Technical description of type de boilers. Thermal calculation of the boiler DE16–14GM Technical characteristics of the models

Steam boiler DE-16-14 GM-O (DE-16-14-225 GM-O)* is a boiler, the main elements of which are the upper and lower drums, a firebox formed by shielded walls, a burner and a bundle of vertical pipes between the drums. These are gas-oil vertical water tube boilers designed to produce saturated steam when burned natural gas, fuel oil, light liquid fuel for technological needs industrial enterprises, in heating, ventilation and hot water supply systems.

Explanation of the name of the boiler DE-16-14GM-O (DE-16-14-225GM-O)*:
DE – boiler type; 16 - steam production (t/h); 14 – absolute steam pressure (kgf/cm2); GM - boiler for burning gaseous fuel / liquid fuel (diesel and stove household fuel, fuel oil, oil); 225 – temperature of superheated steam, °C (if there is no number – saturated steam); O - boiler supplied with casing and insulation.

Price: 5,298,200 rubles, 5,557,800 rubles (*)

Federal Agency for Education of the Russian Federation

State educational institution of higher professional education

Moscow Academy utilities and construction

Faculty of Engineering Systems and Ecology

Department of Heat and Gas Supply and Ventilation

Course project

discipline: Heat generating installations

on the topic: Thermal calculation of boiler DE16 - 14GM

Moscow, 2011

Introduction

Gas-oil vertical water tube steam boiler type DE16 t/h is designed to produce saturated and slightly superheated steam used for the technological needs of industrial enterprises, heating, ventilation and hot water supply systems. The combustion chamber of the boiler is located on the side of the convective beam formed by vertical tubes flared in the upper and lower drums. The width of the combustion chamber along the axes of the side screen pipes is 1790 mm. Main components boilers are upper and lower drums, a convective beam, front, side and rear screens that form the combustion chamber. The pipes of the right side screen, which also forms the floor and ceiling of the combustion chamber, are inserted directly into the upper and lower drums. The front screen pipes are flared in the upper and lower drums. The diameter of the upper and lower drums is 1000 mm. The vertical distance between the drums is 2750 mm. The length of the cylindrical part of the drums is 7500 mm. To access the inside of the drums, there are special holes in the front and rear bottoms of each of them. The material of the drums for boilers with a working pressure of 1.36 MPa and 2.36 MPa is 16GS steel, wall thickness is 13 and 22 mm, respectively. In the water space of the upper drum there is a feed pipe and a pipe for introducing phosphates, and in the steam volume there are separation devices. The lower drum contains perforated pipes for purging, a device for steam heating of water in the drum during kindling, and pipes for draining water.

Boilers with a steam capacity of 16 t/h have continuous blowing from the second stage of evaporation (salt compartment) of the upper drum and periodic purging from the lower drum of the lower manifold of the rear screen, if available. DE16-14GM boilers are made with a two-stage evaporation scheme. The second stage of evaporation, using transverse partitions in the drums, includes the rear part of the right and left furnace screens, the rear screen and part of the convective beam located in an area with more high temperature gases The second evaporation stage is fed from the first through a bypass pipe with a diameter of 108 mm, passing through the transverse dividing wall of the upper drum. The second stage evaporation circuit has unheated downpipes with a diameter of 159x4.5 mm. The descending link of the circulation circuits of the boilers and the first stage of evaporation are the last, least heated rows of convective bundle pipes along the gas flow. The convective beam is separated from the combustion chamber by a gas-tight partition, in the rear part of which there is a window for gases to enter the beam. The partition is made of pipes with a diameter of 51 x 2.5 mm placed closely (S = 55 mm) and welded together. When inserted into the drums, the pipes are separated into two rows. The wiring points are sealed with metal spacers and chamocrete. Flue gases exit the boilers through a window in the left side wall at the end of the convective beam. All standard sizes of boilers have the same circulation circuit. The contour of the side screens and the convective beam are closed directly to the drum.

The superheater is vertical, drained from two rows of pipes with a diameter of 51 x 2.5 mm.

The lining of the front wall is made of fireclay bricks 125 mm thick and several layers of insulating boards 175 mm thick, the total thickness of the front wall lining is 300 mm; the lining of the rear wall consists of a layer of fireclay bricks 65 mm thick and several layers of insulating boards 200 mm thick. The total thickness of the lining is 265 mm. To reduce suction, the gas path of the boiler outside the insulation is covered with metal sheet cladding 2 mm thick, which is welded to the framing frame.

Cast iron economizers made from VTI pipes are used as boiler tail heating surfaces.

The boilers are equipped with stationary blowers located on the left side of them. For blowing boilers, saturated or superheated steam with a pressure of at least 0.7 MPa is used.

Each DE boiler is equipped with two spring safety valves, one of which is a control valve.

Load control range 20-100% of rated steam output. Operation with a load of 110% of the rated steam output is allowed.

Initial data

Steam capacity - 16 t/h (4.44 kg/s)

Pressure - 1.4 MPa (14 atm)

Feedwater temperature - 95°C

Type of fuel - low-sulfur fuel oil.

Air temperature at the boiler inlet -

Heat capacity of air at -

Flue gas temperature - 200°C

Dry residue of source water - 400 mg/kg

The percentage of condensate return is 50%.

Design characteristics of the DE16-14GM boiler unit:

Firebox volume according to drawings

Full surface of furnace walls according to drawings

Beam-receiving surface of the firebox

Convection pipe diameter

Transverse pipe pitch

Pipe pitch longitudinal

Average pipe height

Flue width

Average flue height

Number of pipes in a row of a flue

Number of rows of flue pipes

Cross section for the passage of gases of the flue

Beam heating surface

1.
Calculation of volumes of air and combustion products

Lowest calorific value liquid fuel:

Theoretical amount of air required to burn 1 m3 of fuel:

The theoretical amount of combustion products formed when burning liquid fuel at an excess air ratio:

Triatomic gases:

diatomic gases:

water vapor:

With excess air ratio >1

The value of the coefficient of excess air in the furnace:

Boiler flue:

Economizer:

The volume of excess air in the combustion products in the boiler elements will be:

Gas flue

Economizer

Excessive volume of water vapor in combustion products by boiler elements:

Gas flue

Economizer

Actual total volume flue gases by boiler elements:

Gas flue

Economizer

Volume fraction of triatomic gases by boiler elements:

Gas flue

Economizer

Volume fraction of water vapor by boiler elements:

Gas flue

Economizer

Total volume fraction for boiler elements:

Gas flue

Economizer

2. Enthalpy of air and combustion products

where , , , are the specific heat capacities of triatomic gases, water vapor, diatomic gases (nitrogen) and air, respectively; their values ​​are given in the table.

Enthalpy of air at the entrance to the boiler:

Enthalpy of the theoretically required volume of air.

Combustion chamber:

Boiler flue:

Economizer:

Enthalpy of the theoretically required volume of combustion products.

Combustion chamber:

Boiler flue:

Economizer:

Enthalpy of combustion products with excess air.

where is the enthalpy of excess air at a temperature corresponding to the temperature of the combustion products.

Combustion chamber:

Boiler flue:

Economizer:

3. Estimated heat balance and fuel consumption

The heat balance of a boiler unit is the equality between the heat supplied to it and the sum of the useful heat generated and the heat spent to cover heat losses. The heat entering the boiler unit is called available heat.

where is the lower calorific value of the working mass of fuel, kJ/kg;

Heat introduced into the boiler unit by air when heating it outside the unit, kJ/kg:

where is the excess air coefficient;

Heat content of the theoretically required amount of air at the entrance to the boiler unit and cold air, kJ/kg;

Physical heat contributed by fuel, kJ/kg:

Where - specific heat working fuel, kJ/(kg K);

Fuel temperature, єС, (for fuel oil is taken depending on its viscosity 90-130 єС:

Heat introduced into the unit during steam spraying of liquid fuel, kJ/kg:

where is the enthalpy of steam used for fuel atomization, kJ/kg.

DE series boilers are equipped with gas-oil burners of the GMGm type, with steam-mechanical atomization with insignificant steam consumption, so the value can be neglected.

The heat balance is compiled for a boiler unit per 1 kg of liquid or 1 m3 of gaseous fuel under normal conditions.

The equation heat balance:

where is the useful heat generated by the boiler unit, kJ/kg;

Heat loss with exhaust combustion products, kJ/kg:

where is the enthalpy of exhaust gases, determined by h-t diagram, at the corresponding values ​​of the excess air coefficient behind the boiler and the selected flue gas temperature, kJ/kg;

Enthalpy of the theoretically required volume of cold air, determined at the temperature of the air entering the boiler.

Heat loss from chemical incomplete combustion, kJ/kg;

Heat loss from mechanical incomplete combustion occurs only when burning solid fuel;

Heat loss in environment(from external cooling), kJ/kg;

Physical heat contributed by fuel during fuel combustion. Can be ignored.

Calculation of the heat balance of the boiler unit.

Enthalpy of air at the inlet to the boiler with the heat capacity of the air at the inlet to the boiler:

Exhaust gas enthalpy:

Heat loss with flue gases:

Heat loss from chemical heat of combustion according to the standard method:

Heat loss from mechanical underburning according to the standard method:

Heat losses from losses to the environment according to the standard method:

Amount of heat losses:

Boiler efficiency:

Fuel calculation.

Boiler steam output - .

Feed water temperature at the water economizer inlet:

Enthalpy of feed water at the inlet to the water economizer:

Enthalpy of steam behind the boiler:

Useful boiler power:

Fuel consumption:

Heat retention coefficient in the firebox:

4. Verification calculation of the combustion chamber

A verification calculation of the furnace of a boiler unit is carried out in order to determine the parameters characterizing the thermal operating conditions of the furnace. The compliance of the temperature of the combustion products at the furnace outlet with the operating conditions is checked.

Flue gas temperature:

Total area of ​​the furnace walls (total area of ​​all surfaces limiting the volume of the combustion chamber (screened and unscreened walls, vault, exit window, floor, etc.)):

Area of ​​the beam-receiving surface of the firebox:

Combustion chamber volume:

Firebox screening degree:

air combustion thermal boiler

Coefficient of contamination or closure of screens (takes into account the decrease in heat absorption of screens due to their contamination or the covering of their surface with a refractory mass):

The average value of the thermal efficiency coefficient of the entire firebox:

Temperature field parameter in the furnace:

Effective thickness of the radiating layer:

Net heat release in the firebox:

Theoretical (adiabatic) combustion temperature according to h-t chart diagrams:

Average total heat capacity of combustion products:

where is the enthalpy of combustion products at the exit from the furnace at accepted temperature combustion behind the firebox with subsequent clarification.

The pressure in the combustion chamber (for fireboxes operating without pressurization) is assumed to be -.

Total partial pressure of triatomic gases in the furnace:

Volume fraction of furnace water vapor - :

Blackness level of the non-luminous part of the flame:

where , is the content of carbon and hydrogen in the working mass of liquid fuel;

The coefficient of excess air in the furnace.

Attenuation coefficient of the luminous part of the gas-oil flame:

Blackness degree of the luminous part of the flame:

Blackness level of the firebox.

where is the coefficient of filling the furnace volume with a luminous flame (depends on the thermal voltage of the furnace volume and the type of compressed fuel, so for regardless of the load for liquid fuel. At , for liquid fuel).

When the coefficient is:

Since the difference between the calculated temperature and the previously set temperature is more than 50°C, a repeated calculation is carried out using the obtained calculated value.

Average total heat capacity of combustion products:

Coefficient of attenuation of rays by triatomic gases:

Coefficient of attenuation of rays by the non-luminous part of the combustion environment:

Blackness level of the non-luminous part of the flame:

Coefficient of attenuation of rays by soot particles:

Attenuation coefficient of the luminous part of the gas-oil flame:

Blackness degree of the luminous part of the flame:

Blackness level of the firebox.

where is the effective degree of blackness of the firebox:

Estimated temperature of flue gases at the furnace outlet:

The temperature falls within the interval, we consider it valid.

Enthalpy of combustion products at the exit from the furnace -

Heat transferred by radiation:

Specific load of the beam-receiving heating surface:

5. Verification thermal calculation of convective heating surfaces

We set two temperatures of the combustion products at the excess air coefficient in the boiler flue: :

Heat given off by combustion products:

where is the heat conservation coefficient;

air suction into the convective heating surface, defined as the difference in the coefficients of excess air at the inlet and outlet of it;

enthalpy of air sucked into the convective surface, at air temperature;

Enthalpy of combustion products in front of the heating surface at ;

Enthalpy of combustion products after the calculated heating surface, determined for two previously accepted temperatures after the convective heating surface:

Temperature pressure in the flue:

where is the temperature of combustion products in front of the design gas duct;

- the temperature of the cooling medium, for steam boilers, is assumed to be equal to the boiling point of water at the actual pressure in the boiler (Appendix 1 - table of saturated water vapor).

Average temperature of combustion products in the flue:

Average speed of combustion products in the flue:

Where - fuel consumption;

- the actual total volume of flue gases in the flue generated during the combustion of 1 kg of liquid fuel with the corresponding excess air ratio;

- open cross-sectional area for the passage of combustion products during transverse flow of smooth pipes.

Heat transfer coefficient by convection from combustion products to the heating surface:

where is the correction for the number of rows of pipes along the flow of combustion products, determined by transverse washing of corridor bundles according to the nomogram (Fig. 3 of the “Training aid for course work”);

The correction for the beam arrangement is determined according to the nomogram (Fig. 3 of the “Teaching and methodological manual for course work”):

The coefficient taking into account the influence of changes in the physical parameters of the flow is determined during the transverse washing of corridor beams according to the nomogram (Fig. 3 of the “Training and methodological manual for course work”):

at - ,

at - ;

Heat transfer coefficient determined by nomogram (Fig. 3 of the “Teaching and methodological manual for course work”):

at - ,

at - .

Thickness of the radiating layer for smooth tube bundles:

The pressure in the gas duct (for boilers operating without pressurization) is assumed to be -.

The total volume fraction of triatomic gases is .

Total partial pressure of triatomic gases in the flue:

Attenuation coefficient by triatomic gases:

Total optical thickness:

Blackness degree of the gas flow:

Contaminated wall temperature:

Where - the temperature of the cooling medium, for steam boilers, is assumed to be equal to the boiling point of water at the actual pressure in the boiler (Appendix 1 - table of saturated water vapor). and is the enthalpy of combustion products after the calculated heating surface at

Rice. 7.19. DE series steam boiler:
1 - upper drum; 2 - pipe for phosphating; 3 - pipeline for supplying feed water; 4 - salt compartment of the drum; 5 - purge pipe; 6 - burner; 7 - gas-tight partition; 8 - right screen; 9 - combustion chamber; 10 - lower drum; 11 - convective beam; 12 - blowing device

The vertical water tube boiler of the DE series (D-shaped with natural (E) circulation) is designed to produce saturated and superheated steam with a temperature of 225 ° C, has several standard sizes with a working steam pressure of 1.4 MPa and a nominal steam capacity of 4; 6.5; 10; 16 and 25 t/h. The boilers are specialized for burning gas and fuel oil, which makes it possible to more fully realize the benefits of these fuels with a high calorific value.
Characteristic design feature boilers of the DE series is the location of the combustion chamber 9 (Fig. 7.19) on the side of the convective beam 11, which prevents heating of the upper drum 1 and significantly reduces the area of ​​the enclosing surfaces. Boilers of all standard sizes have a single transverse profile (the width of the combustion chamber is 1,790 mm, the average height of the firebox is 2,500 mm) and differ only in the length and pattern of gas movement in the convective flue.
The boiler firebox is completely shielded and separated from the convective beam by a gas-tight partition 7, made, like all heat-receiving surfaces of the boiler, from pipes 051 x 2.5 mm. In the rear part of the partition there is a window (festoon) for the passage of gases into the convective beam, which is formed by corridor-located vertical pipes. The pipes of the right screen, which also covers the floor and ceiling of the combustion chamber, as well as the left side screen (partition 7 and festoon) and the convective beam are rolled directly into the upper 1 and lower 10 drums.
The rear screen pipes are attached by welding to the lower and upper manifolds 0159^6 mm. Front screen of steam boilers DE-4; -6.5; -10 is similar to the rear one and differs only in the absence of part of the pipes in the middle (to accommodate the embrasure of burner 6 and the manhole combined with the explosion valve).
For DE-16 and DE-25 boilers, the front screen is formed by four pipes connected directly to the upper and lower drums. The furnace area is covered with a layer of refractory brick. One oil-gas burner is installed on the front wall of DE series boilers: on DE-4 boilers; -6.5 and -10 - vortex burners, respectively, GM-2.5; -4.5; -7 thermal power respectively 2.9; 5 and 8 MW (2.5, 4.5 and 7 Gcal/h); on the DE-16 boiler - a GM-10 burner with a cylindrical embrasure with a thermal power of 11.6 MW (10 Gcal/h); on the DE-25 boiler there is a two-stage combustion chamber with a GM-16 burner with a thermal power of 18.6 MW (16 Gcal/h).
The flow diagram of gases in DE boilers is shown in Fig. 7.18, b, c. Flue gases pass through the furnace and enter through the window in the partition into the convective beam. Boilers with steam capacity 4; 6.5 and 10 t/h have longitudinal partitions in convective bundles, which ensures the reversal of gases in the bundle and the exit of gases through the rear wall of the boiler (see Fig. 7.18, b). Boilers with a steam capacity of 16 and 25 t/h do not have such partitions (see Fig. 7.18, c). The transfer of flue gases from the front zone of the boilers to the economizer located at the rear is carried out through a gas box, which is located above the combustion chamber.
The contours of the side screens and the convective beam of all standard sizes of boilers, as well as the front screen of boilers with a steam capacity of 16 and 25 t/h, are directly connected to the drums, and the contours of the rear screen of all boilers and the front screen of boilers with a steam capacity of 4; 6.5 and 10 t/h - through intermediate collectors, with the lower one located horizontally and the upper one inclined.
Boilers with steam capacity 4; 6.5 and 10 t/h do not have stepwise evaporation. At the same time, boilers with a steam capacity of 16 and 25 t/h have a staged evaporation system with an inside-drum salt compartment 4 (see Fig. 7.19). The stepwise evaporation of water in the boiler unit makes it possible to improve the quality of steam (reduce the salt content of steam with a reduced amount of continuous blowing).
The first rows of convective bundle tubes along the gas flow are separated into the second stage of evaporation. The lowering system of the salt compartment circuit consists of unheated pipes 0159 x 4.5 mm (two pipes for a boiler with a steam capacity of 16 t/h and three pipes for a boiler with a steam capacity of 25 t/h). The downward system of the first stage of evaporation includes the last convective beam pipes along the gas flow.
Shields and visors installed in the upper drum are used as separation devices for the first stage of evaporation, directing the steam-water mixture from the screen pipes to the water level. To equalize the steam velocity along the entire length, the boiler drum is equipped with a perforated steam receiving ceiling. On all boilers except the boiler with a steam capacity of 4 t/h, a horizontal louvered separator is installed in front of the steam receiving ceiling. Feed water enters the water space of the drum through pipeline 3. To carry out intra-boiler water treatment - phosphating - through special pipe 2, an aqueous solution of trisodium phosphate is fed into the upper drum, which enters chemical reaction with salts dissolved in boiler water, transforming them into an insoluble state. The resulting sludge enters the lower drum through downpipes.
In the lower drum there are perforated pipes through which all boiler purging is carried out for boilers with a steam capacity of 4...10 t/h. On boilers with a steam capacity of 16...25 t/h, only periodic blowing of the boiler is carried out through these pipes, and continuous blowing is carried out from the salt compartment of the upper drum.
To monitor the operation of the boiler, a boiler pressure gauge and two water indicator glasses are located in the upper drum. In addition, two safety valves, a main steam shut-off valve, and steam extraction pipelines for auxiliary needs are installed on the upper drum. The boilers are equipped with 12 blowers to clean heating surfaces from contaminants. The lining of the side walls of the boiler is made of pipes and consists of fireclay concrete on a grid and insulating slabs. To reduce leaks into the gas path of the boiler, the outside of the pipe lining is covered with metal sheet casing, which is welded to the framing frame. The tail heating surfaces of the boiler are free-standing standard cast iron economizers. Depending on the performance, the boiler efficiency is 90.3...92.8% when operating at gas fuel and 88.7...91.4% when working on fuel oil.

The main elements of boilers are:

1.Upper and lower drums;

3.The left combustion screen is gas-tight;

5. The right combustion screen, the pipes of which are made in the form and overlap the ceiling and bottom part fireboxes (under);

5.Front screen;

6.Rear screen;

7.Two manifolds of the rear combustion screen, made 0 159 * 6 mm;

8. Convective tube bundle;

9. Brickwork;

10.Metal frame;

11.Metal casing;

12.Headset;

13.Fittings;

14.Control and measuring instruments;

15. Three lower pipes, 0 159 * 6 mm for boilers with a steam capacity of up to 16 t/h and 0 219 * 6 mm for DE-25-14 boilers;

16. Recirculation pipe of the rear screen;

17.The blowing device is located on the left side of the convective beam;

18. Boiler piping.

The boiler drums are made of high-quality steel grade 16 GS, inner diameter 1000 mm. The thickness of the drum walls is 13 mm. The convective beam is made along the entire length of the drums from pipes with a diameter of 51ˣ2.5 mm. The left combustion screen is made of pipes 0 51*4 mm. The right combustion screen, front and rear screens are made of pipes d = 51˟2.5 mm. Two rear screen collectors are made of pipes d = 159ˣ6 mm. The recirculation pipe is made of a pipe with a diameter of 76ˣ3.5 mm. Three down pipes with a diameter of 259ˣ6 mm (boilers DE-25-14).

The length of the cylindrical part of the drums increases from 2250 mm for DE-4-14 boilers to 7500 mm for DE-25-14 boilers. The center-to-center distance of the drums is 2750 mm. For access to the inside of the drums, there are manholes in the front and rear bottoms of the drums.

The width of the convective beam is 890 mm for boilers 4; 6.5 and 16 tons of steam and 1000 mm for boilers with a steam capacity of 10 and 25 tons of steam per hour.

The pitch of the convective bundle pipes along the drums is 90 mm, transverse - 110 mm. The middle row of convective bundle pipes along the axis of the drums has a pitch of -120 mm. The pipes of the outer row of the convective bundle have a longitudinal pitch of -55 mm. At the entrance to the drums, the pipes are separated into two rows.

In convective bundles of boilers with a steam capacity of 4; 6.5 and 10 tons of steam per hour, to ensure the required flue gas velocities, longitudinal steel partitions are installed

Boilers with a steam capacity of 16 and 25 tons of steam per hour do not have partitions in the convective beam, and the speed of movement of the flue gases is maintained by changing the width of the convective beam (1000 mm).

The convective beam is separated from the combustion chamber by a gas-tight left combustion screen. Gas tightness is ensured by registering metal plates between the pipes along their entire height from the lower drum to the upper drum.

At the rear of the left combustion screen metal plates(spacers) do not install the pipes of the rear part of the convective bundle are made in a corridor and form “windows” for the flow of flue gases from the furnace into the convective bundle.

The areas where the screen pipes are routed at the entrance to the drums are compacted with chamotte concrete.

The pipes of the right combustion screen form the bottom and ceiling of the firebox.

Front screen pipes in the amount of 4 or 2 (various modifications of boilers) border the burner embrasure on the right and left and are inserted into the upper and lower drums (see in the figure).

Boiler DE-25-14 GM (Rear view)

The cross-section of the combustion chamber is the same for all boilers. The average height of the combustion chamber is 2400 mm, width 1790 mm. The depth of the combustion chamber increases with increasing boiler steam production from 1930 mm for DE-4-14 boilers to 6960 mm for boilers with 25 tons of steam per hour.

The main part of the pipes of the convective bundle, the right combustion screen, as well as the pipes of the front screen are connected to the drums by flaring.

The pipes of the gas-tight partition, as well as part of the pipes of the right combustion screen and the outer row of the convective beam, are welded to the drums by electric welding.

The pipes of the rear furnace screen are welded to the lower and upper collectors 0 159 * 6 mm. The collectors, in turn, are welded to the upper and lower drums.

The ends of the collectors on the side opposite the drums are connected by an unheated recirculation pipe 0 76 * 3.5 mm.

On all boilers, to protect against overheating on the combustion side of the recirculation pipe and the collectors and pipes of the rear screen, two tubes 0 51 * 2.5 mm are installed in the combustion chamber, connected to the drums by flaring (see Fig. No. 2, page 6).

DE boilers with a steam capacity of up to 10 t/h have four circulation circuits:

Water circulation circuit of the convective beam and the left combustion screen;

Circulating water circuit of the right combustion screen;

Front screen water circulation circuit;

Water circulation circuit of the rear combustion screen.

In boilers DE-16-14 and DE-25-14, which have partitions inside the drums and 2-stage evaporation, water circulation is much more complicated.

Boilers with steam capacity 4; 6.5 and 10 tons of steam per hour work with single-stage evaporation. In boilers with a steam capacity of 16 and 25 tons of steam per hour, 2-stage evaporation is used. For these purposes, the drums are made metal partitions dividing the drums into two compartments: a large compartment - finishing and a small compartment - salt. In the upper drum, the partition is not continuous, that is, it does not cover the entire diameter of the drum.

A solid partition is installed in the lower drum.

In the second stage of evaporation, using transverse partitions in the drums, the following are placed:

Rear part of the left and right firebox screens;

Rear screen;

Part of a convective bundle of pipes located in an area with higher flue gas temperatures.

The second stage of the upper drum is supplied with water through an overflow pipe 0133 mm long, at least 2 meters long, passing through the dividing partition of the upper drum.

The second stage evaporation circuit has three lower unheated pipes 0159*6 mm, for DE boilers with a steam capacity of up to 16 tons of steam per hour and 0219*6 mm for DE-25-14 boilers.

The drainage system of the salt compartment circuit consists of unheated pipes. The downward system of the first stage of evaporation consists of the last rows of convective bundle pipes along the gas flow.

The steam volume of the upper drum contains separation devices: a perforated metal sheet and plate separators.

In the water volume of the upper drum there is a feed pipe and a pipe for introducing chemical reagents. Guide shields and visors for cleaning steam from hardness salts.

The upper drum of the boiler also contains stilling columns and impulse tubes from the finishing and salt compartments to the water level indicators.

Water level indicators are connected to pipes (impulse pipes) coming from the steam and water volumes from the finishing and salt compartments of the upper drum.

PURPOSE OF THE PRODUCT

DE boilers are double-drum, vertical-water-tube boilers designed to produce saturated or slightly superheated steam used for the technological needs of industrial enterprises, heating, ventilation and hot water supply systems.

The main technical characteristics of the DE-16-14GMO boiler are given in the table.

Price
RUB 4,800,000

Model specifications

PRODUCT DESCRIPTION

The combustion chamber of the boilers is located on the side of the convective beam, equipped with vertical pipes flared in the upper and lower drums. The width of the combustion chamber along the axes of the side screen pipes is the same for all boilers - 1790 mm. Combustion chamber depth: 1930 - 6960 mm. The main components of the boilers are the upper and lower drums, the convective beam, the front, side and rear screens that form the combustion chamber.

The pipes of the gas-tight partition and the right side screen, which also forms the ceiling of the combustion chamber, are inserted directly into the upper and lower drums. The ends of the rear screen pipes are welded to the upper and lower collectors Ф 159х6 mm. The front screen pipes of the DE-16-14GMO boiler are flared in the upper and lower drums.

In all standard sizes of DE boilers, the diameter of the upper and lower drums is 1000 mm. The distance between the axes of the drums is 2750 mm (the maximum possible under the conditions of transporting the block by rail). Length of the cylindrical part of the boiler drums with capacity

10 t/h - 6000 mm. For access to the inside of the drums, there are manhole gates in the front and rear bottoms of each of them. Drums for boilers with operating absolute pressure of 1.4 and 2.4 MPa (14 and 24 kgf/cm 2) are made from steel sheet in accordance with GOST 5520-79 from steel grades 16GS and 09G2S GOST 19281-89 and have a wall thickness of 13, respectively and 22 mm.

In the water space of the upper drum there is a feed pipe and a pipe for introducing phosphates, and in the steam volume there are separation devices. The lower drum contains a device for steam heating of water in the drum during kindling and pipes for draining water; for boilers with a capacity of 16 t/h, there are perforated pipes for periodic purging.

Boilers with a steam capacity of 16 t/h use two-stage evaporation. The second evaporation stage includes the rear part of the furnace screens and part of the convective beam, located in the zone with a higher gas temperature. The second stage evaporation circuits have an unheated downdraft system.

The convective beam is separated from the combustion chamber by a gas-tight partition, in the rear part of which there is a window for the entry of gases into the beam. The partition is made of pipes Ø 51x2.5 mm placed closely with a pitch of 5 = 55 mm and welded together. When inserted into drums and pipes, they are separated into two rows. The distribution points are sealed with metal spacers and chamotte concrete. The convective bundle is formed by vertical pipes Ø 51 x 2.5 mm arranged in a corridor, flared in the upper and lower drums. The pitch of the pipes along the drum is 90 mm, the transverse pitch is 110 mm (except for the average pitch, which is 120 mm).

DE-16-14GMO boilers do not have stepped partitions in the bundle, but required level gas velocities are maintained by changing the beam width from 890 to 1000 mm. Flue gases pass across the entire cross-section of the convective beam and exit through the front wall into the gas box, which is located above the combustion chamber, and through it they pass to the economizer located at the rear of the boiler.

All boiler sizes have the same circulation scheme. The contours of the side screens and the convective beam of all standard sizes of boilers, as well as the front screen of boilers with a steam capacity of 16 t/h, are closed directly to the drums; the contours of the rear screen of all boilers are connected to the drum through intermediate collectors: the lower one is distributing (horizontal) and the upper one is collecting (inclined). The ends of the intermediate collectors on the side opposite to the drums are united by an unheated recirculation pipe Ф 76 x 3.5 mm.

As the primary separation devices of the first stage of evaporation, guide shields and canopies installed in the upper drum are used, ensuring the delivery of the steam-water mixture to the water level. A horizontal louvered separator and a perforated sheet are used as secondary separation devices of the first stage of the DE-16-14GMO boiler. Separation devices The second stage of evaporation consists of longitudinal shields that ensure the movement of the steam-water mixture, first to the end, and then along the drum to the transverse partition separating the compartments. The staged evaporation compartments communicate with each other via steam through a window above the transverse partition, and via water through a feed pipe Ø 89 - 108 mm, located in the water volume.

On boilers with a capacity of 16 t/h, the superheater is vertical, drained, made of two rows of pipes Ø 51x2.5 mm, the outer row pipes when entering the collectors Ø 159 mm are cased to Ø 38 mm.

Dense shielding of the side walls (relative pitch of the pipes a = 1.08), ceiling and bottom of the combustion chamber makes it possible to use light insulation on boilers in two to three layers of insulating boards with a total thickness of 100 mm, laid on a layer of fireclay concrete on a grid 15-20 mm thick. For DE-16-14GMO boilers, the front wall lining is made of fireclay bricks 125 mm thick and several layers of insulating boards 175 mm thick, the total thickness of the front wall lining is 300 mm. The lining of the rear wall consists of a layer of fireclay bricks 65 mm thick and several layers of insulating boards 200 mm thick; the total thickness of the lining is 265 mm. To reduce suction into the gas path of the boiler, the insulation is covered from the outside with metal sheet cladding 2 mm thick, which is welded to the frame. Cut sheathing sheets are supplied by the factory in packages. The use of pipe lining with a tight pipe pitch can improve the dynamic characteristics of boilers and significantly reduce heat losses to the environment, as well as losses during start-ups and shutdowns.

Standard cast iron economizers EB, proven by long-term operating experience, are used as tail heating surfaces of boilers.

The boilers are equipped with stationary blowers located on the left side of the boiler. For blowing boilers, saturated or superheated steam with a pressure of at least 0.7 MPa (7 kgf/cm2) is used.

All boilers have a support frame to which the mass of the boiler elements operating under pressure, the mass of boiler water, as well as the mass of the piping frame, pipe lining and lining are transferred. The fixed supports of the boilers are the front supports of the lower drum. The middle and rear supports of the lower drum are movable and have oval holes for bolts that are attached to the support frame during transportation.

Each boiler E (DE) is equipped with two spring safety valves, one of which is a control valve. On boilers without a superheater, both valves are installed on the upper drum of the boiler and any of them can be selected as a control valve; on boilers with a superheater, the control valve is the valve of the superheater outlet manifold.

Nominal steam output and steam parameters corresponding to GOST 3619-89,

are provided at a feed water temperature of 100°C when burning fuels: natural gas with a specific heat of combustion of 29300 - 36000 kJ/kg (7000 - 8600 kcal/m3) and fuel oil grades 40 and 100 according to GOST 10588-75.

The control range is from 20 to 100% of the nominal steam output. Short-term operation with a load of 110% of the rated steam output is allowed. Maintaining the superheat temperature in boilers with steam superheaters is ensured in the load range of 70-100%

DE-16-14GMO boilers can operate in the pressure range of 0.7-1.4 MPa (7-14 kgf/cm2). With a decrease in operating pressure, the boiler efficiency does not decrease.

In boiler houses designed to produce saturated steam without imposing strict requirements on its quality, the steam production of DE type boilers at pressures reduced to 0.7 MPa (7 kgf/cm2) can be taken the same as at a pressure of 1.4 MPa ( 14 kgf/cm 2).

For type E (DE) boilers, the throughput of the safety valves corresponds to the rated output of the boiler at an absolute pressure of at least 0.8 MPa (8 kgf/cm2). If the heat-using equipment connected to the boiler has a maximum operating pressure less than the values ​​indicated above, to protect this equipment it is necessary to install additional safety valves. When operating at reduced pressure, the safety valves on the boiler and additional safety valves installed on the equipment must be adjusted to the actual operating pressure.

With a decrease in pressure in boilers to 0.7 MPa (7 kgf/cm2), changes in the configuration of boilers with economizers are not required, since in this case the underheating of water in feed economizers to the steam saturation temperature in the boiler is more than 20 ° C, which satisfies requirements of Rostechnadzor rules.

Boilers are supplied in assembled form one transportable unit, including upper and lower drums with intra-drum devices, a pipe system of screens and a convective beam (if necessary, a superheater), a support frame, a piping frame, casing, insulation, and a burner.