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

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

Natural separation occurs due to the large difference in densities of water and steam. The mechanical inertial principle of separation 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 the direction or twist of the flow of wet steam.

In Fig. 19.22 shows schematic diagrams of separating devices. In Fig. 19.22a shows the principle of natural separation. The high flow rate of the steam-water mixture flowing from the supply screen pipes is quenched in the volume of water that is in the drum. The speed of steam in the drum above the water level is insignificant (0.3 - 0.5 m/s), which promotes the separation of water droplets and steam.

In the diagram shown in Fig. 19.22, b, the steam-water mixture is directed to a continuous fender board. Water flows down the sheet, and steam enters the steam space and, passing through the perforated steam receiving sheet, is removed from the drum. In this scheme, mechanical separation is combined with natural separation in the steam volume of the drum.

Inside the drum cyclone shown in Fig. 19.22, g, serves for intensive swirling of the flow of steam-water mixture. Under the influence of centrifugal forces, water is thrown onto the wall of the separator and flows into the water volume in the form of a film.

The cyclonic separation principle is highly efficient. When the steam volume of the drum is heavily loaded, remote cyclones are used, to which part of the pipes of the evaporation surface of the boiler unit is connected.

Rice. 19.22. Schemes of separation devices.

a - submersible perforated shield: 1 - perforated shield; 2 - steam intake perforated shield; b - fenders and distribution boards; 1 - fender shield; 2 - steam intake perforated shield; c - louvered separator; 1 - fender shield; 2 - louvered separator; 3 - steam intake perforated shield; g - cyclone separator; 1 - cyclone; 2 - steam intake perforated shield.

Rice. 19.23. Scheme of steam flushing with feed water.

1 - shield with washing troughs; 2 - louvered separator; 3 - steam intake panel; 4 - steam outlet; 5 - place for supplying feed water (5a - for flushing; 5b - under the level); 6 - place for supplying the steam-water mixture from the evaporation pipes; 7 - lowering pipes; 8 - perforated shield.

Remote cyclones are located outside the boiler unit (see Fig. 19.18).

A high degree of steam purification is achieved with film separation. The principle of film separation is based on the formation of a stable film when tiny drops of water merge at the moment the flow of wet steam comes into contact with any obstacle (vertical or horizontal plane, etc.). Diagram of the film louver separator shown in Fig. 19.22c gives an idea of ​​the film separation method. A film of water forms on the walls of the wavy channels, which flows down through the perforated ceiling sheet, and the steam is directed to the exit of the drum.

The considered schemes of methods for producing pure steam provide a degree of dryness x = 0.98 - 0.99. For more fine cleaning The steam is removed from impurities and cleaned with nutrient water. The steam washing scheme is shown in Fig. 19.23.

Before washing, the steam undergoes natural separation in the steam volume and then bubbles through a layer of feed water, which contains very few salts. As a result of intensive mass exchange, salts are retained by the feed water. Carrying away drops of feed water no longer poses a great danger to the operation of the superheater.

Auxiliary equipment of the boiler installation - draft devices. For normal operation of the boiler unit, a continuous supply of air for combustion of fuel and continuous removal of combustion products are necessary.

In modern boiler installations, a scheme with vacuum through gas ducts is widespread. The disadvantages of this scheme include the presence of air suction into the flues through leaks in the fences and the operation of smoke exhausters on dusty gases. The advantage of this scheme is the absence of knockout and leakage of flue gases into the boiler room, since a fan forces air into the furnace, and a smoke exhauster removes the flue gases. Recently, in powerful power boiler plants, a supercharged circuit has been widely used. The firebox and the entire gas path are under a pressure of 3 - 5 kPa. The pressure is created by powerful fans; there is no smoke exhauster. The main disadvantage of this scheme is the difficulties associated with ensuring proper tightness of the firebox and gas ducts of the boiler unit.

When gases move through gas ducts, pressure losses occur due to aerodynamic resistance to friction and local resistance (pipe bundles, narrowings, turns, etc.). The total pressure loss in a separate section consists of the friction loss ∆h tr and the loss to overcome local resistance ∆h places, i.e.

here λ is the friction coefficient; l,d eq - length and equivalent diameter of the section; p - gas density; w - gas speed; § m - local resistance coefficient.

When moving gases in vertical flues, it is necessary to take into account the natural pressure that arises due to the difference in the densities of hot flue gases and the surrounding air. This pressure, called gravity (∆h self), in ascending flues is aimed at overcoming resistance, and in descending flues it prevents movement and is a negative value.

In general, for a boiler installation, the pressure loss is

∆Н = ∆h t + ∑∆h tr + ∑∆h places + ∆h itself (19.25)

where ∆h t is the vacuum maintained in the upper part of the furnace (20 - 40 Pa).

The value of ∆Н is determined according to the standards of aerodynamic calculation of boiler units. Overcoming ∆Н is carried out by traction, which can be natural or artificial. Natural draft is created by chimneys, and artificial draft is created using special centrifugal fans (smoke exhausters). For powerful boiler units, axial type smoke exhausters are used. Natural draft is determined by the difference in densities of hot flue gases and cold ambient air. The height of the columns of hot gases and cold air is assumed to be the same (Fig. 19.24).

Rice. 19.24. To the calculation of the natural tag created by the smoke coarse.

The maximum draft generated by the pipe should be 20% higher total loss pressure Chimneys are made of brick, reinforced concrete and steel. At a height of up to 80 m, brick pipes are most widespread, since they are cheaper, more resistant to temperature fluctuations (compared to concrete) and are not susceptible to the harmful effects of sulfur dioxide gases, like steel ones.

The height of the pipe must be sanitary - technical requirements, which provide for a certain radius of dispersion of flue gases in order to avoid exceeding the permissible dust content of the atmosphere.

To obtain draft, it is necessary to increase the height of the pipe or the temperature of the flue gases. However, when using any of these methods, it must be borne in mind that the height of the pipe is limited by its cost and strength, and the temperature of the gases - optimal value Boiler installation efficiency. Therefore, most modern boiler plants are equipped with artificial draft, which is created using a smoke exhauster that overcomes the resistance of the gas path. In this case, the height of the pipe is selected in accordance with sanitary and technical requirements.

The drive power of the smoke exhauster, kW, can be calculated using the formula

where V d is the performance of the smoke exhauster, m 3 /s; N d - (∆Н - ∆h cam) β 2 - vacuum created by the smoke exhauster, Pa (here ∆Н is the resistance of the gas path, Pa; ∆h self is the gravity draft of the chimney, Pa); β 2 = 1.1 ÷ 1.2 - safety factor for the created vacuum; β 3 - power safety factor equal to 1.1; ȵ d - efficiency of the smoke exhauster.

The value of V d is determined by the equality

V d - V r V r T d.tr β 1 /273, (19.27)

where Vr is gas flow, m 3 / m 3; V r - fuel consumption, m 3 / s (kg / s); T d.tr - gas temperature at the entrance to the chimney, K; β 1 - 1.05 ÷ 1.1 - safety factor for productivity.

The air pressure created by the fan should also be determined based on the aerodynamic calculation of the air path (air ducts, air heater, burner device, etc.).

The maximum fan pressure should be 10% greater than β2 = 1.1) pressure loss in the air path of the boiler unit. Blower fan drive power, kW, is determined by the formula

N in = V in N in β 3 10 -3 /ȵ in (19.28)

where V in - air flow, m 3 / s; Н в = ∆Нβ 2 - fan pressure, Pa (here ∆ Н - pressure loss in the air duct, Pa; β 2 = 1.1 - safety factor for the generated pressure); β 3 = 1.1 - power safety factor.

The value of Vz is determined by the equality

where β 1 = 1.05 - performance safety factor; V 0 - theoretical amount of air, m 3 / m 3 (m 3 / kg); α t + α a = α air - excess air coefficient; T air - air temperature in front of the fan; H bar - barometric pressure, kPa.

Auxiliary equipment of a boiler installation - the basics of water treatment. One of the main tasks safe operation boiler installations is the organization of a rational water regime, in which scale does not form on the walls of the evaporating heating surfaces, there is no corrosion 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 steam generated.

In industrial boiler houses, the main irretrievable loss is contaminated steam condensate consumed in technological processes. Purification of this condensate from organic and impurities that have entered it minerals economically unprofitable. The magnitude of this loss depends on the nature of the production where steam is used. For example, the loss of condensate at enterprises in the mechanical engineering industry is 20%, industry building materials- 30, chemical - 40, oil refining - 50%. In heating boiler houses, the proportion of condensate not returned by the heat consumer can vary widely - from a few percent to 100%, depending on the heat supply scheme and the nature of the heat supply. heat consumption. Another part of the loss of condensate is leakage in heating mains (0.5 - 1%). In addition, a certain part of the water (5 - 7%) is removed from the boiler unit during continuous blowing.

Losses of condensate and water during blowing are replenished by adding water from some source. This water must be properly prepared before entering the boiler unit. Water that has undergone preliminary treatment is called additional water, the mixture of returned condensate and additional water is called feed water, and the water that circulates in the boiler circuit is called boiler water.

The normal operation of boiler units depends on the quality of feed water. Physico - Chemical properties water is characterized by the following indicators: transparency, suspended solids content, dry residue, salt content, oxidability, hardness, alkalinity, concentration of dissolved gases (CO 2 and O 2).

Transparency is characterized by the presence of suspended mechanical and colloidal impurities, and the content of suspended substances determines the degree of water contamination with solid insoluble impurities. The content of suspended solids is measured in mg/l. Dry residue is one of the main indicators by which the suitability of water for feeding boiler units is judged. Dry residue is the residue after evaporation of a laboratory water sample, dried at 110 - 120 °C. It contains colloidal and dissolved inorganic and organic impurities in water. The unit of measurement of dry residue is mg/kg.

The salt content of water is characterized by the total concentration of cations (Na+; K+; Mg 2+) and anions (HCO 3; SO 2 4; Cl; SiO 2 3) in water. Salt content determines the degree of mineralization of water in mg/l. Oxidability characterizes the concentration of organic impurities in water. Oxidability is calculated by the amount of oxygen (mg/l) required to oxidize (under certain conditions) organic impurities contained in 1 kg of water. Water hardness is a very important indicator of its quality. It is characterized by the content of calcium and magnesium ions (Ca 2 +; Mg 2 +) in it. There are general hardness Zh 0, carbonate Zhk and non-carbonate Zhn. The total hardness Ж 0 is characterized by the total concentration of Ca and Mg ions, i.e. F 0 = ZhCa + ZhMg. The carbonate hardness of liquid is due to the presence of bicarbonates Ca(HCO 3) 2 and Mg(HCO 3) 2. Carbonate hardness is temporary, since during boiling, bicarbonates decompose with the release of CO 2 and solid sediments CaCO 3 and Mg(OH) 2 (sludge). Non-carbonate hardness is due to the presence of all other calcium and magnesium salts in water (CaSO 4; MgSO 4; CaCl 2; MgCl 2, etc.). The non-carbonate hardness of liquids is sometimes called constant, since it is not possible to decompose these salts by simple boiling due to their properties. Consequently, Zh 0 = Zh k + Zh nc. Usually Zh nc is defined as the difference Zh nc = Zh o - Zh k.

Water hardness is usually measured in mEq/kg or mcg-eq/kg (1 mg-eq = 103 mcg/eq). According to the total hardness, natural water is divided into three groups: soft with F 0< 4 мг-экв/кг; средней жесткости с Ж 0 = 4 ÷ 7 мг-экв/кг и жесткую с Ж 0 >7 mEq/kg. For example, for DKVR boilers at pressures up to 2.4 MPa, a total water hardness of no more than 0.02 mEq/kg is allowed.

Water alkalinity is characterized by the content of bicarbonate HCO 3, carbonate CO 3 and hydroxyl OH ions. The alkalinity value is measured in mEq/kg. In natural waters, alkalinity is mainly due to the presence of bicarbonate ions.

During operation of the boiler unit, there is a continuous accumulation of harmful impurities in the boiler water due to its evaporation and the influx of salts with the feed water. As a rule, there are no impurities in the steam leaving the boiler (the exception is silicon salts in steam at high pressures).

Milligram equivalent is the amount of a substance in milligrams, numerically equal to its equivalent mass, which is the quotient of the molecular weight of the substance divided by its valency in a given compound.

Impurities remain in the boiler water and cause undesirable consequences if appropriate measures are not taken to pre-treat the make-up water.

The most harmful impurities are scale formers - calcium and magnesium salts, which characterize non-carbonate hardness, as well as corrosive dissolved gases O 2 and CO 2. Scale is a mechanically strong layer of scale-forming deposits on the inner walls of heating surfaces.

The ingress of mechanical impurities and salts of carbonate hardness into the boiler unit is undesirable due to the formation of so-called sludge in the evaporation circuit - loose compounds that must be periodically removed. Scale and sludge deposits negatively affect the operation of the boiler unit. The thermal conductivity of scale and sludge is insignificant compared to the thermal conductivity of metal walls. Therefore, scale and sludge increase thermal resistance to the process of heat transfer from gases to water, which in some cases leads to an unacceptable increase in the temperature of the pipe walls and a decrease in their mechanical strength. An increase in thermal resistance also increases fuel consumption, which reduces the efficiency of the boiler unit.

Gases dissolved in water (O 2 and CO 2) at high temperatures are highly corrosive. Corrosion of the metal pipe walls leads to a decrease in their thickness and, consequently, mechanical strength.

The alkalinity of water somewhat reduces the intensity of corrosion processes, but with increasing alkalinity, foaming of water in the drums is observed and foam can be carried away with steam.

The presence of organic compounds in water is also undesirable. The high oxidation of water makes it difficult to process and remove mineral salts and increases foaming. Consequently, certain requirements are imposed on the quality of feed water, which depend on the type of boiler unit (drum, direct-flow, hot water) and the pressure of the generated steam.

There are two methods of water treatment - pre-boiler and intra-boiler. Pre-boiler water treatment involves a set of measures to ensure established standards feed water quality. To maintain the required quality of boiler water within the established limits, pre-boiler treatment alone is sometimes not enough (for example, to power high- and ultra-high-pressure drum boilers) due to the imperfections of the methods and equipment used. In this case, internal boiler water treatment is additionally used, in which chemical reagents (phosphates) are introduced into the boiler drum. Phosphates enter into chemical reactions with salts contained in boiler water and form poorly soluble loose compounds that are removed from the boiler unit.

For direct-flow boilers, only pre-boiler treatment of additional water is used. Despite the preliminary preparation of the feed water, in order to maintain the acceptable salt concentration in the boiler water and prevent sludge deposits, the boiler is purged, i.e. remove part of the boiler water from it. A distinction is made between periodic and continuous blowdown of steam boilers. Periodic purging serves primarily to remove sludge from the boiler circuit. Continuous blowing It is mainly used to remove impurities dissolved in water and produce cleaner steam. The amount of blowdown water removed from the boiler unit is usually determined (or set) as a percentage of the unit's performance (no more than 5 - 6%).

Continuous blowing is carried out from the boiler drum (in double-drum boilers - from the top) at the level of the steam-water mixture input, where the salt content is usually maximum. Periodic purging is carried out from the lower collectors of the boiler, where sludge accumulates. In double-drum boilers, periodic blowing is also carried out from the lower drum.

Pre-boiler water treatment should ensure its clarification (removal of suspended particles), softening, reduction of alkalinity and salt content, as well as removal of dissolved gases (O 2 and CO 2). Large suspended substances are removed by settling, small ones by filtration. Sand, crushed marble chips, and anthracite are used for filters. To remove colloidal and organic substances, water is treated with a coagulant before filtering, i.e. a substance that promotes the enlargement of suspended solids (iron salts FeSO 4 and FeCl 2 or aluminum sulfate A 12 (SO 4) 3. When using urban tap water clarification and coagulation operations are eliminated.

They soften the water, i.e. reduce its hardness by removing Ca 2 + and Mg 2 + cations from the water even before it enters the boiler (pre-boiler water treatment). Softening is carried out thermally or chemical methods. The thermal method is based on the decomposition of calcium and magnesium bicarbonates when heated to 360 - 375 K. The sparingly soluble substances formed in this case (CaCО 3, Mg(OH) 2) precipitate.

Currently, the main method of water softening is the cation exchange method. Its essence lies in the fact that the added water is passed through special devices - cation exchange filters filled with materials that participate in cation exchange with hardness salts. These materials contain sodium (Na+), ammonium (NH+), and hydrogen (H+) cations. Cations of hardness salts replace cations in the filter material. Thus, the cations that make up the compounds of the filter material enter the treated water, and the cations of hardness salts are retained by this material. Cations that have passed into water are no longer scale formers.

Sulfonated coal (hard and brown, treated with concentrated sulfuric acid), which is saturated with Na+, NH 4 + or H+ cations, is used as cation exchange materials in industrial heating boiler houses.

Rice. 19.25. Water treatment plant diagram.

1 - salt solvent; 2, 3 - cation exchange filters; 4 - heat exchanger: 5 - perforated sheets (plates); 6 - deaerator; 7 - feed pump; pipelines; I - Additional raw water; II - softened water; III - removal of the vapor-gas mixture; IV - returned condensate; V - pair; VI - feed water; VII - discharge into drainage.

Depending on the quality of the source and feed water, various cationization methods are used: sodium cationization (Na-cationization), ammonium - cationization (NH 4 -cationization), hydrogen - cationization (H-cationization). Combined methods are also used, which are carried out according to three schemes - sequential, parallel, joint.

In heating and industrial boiler houses, the scheme of joint Na - NH 4 cationization is widely used. Over time, the cation exchanger becomes saturated with calcium and magnesium cations and its activity decreases. To restore lost exchange properties, the cation exchanger is subjected to regeneration by treating it with a weak solution of H 2 SO 4, NaCl or NH 4 C 1 (depending on the type of exchange ion). Detailed methods of water softening, description and calculation various schemes presented in specialized literature.

Oxygen, carbon dioxide and air dissolved in water cause corrosion of the boiler walls, so gases are removed from the water by degassing it. Of all known methods The most common method for degassing water is thermal. This method is based on the property of O 2 and CO 2 gases to reduce the degree of solubility as the water temperature increases until boiling, when at zero partial pressures of O 2 and CO 2 their solubility drops to zero.

In Fig. Figure 19.25 shows a schematic diagram of a water treatment plant (cation exchange softening and degassing).

Additional water from the water supply enters the Na-cation exchange filter, where most of the salts that characterize water hardness are retained. The circuit contains two cation exchange filters. One filter, for example 2, is in operation, and in the other 3 the cation exchanger is being regenerated. A weak solution of NaCl (6 -10%) is fed into filter 3 from salt solvent 1. Softened water is fed into a deaerator (degasser), where dissolved gases are removed from it.

Before the deaerator, the water is heated hot water or steam in a heat exchanger, in order to save steam consumption for deaeration. Purified water and condensate are supplied to the upper part (head) of the deaerator and returned to the boiler room. Passing through the perforated sheets, the water is broken into small jets to increase the surface area of ​​​​contact with the steam, which is supplied down the heads. The water is heated to a boil, and dissolved gases are removed from it through a pipe installed in the upper part of the head. In atmospheric deaerators, a pressure of 0.115 - 0.12 MPa is maintained, which corresponds to a saturation temperature of 376 - 377 K.

Deaerators of this type are used in boiler houses of low and medium pressure. They ensure complete removal of oxygen and sharply reduce the CO 2 content in the feed water. At thermal stations with boilers high pressure use deaerators high blood pressure(0.6 MPa).

The number and productivity of the deaerator (by water) in heating and industrial boiler houses is determined by the amount of feed water and the amount of water for feeding heating networks. The water supply in the deaerator tanks should be for 20 - 30 minutes at maximum flow. The water supply in the tanks of deaerators at thermal power plants must be at least for 15 minutes of operation at maximum flow.

In hot water boiler houses, vacuum-type deaerators are used, in which a vacuum of 0.02 - 0.03 MPa is maintained, which corresponds to a boiling point of 330 - 340 K. The water in them is heated from the hot water supply network.

A disruption in the uninterrupted supply of feed water to the boiler unit can lead to serious accidents. A feed pump supplies water to the boiler unit. Each boiler installation, in accordance with the rules of Gosgortekhnadzor, must have two pumps - the main, or working, and backup. A multistage centrifugal pump with an electric drive is usually installed as the main pump. Serves as a backup piston pump driven by a steam engine. At large thermal power plants, centrifugal pumps driven by a small steam turbine (turbo pumps) are used as backup pumps.

The flow rate of each pump must be at least 110% of the boiler room’s rated capacity, and the pressure created by the feed pump must exceed the pressure in the boiler drum by the total hydraulic resistance of the feed line (including the economizer). The pressure is determined by the formula

Н = р к.а + Н resist (19.30)

where p k.a is the pressure in the boiler drum; N resist - loss of pressure in the supply line (usually N resist = 0.3 ÷ 0.4 MPa).

Drive power feed pump N, kW, found by expression

N = 1.1 D nom Н10 -3 /ȵ n (19.31)

where 1.1 is the safety factor; D nom - nominal productivity of the boiler room, m 3 / s; N - total pump pressure, Pa; ȵ n - pump efficiency; For centrifugal pumpsȵ n = ​​0.5 ÷ 0.7 (depending on productivity).

Auxiliary equipment of the boiler installation - fuel supply. For normal and uninterrupted operation of boiler systems, it is necessary that fuel be supplied to them continuously. The fuel supply process consists of two main stages: 1) supply of fuel from the place of its production to warehouses located near the boiler room; 2) supply of fuel from warehouses directly to boiler rooms. The first stage is carried out using rail or water transport or dump trucks; at the second stage, narrow-gauge trolleys with a capacity of up to 1.5 m 3, belt conveyors, forklifts, cable cars, hoists and other devices that mechanize this process are used to move fuel.

Warehouses for solid fuel, as a rule, are open and their capacity is usually designed for no more than a two-month supply. Fuel is stored in these warehouses in the form of stacks. To avoid spontaneous combustion, the height of a peat stack should not exceed 1.5 m. The dimensions of stacks of other types of solid fuel are not standardized.

Liquid fuel storage facilities are steel (above ground) and concrete (underground) tanks with a volume of 100 m3 or more. They are located outside the boiler rooms. It is preferable to use concrete storage facilities. Fuel oil is delivered to warehouses in railway tanks. With the help of steam supplied by special hoses, the fuel oil in the tanks is heated to 340 - 350 K and poured into a tray, the bottom of which is also heated by steam lines. The fuel oil flows through the tray into storage facilities, which are connected to pumping station equipped with filters and fuel oil heaters. A diagram of the fuel oil system of the boiler room is shown in Fig. 19.26.

Gaseous fuel is supplied to boiler houses through gas pipelines. Depending on the gas pressure, the pipelines may be low pressure(up to 0.5 kPa), medium (from 0.5 kPa to 0.3 MPa) and high (more than 0.3 MPa). In Fig. Figure 19.27 shows a diagram of a gas control point for supplying gas to the burners of boiler units.

After entering the gas pipeline into the boiler room, a shut-off valve is installed on it gas network, pressure gauge 2 and shut-off valve 1 of the gas network of the boiler room. Then install a filter 3, a safety valve 4 and a pressure regulator 5, which maintains the gas pressure in front of the burners at the required level. In exceptional cases, gas can be taken in addition to the regulator. If the gas pressure in front of the burners unexpectedly increases above the set value, the relief safety valve 6 is activated and the gas is vented to the atmosphere through a purge candle 12 installed above the roof of the boiler house building. Gas consumption is taken into account by meter 7. The gas control point can be installed both inside the boiler room itself and outside it.

Cleaning flue gases and removing ash and slag. When burning solid fuel, a lot of ash is formed.

Rice. 19.26. Scheme of the fuel oil economy of the boiler room.

1 - railway track for the tank; 2 - drain flow; 3 - fuel oil tank; 4 - coils for heating fuel oil in the tank; 5 - drainage pit; 6 - steam pump; 7 - fuel oil pit; 8 - air cap; 9 - filter; 10 - fuel oil heaters; 11 - fuel oil pipeline; 12 - boiler units; 13 - nozzles; 14 - fuel oil line.

During the layer combustion process, the main part of the mineral impurities of the fuel (60 - 70%) turns into slag and falls through the grates into the ash pit. In pulverized coal furnaces, most (75 - 85%) of the ash is carried away from the boiler units with flue gases. The release of highly dusty gases through the pipe into the atmosphere is not allowed due to pollution of the surrounding air and deterioration of sanitary and hygienic conditions in populated areas located near the boiler house. In addition, ash causes abrasive wear of smoke exhauster blades. All these reasons make it necessary to capture ash from flue gases.

Currently, the following types of ash collectors are used in boiler houses: 1) inertial mechanical; 2) wet; 3) electric precipitators; 4) combined.

Inertial (mechanical) ash collectors operate on the principle of separating ash particles from a gas flow under the influence of inertial forces (with a sharp change in the direction of flow, when the gas flow swirls, etc.).

Rice. 19.27. Schematic diagram of a gas control point.

1 - valve; 2 - pressure gauge; 3 - filter; 4 - safety shut-off valve (SCV); 5 - pressure regulator; 6 - safety relief valve (PSV); 7 - counter; 8 - thermometer; 9 - liquid pressure gauge; 10 - line to boilers; 11 - discharge line from PSK; 12 - purge spark plug; 13 - impulse line.

In Fig. Figure 19.28 shows a diagram of a cyclone ash collector. Due to the tangential entry into the cyclone, the dust and gas flow receives a rotational movement, as a result of which ash particles are thrown by centrifugal forces towards the wall of the housing, fall out of the flow and are poured into the hopper. Since the centrifugal force with which ash particles are thrown away, all other things being equal, will be greater the smaller the radius of the cyclone, recently they prefer to build battery cyclones from several dozen small cyclones instead of one cyclone. The disadvantage of cyclone ash collectors is the relatively large (up to 40% in single-body and up to 20% in battery-type) infiltration of fine dust into the flue gases behind the cyclone. This type of ash collectors is used in heating and industrial boiler houses with a flue gas flow rate of up to 50,000 m 3 /h, reduced to normal conditions.

Currently, wet-type ash collectors are widely used. Ash particles are released from the flow under the influence of inertial forces. The wall of the ash catcher is wetted with a film of water, which is introduced into the catcher through various spray devices. In Fig. Figure 19.29 shows a diagram of a wet ash collector (scrubber) with a lower tangential supply of dust-laden gas.

Collected ash and contaminated water are removed from the bottom, and purified gases are removed from the top of the scrubber body. A wet-type ash catcher is used in boiler houses with a flue gas flow rate of more than 100,000 m 3 /h, reduced to normal conditions, provided that the reduced volatile sulfur content S rl.p ≤ 1%.

The principle of operation of electric precipitators is that dusty gases pass through electric field, formed between a steel cylinder (positive pole) and a wire running along the axis of the cylinder (negative pole). The bulk of the ash particles receives a negative charge and is attracted to the walls of the cylinder, while a small part of the ash particles receives a positive charge and is attracted to the wire. By periodically shaking the electrostatic precipitator, the electrodes are freed from ash. Electricity consumption is low (0.1 - 0.15 kW per 1000 m 3 of gas), but high voltage(up to 90,000 V) requires special care when servicing electrostatic precipitators. Electrical precipitators are used in boiler houses with a flue gas flow rate of more than 70,000 m 3 / h, referred to as normal conditions.

Combined ash collectors are two-stage, and the operation of each stage is based on different principles.

Most often, a combined ash collector consists of a battery cyclone (first stage) and an electric precipitator (second stage).

Rice. 19.28. Cyclonic ash collector. a - diagram of the cyclone; b - general form battery cyclone; c - cyclone snail; 1 - cyclone; 2 - spiral snail; 3 - input manifold; 4 - cover; 5 - exhaust pipe; 6 - cyclone body; 7 - ash and dust collection booker.

Rice. 19.29. Diagram of a centrifugal scrubber designed by VTI

1 - body; 2 - inlet pipe; 3 - valve; 4 - water supply manifold; 5 - irrigation nozzles.

The efficiency of ash collectors is assessed by the value of the cleaning (dust removal) coefficient.

ɛ = S y /S d 100%

where S y, S d - ash content in gases, respectively, after the catcher and before it.

Single-body cyclone catchers have ɛ = 40 ÷ 50%, for battery cyclones ɛ = 75 ÷ 85%, for wet ash collectors ɛ = 90 ÷ 94%, for electric precipitators ɛ = 90 ÷ 95%; with combined cleaning ɛ = 98%.

The ash and slag removal process can be divided into two main operations: cleaning slag and ash bunkers and transporting ash and slag to ash dumps or slag concrete plants.

There are three ways to remove focal remains:

1. mechanical - using various mechanisms - scrapers, lifts, augers, slag unloaders, etc.;
2. pneumatic, based on the ability of air flow to move bulk materials;
3. hydraulic, which is the most advanced in terms of mechanization of the process.

Its essence lies in the fact that slag and ash, after being unloaded from furnaces and flues, are washed into channels and carried along them to a central point. From there, using a hydraulic elevator jet under a pressure of up to 2.5 MPa, the slag is crushed and, together with the ash, is pumped through pipelines to the dumps. Methods for purifying fuel combustion products from sulfur-containing compounds and nitrogen oxides are currently still in the stages of laboratory and pilot industrial testing. The maximum permissible total concentrations of these compounds according to the standards adopted in Russia are 0.085 mg/m 3 .

Boiler plant Energia-SPB produces boiler and auxiliary equipment for boiler plants:

Transportation of boiler and auxiliary equipment is carried out by motor transport, railway gondola cars and river transport. The boiler plant supplies products to all regions of Russia and Kazakhstan.

Currently, there are a great variety of boiler heating systems. Their future functionality determines the potential configuration of boiler equipment, and the list of components for such systems is very, very impressive. This article will tell you about boiler equipment for the home, its features and purpose in common system heating.

Boiler

Anyone's heart heating system- boiler. A thermal boiler is a device that is a closed structure where the coolant takes over thermal energy heating elements or heat from burning fuel.

Below is a small list important features boilers

Fuel type

At the moment, it is not difficult to find boilers on the market adapted for liquid, gas, solid fuel, as well as electricity.
Gas boilers have gained the most popularity. About 70% are made up of them, which, however, is natural, taking into account the prevalence of gas pipelines and the low cost of gas.

Diesel boilers proudly follow. An important factor in their use is the replaceable burner, which allows it to be used in boilers of different designs.

Solid fuel boilers are the oldest representative of these mechanisms; their advantage is autonomy from the power supply, as well as high efficiency.

Electric heating boilers close the list - the built-in equipment of the boiler room in the house allows you to adjust the temperature program, but they are rarely used independently; most often they act as a reserve for solid fuel boilers in case of fuel burnout, which is effective for small rooms.

Power

The parameter shows the efficiency of installing a particular boiler under specific conditions. To calculate it, a team of specialists is required; the calculation process itself depends on a number of factors, ranging from the size of the room to the purpose of the heated premises.

Another important parameter is the number of circuits. A single-circuit boiler is capable of heating the room, but a double-circuit boiler is capable of providing cooking hot water for household needs.

Installation method

Floor and wall. Most often these parameters are applied to gas boilers. The wall-mounted option perfectly saves space in the room; at the same time, the concept of one or two circuits is often applicable to them. Single-circuit systems provide the house with heat, and together with an indirect heating boiler and hot water, while double-circuit systems are capable of providing small house hot water.

It is worth mentioning the universal boiler options. An example is a boiler that has a combustion chamber for solid fuel and with additional boiler room equipment in the house, providing combustion of gas or liquid fuel.

Another option is a wood-gas boiler. When wood burns, a process occurs in it that produces flammable gas, which, in turn, is burned in the boiler, significantly increasing efficiency.

Indirect heating boiler

To provide the house with hot water, an indirect heating boiler is located in the boiler room. The water in the boiler is heated from the same boiler that heats the home. Indirect heating boilers can be floor-mounted or wall-mounted.

The advantages of such a boiler include:

• high performance at correct installation;
• provision of water without prior drainage;
• efficiency.

But it also has disadvantages:

• with frequent heating, the amount of heat released to heat the premises decreases.

Circulation pump

Many heating systems use the principle of natural coolant circulation, but there is a more advanced option for fluid movement. It is achieved by installing circulation pumps in the pipes, as well necessary equipment boiler room in the house, resulting in increased efficiency of the entire heating system. This occurs due to an increase in the coolant velocity. Due to the accelerating movement of the coolant, heating and heat transfer occur as quickly as possible, as a result of which it becomes possible to reduce the diameter of the pipes and reduce the load on the boiler.

The structure of the pump is very simple; it most often consists of a cast iron body, inside of which a rotor rotates with an impeller attached to it. The most interesting thing is that, despite the amount of fluid being pushed, a quality rotor makes almost no noise when installed correctly. One of the main installation principles is the strictly horizontal position of the rotor. It is recommended to pay attention to products made in Germany and Italy, as they are considered to be of the highest quality and relatively inexpensive.

Distribution manifold

This is home boiler room equipment that controls processes in each individual heating circuit. This part of the system is perfectly suited for systems such as and various types of radiators. This system, intricate at first glance, is designed by its existence to establish a proportional distribution of heat flows from the boiler to heat consumers. Thanks to the existence of this system, the temperature in each individual part of the living space is easily regulated.

The appearance of this boiler room equipment in a house can be described as follows - it is a metal comb with a number of leads to which coolant is supplied from the boiler and which distributes the coolant throughout all heating circuits. Externally, they differ little, but there is a significant difference in the materials used and the complexity of the design. Most often they are made of steel, copper, brass and polymers. Simple combs are limited in the operating capabilities of the device, while they are modified with a variety of sensors, control units, as well as electronic valves and air release devices.

Installing a collector system guarantees the most reasonable heat distribution in the house, but it should be borne in mind that this system is useless without the use of circulation pumps, and the technology itself has a fairly high price.

Hydroarrow

At the hydraulic gun, as a representative boiler room equipment in the house There is whole line other names, it can be called a hydraulic separator, hydrodynamic thermal separator, “bottle”. This device has a fairly simple shape - it is a cylindrical or rectangular vertical structure with nozzles located opposite each other: two on each side (however, there may be more). Its functionality is to separate the temperature and coolant flows within the coolant outlet and inlet into the boiler; thanks to its operation, efficiency increases significantly, but only if it is suitable for your heating system, which most often requires accurate and error-free calculations. It is important to take into account that for the hydraulic arrow to function, the presence of a circulation pump in the system is indispensable; it must be attached to each circuit.

Expansion tank

Also important equipment for the boiler room in the house. The boiler system is filled with a coolant substance, most often it is, of course, water, but when the system heats up, there may be a tendency for excess pressure to form against the background of thermal expansion of the liquid. To avoid breakdowns and any violations in the integrity of the heating system, an expansion tank is used.

There are two types of tanks for equipping a boiler room in a house. The first is open, at the moment it has almost ceased to be used, technically it compensates for changes in the volume of the coolant, opening the outlet to the atmosphere, but this technology is extremely crude, it requires constant monitoring and topping up of liquid, it is difficult to install and is often prone to corrosion.

Open tanks (or membranes) soon replaced open tanks. Most often they have a sealed cylindrical shape made of steel. The internal volume of these tanks is occupied by a membrane that separates inert gas or excess air from excess coolant coming from the boiler system during its expansion. Under the pressure of the liquid, the air is compressed, but as soon as the temperature (and, consequently, the pressure) drops, the gas regains its original volume and, with the help of a membrane, pushes the coolant back into the system for its further circulation.

Pipes

You should pay close attention to even such seemingly trifle equipment of the boiler room in the house.
It is quite logical that they are very popular metal pipes. The most common materials used for them are steel and copper. Steel pipes- tolerate high temperatures well, withstand high pressure, have a low price, but, unfortunately, are very prone to corrosion. Copper pipes are not susceptible to rust and are recognized the best option for home heating, but they are very expensive.

Equivalents to copper pipes are polypropylene pipes. They are not prone to rust and are extremely resistant to high temperature and aggressive substances, have a large margin of safety also due to their smooth structure. They are cheaper than copper ones, which is why they are currently enjoying the greatest (and it should be noted, well-deserved) popularity.

Also known metal-plastic pipes, in fact, these are nothing more than pipes made of the same polypropylene reinforced with some metal; they literally combine the best possible properties of the materials described above. Moreover, they are able to change their shape and bend in any way necessary.

Auxiliary equipment of boiler plants is:

• electrical filters;
• air heaters;
• chimneys.

These elements are the main parts among auxiliary equipment. They are installed above the boiler. The main and auxiliary equipment of the boiler room must be designed according to such technical diagrams, which will allow you to automate control.

Boiler system installation and safety

When building their own home, everyone carefully plans the interior, tries to carry out all the work and repairs, and, of course, installing the boiler efficiently. Boiler plant equipment – the most important stage to achieve complete comfort in your own home. The installation of this system must be treated responsibly so as not to pay fines in the future and not to redo anything.

Work must be carried out under the strict supervision of a specialist to avoid fires and explosions.

In order to avoid repair of boiler equipment and serious consequences, a serious list of installation and organization services is provided. It all starts with collecting documents and ends with launching the heating system for use. To ensure that the operation of the boiler and the entire system runs smoothly, reliably and economically, all services related to the use of the installation and commissioning works boiler equipment must be carried out by a highly qualified specialist. He must have a license and permission to carry out such work.

1. The entire heating system is pre-wired.
2. Checking the correct operation of the entire system to avoid repairs of boiler equipment and accidents.
3. Carrying out final setup of equipment for the boiler room.
4. Receive instructions from specialists.

System Maintenance

If the installation and adjustment of boiler equipment and the boiler were carried out in accordance with all norms and rules, during use situations may still arise that will require additional repairs of the auxiliary equipment of the boiler installation. The most common cause of such breakdowns is poor quality water, which does not meet boiler equipment standards. Boiler adjustment, repairs, and related work are quite expensive.

Rice. 1

To reduce the cost of repairing boiler rooms and boiler equipment in the future, the construction of a heating system should be carried out by companies that have a wide range of services:

• Post-warranty maintenance of the constructed facility.
• Reconstruction.
• Necessary repairs and setup.

The main task of the owner is to carry out timely maintenance of the boiler room premises.

Main (Fig. 1) and auxiliary elements of the heating system

A boiler room is a set of devices that is completely ready to convert the chemical energy of fuel into thermal energy hot energy, or a couple of necessary parameters.

The boiler equipment manufacturer offers the following main components:

• water economizer;
• air heater;
• frame with ladders and service shelves;
• frame;
• thermal insulation;
• sheathing;
• fittings;
• headset;
• flues.

Equipment for the boiler room (needs adjustment) has additional settings from any manufacturer:

• fans;
• smoke exhausters;
• feeding, make-up and circulation pumps;
• water treatment plants;
• fuel transfer systems;
• ash collection plant;
• vacuum ash remover.

Manufacturers of boiler equipment have developed basic installations in fuel oil industry during gas combustion, a gas control point or gas control unit.

Rice. 2

Adjustment of the entire heating system, commissioning process is the key to uninterrupted operation and comfort for everyone.

1. Steam boiler installation. This is a device that consists of a firebox and evaporating surfaces. Its main job is to evaporate the steam that was used outside the device. Incorrect adjustment of the process provokes steam to escape outside the boiler under pressure that is higher than the atmospheric heat account and is released during fuel combustion.
2. Water heating boiler. This is a heat exchange device in which the main source of thermal energy is water.
3. Combustion device. The operation of this unit is to burn fuel, converting its energy into heat.
4. Boiler lining. This system is provided by manufacturers to perform work to reduce heat losses and ensure gas density.
5. Kazan. This metal structure. Its main job is to hold the boiler and individual loads, ensuring the required relative placement of the boiler elements.
6. Steam superheater. This device increases the steam temperature above the pressure saturation temperature in the boiler. The manufacturer has provided for the operation of this coil system, where complete adjustment of boiler equipment involves connecting saturated steam at the inlet to the boiler drum, and at the outlet to a superheated steam chamber.
7. Water economizer. The essence of the work of this device consists in heating it with fuel combustion products, which, in turn, partially heats or completely evaporates the water in the boiler.
8. Air heater. Its main job is to heat the air with fuel combustion products before the fuel enters the boiler furnace.

Need for repairs within the warranty period

Parts for the boiler may be needed while the unit is still under warranty.

Repair of boiler equipment is possible:

• the boiler installation work was carried out incorrectly;
• the unit is not used correctly;
• Maintenance carried out at the wrong time;
• voltage drops (you can purchase a stabilizer that will eliminate this problem);
• low-quality coolant (you can install it on the inlet pipeline as a filter for a boiler).

Rice. 3

To avoid repairing boiler equipment, it is worth thinking through all the nuances in advance rather than urgently solving the problem.

Breaking? Don't panic

Of course, if repairs to boiler equipment are needed before heating season, then this is not so bad, and if it’s in the midst of cold weather, the main thing is not to panic. But you need to take the problem seriously, because the adjustment of the boiler and the entire system may go wrong. If the failure of the installation is not serious, you can repair it yourself. But if there are doubts about the causes and consequences, the repair should be entrusted to a professional.

The successful operation of the installation depends not only on the manufacturer, but also on the choice of model in the store. The choice determines whether the unit will cope with the assigned tasks and the amount of work - the entire commissioning process. It is better if the company that made the sale had service center somewhere nearby. So that she could help with the commissioning process at any time, she inspected and repaired the boiler (Fig. 2).

Of course, the manufacturer of boiler equipment is responsible for its product, but the owner must carry out operation according to the instructions and rules so that there are no failures in setting up the installation and waste on repairs. Statistics from boiler and heating system repair companies claim that almost 70% of the causes of breakdowns are due to improper use and operation of devices, violation of requirements and standards. Therefore, repairs of boiler equipment happen mainly through the fault of the consumer, rather than the manufacturer.

Rice. 4

Device setup and repair

If a person does not understand repair issues, then it will be difficult for him to understand this process with boilers and appliances for it.

In the list you can see the most common problems:

• Electronic board. The manufacturer has assigned this device responsibility for all processes. It regulates the device, turns it on and off, controls it, and influences the commissioning process. A small malfunction will result in an explosion. To avoid breakdowns, it is better to mount such an element as a voltage stabilizer.
• (Figure 3). If the sale of boiler equipment was carried out with defects from the manufacturer, not a single commissioning process will help. Problems with the operation of installations arise in the first months of operation. To eliminate the deficiency, you will have to completely replace the heat exchanger. But much more common is the problem of the passage being clogged with various deposits and salts. The coolant flow begins to decrease, and one day the boiler boils. To avoid repairs and commissioning, attention must be paid to water quality. And also, when selling the unit, pay attention to its quality, whether there is any defect from the manufacturer.
• (Figure 4). The commissioning process of installation implies continuous operation of this pump. But if it turns off, the boiler will boil. The unit will turn off thanks to a safety thermostat (available on sale). But the problem will not go away and repairs are guaranteed. The fault is the coolant - liquid for heating boilers. The pump can stop for two reasons: the appearance of scale; increase in debris in the middle of the body. To avoid this problem, there is a special filter on sale that is installed on the inlet pipe.
• Gas automatics. Repairing this boiler element is practically impossible. Usually, this component is completely changed. To avoid having to adjust the boiler again, it is better to prevent this breakdown than to solve it. Low quality fuel is available on sale. Therefore, to prevent damage gas automation it's worth buying fuel High Quality and use clean water for coolant.

Today there are many retail outlets that offer components for boilers. It is worth noting that well-known branded parts from popular companies are always recommended by professionals. They are of high quality, have a simple commissioning process, and the boiler is set up quite quickly.

IN suburban construction The boiler room serves as a heat source for a private house, cottage or cottage. Boiler equipment not only provides heating of the coolant for the heating system, the range of tasks it solves is much wider. In addition to heating, the boiler room equipment complex distributes the coolant throughout the heating circuits, as well as controls its parameters, such as temperature and pressure. In most cases, a boiler is also installed in the boiler room to prepare water for hot water supply. Before giving a description of the boiler room equipment and its functions, we will tell you what a heating circuit is.

The heating circuit is part of the building's heat supply system with individual parameters of the coolant in it. The standard design is a system with three circuits:

• heating radiators
• heated floor system
• hot water boiler

For example, a coolant with a temperature of 80 C˚ comes from the boiler. In the radiators its temperature should be 70 C˚, in the heated floor system 40 C˚, and the hot water boiler should receive coolant at a temperature of 80 C˚. The coolant is distributed along the circuits in a special unit - distribution manifold, which includes pumping and mixing groups, one for each circuit, responsible for circulating the coolant and controlling its temperature. Additional circuits make it possible to separately control the temperature in different rooms of the house, for example, you can select your own heating modes for the bedroom and garage, which allows you to save significant money on fuel for the boiler room.

Composition of boiler room equipment

Depending on the type of fuel on which the heating boiler operates, Various equipment can be installed in the boiler room. For a diesel boiler this will be a tank and a fuel pump, for a pellet boiler there will be a special bunker for storing wood pellets and a system for supplying them to the burner. About the features of the design of boiler houses operating on various types fuel can be found in separate articles on our website. Here we list the components and equipment common to all boiler houses.

• boiler serves as a heat generator in the boiler room. IN combustion chamber The boiler burns fuel, releasing heat, which heats the coolant circulating through the heat exchanger. Two pipelines are connected to the boiler, supply and return, through which the cooled coolant is supplied for reheating
• boiler safety group protects the building's heat supply system from emergency pressure increases, as well as from the occurrence of air locks. This unit consists of a pressure gauge, a spring safety valve and an automatic air vent
• boiler control system at most simple version consists of a thermostat that allows you to set maximum temperature coolant, start/stop button, pressure gauge and thermometer. Modern boilers are equipped with electronic automation systems equipped with displays to display various parameters boiler operation and convenient access to various system operation settings
• The chimney ensures the removal of flue gases generated during the combustion process. Properly designed and installed chimney ensures maximum efficiency and high efficiency boiler room

Distribution manifold

The distribution manifold is a unit responsible for distributing the heated coolant coming from the boiler along the heating circuits, or as consumers are also told. Consumers are heating radiators, heated floors, hot water tanks. This unit includes the following equipment:

• distribution comb (collector) The boiler room is a chamber with a larger cross-section than the main pipeline, to which pumping and mixing groups are connected. The comb ensures the distribution of coolant throughout the heating circuits and protects the circulation pumps from mutual influence
• pumping and mixing group This is a unit that ensures coolant circulation and temperature control in one circuit. Accordingly, as many circuits in the heat supply system as many pump groups will be installed in the boiler room. Responsible for coolant circulation circulation pump, and for temperature control the mixing valve and measuring instruments
• hydraulic separator optimizes coolant circulation, extending the service life of the boiler and other boiler equipment. Removes dissolved air and the smallest particles of dirt from the coolant

Other equipment

• The DHW boiler provides water preparation for hot water supply. The coolant passes through a heat exchanger located inside the tank, heating the hot water.
• expansion tanks heating and hot water supply serve to compensate for the expansion of the coolant and DHW water as a result of heating
• supply and exhaust ventilation The boiler room must provide three air exchanges within 1 hour + air consumed for fuel combustion
• heating system recharge replenishes the lack of coolant resulting from its evaporation through the air vent or due to leaks. When the coolant pressure drops below a certain value, the entire system automatically stops. To avoid this, it is necessary to regularly check the tightness of pipelines and connections. However, in any system there is a “natural” loss of coolant through the air vent, so installing a make-up system is mandatory

Complete set of boiler equipment from TEPLOSTROYMONTAZH LLC

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 used to convert the chemical energy of fuel into the thermal energy of 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 pumps - for circulating water in the heating system, make-up pumps - to compensate for 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 a working 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.

Rice. 1.

Rice. 2.

Rice. 3.

Rice. 4.

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 - steam 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. feed water, heating up, it 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.

Rice. 13.

Rice. 14.

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.

Rice. 15.

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