively low price, ease of installation, light and compact, they can be hung on the wall, as a result - space saving, safety (no open flame), ease of operation, electric boiler does not require a separate room (boiler room), electric boiler does not require installation of a chimney, the electric boiler does not need special care, it is silent, the electric boiler is environmentally friendly, there are no harmful emissions and odors. In addition, in cases where power outages are possible, an electric boiler is often used in tandem with a backup solid fuel boiler. The same option is also used to save electricity (first, the house is heated using a cheap solid fuel, and then in automatic mode the temperature is maintained using an electric boiler).

It is worth noting that when installed in large cities with strict environmental regulations and coordination problems, electric boilers also often outperform all other types of boilers (including gas ones). Briefly about the device and configuration of electric boilers. An electric boiler is a fairly simple device. Its main elements are a heat exchanger, consisting of a tank with electric heaters (heaters) fixed in it, and a control and regulation unit. Electric boilers of some companies are supplied already equipped with a circulation pump, programmer, expansion tank, safety valve and filter. It is important to note that low-power electric boilers come in two different versions - single-phase (220 V) and three-phase (380 V).

Boilers with a power of more than 12 kW are usually produced only three-phase. The vast majority of electric boilers with a power of more than 6 kW are produced in multi-stage, which makes it possible to rationally use electricity and not turn on the boiler at full capacity during the transitional periods - in spring and autumn. When using electric boilers, the most relevant is the rational use of energy.

2.3 Solid fuel boilers

Fuel for solid fuel boilers can be firewood (wood), brown or coal, coke peat briquettes. There are both "omnivorous" models that can operate on all of the above types of fuel, and those that operate on some of them, but at the same time have greater efficiency. One of the main advantages of most solid fuel boilers is that they can be used to create a completely autonomous heating system. Therefore, such boilers are more often used in areas where there are problems with the supply of main gas and electricity. There are two more arguments in favor of solid fuel boilers - availability and low cost of fuel. The disadvantage of most representatives of boilers of this class is also obvious - they cannot operate in a fully automatic mode and require regular fuel loading.

It is worth noting that there are solid fuel boilers that combine the main advantage of models that have existed for many years - independence from electricity and at the same time capable of automatically maintaining the set temperature of the coolant (water or antifreeze). Automatic temperature maintenance is carried out as follows. The boiler is equipped with a sensor that monitors the temperature of the coolant. This sensor is mechanically connected to the damper. If the temperature of the coolant becomes higher than the one you set, the damper automatically closes and the combustion process slows down. When the temperature drops, the damper opens slightly. Therefore, this device does not need to be connected to electrical network. As mentioned above, most traditional solid fuel boilers are able to work on brown and hard coal, wood, coke, briquettes.

Overheating protection is provided by the presence of a cooling water circuit. This system can be manually controlled, i.e. when the coolant temperature rises, it is necessary to open the valve on the coolant outlet pipe (the valve on the inlet pipe is constantly open). In addition, this system can also be controlled automatically. To do this, a temperature reduction valve is installed on the outlet pipe, which will automatically open when the coolant reaches the maximum temperature. In addition to what fuel to use for heating your home, it is very important to choose the right boiler power. Power is usually expressed in kW. Approximately 1 kW of power is required for heating 10 square meters. m of a well-insulated room with a ceiling height of up to 3 m. It must be borne in mind that this formula is very approximate.

The final calculation of power should be trusted only to professionals who, in addition to the area (volume), will take into account many more factors, including the material and thickness of the walls, type, size, number and location of windows, etc.

Boilers with pyrolysis combustion of wood have a higher efficiency (up to 85%) and allow automatic power control.

The disadvantages of pyrolysis boilers, first of all, include a higher price compared to traditional solid fuel boilers. By the way, there are boilers that work not only on wood, but also boilers on straw. When choosing and installing a solid fuel boiler, it is very important to comply with all requirements for the chimney (its height and internal section).

3. Types of boilers for heat supply of buildings

gas boiler heat supply

There are two main types of steam boilers: gas-tube and water-tube. All boilers (fire-tube, smoke-fire and smoke-fire-tube) in which high-temperature gases pass inside the flame and fire tubes, giving off heat to the water surrounding the pipes, are called gas-tube boilers. In water-tube boilers, heated water flows through the pipes, and flue gases wash the pipes from the outside. Gas-tube boilers rest on the side walls of the furnace, while water-tube boilers are usually attached to the frame of the boiler or building.

3.1 Gas-tube boilers

In modern thermal power engineering, the use of gas-tube boilers is limited to a thermal power of about 360 kW and an operating pressure of about 1 MPa.

The fact is that when designing a pressure vessel, which is a boiler, the wall thickness is determined by given values diameter, working pressure and temperature.

When the specified limiting parameters are exceeded, the required wall thickness turns out to be unacceptably large. In addition, safety requirements must be taken into account, since the explosion of a large steam boiler, accompanied by the instantaneous release of large volumes of steam, can lead to a catastrophe.

With the current state of the art and existing safety requirements, gas-tube boilers can be considered obsolete, although many thousands of such boilers with a thermal power of up to 700 kW are still in operation, serving industrial enterprises and residential buildings.

3.2 Water tube boilers

The water tube boiler has been developed in response to ever increasing demands for higher steam output and steam pressure. The fact is that when the steam and water of increased pressure are in a pipe of not very large diameter, the requirements for wall thickness are moderate and easily achievable. Water-tube steam boilers are much more complex in design than gas-tube ones. However, they heat up quickly, are practically explosion-proof, easily adjust to load changes, are easy to transport, are easily reconfigurable in design solutions, and allow significant overloading. The disadvantage of a water-tube boiler is that there are many units and assemblies in its design, the connections of which should not allow leakage at high pressures and temperatures. In addition, the units of such a boiler operating under pressure are difficult to access during repairs.

The water-tube boiler consists of tube bundles connected at their ends to a drum (or drums) of moderate diameter, the whole system being mounted above the combustion chamber and enclosed in an outer casing. The baffles force the flue gases to pass through the tube bundles several times, thereby ensuring a more complete heat transfer. Drums (of various designs) serve as water and steam reservoirs; their diameter is chosen to be minimal in order to avoid the difficulties inherent in gas-tube boilers. Water tube boilers are of the following types: horizontal with a longitudinal or transverse drum, vertical with one or more steam drums, radiant, vertical with a vertical or transverse drum, and combinations of these options, in some cases with forced circulation.

Conclusion

So, in conclusion, we can say that boilers are an important element in the heat supply of a building. When choosing stakes, it is necessary to take into account technical, technical-economic, mechanical and other indicators for the best type of building heat supply. Boiler plants, depending on the nature of consumers, are divided into energy, production and heating and heating. According to the type of heat carrier produced, they are divided into steam and hot water.

In my work, gas, electric, solid fuel types of boilers, as well as types of stakes, such as gas-tube and water-tube boilers, are considered.

From the above, it is worth highlighting the pros and cons various kinds boilers.

The advantages of gas boilers are: cost-effectiveness, compared to other types of fuel, ease of operation (boiler operation is fully automated), high power (a large area can be heated), the ability to install equipment in the kitchen (if the boiler power is up to 30 kW), compact size, environmental friendliness ( few harmful substances will be released into the atmosphere).

Cons of gas boilers: before installation, you must obtain permission from Gazgortekhnadzor, the risk of gas leakage, certain requirements for the room where the boiler is installed, the presence of automation that blocks gas access in case of leakage or lack of ventilation.

The advantages of electric boilers: low price, ease of installation, compactness and light weight - electric boilers can be hung on the wall and save usable space, safety (no open flame), ease of operation, electric boilers do not require a separate room (boiler room), do not require the installation of a chimney, do not require special care, silent, environmentally friendly - no harmful emissions and odors.

The main reasons limiting the distribution of electric boilers are far from being in all areas, it is possible to allocate several tens of kilowatts of electricity, the rather high cost of electricity, and power outages.

First, let's highlight the disadvantages of solid fuel boilers: first of all, solid fuel heating boilers use solid fuel, which has a relatively low heat transfer. Indeed, in order to qualitatively heat a large house, you will have to spend a lot of fuel and time. In addition, the fuel will burn out quite quickly - in two to four hours. After that, if the house is not heated enough, you will have to rekindle the fire. And for this, you will first need to clean the firebox from the formed coals and ash. Only after that it will be possible to lay the fuel and kindle the fire again. All this is done by hand.

On the other hand, solid fuel boilers have some advantages. For example, not picky about fuel. Indeed, they can work effectively on all types of solid fuels - wood, peat, coal, and in general, everything that can burn. Of course, it is possible to obtain such fuel in most regions of our country quickly and not too expensive, which is a serious argument in favor of solid fuel boilers. In addition, these boilers are completely safe, so they can be installed either in the basement of the house, or just not far from it. At the same time, you can be sure that a terrible explosion will not occur due to a fuel leak. Of course, you don't have to equip special place for fuel storage - bury containers for storing gas or diesel fuel in the ground.

Currently, there are two main types of steam boilers, namely: gas-tube and water-tube. Gas-tube boilers include those boilers in which high-temperature gases flow inside the flame and fire tubes, thereby giving off heat to the water that surrounds the tubes. Water-tube boilers are distinguished by the fact that heated water flows through the pipes, and the pipes are washed from the outside with gases.

Bibliography

1.Boyko E.A., Shpikov A.A., Boiler plants and steam generators (structural characteristics of power boiler units) - Krasnoyarsk, 2003.

.Bryukhanov O.N. Gasified boiler units. Textbook. INFRA-M. - 2007.

.GOST 23172-78. Kotlystationary. Terms and definitions. - Definition of boilers "for producing steam or for heating water under pressure".

.Dvoinishnikov V.A. et al. Design and calculation of boilers and boiler plants: A textbook for technical schools in the specialty "Boiler building" / V.A. Dvoinishnikov, L.V. Deev, M.A. Izyumov. - M.: Mashinostroenie, 1988.

.Levin I.M., Botkachik I.A., Smoke exhausters and fans of powerful power plants, M. - L., 1962.

.Maksimov V.M., Boiler units of high steam capacity, M., 1961.

.Tikhomirov K.V. Sergeenko E. S. "Heat engineering, heat and gas supply and ventilation." Proc. for universities. 4th ed., revised. and additional - M.: Stroyizdat, 1991

.Encyclopedia "KrugosvetUniversal" popular science online encyclopedia.

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Development of an optimal technical solution for the manufacture of a boiler house, taking into account all specifications provided by the Customer

About company

Since the summer of 2004, our company has been producing modular boiler plants of the COMPACT container type. Boiler houses COMPACT with a heat output from 100 kW to 20,000 kW are designed for heating and hot water supply of residential, industrial and public facilities, as well as for providing hot water or steam for the technological needs of various industries

What are the boiler rooms

The energy industry requires the use of various types of boilers, classified according to various criteria: the type of fuel used and the coolant, the location, the principle of mechanization or automation, the goals and requirements of customers.

Types of boiler houses by type of fuel:

• gas boilers, their main advantage is efficiency and environmental friendliness. They do not require complex large-sized equipment and can work offline;
• liquid fuel boilers - operate on fuel oil, oil, diesel fuel and waste oil, quickly put into operation and do not require permits for their use, connection and are not limited by fuel volumes;
• solid fuel boilers - work on wood, peat, waste from the timber industry, coal. Their "trick" lies in the low cost of fuel and availability, but they require the installation of fuel supply systems and systems for removing ash and slag.

Types of boiler rooms depending on the coolant:

• hot water- boiler houses used in hot water supply and heating systems for residential and non-residential buildings. As a heat carrier, water is used, heated to a maximum of +95 ... + 110 ° С;
• steam- steam is used as a coolant, and most often such boiler houses are equipped in industries;
• combined- they use boilers of both types, moreover, hot water covers the loads for ventilation and heating needs and water supply, and steam is used for technological processes;
• oily– diathermic oil and other organic liquids heated to a temperature of +300°C are used as a heat carrier.

Types of boiler rooms depending on their location

1. Block-modular systems have a number of advantages compared to stationary boilers. They are characterized by quick installation and commissioning, the possibility of increasing capacity due to the addition of modular units and autonomy, high coefficient and mobility. They can be attached to the wall, built into it, placed on the roof and in the basement, stand separately from each other.
2. Stationary boiler houses are used when a power of 30 MW or more is required or when it is impossible to build a block-modular system. They are capital, solid and require installation at the work site.

Types of boiler houses according to the degree of mechanization or automation of work processes:

• automated- fully automated and require little or no human intervention;
• mechanized- equipped with mechanized elements - conveyor belts, coal crushers, chip catchers, etc., which greatly facilitates the work of the operator;
• manual- equipped with manual fuel supply modules (trolley or hopper with an external loading system), ash and slag removal is also carried out manually.

Water vapor is used in steam engines, steam power plants of thermal power plants, in technological installations of enterprises, in heating, ventilation and hot water supply systems of industrial, public and residential buildings. Hot water - mainly in the heating and ventilation systems of buildings, as well as to meet the sanitary needs of production and the population. Sometimes - for heat supply of technological consumers. In many cases, steam or hot water produced in boilers is used as a heat carrier to supply heat to heating points called central heating points (CHPs), in which heat exchangers (recuperative or mixing) are installed to heat the water circulating between the CHP and consumers connected to them. (two-circuit schemes). It is also possible to connect consumers to the central heating station through additional heating points (boiler rooms) to supply heat to individual or groups of consumers (three-circuit schemes). See [9] for more details.

Steam and hot water in boiler houses, with the exception of boiler houses with nuclear reactors, are obtained using the heat of combusted organic fuel in special units, respectively called steam, hot water and steam hot water boilers.

Depending on the purpose, boiler houses are divided into energy, industrial, industrial and heating, boiler houses of the public utility sector (KBS) or housing and communal services (HCS). The latter cover the needs of housing and communal services in heat mainly for the purpose of heating and hot water supply. Power boilers are designed to supply steam to turboelectric generators of thermal power plants (TPPs), steam engines. The power boiler house is integral part TPP. Industrial boiler houses provide steam and hot water to technological consumers and systems of heating, ventilation, air conditioning and hot water supply.

In industry, large technological consumers of steam are evaporators, distillation, distillation, drying plants, chemical reactors, plants for sorption-desorption purification of natural gas from hydrogen sulfide and carbon dioxide, washing machines, presses, heated baths of electroplating lines, machines for laminating (coating with polymer films) papers, etc.

In table. 1.1 shows some characteristics of the heat consumption of enterprises various industries industry [2].

Industrial and heating boiler houses are designed to generate steam or hot water used both in production and for heating industrial, administrative and other buildings on the territory of the enterprise, as well as heating and supplying hot water to nearby residential areas.

Steam boilers are more often installed in industrial and industrial heating boiler houses. In heating boiler houses, they mainly receive hot water intended for heating buildings and satisfying household needs of the population. Therefore, both steam and hot water boilers are used in heating boilers. At modern heat supply stations for housing and communal services - mainly hot water boilers. And the steam boilers available there - to cover the station's own needs, mainly to supply fuel oil facilities with steam (fuel oil is used as a backup or emergency fuel in gas boilers). A promising direction is the use of combined steam boilers in heating boiler houses. In the last ten years, autonomous rooftop and block-modular boiler houses, steam and hot water plants have also become widespread. Block-modular boiler rooms are assembled at the factory and delivered to the place of their installation assembled. To put them into operation, it is enough to install them after delivery, connect them to consumers and a fuel supply source, and carry out commissioning work in the prescribed manner.

Schematic diagrams of the steam and hot water boiler plant are shown in fig. 1.1 and 1.2.

Depending on the number of consumers connected to the HPU heat supply source, district, group, and individual boiler houses are distinguished [1]. District and group boiler houses are located, as a rule, in separate buildings. Individual - more often in basements or on the roofs of heated buildings. Autonomous automated rooftop boilers operating on natural gas have become widespread only in recent years.

Rice. 1.1. Schematic diagram of a steam boiler house

1 - boiler units; 2 – live steam collector; 3 - reducing installation; 4 - steam collector R= 0.6 MPa; 5 - steam collector R= 0.3…0.12 MPa; 6 – continuous purge separator; 7 - steam-water heaters; 8 - condensate coolers after steam-water heaters; 9 - thermal deaerator; 10 – vapor cooler; 11 - water-water heater; 12 - steam-water heater; 13 - chemical water treatment device; 14 - feed pumps with electric drive; 15 - steam feed pumps; 16 - network pumps; 17 - make-up pump;

symbols of pipelines: T1 - hot water supplied for heating and ventilation (HV); T2 - return water from the heating system; T21 - reverse, after heating in the condensate cooler (OK); T3 - domestic hot water supply, supplying; T4 - return water from the hot water supply system; T5 - hot water for technological needs; T6 - return water after technological needs; T61 - return water after OK; T71 - steam from the boiler; T73 - pair after the reduction device ( R= 0.3…0.12 MPa); T72 - pair after reduction ( R= 0.6 MPa); T74 - steam from the continuous purge separator; T79 - steam from the deaerator; T81 - condensate at R= 0.6 MPa; T82 - condensate at R= 0.2 MPa; T84 - condensate from production; T91 - feed water; T92 - continuous purge; T93 - purge water after evaporation; B1 - raw water from the water supply; B20 - water after chemical water treatment

Rice. 1.2. Principal thermal diagram of a hot water boiler house

1 - hot water boiler; 2 - network pump; 3 - recirculation pump; 4 – recirculation regulator; 5 – network water temperature controller; 6 – vacuum deaerator; 7 – deaerator vapor cooler; 8 - water-water heat exchanger; 9 - pump of chemically purified water; 10 - gas-water ejector; 11 - supply tank of working water; 12 – raw water pump; 13 - heat exchanger-heater of raw water; 14 - transfer pump; 15 – make-up water storage tank; 16 - make-up pump; 17 - water temperature controller in front of the deaerator; a, b - supply and return of hot water from production; c - raw water from the water supply; d - return of network water

• 
  
• 
  burners
• 
  water treatment plants
• 
  boiler pipes, valves
• 
  heat generators
• 
  water level indicators
• 
  sensors and controllers
• 
  and much more

Gas boilers

At industrial enterprises, gas-fired boilers are the main source of heat supply for technological processes and for providing heat to working personnel. At the same time, gas-fired boiler houses also began to appear more often in private residential buildings. People appreciated the advantages of such installations.

Gas boilers are an indispensable source of energy, cheaper than electricity.

Modular boiler rooms

The modular boiler rooms include the following equipment:

• 
  hot water boilers
• 
  technological equipment
• 
  automation systems
• 
  water treatment systems
• 
  and much more

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

The combustion device serves 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 blowers, a system of gas ducts, smoke exhausters and a chimney, with the help of which the required amount of air is supplied to the furnace and the movement of combustion products through the boiler flues, as well as their removal into the atmosphere. Combustion products, moving through the gas ducts and in contact with the heating surface, transfer heat to the water.

To ensure more economical operation, modern boiler plants have auxiliary elements: a water economizer and an 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 the normal and uninterrupted operation of all parts of the boiler room.
Classification.

Block modular boiler rooms with a capacity of 200 kW to 10,000 kW (model range)

There are individually designed boiler rooms of different types:

• 
  Rooftop boilers
• 
  Stand-alone boiler rooms
• 
  Block and modular boiler rooms
• 
  Built-in boiler rooms
• 
  Attached boiler rooms
• 
  Transportable and mobile boiler rooms

Control of all parameters of work is carried out by automated control systems without the presence of a person.

Composition boiler houses in basic version:

• 
  Hot water boilers
  Reliability of heat release is guaranteed by the presence of boiler houses at least two boiler units, represented by steel fire-tube boilers of reliable and successfully proven German companies on the Russian market Buderus, Viessmann.
• 
  Weishaupt burners
  Used in boiler rooms burners of the German company Weishaupt. Used to burn natural gas burners in LN version, providing a low content of harmful impurities in combustion products.
• 
  Internal gas supply
  Gas supply system equipment boiler houses regulates the gas flow and controls the minimum and maximum gas pressure levels. In case of emergency situations, the flow of gas into boiler room stops automatically.
• 
  Heating water temperature control
  Microprocessor programmable controllers are used that automatically control the network water temperature control system depending on the outdoor temperature and the needs of the Consumer.
• 
  Pump equipment
  Boiler circuit pumps provide independent operation boilers. Dual circuit circulation pumps guarantee 100% redundancy.
• 
  Water treatment and pressure maintenance in the heating system
  The water treatment plant reduces the hardness of the boiler water and prevents the formation of scale on the heat exchange surfaces of the equipment. The pressure maintenance device automatically feeds the boiler and network circuits with water, providing the necessary pressure level in the heating system.
• 
  hydraulic separator
  Equipment for hydraulic decoupling of the boiler and network circuits makes it possible to ensure the stable operation of the boiler house in systems with a large volume of water with intensive dynamics of changes in flow rates, temperature and pressure.
• 
  Signaling
  The boiler rooms are equipped with fire alarm and gas alarm systems for methane and carbon monoxide.
• 
  Metering devices
  Control and measuring devices are used, registered in the State Register of Measuring Instruments, allowing to carry out:
  – metering of supplied thermal energy
  – accounting for cold water consumption
  – accounting for gas consumption
  – metering of consumed electricity
  – control of operating parameters of the boiler room equipment.
• 
  Integrated automation
  The integrated automation system ensures the stable operation of boiler rooms without the constant presence of maintenance personnel. remote control operation of the main equipment of the boiler room is carried out by means of a remote dispatching alarm panel (included in the scope of delivery).
• 
  Modem communication for remote dispatching
  Boiler houses at the time of installation or any period of further operation can be connected to modern remote dispatching systems. Integrated system automation has a built-in block modem for transmitting data on the operation of boiler room equipment via telephone channels or the Internet.
• 
  Chimneys
  The outer and inner walls of the chimneys are made of stainless steel and insulated with rigid mineral wool insulation. The used chimneys have a certificate of compliance with fire safety standards. A separate pipe is installed for each heating boiler. Chimneys with a height of 6 meters are included in the scope of supply for boiler rooms from 200 kW to 10 MW. At will, the Buyer may refuse the chimney, and also has the opportunity to install chimneys of a different height.

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

Boilers of medium and high power - 3.5 MW and above - are distinguished by the complexity of the equipment and the composition of service and amenity premises. Space-planning solutions for these boiler houses must meet the requirements of the Sanitary Design Standards for Industrial Enterprises (SI 245-71), SNiP P-M.2-72 and 11-35-76.

Classification of boiler plants
Boiler plants, depending on the nature of consumers, are divided into energy, production and heating and heating. According to the type of heat carrier produced, they are divided into steam (for generating steam) and hot water (for generating hot water).

Power boiler plants produce steam for steam turbines in thermal power plants. Such boiler houses are equipped, as a rule, with boiler units of large and medium power, which produce steam with increased parameters.

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

Heating boiler plants (mainly water-heating, 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 divided into local (individual), group and district.

Local boiler houses are usually equipped with hot water boilers with water heating up to a temperature of not 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 plants provide heat to groups of buildings, residential areas or small neighborhoods. Such boiler houses are equipped with both steam and hot water boilers, as a rule, with higher heat output than boilers for local boiler houses. These boiler houses 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.

boiler plant with steam boilers. The installation consists of a steam boiler, which has two drums - upper and lower. The drums are interconnected by three bundles of pipes forming the heating surface of the boiler. When the boiler is operating, the lower drum is filled with water, the upper drum is filled with water in the lower part, and saturated steam in the upper part. In the lower part of the boiler there is a furnace with a mechanical grate for burning solid fuel. When burning liquid or gaseous fuels, nozzles or burners are installed instead of a grate, through which fuel, together with air, is supplied to the furnace. The boiler is limited by brick walls - brickwork.

Boiler plants located in specially designated areas where unauthorized persons have no access. And already heating mains and heat pipelines connect boiler houses and consumers.

Classification of boiler rooms.

Modern boiler plants have a different classification. Each of them is based on a certain principle or certain meanings. To date, there are several main differences:

Location.

Depending on where the installation is located, there are:

• 
  Roof;
• 
  built into the building;
• 
  Block-modular;
• 
  Frame.

• 
  steam boilers
• 
  Water heating;
• 
  mixed;
• 
  Cauldrons for diathermic oil.

• 
  Solid fuel. For this, firewood, coal and other types of solid fuels are used.
• 
  Liquid fuel - oil, gasoline, fuel oil and others.
• 
  Gas.
• 
  Mixed or combined. The use of various types and types of fuel is expected.

Boilers with natural circulation;

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

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

Modern steam boilers with natural circulation are made of vertical pipes located between two collectors (drums). One part of the pipes, called heated "lifting pipes", is heated by a torch and combustion products, and the other, usually not heated part of the pipes, is located outside the boiler unit and is called "down pipes". In heated riser 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 downcomer 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 downcomer and the column of the steam-water mixture in the riser pipes.

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 once-through steam boilers, the circulation ratio is one, i.e. Feed water, heating up, successively turns into a steam-water mixture, saturated and superheated steam. In hot water boilers, when moving along the circulation circuit, water is heated in one revolution from the initial to the final temperature.

According to the type of heat carrier, boilers are divided into water-heating and steam boilers. The main indicators of a hot water boiler are thermal power, i.e. heat 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 obtain hot water of specified parameters, are used for heat supply of heating and ventilation systems, domestic and technological consumers. Hot water boilers, usually operating on a once-through principle with a constant water flow, 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.

Steam boiler - an installation designed to generate saturated or superheated steam, as well as to heat water (heating boiler).

According to 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 the flue gases wash the pipes from the outside. In Russia in the 20th century, Shukhov's water-tube boilers were predominantly used. In fire tubes, on the contrary, flue gases move inside the pipes, and water washes the pipes from the outside.

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

As a charging pump, a high-pressure three-plunger pump of the P21 / 23-130D or P30 / 43-130D series is usually used.

Boilers over critical pressure (SKP) - steam pressure over 22.4MPa.

The main elements of steam and hot water boilers
Furnaces for combustion of gaseous, liquid and solid fuels. When burning gas and fuel oil, as well as solid pulverized coal, as a rule, chamber furnaces are used. The furnace is limited by the front, rear, side walls, as well as the hearth and vault. Evaporative heating surfaces (boiler pipes) with a diameter of 50...80 mm are located along the walls of the furnace, perceiving the radiated heat from the torch and combustion products. When burning gaseous or liquid fuels under the chamber furnace, they usually do not shield, and in the case of coal dust, a “cold” funnel is made in the lower part of the combustion chamber to remove the ash falling from the burning torch.

The upper ends of the pipes are rolled into a drum, and the lower ends are connected to the collectors by rolling or welding. In a number of boilers, the boiling pipes of the rear screen, before being connected to the drum, are bred in the upper part of the furnace in several rows, arranged in a checkerboard pattern and forming a scallop.

To service the furnace and gas ducts in the boiler unit, the following headset is used: manholes, lockable doors, peepers, explosive valves, gate valves, rotary dampers, blowers, shot cleaning.

Closable doors, manholes in brickwork are designed for inspection and repair work when the boiler is stopped. To monitor the process of fuel combustion in the furnace and the state of convective gas ducts, peepers are used. Explosive safety valves are used to protect the lining from destruction during popping in the furnace and boiler flues and are installed in the upper parts of the furnace, the last gas flue of the unit, the economizer and in the roof.

To regulate the draft and overlap the hog, cast-iron smoke dampers or rotary dampers are used.

When working on gaseous fuels, in order to prevent the accumulation of combustible gases in the furnaces, chimneys and flues of the boiler installation during a break in work, a small draft must always be maintained in them; To do this, each separate flue of the boiler to the combined flue must have its own gate valve with a hole in the upper part with a diameter of at least 50 mm.

Blowers and shot cleaners are designed to clean heating surfaces from ash and soot.

Steam boiler drums. It should be noted the multi-purpose purpose of the drums of steam boilers, in particular, the following processes are carried out in them:

Separation of the steam-water mixture coming from the lifting heated pipes into steam and water and steam collection;

Feed water intake from the water economizer or directly from the feed line;

Intra-boiler water treatment (thermal and chemical water softening);

Continuous purge;

Drying of steam from droplets of boiler water;

Washing steam from salts dissolved in it;

Steam pressure protection.

Boiler drums are made of boiler steel with stamped bottoms and a manhole. The inner part of the volume of the drum, filled to a certain level with water, is called the water volume, and filled with steam during the operation of the boiler - the steam volume. The surface of boiling water in the drum, which separates the water volume from the steam volume, is called the evaporation mirror. In a steam boiler, only that part of the drum that is cooled by water from the inside is washed by hot gases. The line separating the surface heated by gases from the unheated one is called the firing line.

The steam-water mixture enters through lifting boiler pipes rolled into the bottom of the drum. From the drum, water is fed through downpipes to the lower collectors.

Emissions, ridges and even fountains appear on the surface of the evaporation mirror, while a significant amount of boiler water droplets can get into the steam, which reduces the quality of the steam as a result of an increase in its salinity. Drops of boiler water evaporate, and the salts contained in them are deposited on the inner surface of the superheater, impairing heat transfer, as a result of which the temperature of its walls rises, which can lead to their burnout. Salts can also be deposited in the fittings of the steam lines and lead to a violation of its tightness.

Various separation devices are used to uniformly supply steam to the steam space of the drum and reduce its moisture content.

To reduce the possibility of scale deposits on the evaporative heating surfaces, intra-boiler water treatment is used: phosphating, alkalizing, the use of complexing agents.

Phosphating aims to create conditions in the boiler water under which the scale formers are separated in the form of non-stick sludge. To do this, it is necessary to maintain a certain alkalinity of the boiler water.

In contrast to phosphating, water treatment with complexones can provide scale-free and sludge-free regimes of boiler water. It is recommended to use Trilon B sodium salt as a complexing agent.

Maintaining the permissible salt content in the boiler water is carried out by blowing the boiler, i.e. removing from it some part of the boiler water, which always has a higher concentration of salts than the feed water.

For the implementation of the staged evaporation of water, the boiler drum is divided by a partition into several compartments with independent circulation circuits. Feed water enters one of the compartments, called "clean". Passing through the circulation circuit, the water evaporates, and the salinity of the boiler water in the clean compartment rises to a certain level. To maintain the salinity in this compartment, part of the boiler water from the clean compartment is directed by gravity through a special hole - a diffuser in the lower part of the partition into another compartment, called "salt", since the salt content in it is significantly higher than in the clean compartment.

Continuous purging of water is carried out from a place with the highest concentration of salts, i.e. from the salt compartment. The steam generated in both evaporation stages is mixed in the steam space and exits the drum through a series of pipes located in its upper part.

With an increase in pressure, steam is able to dissolve some impurities in the boiler water (silicic acid, metal oxides).

To reduce the salinity of steam, some boilers use steam flushing with feed water.

Boiler superheaters. Obtaining superheated steam from dry saturated steam is carried out in a superheater. The superheater is one of the most critical elements of the boiler unit, since of all heating surfaces it operates under the most severe temperature conditions (overheating temperature up to 425 ° C). The superheater coils and headers are made of carbon steel.

According to the method of heat absorption, superheaters are divided into convective, radiation-convective and radiation. In boiler units of low and medium pressure, convective superheaters with vertical or horizontal pipes are used. To obtain steam with a superheat temperature of more than 500 °C, combined superheaters are used, i.e. in them, one part of the surface (radiation) perceives heat due to radiation, and the other part - by convection. The radiation part of the heating surface of the superheater is located in the form of screens directly in the upper part of the combustion chamber.

Depending on the directions of movement of gases and steam, there are three main schemes for including a superheater in a gas flow: direct-flow, in which gases and steam move in the same direction; countercurrent, where gases and steam move in opposite directions; mixed, in which in one part of the coils of the superheater gases and steam move in direct flow, and in the other - in opposite directions.

Optimal in terms of reliability of operation is a mixed scheme for switching on a superheater, in which the first part of the superheater along the steam flow is counterflow, and the completion of steam superheating occurs in its second part with direct flow of heat carriers. At the same time, in the part of the coils located in the region of the highest heat load of the superheater, at the beginning of the flue there will be a moderate steam temperature, and the completion of steam superheating occurs at a lower heat load.

Steam temperature in boilers with pressure up to 2.4 MPa is not regulated. At a pressure of 3.9 MPa and above, the temperature is controlled in the following ways: by injection of condensate into steam; using surface desuperheaters; using gas control by changing the flow rate of combustion products through the superheater or moving the position of the flame in the furnace using rotary burners.

The superheater must have a pressure gauge, a safety valve, a shut-off valve to disconnect the superheater from the steam line, and a device for measuring the temperature of the superheated steam.

Water economizers. In the economizer, feed water is heated by flue gases before being fed into the boiler by using the heat of the fuel combustion products. Along with preheating, partial evaporation of the feed water entering the boiler drum is possible. Depending on the temperature to which water is heated, economizers are divided into two types - non-boiling and boiling. In non-boiling economizers, according to the conditions of their reliability, water is heated to a temperature of 20 ° C below the temperature of saturated steam in a steam boiler or the boiling point of water at the existing operating pressure in a hot water boiler. In boiling economizers, not only water is heated, but also partial (up to 15 May.%) its evaporation.

Depending on the metal from which economizers are made, they are divided into cast iron and steel. Cast iron economizers are used at a pressure in the boiler drum of not more than 2.4 MPa, while steel economizers can be used at any pressure. In cast iron economizers, boiling water is unacceptable, as this leads to hydraulic shocks and destruction of the economizer. To clean the heating surface, water economizers have blowers.

Air heaters. In modern boiler units, the air heater plays a very significant role, taking heat from the exhaust gases and transferring it to air, it reduces the most noticeable heat loss item with the exhaust gases. When using heated air, the combustion temperature of the fuel rises, the combustion process intensifies, and the efficiency of the boiler unit increases. At the same time, when installing an air heater, the aerodynamic resistances of the air and smoke paths increase, which are overcome by creating artificial draft, i.e. by installing a smoke exhauster and a fan.

The air heating temperature is selected depending on the combustion method and type of fuel. For natural gas and fuel oil burned in chamber furnaces, the temperature of hot air is 200...250°C, and for pulverized coal combustion of solid fuel - 300...420°C.

If the boiler unit has an economizer and an air heater, the economizer is installed first along the gas flow, and the air heater is installed second, which allows for deeper cooling of the combustion products, since the cold air temperature is lower than the temperature of the feed water at the economizer inlet.

According to the principle of operation, air heaters are divided into recuperative and regenerative. In a recuperative air heater, the transfer of heat from combustion products to air occurs continuously through a separating wall, on one side of which the combustion products move, and on the other - heated air.

In regenerative air heaters, the transfer of heat from the combustion products to the heated air is carried out by alternately heating and cooling the same heating surface.

Gas installations. The gas-piston unit (GPU) is designed to supply electricity to consumers of three-phase (380/220 V, 50 Hz) alternating current. Gas power plants are used as a source of constant and guaranteed power supply for hospitals, banks, shopping malls, airports, industrial and oil and gas producing enterprises. The motor resource of a gas engine is higher than that of gasoline generators and diesel power plants, which leads to a decrease in the payback period. The use of gas-fired power generators allows the owner to be independent from planned and emergency power outages, and often completely refuse the services of electricity suppliers.

The operation of gas piston engines (hereinafter referred to as GPE) is based on the principle of operation of an internal combustion engine. An internal combustion engine is a type of engine, a heat engine in which the chemical energy of a fuel (usually liquid or gaseous hydrocarbon fuels) that burns in the working area is converted into mechanical work.

On the this moment In industry, two types of piston engines operating on gas are produced: gas engines - with electric (spark) ignition, and gas diesel engines - with ignition of the gas-air mixture by injection of pilot (liquid) fuel. Gas engines have gained widespread use in the energy sector due to the widespread trend to use gas as a cheaper fuel (both natural and alternative) and relatively more environmentally friendly in terms of exhaust emissions.

From GPU with heat exchangers, in principle, everything is similar, but a heat recovery system is additionally used.

The unit runs on multiple fuels, has a relatively low initial investment per kW, and has a wide range of power outputs.

Fuel for gas-piston installations. One of highlights when choosing the type of gas turbine is the study of the composition of the fuel. Manufacturers of gas engines have their own requirements for the quality and composition of the fuel for each model.

Currently, many manufacturers are adapting their engines to the appropriate fuel, which in most cases does not take much time and does not require large financial costs.

In addition to natural gas, gas piston units can use as fuel: propane, butane, associated petroleum gas, chemical industry gases, coke oven gas, wood gas, pyrolysis gas, landfill gas, sewage gas, etc.

The use of these specific gases as fuel makes an important contribution to the preservation of the environment and, in addition, allows the use of regenerative energy sources.

Gas control station. Gas control point - a system of devices for automatically reducing and maintaining a constant gas pressure in gas distribution pipelines. The gas control station includes a pressure regulator for maintaining gas pressure, a filter for trapping mechanical impurities, safety valves that prevent gas from entering distribution gas pipelines in case of emergency gas pressure in excess of permissible parameters, and instrumentation for accounting for the amount of passing gas, temperature, pressure and telemetric measurement these options.

Gas control points are built on urban gas distribution pipelines, as well as on the territory of industrial and municipal enterprises with an extensive network of gas pipelines. Items mounted directly at consumers and designed to supply gas to boilers, furnaces, and other units are usually called gas control devices. Depending on the gas pressure at the inlet, gas control points are: medium (from 0.05 to 3 kgf / cm 2 ) and high (up to 12 kgf/cm 2 ) pressure (1 kgf/cm 2 \u003d 0.1 Mn / m 2).

Safety devices and instrumentation. For hot water boilers, bypass lines with non-return valves (Fig.), which pass water in the direction from the boiler to the pipeline of the heating system, can serve as a safety device against increasing pressure in them. With such a simple device, if the valves installed at the boiler for some reason turn out to be closed, then all the same, the connection with the atmosphere through the expansion vessel will not be broken.

If there are any other shut-off valves on the pipeline between the boilers and the expansion vessel, in addition to the valves indicated, then lever safety valves must be installed.

Steam boilers up to 70 kPa are equipped with a safety device in the form of a hydraulic seal

For safe and proper operation, steam boilers, in addition to safety devices, are equipped with water-indicating devices, plug valves and pressure gauges.

To account for the consumption of feed water supplied to the steam boiler, or water circulating in the water heating system, a water meter or diaphragms are installed. To measure the temperature of the water entering the water heating system and returning to the boiler, thermometers are provided in special cases.