Blower fan

productivity - 1000 m / h;

head - 120 m. Art .;

motor power 7.0 kW

number of revolutions - 1000 rpm;

voltage 380 V.

Oil-gas burners

Fuel oil productivity - 9000 kg / h at Pmaz = 18 - 20 atm.

The burner has a peripheral gas supply and a mechanical fuel oil atomizer; the nozzles are cooled by air from the blowing fans during operation. Inoperative injectors must be removed.

To clean the convective heating surface of the boiler from aeolian deposits, blowing with network water is provided.

Quality network water entering the boiler must comply with the following standards:

A) carbonate hardness should not exceed 4000 meq / kg;

C) free carbon dioxide should be absent.

Boiler combustion chamber

The boiler combustion chamber is designed for burning high-calorific fuel oil and natural gas. The dimensions of the combustion chamber are 6.23 x 6.28 sq. M, the height of the prismatic part is 5.3 m. The walls are completely shielded with pipes  60 x 3.5 with a pitch of 64 mm. The sloping parts of the cold funnel of the furnace are covered with fireclay. The burner embrasures are made of studded tubular rings included in the boiler circulation, covered with chromite mass. The embrasures of burners No. 3, 4, 13, 14 are inclined by 15 0, the rest by 10 0, all screen pipes are interconnected horizontal belts stiffness with a height step of 2.8 m.

The volume of the combustion chamber is 245 m 3, the radiation surface of the screens is 224 m 2. When washing, the flushing water is discharged through the hydraulic locks of the sludge chest of drawers into the sour water sump.

Convective part

The convective section consists of 96 sections. Each section consists of “u-shaped” coils made of pipes 28x3 mm, welded into the risers 88x3.5 mm. The coils are staggered with a pitch of 64 mm and 38 mm. In the course of gases, the convective part is divided into 2 packages, the distance between which is 60 mm. The heating surface of the convective part is 2960 m 2.

Boiler rinsing

To clean the convective part of the boiler from ash deposits, it is rinsed with network water. Washing is carried out by supplying heating water through nozzles fixed on pipes located in the gas box above the convection part.

Boiler safety valves

Safety valves are installed at the outlet of the boiler mains pipeline:

The safety valve is “adjusted to P = 16m / cm2, No. 2 to P = 16; No. 3, No. 4 is the same.

Protection of PVK 1-2-3-4 when boilers are operating on fuel oil.

To ensure reliable and uninterrupted operation of the boiler, the following PVC protection is provided, which acts on the boiler shutdown for fuel:

When the water pressure behind the boiler rises above 16 ata.

When the water pressure behind the boiler drops below 8.0 ata

With a decrease in water consumption through the boiler:

at peak conditions below 1750t / h;

When the water temperature behind the boiler rises above 1550C

With a decrease in pressure, fuel oil to P = 10 ata

When the torch goes out in the furnace for 3 sec.

Technological interlocks PVK 1-2-3-4

1. The gate valve on the common fuel oil pipeline to the boiler, the gate valve on the return of fuel oil from the boiler can be opened only if:

the presence of a certain water flow through the boiler at least 1700 t / h, for which it is necessary to open the valves 1640, 1641 and adjust the flow by the valve 1642 at least 1700 t / h;

turning on the key of the protection circuits to the "on" position;

pressure in the fuel oil pipeline is not less than 10 ata;

turning on the fans of the pilot burners for ventilation of the furnace at least 2 - in this combination: 5 and 12 or 6 and 11, or all of the above four fans.

2. Gate valve No. 1640 on the water pipeline to the boiler can be closed only after closing the gate valve on the common fuel oil pipeline to the boiler and returning fuel oil from the boiler.

3. Fuel supply to the pilot burners is possible only after turning on the keys, ignition devices in the "on" position and turning off the fans of the pilot burners.

4. When closing the valve no. 1640 before the boiler, the valve no. 1641 after the boiler is automatically closed.

PVC management

In addition to the burners, the following are controlled from the heat shield:

valves on the water supply to the boiler 31640

gate valves on the water outlet from the boiler No. 1641

gate valve of the bypass line of network water No. 1642

gate valve on the fuel oil inlet and outlet from the boiler

valve on the gas supply to the ignition devices.

The shield is installed:

fuel type switches 1pt 2pt

protection switch ZPT (for gas and fuel oil)

key for testing signaling and protection of OZ

KS signal pickup key.

Process signaling

On the light board of the switchboard, there are signals of operation of any of the boiler protections, as well as signals for disconnecting protection circuits, lowering the temperature of fuel oil to the boiler and malfunctions on assemblies of valves No. 1640 and No. 1641. The signal is removed with the KS key. The light board will go out only after the malfunction is eliminated. The signaling is tested with the KS key. In this case, the call and the entire display are tested simultaneously.

Alarm

The alarm provides for a light and sound signaling of emergency shutdown of fans, burners, and, in addition, for automated burners (No. 7, 8, 9, 10) - light and sound signaling of a discrepancy between the position of shut-off valves and fans of the corresponding burners. Moreover, the circuit for fans, automated burners provides for signaling their emergency shutdown. The light signaling for all automated burners is provided by the signal lamps.

Technological control

The following devices are displayed on the heat shield:

Measurement and registration of the temperature of the heating water before and after the boiler and flue gases.

Control of ignition devices of ignition burners.

Fuel oil temperature measurement

Measurement of water pressure before and after the boiler, fuel oil.

Vacuuming in the furnace behind the boilers.

Registration of water consumption through the boiler.

Name of quantity

Dimension

Peak mode

Basic Mode

Fuel consumption

kgm 3 / hour

Boiler inlet water temperature

Boiler outlet water temperature

Outdoor temperature

Boiler efficiency

Apparent thermal stress of the furnace volume

Kcal / m 3 / hour

Gas temperature at the outlet of the furnace

Gas temperature behind the lower packages of the convective part

Flue gas temperature

Water volume together with pipelines within the boiler room

A boiler plant (boiler room) is a structure in which the working fluid (heat carrier) (usually water) is heated for the heating or steam supply system, located in one technical room... Boiler rooms are connected to consumers using heating mains and / or steam pipelines. The main device of the boiler room is a steam, fire tube and / or hot water boilers. Boiler houses are used for centralized heat and steam supply or for local heating 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 couple or hot water... Its main elements are a cauldron, combustion device(firebox), feeding and draft devices. In general, a boiler plant is a combination of a boiler (s) and equipment, including the following devices: fuel supply and combustion; purification, chemical preparation and deaeration of water; heat exchangers for various purposes; initial (raw) water pumps, network or circulation - for circulation of water in the heat supply system, make-up - to replace water consumed by the consumer and leaks in networks, feed pumps for supplying water to steam boilers, recirculation (mixing); feed tanks, condensation tanks, hot water storage tanks; blowing fans and air duct; smoke exhausters, gas duct and chimney; ventilation devices; systems automatic regulation and safety of fuel combustion; heat shield or control panel.

The boiler is heat exchanger, in which the heat from the hot combustion products of the fuel is transferred to the water. As a result, in steam boilers, water turns into steam, and in hot water boilers it is heated to the required temperature.

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

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

The draft device consists of blowing fans, a system of gas ducts, smoke exhausters and a chimney, with the help of which the supply the required amount air into the furnace and the movement of combustion products through the boiler gas ducts, 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 systems are equipped with auxiliary elements: a water economizer and an air heater, serving respectively for heating water and air; devices for fuel supply and ash removal, for cleaning flue gas and feed water; thermal control devices and automation equipment that ensure normal and smooth operation all links of the boiler room.

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

Power boiler houses supply steam steam power plants generating electricity, and are usually part of a power plant complex. Heating and industrial boilers are located on industrial enterprises and provide heat to the heating and ventilation systems, hot water supply of buildings and technological processes production. Heating boiler houses solve the same problems, but serve residential and public buildings... They are divided into free-standing, interlocked, i.e. adjacent to other buildings, and embedded in buildings. Recently, more and more freestanding enlarged boiler houses are being built with the expectation of servicing a group of buildings, a residential quarter, a microdistrict.

The device of boiler houses built into residential and public buildings is currently allowed only with appropriate justification and agreement with the sanitary supervision authorities.

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

2. Classification of boiler plants

Boiler plants, depending on the nature of the consumers, are divided into energy, production-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 generate steam for steam turbines in thermal power plants. Such boiler rooms are equipped, as a rule, with large and average power, which generate steam of increased parameters.

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

Heating boiler installations (mainly hot water, but they can also be steam) are designed to service heating systems of 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 to a temperature of no more than 115 ° C or steam boilers with an operating pressure of up to 70 kPa. Such boiler rooms are designed to supply heat to one or more buildings.

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

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

Rice. 1.

Rice. 2.

Rice. 3.

Rice. 4.

Individual elements It is customary to conventionally show the schematic diagram of a boiler plant in the form of rectangles, circles, etc. and connect them to each other with lines (solid, dotted), denoting a pipeline, steam pipelines, etc. B schematic diagrams steam and hot water boiler plants, there are significant differences. 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 collector 11, to which flue gases suitable for collecting hog 12. For exhausting flue gases in the area between the ash catcher 11 and the chimney 9 installed smoke exhausters 7 with electric motors 8. For the boiler room without smoke exhausters installed dampers (dampers) 10.

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

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

The hot water boiler plant (Fig. 4, b) consists of two hot water boilers 1, one group water economizer 5 serving both boilers. The flue gases at the outlet of the economizer through the common collecting hog 3 are fed 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 into the boilers. Water in a closed loop (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

In fig. 6 shows a diagram of a boiler unit with a steam boiler having an upper drum 12. In the lower part of the boiler there is a furnace 3. For combustion of liquid or gaseous fuel, nozzles or burners 4 are used, through which the fuel, together with air, is fed into the furnace. Boiler limited brick walls- brickwork 7.

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

Fig. 6.

Flue gases from the furnace enter the boiler gas ducts formed by the lining and special partitions installed in the bundles of pipes. When moving, the gases wash around 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 through the chimney 19 into the atmosphere by means of the smoke exhauster 17. Flue gases from the boiler can be discharged even without a smoke exhauster due to the natural draft generated by the chimney.

Water from the water supply source through the feed 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 a water indicator glass installed on the drum. In this case, the water evaporates, and the resulting steam is collected in the upper part of the upper drum 12. Then the steam enters the superheater 11, where 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 in the form of hot water (condensate) returns back to the boiler room.

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

The air required for fuel combustion is taken, as a rule, from the top of the boiler room and supplied by the fan 18 to the air heater 6, where it is heated and then sent to the furnace. In boilers of small capacity, air heaters are usually absent, and cold air is supplied to the furnace either by a fan or by vacuum in the furnace created by the 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 correct installation all elements of the boiler room use wiring diagram, an example of which is shown in Fig. nine.

Rice. nine.

Hot water boilers 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, a steam boiler room must have separate pipelines for steam and water, as well as tanks for collecting condensate. However, this does not mean that the schemes of hot water boiler houses are simpler than steam ones. Hot water and steam boilers are different in terms of the complexity of the device depending on the type of fuel used, the design of boilers, furnaces, etc. ... All of them are connected by common communications - pipelines, gas pipelines, etc.

Boiler device less power shown below in paragraph 4 of this topic. In order to better understand the structure and principles of operation of boilers of different power, it is advisable to compare the device of these less powerful boilers with the device of the boilers described above with a higher power, and find in them the main elements that perform the same functions, and also understand the main reasons for the differences in designs.

3. Classification of boiler units

Boilers like technical devices for the production of steam or hot water are distinguished by a variety of design forms, operating principles, used fuels 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:

Natural circulation boilers;

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

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

Modern steam boilers with natural circulation 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 drums with pipes connecting them is shown in Fig. 11, and placement in the boiler room is shown in Fig. 12. One part of the pipes, called heated "riser pipes", is heated by the torch and the combustion products, while the other, usually unheated part of the pipes, is located outside the boiler unit and is called "downpipes". In the heated riser pipes, the water is heated to a boil, partially evaporates and in the form of a steam-water mixture enters the boiler drum, where it is separated into steam and water. Water from the upper drum enters the lower collector (drum) through the lowering unheated pipes.

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. ten.

Rice. eleven.

Rice. 12.

In steam boilers with multiple forced circulation heating surfaces are made in the form of coils forming 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 rate is one, i.e. feed water being heated, it successively turns into a steam-water mixture, saturated and superheated steam.

In hot water boilers, when moving along the circulation circuit, water heats up in one revolution from the initial to the final temperature.

According to the type of heat carrier, boilers are divided into hot water and steam boilers. The main indicators of a hot water boiler are thermal power, that is, heating capacity, and water temperature; main indicators steam boiler- steam capacity, pressure and temperature.

Hot water boilers, the purpose of which is to obtain hot water given parameters, are used for heat supply of heating and ventilation systems, household and technological consumers. Hot water boilers, which usually work according to the direct-flow principle with a constant water flow, are installed not only at CHPPs, but also in district heating, as well as heating and industrial boilers as the main source of heat supply.

Rice. 13.

Rice. fourteen.

According to the relative movement of heat exchanging 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 outside. In Russia in the 20th century, Shukhov's water-tube boilers were mainly used. In a fire-tube, 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 with forced circulation. The latter are subdivided into direct-flow and multiple-forced circulation.

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

Rice. 15.

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

A steam boiler is a device that is used in everyday life and industry. It is designed to convert water to steam. The resulting steam is then used to heat housing or to rotate turbomachines. What kind of steam engines are there and where are they most in demand?

Steam boiler is a unit for generating steam. In this case, the device can give 2 types of steam: saturated and superheated. Saturated steam has a temperature of 100ºC and a pressure of 100 kPa. Superheated steam is characterized by high temperature (up to 500ºC) and high pressure (more than 26 MPa).

Note: Saturated steam is used in heating private houses, while superheated steam is used in industry and energy. It tolerates heat better, so use superheated steam increases the efficiency of the installation.

Where are steam boilers used:

1. In the heating system, steam is an energy carrier.
2. In power engineering, industrial steam engines (steam generators) are used to generate electricity.
3. In industry, superheated steam can be used to convert it into mechanical motion and move vehicles.

Steam boilers: scope

Household steam devices are used as a heat source for heating a house. They heat the container with water and drive the generated steam into the heating pipes. Often such a system is equipped with a stationary coal furnace or boiler. Usually, Appliances for heating with steam, only saturated, unheated steam is created.

For industrial applications the steam is superheated. It continues to be heated after evaporation to raise the temperature even more. Such installations require high-quality performance in order to prevent the explosion of the steam container.

Superheated steam from the boiler can be consumed in the formation of electricity or mechanical movement. How does this happen? After evaporation, the vapor enters the steam turbine... Here the steam turns the shaft. This rotation is further processed into electricity. This is how electrical energy is obtained in the turbines of power plants - when the shaft of the turbomachines rotates, an electric current is generated.

Besides education electric current, the rotation of the shaft can be transmitted directly to the engine and to the wheels. As a result, steam transport starts to move. Famous example steam engine- steam locomotive. When burning coal, water was heated in it, saturated steam, which rotated the shaft of the engine and wheels.

The principle of operation of a steam boiler

The source of heat for heating water in a steam boiler can be any type of energy: solar, geothermal, electric, heat from the combustion of solid fuel or gas. The resulting steam is a heat carrier, it transfers the heat of combustion of the fuel to the place of its application.

V various designs steam boilers used general scheme heating water and turning it into steam:

• Water is purified and supplied to the reservoir using an electric pump. Typically, the reservoir is located at the top of the boiler.
• From the reservoir through pipes, water flows down into the collector.
• From the collector, water rises up again through the heating zone (fuel combustion).
• Steam is generated inside the water pipe, which rises upward due to the pressure difference between liquid and gas.
• At the top, steam passes through the separator. Here it is separated from the water, the remains of which are returned to the reservoir. Then the steam enters the steam line.
• If this is not a simple steam boiler, but a steam generator, then its pipes pass through the combustion and heating zone for the second time.

Steam boiler device

A steam boiler is a container within which heated water evaporates and forms steam. As a rule, this is a pipe of various sizes.

In addition to a pipe with water, the boilers have a combustion chamber (fuel burns in it). The design of the furnace is determined by the type of fuel for which the boiler is designed. If it is hard coal, firewood, then there is a grate at the bottom of the combustion chamber. Coal and firewood are placed on it. From below, air passes through the grate into the combustion chamber. For effective traction (air movement and fuel combustion), the furnaces are arranged at the top.

If the energy carrier is liquid or gaseous (fuel oil, gas), then a burner is introduced into the combustion chamber. For air movement, inlet and outlet are also made ( grate and chimney).

Hot gas from fuel combustion rises to a container with water. It heats up the water and comes out through the chimney. The water heated to the boiling point begins to evaporate. The steam rises up and enters the pipes. This is how it goes natural circulation steam in the system.

Steam boiler classification

Steam boilers are classified according to several criteria. By the type of fuel they run on:

• gas;
• coal;
• fuel oil;
• electrical.

By destination:

• household;
• industrial;
• energy;
• recycling.

By design features:

• gas-tube;
• water tube.

Let's look at the difference between the design of gas-tube and water-tube machines.

Gas and water tube boilers: differences

The steam generation vessel is often a pipe or multiple pipes. The water in the pipes is heated by the hot gases generated during the combustion of the fuel. Devices in which gases rise to pipes with water are called gas-tube boilers. The diagram of the gas-tube unit is shown in the figure.

Diagram of a gas-tube boiler: 1- fuel and water supply, 2 - combustion chamber, 3 and 4 - smoke tubes with hot gas that comes out further through the chimney (positions 13 and 14 - chimney), 5 - grate between the pipes, 6 - water inlet , the outlet is designated by number 11 - its outlet, in addition, at the outlet there is a device for measuring the amount of water (designated by number 12), 7 - steam outlet, the zone of its formation is designated by number 10, 8 - steam separator, 9 - outside surface a container in which water circulates.

There are other designs in which gas moves through a pipe inside a container with water. In such devices, water containers are called drums, and the devices themselves are called water-tube steam boilers. Depending on the location of the drums with water, water tube boilers are classified into horizontal, vertical, radial, as well as combinations of different pipe directions. A diagram of the movement of water through a water-tube boiler is shown in the figure.

Diagram of a water tube boiler: 1 - fuel supply, 2 - furnace, 3 - pipes for water movement; the direction of its movement is indicated by the numbers 5, 6 and 7, the water entry point - 13, the water exit point - 11 and the drain point - 12, 4 - the zone where water begins to turn into steam, 19 - the zone where there is both steam and water , 18 - steam zone, 8 - partitions that direct the movement of water, 9 - chimney and 10 - chimney, 14 - steam outlet through separator 15, 16 - outer surface of the water tank (drum).

Gas and water tube boilers: comparison

To compare gas and water tube boilers, we will give some facts:

1. The size of pipes for water and steam: for gas-tube boilers, the pipes are larger, for water-tube boilers, smaller.
2. The power of a gas-tube boiler is limited by a pressure of 1 MPa, and a heat-generating capacity - up to 360 kW. It's connected with large size pipes. They can generate a significant amount of steam and high pressure... Increasing the pressure and the amount of heat generated requires significant wall thickening. The price of such a thick-walled boiler will be unreasonably high and not economically viable.
3. The power of a water-tube boiler is higher than that of a gas-tube boiler. Small diameter pipes are used here. Therefore, the pressure and temperature of the steam can be higher than in gas-tube units.

Note: Water tube boilers are safer, more powerful, produce high fever and allow significant overloads. This gives them an advantage over gas-tube units.

Additional elements of the unit

The design of a steam boiler can include not only a combustion chamber and pipes (drums) for the circulation of water and steam. Additionally, devices are used that increase the efficiency of the system (raise the temperature of the steam, its pressure, quantity):

1. Superheater - increases the steam temperature above + 100ºC. This, in turn, increases the economy and efficiency of the machine. The temperature of the superheated steam can reach 500 ºC (this is how steam boilers work in nuclear power plants). Steam is additionally heated in pipes, into which it enters after evaporation. Moreover, it can have its own combustion chamber or be built into a common steam boiler. Convection and radiation superheaters are structurally distinguished. Radiation structures heat steam 2-3 times more than convection ones.
2. Steam separator - removes moisture from the steam and makes it dry. This increases the efficiency of the device, its efficiency.
3. A steam accumulator is a device that takes steam from the system when there is a lot of it, and adds it to the system when there is not enough of it.
4. Water treatment device - reduces the amount of oxygen dissolved in water (which prevents corrosion), removes minerals dissolved in water (with chemical reagents). These measures prevent the pipes from clogging up with scale, which impairs heat transfer and creates conditions for pipes to burn out.

In addition, there are valves for draining condensate, air heaters, and, of course, a monitoring and control system. It includes a switch and a combustion switch, automatic regulators consumption of water, fuel.

Steam generator: powerful steam engine

A steam generator is a steam boiler that is equipped with several additional devices... Its design includes one or more intermediate superheaters, which increase the power of its work tenfold. Where are powerful steam engines used?

The main application of steam generators is found in nuclear power plants. Here, with the help of steam, the decay energy of an atom is converted into electricity. We describe two methods for heating water and generating steam in a reactor:

1. Water washes the reactor vessel from the outside, while it heats up and cools the reactor. Thus, the formation of steam occurs in a separate circuit (water heats up against the walls of the reactor and transfers heat to the evaporator circuit). In this design, a steam generator is used - it acts as a heat exchanger.
2. The pipes for heating the water run inside the reactor. When pipes are fed into the reactor, it becomes combustion chamber, and the steam is transferred directly to the generator. This design is called a boiling-water reactor. A steam generator is not needed here.

Industrial steam units - powerful machines that provide people with electricity. Household appliances - also work in the service of man. Steam boilers allow you to heat the house and perform various jobs and also give the lion's share electrical energy for metallurgical plants. Steam boilers are the backbone of the industry.

The boiler is one of the constituent parts of any heating system. It is designed to convert the energy of fuel combustion (in the case of gas boiler such fuel is gas) into heat for heating the liquid, which is then supplied to the heating batteries. Internal organization modern gas boilers are subordinated to the solution of the main task - to ensure maximum convenience and safety of use while minimizing mandatory human control.

Before proceeding to detailed description the main components of gas boilers, it is necessary to pay some attention to their classification. Despite the fact that all boilers are arranged in approximately the same way, each type has its own specific features that require specific modifications of the used parts to support. So, boilers are:

• Wall and floor. Wall option more compact and convenient and is usually used in private houses. The advantage of a floor-standing boiler is the possibility of heating large areas due to its much higher power. Therefore, such units are most often installed in production facilities.
• Atmospheric and turbocharged... The principle of operation of an atmospheric boiler is the same as that of a conventional stove: air is taken from the room and discharged into a specially built chimney due to natural draft. In turbocharged models, a built-in fan generates traction, the combustion chamber is completely closed, and air is taken from the street.
• Single-circuit and double-circuit... The device with one circuit is intended only for heating rooms, the task double-circuit boiler- also provide residents with hot water.
• With conventional or modulating burner... The device of boilers with modulating burner assumes automatic adjustment power, due to which significant savings in gas consumption are achieved.
• With electronic or piezoceramic ignition. Electronic ignition is more convenient - the ignition of gas vapors in the combustion chamber occurs without human intervention, while in systems with piezo ignition, it is required to press the corresponding button each time.

The main elements of a gas boiler

As we noted above, the device of a gas boiler is approximately the same for all versions of its design. This means that the main components from which the boilers are assembled are the same:

• Gas-burner... Perforated construction rectangular... Inside it there are nozzles through which gas is supplied to the combustion chamber. The nozzles provide even distribution flame throughout the burner, thus creating conditions for the most efficient heating of the coolant inside the gas boiler.
• Heat exchanger- a metal box with a built-in radiator, inside which there are pipes with a coolant. The energy of the combustion gas heats up the heat exchanger and transfers the heat to the liquid. A single-circuit boiler always has one heat exchanger, a double-circuit boiler can have two of them - primary and secondary.
• Circulation pump... Provides line pressure gas heating with forced circulation. Not present in all models of gas boilers.
• Expansion tank... Serves for temporary removal of the coolant during its intense heating and expansion. Has a capacity sufficient for average conditions. For heating large areas an additional tank is often installed in the system.
• Combustion products removal device... For atmospheric boilers, the outlet must be connected to a separate chimney with natural draft, turbocharged models have a double coaxial pipe for the output of gas waste, the draft in which is created by a built-in fan.
• Automation system... This is a boiler control unit that includes electronic circuit, which sets the operating mode of the system depending on the readings of the connected and built-in sensors.

A specific modification of a gas boiler can add some features to its device. So, for example, for single-circuit unit an external boiler can be used for heating sanitary water, and the device of a double-circuit gas boiler can include a combined heat exchanger, in which the heat carrier is prepared for both circuits.

Now let's look at the main components of gas boilers in more detail.

Gas-burner

Depending on the type of boiler, the burner can be atmospheric or forced draft. Boilers with atmospheric burners cheaper, less noisy, but have little performance. Pressurized burners, especially as part of a floor-standing gas boiler, can provide a capacity of up to several thousand kilowatts.

In addition, burners are subdivided into:

• one-stage;
• two-stage;
• modulated.

The most efficient are modulated burners. They allow you to smoothly adjust the flame height and the degree of heating of the coolant depending on the room temperature and provide significant savings in gas fuel.

Heat exchanger

The main indicator of the quality of the heat exchanger is the material from which it is made.

The most reliable and durable is cast iron. Cast iron heat exchangers can operate for several decades, thereby determining long term service of the whole gas boiler. This material keeps heat well, so it is great for a two-circuit heating system. The disadvantages of cast iron include its fragility and high weight.

Steel heat exchangers do not crack or break from unexpected shocks or sudden temperature changes. But they burn out much faster and are subject to corrosion. In expensive models of gas boilers, heat exchangers made of special grades of steel are used, which, in terms of their durability, are comparable to cast iron. Often, to extend the service life, steel heat exchangers are coated with a layer of copper on the inside, and with a special heat-resistant paint on the outside.

Circulation pump and hydraulic group

The pump parameters are usually selected by the manufacturer, based on the power of the boiler. Therefore, the pump does not have a big impact on the quality of the product as a whole. It is worth paying attention to the material of the pipes through which the coolant and water pass inside the gas boiler (in the case double-circuit unit). It is best if they are made of copper or quality plastic. You can also ask about the manufacturer of the pump - it is good if it is a well-known company such as Grundfos, Jileks, Vortex and others.

Expansion tank

This is an important component gas boilers. The heating system must have an expansion tank, where the excess coolant is discharged when it is heated. The size of this container is calculated using special methods; it can be roughly estimated as 10% of the volume of all liquid in the system. Therefore, when choosing a boiler, it is advisable to know the length of the heating line and the required volume of the tank.

It is important to note that the volume of the expansion tank is calculated only by the amount of coolant for the heating system. Therefore, for both single-circuit and double-circuit boilers, the same expansion tank volume is required.

Automation systems

Built-in automation controls the operation of the boiler in all its modes and includes:

Knowledge of the principles of the gas boiler design will make the process of choosing it simpler and more understandable and will help save money both when buying a heating unit and during its operation.

On modern market the most diverse models of heating boilers are presented. The fundamental difference between different models - the energy carrier that ensures their work. It can be gas, electricity, solid fuel, liquid fuel, or combinations thereof.

However, the device different models very similar, only some specific nuances differ.

The heating boiler is key element heating system. It can also be used to provide hot water in the home. Depending on the functionality, it can be single-loop or double-loop. The former are intended exclusively for heating, the latter for heating and water heating.

Single-circuit and double-circuit heating devices

The device of a single-circuit device includes only a circuit with a coolant, which provides heating of radiators in the heating system. The coolant can be water or antifreeze. To provide hot water supply, you must connect to single-circuit device special boiler.

If you have a double-circuit boiler installed, then you will not need to install and connect an additional boiler. One of them will provide heating of the heating system coolant, and the second - water, which will be supplied to the hot water supply pipeline.

In most cases, as an energy carrier for heating boiler gas is used. The popularity of this type of fuel is associated with its relative availability and low cost. Some models of gas powered equipment are equipped with closed chamber combustion. In this case, the room air will not be used for gas combustion. Such a device allows you to install equipment in any room of the house; you do not need the equipment of a special separate boiler room for this.

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Main and auxiliary elements of the boiler structure

The distribution of fuel can be done through a special manifold, and for safety reasons, the device is equipped with a flame monitoring system. This prevents fire or gas explosion. The design of the heating boiler includes a burner with special rods for heat dissipation. If it comes not about gas equipment, then a firebox or heating element is located in place of the burner, depending on the energy carrier used. The body is equipped with an efficient insulating layer that allows you to use the heat to the maximum advantage.

Necessarily includes the following elements:

• an operation control system, which includes a pressure indicator and distribution taps, which make it possible to evenly distribute the supply of heated coolant both to the radiators closest to the boiler and to the most distant ones;
• firebox, burner or piezo lighter;
• spiral along which the coolant moves;
• ignition transformer;
• main switch.

In addition to control devices and heating elements, device heating equipment includes expansion tank and a circulation pump. The first one is designed to accept a coolant, which will increase in volume after heating. The second ensures the movement of the coolant through the system.

An interesting design for combined devices. For example, if the boiler can operate on gas and diesel, then to change the working fuel, it is enough to replace the head. Combined boilers are appropriate if you plan to refurbish in the future heating system and change the main type of fuel used. In this case, you do not have to perform a hardware replacement.

Modern heating devices equipped with a dashboard that allows you to easily monitor the health of the device. Even boilers for solid fuel can have such panels, including indicators of temperature, pressure, etc.

Thus, the design of modern heating boilers is constantly being improved and becomes more and more functional. Thanks to this, the operation of any boiler model is greatly simplified.