General information about boiler installations, types of boilers for building heat supply. Boiler plants

21.11.2020

The boiler plant is a heat generator in which the chemical energy of the fuel is converted into the thermal energy of the working fluid, which is used as water and steam. The working fluid, called in this case the heat carrier, is transported to the heat receivers of consumers and, after using the thermal potential, returns to the boiler plant to repeat the cycle.

According to the type of coolant produced, boiler plants are steam and hot water. According to their purpose, they are divided into three main types:

- energy - installations that produce thermal energy for its subsequent conversion into electrical energy and are therefore included in the complex of energy facilities of power plants.

They produce superheated water vapor of medium, high and super-critical parameters;

- production - installations that produce thermal energy for the technological needs of various industries. They, as a rule, are steam generating dry saturated or superheated steam of low and medium parameters;

- heating - installations that produce thermal energy for the purpose of heating cities. As a rule, they are water-heating

and are designed to produce superheated water with a temperature

Often there are combinations of industrial and heating boiler plants that simultaneously produce steam for industrial and technological needs and hot water for domestic heating purposes.

The working processes of a steam boiler plant can be schematically represented as two organized flows - gases and liquids moving through the same heat exchange system and exchanging energy with each other through the metal walls separating them, called heating surfaces (Fig. 5.1) .

The organization of flows in boiler plants is very diverse and depends on many factors: the purpose of the boiler room and its performance, the type of fuel used and the method of combustion, the type of coolant and methods of its circulation, and is also determined by the tasks of ensuring the maximum effect of converting fuel energy into heat water energy.

In accordance with the above diagram, the boiler unit itself includes:

a combustion device in which fuel is burned and flue gases are formed - highly heated combustion products;

a boiler (metal container), inside which the coolant circulates and through the surface of which heat is transferred from gases to the coolant;

a system of gas ducts used to remove flue gases into the atmosphere;

devices for supplying fuel and air to the furnace, removing residues of fuel combustion and combustion products, circulating the heat carrier;

systems of pipelines for water, steam, air, structurally made as a whole with the boiler unit.

Boiler plant(Fig. 5.2) - a set of one or more boiler units installed in one room and equipped with common auxiliary devices for fuel preparation, ash-ash removal, water treatment and boiler feed, gas cleaning and removal.

Crushed fuel supply

	continuous	purge

superheated steam		Air


				Steam		TLU
					Feeder-
			water

	Air			Mon

						Leaving
					gases

Rice. 5.2. Technological scheme of the boiler plant for the production of water vapor: 1 - fuel bunker; 2 - mill for grinding fuel; 3 - burner; 4 - boiler unit; 5 - combustion chamber; 6 - ash and slag removal device; 7 - screen pipes; 8 - superheater; 9 - boiler drum; 10 - lower screen collectors; 11 - economizer; 12 - air heater; 13 - air intake box; 14 - fan; 15 - ash catcher; 16 - hydraulic ash removal device; 17 - smoke exhauster; 18 - chimney; 19 - deaerator; VPU - water treatment plant; PN - feed pump

One of the main tasks for the safe operation of boiler plants is the organization of a rational water regime, in which scale does not form on the walls of the evaporative heating surfaces, their corrosion is absent and the high quality of the generated steam is ensured. The steam generated in the boiler plant is returned from the consumer in a condensed state; in this case, the amount of condensate returned is usually less than the amount of generated steam.

Losses of condensate and water during blowdown are replenished by adding water from any source. This water must be suitably treated before entering the boiler unit. Water that has undergone preliminary treatment is called additional, a mixture of returned condensate and make-up water - nutritional, and the water that circulates in the boiler circuit boiler room.

steam boiler- this is a device that has a system of heating surfaces for obtaining steam from feed water continuously entering it by using the heat released during the combustion of organic fuel. In modern steam boilers, flare combustion of fuel is organized in a chamber furnace, which is a prismatic vertical shaft. The flare combustion method is characterized by the continuous movement of fuel along with air and combustion products in the combustion chamber.

Fuel and the air necessary for its combustion are introduced into the boiler furnace through special devices - burners.

The furnace in the upper part is connected by a horizontal flue with one or two prismatic vertical shafts, called convective shafts according to the main type of heat exchange occurring in them.

In the furnace, horizontal flue and convective shaft there are heating surfaces made in the form of a system of pipes in which the working medium moves.

Depending on the predominant method of transferring heat to heating surfaces, they can be divided into the following types: radiation - heat is transferred mainly by radiation; radiative-convective - heat is transferred by radiation and convection in approximately equal amounts; convective - heat is transferred mainly by convection.

In the combustion chamber, along the entire perimeter and along the entire height, there are pipe flat systems - furnace screens, which are radiation heating surfaces.

The heating surface in which water is heated to saturation temperature is called an economizer; steam formation occurs in the steam-generating (evaporative) heating surface, and its overheating occurs in the superheater. The system of tubular elements of the boiler, in which they move

feed water, steam-water mixture and superheated steam form its steam-water path.

Water economizers are designed to cool combustion products and heat feed water before it enters the evaporator part of the boiler unit. Pre-heating of water due to the heat of flue gases significantly increases the efficiency of the boiler unit. Depending on the material used, economizers are divided into cast iron and steel, according to the type of surface - into ribbed and smooth-tube ones, according to the degree of water heating - into non-boiling and boiling ones.

The superheater is a coiled heat exchange surface designed to superheat the steam produced in the evaporative part of the boiler unit. Steam moves inside the tubes, which are washed from the outside by flue gases.

To continuously remove heat and ensure the required temperature regime of the metal of the heating surfaces, a continuous movement of the working medium is organized. In this case, water in the economizer and steam in the superheater can pass once or repeatedly.

In the first case, the boiler is called a direct-flow boiler, and in the second - a scrap boiler with multiple circulation.

The steam-water system of a once-through boiler is a hydraulic system, in all elements of which the working medium moves under pressure created by the feed pump. In once-through boilers, there is no clear fixation of the economizer, steam generating and superheating zones.

In boilers with multiple circulation (Fig. 5.2), there is a closed circuit formed by a system of heated and unheated pipes, united at the top by a drum, and at the bottom by a collector. The collector is a pipe muffled from the ends, into which screen pipes are welded along the length. The drum is a cylindrical horizontal vessel having water and steam volumes, which are separated by a surface called evaporation mirror. In the drum, the resulting steam is separated and enters the superheater.

Wet saturated steam produced in the drum of low and medium pressure boilers can carry away drops of boiler water containing salts dissolved in it. In high and ultra-high pressure boilers, steam pollution is also caused by additional entrainment of silicic acid salts and sodium compounds, which are dispersed

are made in pairs. Impurities carried away with steam are deposited in the superheater, which is extremely undesirable, since it can lead to burnout of the superheater pipes. Therefore, steam is separated before leaving the boiler drum, during which drops of boiler water are separated and remain in the drum. Steam separation is carried out in special separating devices, in which conditions are created for natural or mechanical separation of water and steam.

Natural separation occurs due to the large difference in the densities of water and steam. The mechanical inertial separation principle is based on the difference in the inertial properties of water droplets and steam with a sharp increase in speed and a simultaneous change in direction or swirl of the wet steam flow.

In natural circulation boilers, the feed water supplied by the pump is heated in the economizer and enters the drum. From the drum, through the downcomer unheated pipes, water enters the lower collectors of the screens, from where it is distributed into the heated screen pipes, in which it boils. Circulation occurs due to the difference in densities of the steam-water mixture in the screen pipes and water in the culvert pipes.

In boilers with multiple forced circulation, a circulation pump is additionally installed to improve circulation, which allows the steam-water mixture to move along inclined and horizontal pipes.

The temperature in the furnace in the combustion zone of the torch reaches 1400-1600 °C. The walls of the combustion chamber are made of refractory material, their outer part is covered with thermal insulation. Partially cooled in the furnace, the combustion products with a temperature of 900-1200 ° C enter the horizontal flue of the boiler, where the superheater is washed, and then sent to the convective shaft, which houses the intermediate superheater, water economizer and the latter along the gas flow along - heating surface - an air heater in which the air is heated before being fed into the boiler furnace. Hot air directed to the boiler furnace improves the conditions for fuel combustion, reduces heat losses from chemical and mechanical incompleteness of fuel combustion, increases its combustion temperature, intensifies heat transfer, which ultimately increases the efficiency of the installation. On average, every 20–25 °C decrease in flue gas temperature increases the efficiency by approximately 1%.

Combustion products behind the air heater are called flue gases; they have a temperature of 110-160 °C. Since further utilization of heat is unprofitable, the exhaust gases are removed into the chimney using a smoke exhauster through an ash catcher.

The quality of the feed water is of great importance for the reliable operation of the boiler. Despite the desalination and deaeration of water (removal of corrosive gases from water O 2 and SO 2) at the water treatment plant, a certain amount of dissolved salts and suspended particles are continuously fed into the boiler with feed water. A very small part of the salts is carried away by the generated steam. In boilers with multiple circulation, the main amount of salts and solid particles is retained in the boiler, due to which their content in the boiler water gradually increases. When water boils in a boiler, salts fall out of solution, and scale forms on the inner surface of the screen pipes, which poorly conducts heat. As a result, the screens are not sufficiently cooled by the medium moving in them and can collapse under the action of internal pressure. Therefore, part of the water with a high salt concentration must be removed from the boiler. Feed water with a lower concentration of impurities is supplied to replenish the removed amount of water. This process of replacing water in a closed circuit is called continuous purge. Continuous blowing is carried out from the boiler drum.

In once-through boilers, due to the absence of a drum, continuous blowing is difficult, therefore, increased requirements are placed on the quality of the feed water of these boilers.

A boiler plant is a device consisting of one or more boilers and auxiliary equipment.

Auxiliary equipment is designed to ensure the normal operation of the boilers and includes:

devices for receiving, storing fuel and preparing it for combustion and supply to boilers, usually called a fuel economy;

· draft installations for supplying air to boilers, ensuring the movement of gases in boilers and boiler rooms and removing gases into the atmosphere;

devices for removing ash and slag;

· devices for cleaning gases from ash and other harmful impurities in order to protect the environment from pollution;

· water treatment plants for water purification from substances that cause scale formation, steam pollution and metal corrosion;

installations for the formation of hot network water;

installations for collecting, pumping condensate and feeding steam boilers with water;

pipelines for various purposes;

· devices of safety automatics, automatic regulation, control, signaling and control of technological processes;

· electrical equipment, plumbing, sewerage, ventilation and other systems.

On fig. 3 shows a technological scheme of a boiler house with two steam boilers operating on fuel oil. Fuel oil is taken from tank 1 and supplied by pump 2 to the burners of boilers 6. Air is supplied to the combustion of fuel oil by blow fans 7.

Fig.3. Scheme of the device and operation of the boiler plant:

1 - fuel storage; 2 - fuel pump; 3 - chimney; 4 - smoke exhausters; 5 - water economizers; 6 - steam boilers; 7 - blow fans; 8 - feed pumps; 9 - deaerator; 10 - water heater; 11 - steam pipeline; 12 - water treatment plant.

Combustion products are sucked out of the boilers by smoke exhausters 4, they are forced into the chimney 3, through it they enter the atmosphere and are dispersed in it.

Steam from the boilers through the steam pipeline 11 is supplied to external consumers and to the water heater 10. In the heater, the steam heats the network water for heating and hot water supply systems.

Condensate from the water heater and steam consumers enters the deaerator 9. Here the condensate is boiled to remove corrosive gases (oxygen and carbon dioxide).

Losses of steam, condensate and water in the boiler house and in heating networks are replenished with raw water. Since the water contains various impurities that contaminate the heating surfaces with scale and sludge, the water is initially purified from solid impurities (clarified, softened) in the water treatment plant 12. Corrosive gases (oxygen and carbon dioxide) are removed from the water in the deaerator 10.

A boiler house operating on solid fuel (for example, coal) has a similar technological scheme. In such cases, the boiler room is equipped with a fuel storage and devices for supplying coal to the boilers. Slag and ash are removed outside the boiler house by various mechanical devices, such as scraper buckets and scraper conveyors. To protect the OPS from ash, combustion products are cleaned in ash collectors.

Depending on the purpose and nature of the connection of consumers, SNiP II-35-76 "Boiler plants" subdivides boiler rooms into the following types:

heating - to provide heat for heating, ventilation and hot water supply systems of residential and public buildings;

· industrial - for process heat supply of industrial enterprises.

· heating and production - to provide heat to heating, ventilation, hot water and process heat supply systems.

In addition, according to the type of installed boilers, boiler houses are divided into steam, water heating and steam water heating.

According to the heat supply scheme, boiler houses are divided into boiler houses operating on a closed heat supply system (all water supplied to the heating networks is returned back to the boiler room) and boiler houses operating on an open heat supply system (part of the hot water remains with the consumer).

By capacity, boiler houses are conditionally divided into low-power boiler houses (up to 20 MW), medium-power boiler houses (from 20 to 100 MW) and large boiler houses (from 100 to 600 MW). At the objects of the Moscow Region, boiler houses of small and medium power are mainly used.

1.1 Selecting the type of heat transfer fluid

2. Selection and justification of the heat supply system and its composition

3. Construction of graphs of changes in the supply of heat. Annual supply of reference fuel.

4. Choice of control method. Calculation of the temperature graph

4.1 Choice of the heat supply control method

4.2 Calculation of water temperatures in heating systems with dependent connection

4.2.1 Water temperature in the supply line of the heating network, ° С

4.2.2 Water temperature at the outlet of the heating system

4.2.3 Water temperature after mixing device (elevator)

4.3 Adjustment of the hot water system

4.4 Calculation of water flow from the heating network for ventilation and water temperature after ventilation systems

4.5 Determining the consumption of network water in the supply and return pipelines of the water heating network

4.5.1 Water flow in the heating system

4.5.2 Water flow in the ventilation system

4.5.3 Water consumption in the DHW system.

4.5.4 Weighted average temperature in the return line of the heating network.

5. Construction of graphs of network water consumption by facilities and in total

6. The choice of type and method of laying a heating network

7. Hydraulic calculation of the heat network. Building a piezometric graph

7.1. Hydraulic calculation of the water heating network

7.2 Hydraulic calculation of branched heat networks

7.2.1 Calculation of the section of the main highway I - TK

7.2.2 Calculation of branch TC - Zh1.

7.2.3 Calculation of throttle washers on the branches of the heating network

7.3 Building a piezometric graph

7.4 Pump selection

7.4.1 Selecting the mains pump

7.4.2 Selecting a make-up pump

8. Thermal calculation of thermal networks. Calculation of the thickness of the insulating layer

8.1 Basic network settings

8.2 Calculation of the thickness of the insulating layer

8.3 Calculation of heat losses

9. Thermal and hydraulic calculations of the steam pipeline

9.1 Hydraulic calculation of the steam pipeline

9.2 Calculation of the thickness of the insulating layer of the steam pipeline

10. Calculation of the thermal scheme of the heat supply source. Choice of main and auxiliary equipment.

10.1 Table of initial data

11. Choice of main equipment

11.1 Selection of steam boilers

11.2 Selection of deaerators

11.3 Selection of feed pumps

12. Thermal calculation of network water heaters

12.1 Steam heater

12.2 Calculation of the condensate cooler

13. Technical and economic indicators of the heat supply system

Conclusion

Bibliography

introduction

Industrial enterprises and the housing and communal sector consume a huge amount of heat for technological needs, ventilation, heating and hot water supply. Thermal energy in the form of steam and hot water is generated by combined heat and power plants, industrial and district heating boiler houses.

The transfer of enterprises to full cost accounting and self-financing, the planned increase in fuel prices and the transition of many enterprises to two- and three-shift work require a serious restructuring in the design and operation of production and heating boilers.

Production and heating boiler houses must ensure uninterrupted and high-quality heat supply to enterprises and consumers of the housing and communal sector. Increasing the reliability and efficiency of heat supply largely depends on the quality of the boilers and rationally. the designed thermal scheme of the boiler house. Leading design institutes have developed and are improving rational thermal schemes and standard designs for industrial and heating boiler houses.

The purpose of this course project is to gain skills and familiarize with the methods for calculating the heat supply to consumers, in a particular case, the calculation of the heat supply of two residential areas and an industrial enterprise from a heat supply source. The goal was also set to get acquainted with the existing state standards, and building codes and regulations relating to heat supply, familiarization with the typical equipment of heating networks and boiler houses.

In this course project, graphs of changes in the supply of heat to each object will be built, the annual supply of reference fuel for heat supply will be determined. Temperature graphs will be calculated and built, as well as graphs of network water consumption by objects and in total. A hydraulic calculation of heat networks was made, a piezometric graph was built, pumps were selected, a thermal calculation of heat networks was made, and the thickness of the insulating coating was calculated. The flow rate, pressure and temperature of the steam generated at the heat supply source are determined. The main equipment has been selected, the network water heater has been calculated.

The project is educational in nature, therefore, it provides for the calculation of the thermal scheme of the boiler house only in the maximum winter mode. Other modes will also be affected, but indirectly.

1. Choice of the type of heat carriers and their parameters

1.1 Selecting the type of heat transfer fluid

The choice of heat carrier and heat supply system is determined by technical and economic considerations and depends mainly on the type of heat source and the type of heat load.

In our course project, there are three heat supply facilities: an industrial enterprise and 2 residential areas.

Using the recommendations, for heating, ventilation and hot water supply of residential and public buildings, we accept a water heating system. This is because water has a number of advantages over steam, namely:

a) higher efficiency of the heat supply system due to the absence of condensate and steam losses in subscriber installations that occur in steam systems;

b) increased storage capacity of the water system.

For an industrial enterprise, steam is used as a single heat carrier for technological processes, heating, ventilation and hot water supply.

1.2 Selecting the parameters of heat transfer fluids

Process steam parameters are determined according to the requirements of consumers and taking into account pressure and heat losses in heating networks.

Due to the fact that there is no data on hydraulic and heat losses in networks, based on operating and design experience, we accept specific pressure losses and a decrease in coolant temperature due to heat losses in the steam pipeline, respectively

and . To ensure the specified steam parameters at the consumer and to exclude steam condensation in the steam pipeline based on the accepted losses, the steam parameters at the source are determined. In addition, for the operation of the heat exchange equipment of the consumer, it is necessary to create a temperature difference.

Taking into account the above, the steam temperature at the consumer inlet is 0 С:

\u003d 10-15 0 С

According to the saturation pressure of the steam at the received steam temperature at the consumer

is .

The steam pressure at the source outlet, taking into account the accepted hydraulic losses, will be, MPa:

, (1.1) - the length of the network from the source to the industrial enterprise, m. MPa

Steam saturation temperature at pressure

MPa is 147.5 0 С. The steam temperature required to compensate for the accepted heat losses will be, 0 С: , (1.2)

where 0 C

So finally accepted

0 С, MPa.

In the heat supply system, water is used as a heat carrier to meet the loads of heating, ventilation and hot water supply. The choice is due to the fact that in residential and public buildings in district heating systems, in order to comply with sanitary standards, it is necessary to take water as a heat carrier. The use for enterprises as a heat carrier of steam for technological processes, heating, ventilation and hot water supply is allowed with a feasibility study. In view of the lack of data for conducting a feasibility study, and the absence of the need for this (not provided for by the assignment), hot water is finally accepted as a coolant for heating, ventilation and hot water supply in residential areas and industrial enterprises.

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

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

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 along 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 use of their heat, 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 found in industrial enterprises and provide heat for heating and ventilation systems, hot water supply of buildings and technological production processes. Heating boilers solve the same problems, but serve residential and public buildings. They are divided into separate, interlocked, i.e. adjacent to other buildings, and built into buildings. Recently, 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.

2. 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 obtained, 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 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. They are equipped with both steam and hot water boilers of greater 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.

Rice. one.

Rice. 2.

Rice. 3.

Rice. 4.

It is customary to conditionally show individual elements of the boiler plant circuit diagram in the form of rectangles, circles, etc. and connect them with each other with lines (solid, dotted) denoting a pipeline, steam pipelines, etc. There are significant differences in the schematic diagrams of steam and hot water boiler plants. A steam boiler plant (Fig. 4, a) of two steam boilers 1, equipped with individual water 4 and air 5 economizers, includes a group ash catcher 11, to which the flue gases are supplied along the collecting hog 12. To suck the flue gases in the area between the ash catcher 11 and smoke exhausters 7 with electric motors 8 are installed in the chimney 9. Gates (flaps) 10 are installed for the operation of the boiler room without smoke exhausters.

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

In the event that part of the condensate is lost at the consumer, a mixture of condensate and additional water is supplied from the condensate tank by pumps 13 through the supply pipeline 2, first to the economizer 4, and then to the boiler 1. The air necessary for combustion is sucked in by centrifugal draft fans 6 partially from the room boiler room, partly from the outside and through air ducts 3 is supplied first to the air heaters 5, and then to the furnaces of the boilers.

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

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

On fig. 6 shows a diagram of a boiler unit with a steam boiler having an upper drum 12. A furnace 3 is located in the lower part of the boiler. Nozzles or burners 4 are used to burn liquid or gaseous fuel, through which fuel is supplied to the furnace along with air. The boiler is limited by brick walls - brickwork 7.

When fuel is burned, the released heat heats the water to a boil in tube screens 2 installed on the inner surface of the furnace 3, and ensures its conversion into water vapor.

Fig 6.

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

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

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

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

The air necessary for fuel combustion is taken, as a rule, from the top of the boiler room and is supplied by the fan 18 to the air heater 6, where it is heated and then sent to the furnace. In boiler houses of small capacity, air heaters are usually absent, and cold air is supplied to the furnace either by a fan or due to rarefaction in the furnace created by a chimney. Boiler plants are equipped with water treatment devices (not shown in the diagram), instrumentation and appropriate automation equipment, which ensures their uninterrupted and reliable operation.

Rice. 7.

For the correct installation of all elements of the boiler room, a wiring diagram is used, an example of which is shown in fig. 9.

Rice. 9.

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

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

A hot water boiler house has one heat carrier - water, in contrast to a steam boiler house, which has two heat carriers - water and steam. In this regard, in the steam boiler house it is necessary to have separate pipelines for steam and water, as well as tanks for collecting condensate. However, this does not mean that the schemes of hot water boilers are simpler than steam ones. Water-heating and steam boiler plants vary in complexity depending on the type of fuel used, the design of boilers, furnaces, etc. Both a steam and a water-heating boiler plant usually include several boiler units, but not less than two and not more than four to five . All of them are interconnected by common communications - pipelines, gas pipelines, etc.

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

3. Classification of boiler units

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

Boilers with natural circulation;

Boilers with forced movement of 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 natural circulation steam boilers are made from vertical pipes located between two collectors (upper and lower drums). Their device is shown in the drawing in fig. 10, a photograph of the upper and lower drum with pipes connecting them - in fig. 11, and placement in the boiler room - in fig. 12. One part of the pipes, called heated "lifting pipes", is heated by a torch and combustion products of fuel, 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.

Rice. 10.

Rice. eleven.

Rice. 12.

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

In 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, that is, 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.

Rice. thirteen.

Rice. 14.

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.

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

Rice. 15.

Rice. sixteen. Examples of placement of household boilers and other equipment

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 heating systems of a building with hot water or steam. 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.

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 necessary 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 along the gas ducts and in contact with the heating surface, transfer heat to the water.

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. Recently, 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).

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.

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, mounted) 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. Indeed, 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 there are no such problems in Western countries, 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 implemented 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 implemented 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. 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 limiting 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 square meters 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 cheap solid fuel, and then the temperature is automatically 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 hard 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. Thus, this device does not require connection to the 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 the given values of the diameter, operating 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 foregoing, it is worth highlighting the pros and cons of various types of 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, it is not necessary to equip a special place for storing fuel - to 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

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.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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