If Vacation home used not just for summer holidays, but for year-round permanent residence, it is worth thinking about installing a private boiler room. A properly designed and installed boiler installation will be able to service all necessary communications: heating systems, hot and cold water, ventilation. In order to prevent errors in equipment installation and correctly calculate technical nuances, a thermal diagram of the boiler room must first be drawn up, indicating the main equipment and materials.

General design provisions

Each step of installing a boiler installation must be thought out, so you should not try to design communications and install equipment yourself; it is better to contact specialists who have extensive experience in installation engineering systems for private cottages. They will give a number of valuable tips, for example, help you choose the most optimal boiler model and determine the location of its installation.

Suppose for a small country house A wall-mounted unit is enough, which can easily be located in the kitchen. Two-story cottage, accordingly, needs a specially designated room, which must be equipped with ventilation, a separate exit and a window. There should be enough space to accommodate the remaining components: pumps, connecting elements, pipes, etc.

The process of designing a boiler room for a private house includes several points:

• preparing a diagram of the boiler room regarding its location inside the house;
• equipment distribution diagram indicating the main technical characteristics;
• specification for materials and equipment used.

In addition to purchasing system components and their installation, as well as graphic work, which should include a schematic diagram, professionals will help with the preparation of the necessary documents.

An example of a schematic diagram of a hot water boiler house: I – boiler; II – water evaporator; III – source water heater; IV – heat engine; V – capacitor; VI – heater (additional); VII – battery tank

More information about the boiler room circuit diagram

A well-drawn graphic drawing must reflect, first of all, all the mechanisms, instruments, apparatus and pipes connecting them. Standard boiler schemes for private houses include a combination of boilers, recirculation, make-up and network pumps, storage and condensation tanks, fuel supply and combustion devices, water deaeration devices, heat exchangers, fans, control panels, heat panels. The choice and location of equipment is influenced by the type of coolant and thermal communications, as well as the quality of the water used.

In the process of drawing up a diagram of a hot water boiler house, it is necessary to ensure compliance with the technical characteristics of the equipment, which must meet the requirements of the selected temperature regime

Heating networks operating on water can be divided into two groups:

• open, in which the liquid is taken from local installations;
• closed, in which the water, having given off heat, returns to the boiler.

An example of a schematic diagram can serve as an example of an open-type hot water boiler house. Installed on the return line circulation pump, which ensures the delivery of water to the boiler and further through the system. The calculated temperature regime of this scheme is 155-70°C. Two types of jumpers (recirculation and bypass) connect the two main lines - supply and return.

Schematic diagram of the boiler room: 1 – network pump; 2 – make-up pump; 3 – make-up water tank; 4 – source water pump; 5 – feed pump; 6 – supply tank; 7 – ejector; 8 – cooler; 9 – vacuum deaerator; 10 – purified water heater; 11 – cleaning filter; 12 – source water heater; 13 – hot water boiler; 14 – recirculation pump; 15 – bypass

Corrosion may occur due to flue gases. metal coatings sulfuric acid or low-temperature origin. To avoid its occurrence, you should control the water temperature. Optimal value at the entrance to the boiler - 60-70˚С. To increase the temperature to the required parameters, it is necessary to install a recirculation pump.

To hot water boilers serve for a long time, properly and economically, you should monitor the constancy of water consumption. The minimum flow rate is set by the equipment manufacturer.

For better work boiler plants use vacuum deaerators. A water jet ejector creates a vacuum, and the released steam is used for deaeration.

Automation of boiler equipment operation

It would be foolish not to take advantage of the features that make it easier to use heating systems. Automation allows you to use a set of programs that control heat flow depending on the daily routine, weather conditions, and also help to provide additional heating separate rooms, for example, a swimming pool or a children's room.

An example of principle automated scheme: automatic operating mode of the boiler room controls the operation of water recirculation circuits, ventilation, water heating, heat exchanger, 2 underfloor heating circuits, 4 building heating circuits

There is a list of user functions that adapt the operation of the equipment depending on the lifestyle of the inhabitants of the house. For example, in addition to the standard software hot water, there is a set of individual solutions that are more convenient and even economical for residents. For this reason, a boiler room automation scheme can be developed with the choice of one of the popular modes.

Good night program

It has been proven that the optimal night air temperature in a room should be several degrees lower than the daytime temperature, that is perfect option– while sleeping, lower the temperature in the bedroom by about 4°C. At the same time, a person experiences discomfort when waking up in an unusually cool room, therefore, early in the morning the temperature must be restored. Inconveniences are easily resolved by automatically switching the heating system to night mode and back. The companies DE DIETRICH and BUDERUS are involved in the controllers that regulate the night hours.

Hot water priority system

Automatic flow control hot water is also one of the functions of general equipment automation. It is divided into three types:

• priority, in which the heating system is completely turned off while using hot water;
• mixed, when the boiler power is divided into servicing water heating and heating the house;

non-priority, in which both systems act together, but in the first place is heating the building.

Automated diagram: 1 – hot water boiler; 2 – network pump; 3 – source water pump; 4 – heater; 5 – HVO block; 6 – make-up pump; 7 – deaeration block; 8 – cooler; 9 – heater; 10 – deaerator; 11 – condensate cooler; 12 – recirculation pump

Low temperature operating conditions

The transition to low-temperature programs is becoming the main focus of recent developments by boiler house manufacturers. The advantage of this approach is the economic nuance - reducing fuel consumption. It is the automation that allows you to regulate the temperature, select the right mode and thereby reduce the heating level. All of the above points must be taken into account at the stage of drawing up a thermal diagram of a hot water boiler house.

Principal thermal diagram (PTS) of a boiler room with steam boilers for steam and hot water consumers is shown in Fig. 8.

Steam boiler houses are most often designed to simultaneously supply steam and hot water, therefore their thermal circuits contain installations for heating hot water.

Steam boilers are usually installed low pressure 14 ata, but not higher than 24 ata.

Raw water comes from the water supply with a pressure of 30–40 m of water. Art. If the raw water pressure is insufficient, install raw water pumps 5.

Raw water is heated in a cooler continuous blowing steam boilers 11 and in a steam-water heater of raw water 12 to a temperature of 20-30 ºС. Next, the water passes through a water treatment unit (WPU), and part of it is sent to the chemically purified water heater 13, part passes through the deaerator vapor cooler 4 and enters the deaerator feed water(DPV) 2. Condensate and steam flows from the reduction-cooling unit (ROU) 17 with a pressure of 1.5 atm are also sent to this deaerator to heat the deaerated water to 104 0 C. The deaerated water is supplied to the feed pump (PN) 6 water economizers of the boiler and to the ROU cooler. Part of the steam produced by the boilers is reduced into the ROU and used for heating raw water and deaeration.

Rice. 8. Schematic thermal diagram of a boiler room with steam boilers

1 – steam boiler, 2 – feed water deaerator (FW), 3 – make-up water deaerator, 4 – vapor cooler, 5 – raw water pump, 6 – feed pump (PN), 7 – make-up pump, 8 – network pump (SN ), 9 – condensate pump (KN), 10 – condensate tank, 11 – blow-off water cooler (BWC), 12 – raw water heater, 13 – chemical heater. purified water (PHOV), 14 – make-up water cooler, 15 – condensate cooler, 16 – network water heater, 17 – reduction-cooling unit (RCU), 18 – continuous blowdown separator, 19 – blowdown well, WPU – water treatment unit.

The second part of the chemical flow. purified water is heated in the heater 14, partially in the vapor cooler 4 and sent to the make-up water deaerator for heating networks 3. The water after this deaerator passes through the water-water heat exchanger 14 and heats up the chemical. purified water. The make-up pump 7 supplies water to the pipeline in front of the network pumps 8, which pump network water first through the condensate cooler 15 and then through the network water heater 16, from where the water goes into the heating network.

Makeup water deaerator 3 also uses low pressure steam after the ROU. At closed system heat supply, water consumption to recharge heating networks is usually insignificant. In this case, quite often they do not allocate a separate deaerator for preparing the feed water of heating networks, but use a deaerator for the feed water of steam boilers.

The above diagram provides for the use of heat from continuous blowing of steam boilers. For this purpose, a continuous blowing separator 18 is installed, in which the water is partially evaporated by reducing its pressure from 14 to 1.5 atm. The resulting steam is discharged into the steam space of the deaerator, hot water is sent to the raw water-water heat exchanger 11. The cooled blowdown water is discharged into the blowdown well.

Continuous blowing ensures uniform removal of accumulated dissolved salts from the boiler and is carried out from the place of their highest concentration in the upper drum of the boiler. Periodic blowdown is used to remove sludge deposited in the boiler elements and is carried out from the lower drums and boiler collectors every 12-16 hours. Sometimes provision is made for the supply of blowdown water to feed closed heating networks. Feeding heating networks with blowdown water is allowed only if the total hardness of the heating water does not exceed 0.05 mEq/kg.

The PTS of a boiler room for open heating systems differs from the one shown only in the installation of an additional deaerator for deaeration of the make-up water of heating networks and the installation of storage tanks.

In all cases, condensate from steam-water heaters under the pressure of heating steam should be directed to the DPV, bypassing condensate tanks 10 and pumps 9. In open heat supply systems, deaeration of make-up water is usually installed atmospheric deaerators. The use of boiler blowdown water as make-up water for open systems is not permitted. The temperature of the feed water after the deaerator is 104 °C. The temperature of condensate returned from production is 80–95 °C.

Schematic thermal diagram of a boiler room with hot water boilers for closed heat supply systems

PTS of boiler houses with hot water boilers for closed heat supply systems is shown in Fig. 9.

Water from the return line of heating networks with a low pressure of 20–40 m of water. Art. is supplied to network pumps 2. Water is also supplied there from make-up pumps 5, compensating for leaks in heating networks. Pump 2 is also supplied with hot network water, the heat of which is partially used in heat exchangers for heating the chemicals. purified water 8 and raw water 7.

To ensure the water temperature at the inlet to the boiler, set according to the conditions for preventing corrosion, the required amount of hot water coming out of water heating boilers 1 is supplied to the pipeline behind the network pump 2. Water is supplied recirculation pump 3.

In all operating modes of the heating network, except for the maximum winter one, part of the water from the return line after pumps 2, bypassing the boilers, is supplied through the bypass line in the amount G per into the supply line, where the water, mixing with hot water from the boilers, provides the specified design temperature in the supply main of heating networks.

Chemical additive purified water is heated in heat exchangers 9, 8, 11 and deaerated in deaerator 10. Water for feeding heating networks is taken from tanks 6 by make-up pump 5 and supplied to the return line.

To reduce water consumption for recirculation, its temperature at the outlet of the boilers is usually maintained above the water temperature in the supply line of the heating network. Only at the calculated maximum winter mode The temperature of the water leaving the boilers and in the supply line will be the same.

For closed systems, even in powerful hot water boiler houses, you can get by with one make-up water deaerator with low productivity. The power of make-up pumps 5 and the water pumping equipment are also reduced, and the requirements for the quality of make-up water are reduced compared to open systems.

The disadvantage of closed systems is a slight increase in the cost of equipment for hot water supply subscriber units.

Hot water boilers operate reliably only if the amount of water passing through them is maintained constant. Water flow must be constant, regardless of fluctuations in thermal loads. Therefore, regulation of the supply of thermal energy to the network must be carried out by changing the temperature of the water at the outlet of their boilers G lane

To reduce the intensity of external corrosion of the pipe surfaces of steel water-heating boilers, it is necessary to maintain the temperature of the water at the inlet to the boilers above the dew point temperature of the flue gases.

Minimum permissible temperature at the entrance to the boilers, the following is recommended: when working on natural gas– not lower than 60 °C; when working on low-sulfur fuel oil - not lower than 70 °C; when working on high-sulfur fuel oil - not lower than 110°C. Since the temperature of the return network water is almost always below 60 °C, a recirculation line is provided in the thermal circuits.

To determine the water temperature in heating networks for various design temperatures of the outside air, graphs developed by the thermal power project are constructed. For example, from this graph it is clear that at outdoor temperatures of +3 ºС and above until the end heating season the temperature of direct network water is constant and equal to 70 0 C.

Average hourly consumption per day of heat for hot water supply is usually 20% of the total heating output of the boiler house:

3% – losses of external heating networks;

3% – expenses for own needs from the installed heating capacity of the boiler room;

0.25% – leakage from heating networks of closed systems;

0.25% – the volume of water in the pipes of heating networks.

Rice. 9. Schematic thermal diagram of a boiler room with hot water boilers for a closed heat supply system

1 – hot water boiler, 2 – network pump (SN), 3 – recirculation pump, 4 – raw water pump (RW), 5 – make-up water pump, 6 – make-up water tank, 7 – raw water heater, 8 – chemical heater. purified water (PHW), 9 – make-up water cooler, 10 – deaerator, 11 – vapor cooler, 12 – water treatment unit (WPU).

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

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

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

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

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

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

To ensure more economical operation, modern boiler systems have auxiliary elements: 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 normal and uninterrupted operation of all parts of the boiler room.

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

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

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

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

2. Classification of boiler installations

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

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

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

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

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

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

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

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

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

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

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

The water heating boiler installation (Fig. 4, b) consists of two water heating boilers 1, one group water economizer 5, serving both boilers. Flue gases leaving the economizer through a common collection duct 3 enter directly into the chimney 4. Water heated in the boilers enters the common pipeline 8, from where it is supplied to the consumer 7. Having given off heat, the cooled water through the return pipeline 2 is sent first to the economizer 5 , and then again into the boilers. Water is moved through a closed circuit (boiler, consumer, economizer, boiler) 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. Figure 6 shows a diagram of a boiler unit with a steam boiler having an upper drum 12. At the bottom of the boiler there is a firebox 3. To burn liquid or gaseous fuel, nozzles or burners 4 are used, through which the fuel together with air is supplied to the firebox. Boiler limited brick walls- lining 7.

When burning fuel, the heat released heats water to a boil in tube screens 2 installed on the inner surface of the firebox 3 and ensures its transformation into water vapor.

Fig 6.

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

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

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

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

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

Rice. 7.

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

Rice. 9.

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

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

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

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

3. Classification of boiler units

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

Boilers with natural circulation;

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

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

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

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

Rice. 10.

Rice. eleven.

Rice. 12.

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

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

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

Based on the type of coolant, boilers are divided into hot water and steam boilers. The main indicators of a hot water boiler are thermal power, that is, heating capacity, 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 to supply heat to heating and ventilation systems, household and technological consumers. Hot water boilers, usually operating on the direct-flow principle with a constant flow of water, are installed not only at thermal power plants, but also in district heating, as well as heating and industrial boiler houses as the main source of heat supply.

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

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

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

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

Thermal circuits boiler rooms

According to their purpose, boiler houses of low and medium power are divided into the following groups: heating, intended for heat supply to heating systems, ventilation, hot water supply of residential, public and other buildings; production processes providing steam and hot water to industrial enterprises; industrial and heating systems, providing steam and hot water to various consumers. Depending on the type of coolant produced, boiler houses are divided into water-heating, steam and steam-water-heating.

In general, a boiler installation is a combination of a boiler (boilers) and equipment, including the following devices. Fuel supply and combustion; purification, chemical preparation and deaeration of water; heat exchangers for various purposes; source (raw) water pumps, network or circulation - for circulating water in the heating system, make-up - to replace water consumed by the consumer and leaks in networks, feed pumps for supplying water to steam boilers, recirculation (mixing) pumps; nutrient tanks, condensation tanks, hot water storage tanks; blower fans and air duct; smoke exhausters, gas path and chimney; ventilation devices; systems for automatic regulation and safety of fuel combustion; heat shield or control panel.

The thermal design of a boiler house depends on the type of coolant produced and on the design of the heating networks connecting the boiler house with consumers of steam or hot water, and on the quality of the source water. Mermen heating network There are two types: closed and open. With a closed system, water (or steam) gives up its heat in local systems and is completely returned to the boiler room. In an open system, water (or steam) is partially, and in rare cases completely, removed in local installations. The design of the heating network determines the performance of water treatment equipment, as well as the capacity of storage tanks.

As an example, a schematic thermal diagram of a hot water boiler house is given for open system heat supply with calculated temperature conditions 150-70°C. A network (circulation) pump installed on the return line ensures the flow of feed water into the boiler and further into the heating system. The return and supply lines are connected to each other by jumpers - bypass and recirculation. Through the first of them, in all operating modes except the maximum winter one, part of the water from the return line is transferred to the supply line to maintain the set temperature.

Schematic thermal diagram of a hot water boiler house

To prevent metal corrosion, the water temperature at the boiler inlet when operating on gas fuel must be at least 60 °C to avoid condensation of water vapor contained in the flue gases. Since the return water temperature is almost always below this value, in boiler rooms with steel boilers, part of the hot water is supplied to the return line by a recirculation pump.

Makeup water (a pump that compensates for water consumption from consumers) enters the network pump manifold from the tank. The source water supplied by the pump passes through a heater, chemical water treatment filters and, after softening, through a second heater, where it is heated to 75-80 °C. Next, the water enters the column vacuum deaerator. The vacuum in the deaerator is maintained by suctioning the steam-air mixture from the deaerator column using a water-jet ejector. The working fluid of the ejector is water supplied by a pump from the tank of the ejector unit. The steam-water mixture removed from the deaerator head passes through a heat exchanger - a vapor cooler. In this heat exchanger, water vapor condenses, and the condensate flows back into the deaerator column. The deaerated water flows by gravity to the make-up pump, which supplies it to the suction manifold of the network pumps or to the make-up water tank.

Heating of chemically purified and source water in heat exchangers is carried out by water coming from the boilers. In many cases, the pump installed on this pipeline (shown by the dashed line) is also used as a recirculation pump.

If the heating boiler room is equipped with steam boilers, then hot water for the heating system is obtained in surface steam-water heaters. Steam-water water heaters are most often free-standing, but in some cases heaters are used that are included in the circulation circuit of the boiler, as well as built over boilers or built into boilers.

Shown is a basic thermal diagram of a production heating boiler house with steam boilers supplying steam and hot water to closed two-pipe water and steam heat supply systems. One deaerator is provided for the preparation of boiler feed water and heating network make-up water. The scheme involves heating source and chemically purified water in steam-water heaters. Blowdown water from all boilers enters a continuous blowdown steam separator, which is maintained at the same pressure as the deaerator. Steam from the separator is discharged into the steam space of the deaerator, and hot water enters the water-water heater to preheat the source water. The blowdown water is then discharged into the sewer or into the make-up water tank.

The steam network condensate returned from consumers is pumped from the condensate tank to the deaerator. The deaerator receives chemically purified water and condensate from a steam-water heater of chemically purified water. Network water it is heated sequentially in the condensate cooler of the steam-water heater and in the steam-water heater.

In many cases, in steam boiler houses for the preparation of hot water, hot water boilers are also installed, which completely satisfy the need for hot water or are peak ones. The boilers are installed behind the steam-water heater along the water flow as the second heating stage. If a steam-water-heating boiler house serves open water networks, the thermal design provides for the installation of two deaerators - for feed and make-up water. To equalize the hot water preparation mode, as well as to limit and equalize the pressure in hot and cold water supply systems, storage tanks are installed in heating boiler rooms.

Schematic thermal diagram of a steam boiler house with closed networks.

FITTINGS AND BOILER ACCESSORIES

Boiler fittings

Devices and instruments used to control the operation of parts of the boiler unit under pressure, to turn on, turn off and regulate pipelines for water and steam, basic safety devices are called fittings.

According to their purpose, valves are divided into shut-off, control, purge and safety.

The fittings are made with forced drive and self-acting.

By design, drive valves are divided into valves, gate valves and taps, and self-acting valves are divided into safety and check valves and steam traps.

Fittings also include water gauge glasses and other water indicating devices.

Valves and gate valves

Valves are used as control and shut-off devices (Fig. 3). How shut-off valves they are used for passage diameters up to 109-150 mm.

a - shut-off flange; b - regulating:

1 - body; 2 - shutter; 3 - flange; 4-piston seal;

5 - spindle; 6 - shtl rach (flywheel); 7 - traverse; 8 - cover;

9 - valve seat

In a shut-off valve, the sealing surface of the valve is tightly adjacent to the surface of the seat. The valve consists of a body, a cover, a spindle on which the valve hangs. The body contains a valve seat. An oil seal is installed where the spindle passes through the cover.

In a control valve, the valve has a variable cross-section. This makes it possible to change the flow area. The control valve is made in the form of a profiled needle, a hollow spool, etc. When fully closed, they do not provide full tightness. Typically control valves are designed to operate at a pressure drop of 1.0 MPa.

The main indicator of the operation of a control valve is its characteristic (dependence of the relative flow rate of the medium on the degree of opening of the valve) (Fig. 3 b).

For regulatory purposes, the linear characteristic is most favorable, which requires the implementation of regulatory bodies with a complex profile of opening windows for the flow of medium. A spool-type control valve has a hollow spool with profiled windows, which is driven by a spindle in translational motion. When the spool moves relative to the two seats, the degree of opening of the windows changes.

In rolling control valves, the control element is made in the form of a rolling pin, which has a conical shape near the seats. When moving the rolling pin, the annular gap between it and the valve seats changes.

In needle control valves, adjustment is achieved by moving a profiled needle.

Valves are mainly used as shut-off devices (Fig. 4), although special designs of control valves are also available. In valves, the closing element (wedge, discs) moves in a direction perpendicular to the flow. Based on the principle of pressing the shut-off element, valves are divided into wedge valves, parallel-forced valves, and self-sealing valves.

In wedge valves, the locking element is made of a whole or split wedge.

The coefficient of hydraulic resistance of valves is b = 0.25-0.8, and for shut-off valves b = 2.5-5.

Valves

a - wafer wedge with drive; b - parallel flange

1- sealing discs; 2 - spacer device; 3 - body;

4 - cover; 5 - remote drive lever; 6 - flywheel; 7 - gear; 8 - traverse; 9 - joint seal;

10 - spindle; 11 - sealing ring.

Valves

A valve is an automatic shut-off or regulating body.

Steam boilers have check, feed, pressure and safety valves.

Check valve impedes movement working environment in the opposite direction. For example, check valves on the supply lines close in the event of an emergency drop in pressure in the supply pipelines and prevent the release of water from the boiler.

By design, check valves are divided into lift and rotary.

In lift valves (Fig. 5, a), the shut-off element is a plate (spool) 2, the shank of which fits into the guide channel of the cover boss 1.

In rotary valves (Fig. 5, b), plate 6 rotates around axis 7 and blocks the passage.

Check valves installed in boiler rooms, usually on pressure lines centrifugal pumps, on the supply lines in front of the boiler to allow water to flow in only one direction and in other places where there is a danger of reverse flow of the medium.

a - lifting; b - rotary:

1 - cover; 2 - spool; 3 - body; 4 - valve axis; 5 - lever;

6 - plate; 7 - lever axis.

Feed valve serves to automatically regulate the boiler power supply in accordance with steam consumption.

In valves installed on modern boilers, water presses a vertical gate against the seat.

Safety valve is a shut-off device that automatically opens when pressure increases. Install it on drum boilers, steam pipelines, tanks, etc. When the valve opens, the medium is released into the atmosphere. Safety valves can be lever (Fig. 7 a), spring (Fig. 7 b) and pulse (Fig. 8).

a - single lever; b - spring:

1 - body; 2 - shutter; 3 - spindle;

4 - cover; 5 - lever; 6 - load; 7 - spring

IN lever valve the locking organ (plate) is held closed by a weight. In a spring safety valve, the pressure of the medium on the plate is counteracted by the tension force of the spring.

Safety valves are available in both single and double versions. Depending on the lifting height of the disc, valves are divided into low-lift and full-lift. In fully lifting valves, the area open to the passage of the medium when the valve is lifted exceeds the passage of the seat. They have greater throughput than low-lift ones.

In accordance with the rules, each boiler with a steam capacity of more than 100 kg/h must be equipped with at least two safety valves, one of which must be a control valve. On boilers with a capacity of 100 kg/h or less, the installation of one safety valve may be allowed.

The total capacity of the valves must be no less than the hourly productivity of the boiler. If the boiler has a non-switchable superheater, part safety valves with a throughput of at least 50% of the total bandwidth must be installed on the outlet manifold.