Biomass gas organic heat carrier boiler combustion chamber

Abstract

The invention discloses a biomass gas organic heat carrier boiler combustion chamber, and belongs to the technical field of boilers, the combustion chamber comprises a shell internally provided with a hearth, a combustor arranged at the front end of the shell, a furnace arch arranged above the hearth and a tail furnace wall arranged at the tail end of the hearth, and a first oil cooling pipe is arranged in the furnace arch; and a second oil cooling pipe is arranged in the tail furnace wall. The oil cooling pipes are arranged in the tail furnace wall and the furnace arch opposite to flames, heat conduction oil is used for cooling the tail furnace wall and the furnace arch, and the collapse risk of the furnace arch and the tail furnace wall is reduced; the extension lines of the first smoke inlet pipe and the second smoke inlet pipe are tangent to the minimum circle surrounding the flame, after smoke on the two sides enters the hearth, the flame is combusted like cyclone, the temperature field is more balanced, and combustion is more sufficient; the oil cooling pipe serves as an internal supporting structure of the furnace arch and the tail furnace wall, and collapse of the furnace arch and the tail furnace wall is effectively prevented; cooling equipment does not need to be independently arranged, energy is saved, consumption is reduced, and heat conduction oil entering the high-temperature heating surface of the boiler can be preheated.

Description

Technical Field

[0001] The invention belongs to the technical field of boilers, and in particular relates to a combustion chamber of a biomass gas organic heat carrier boiler. Background Art

[0002] The development and utilization of various new energy sources are of great significance to sustainable development. Biomass energy has gradually gained favor from the society due to its renewable, low-pollution, wide distribution, and abundant total amount. Biomass gas is a high-grade combustible gas produced by heating solid biomass in a gasifier, which contains a large amount of tar and dust. Organic heat carrier boilers generally refer to hot oil boilers, which use heat transfer oil as the medium, use hot oil circulation pumps to force the medium to circulate in liquid phase, and then return the heat energy to the heating equipment and then return to the heating furnace for reheating. When biomass gas is used as the fuel of an organic heat carrier boiler, it needs to enter the adiabatic combustion chamber through a burner for combustion. After the high-temperature flue gas enters each heating surface for heat exchange in turn, the tail gas is finally discharged into the atmosphere after treatment. Flue gas recirculation technology is widely used in oil and gas industrial boilers. Part of the flue gas is extracted from the boiler outlet and directly enters the furnace, which reduces the oxygen content and combustion temperature in the furnace and reduces the generation of NOx.

[0003] There are some problems with the existing biomass gas organic heat carrier boiler. The traditional adiabatic combustion chamber has a high temperature and is prone to generate thermal NO X The combustion area is concentrated, the temperature field is uneven, the furnace wall and the tail end of the furnace arch facing the flame are prone to collapse, the high-temperature resistant furnace wall and insulation pouring cost is high and the process is complicated, and tar and dust are wrapped together and gathered at the bottom of the furnace wall and are difficult to clean. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a biomass gas organic heat carrier boiler combustion chamber to reduce the risk of collapse of the furnace arch and the furnace wall directly facing the flame.

[0005] Technical solution: In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] A biomass gas organic heat carrier boiler combustion chamber comprises a shell with a furnace arranged inside, a burner arranged at the front end of the shell and used to form a flame in the furnace, a furnace arch arranged above the furnace and a tail furnace wall arranged at the rear end of the furnace, a first oil cooling pipe is arranged in the furnace arch, and a second oil cooling pipe is arranged in the tail furnace wall.

[0007] Preferably, an oil inlet pipe connected to the first oil cooling pipe is provided on the shell, the second oil cooling pipe is connected to the first oil cooling pipe, and an oil outlet pipe connected to the second oil cooling pipe is provided on the shell.

[0008] Preferably, a plurality of first oil cooling pipes are arranged side by side, and the diameter of the first oil cooling pipe is D1 The center distance between adjacent pipes in the plurality of first oil cooling pipes is A, and A≥2D 1 .

[0009] Preferably, a plurality of second oil cooling pipes are arranged side by side, and the diameter of the second oil cooling pipe is D 2 The center distance between adjacent pipes in the plurality of second oil cooling pipes is B, and the 3D 2 ≤B≤4D 2 .

[0010] Preferably, the fire-facing surfaces of the first oil cooling tube and the second oil cooling tube are both connected with pins.

[0011] Preferably, a recirculating flue gas inlet pipe communicating with the furnace is provided on the side wall of the shell, and the recirculating flue gas inlet pipe comprises a first flue gas inlet pipe located on one side of the shell and a second flue gas inlet pipe located on the other side of the shell.

[0012] Preferably, the plane where the first flue gas inlet pipe and the second flue gas inlet pipe are located longitudinally cuts the flame in the furnace, the smallest circle surrounding the flame on the longitudinal section of the flame is the first circle, the first flue gas inlet pipe is at the same height as the upper end of the first circle, and the second flue gas inlet pipe is at the same height as the lower end of the first circle.

[0013] Preferably, a secondary air nozzle is provided at the rear end of the shell, and a tar air supply pipe is provided at the front end of the shell.

[0014] Preferably, the shell is provided with an ash outlet connected to the bottom of the furnace, and the bottom of the furnace is in the shape of an inverted frustum.

[0015] Preferably, a smoke-isolating wall is arranged above the furnace arch, a soot-blowing pipe is arranged in the smoke-isolating wall, and the soot-blowing pipe comprises a soot-blowing branch pipe facing the top wall of the furnace arch.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0017] 1. Oil cooling pipes are installed in the tail furnace wall and furnace arch facing the flame, and heat transfer oil is used to cool the tail furnace wall and furnace arch, reducing the risk of collapse of the furnace arch and tail furnace wall;

[0018] 2. Set up a recirculating flue gas inlet pipe to reduce the combustion temperature in the furnace and reduce NO X The recirculating flue gas inlet pipe is divided into a first flue gas inlet pipe and a second flue gas inlet pipe on both sides. The extension lines of the first flue gas inlet pipe and the second flue gas inlet pipe are tangent to the minimum circle surrounding the flame. After the flue gas on both sides enters the furnace, the flame burns like a cyclone, the temperature field is more balanced, and the combustion is more complete.

[0019] 3. The gap between the oil cooling pipes is relatively appropriate, which can ensure the cooling effect while maintaining a certain strength. The oil cooling pipes serve as the internal supporting structure of the furnace arch and the tail furnace wall, effectively preventing the collapse of the furnace arch and the tail furnace wall, and the maintenance and replacement are also relatively simple;

[0020] 4. An ash collecting trough is set at the bottom of the furnace, where dust is relatively concentrated, making it easy to clean;

[0021] 5. Set up secondary air nozzles. Set butterfly valves on the secondary air nozzles and the recirculating flue gas inlet pipes to adjust the air volume so that the boiler always maintains the best thermal efficiency;

[0022] 6. The heat transfer oil of the oil cooling tube uses the heat transfer oil after heat exchange and cooling in the organic heat carrier boiler. There is no need to set up a separate cooling device, which saves energy and reduces consumption. It can also preheat the heat transfer oil entering the high-temperature heating surface of the boiler, thereby increasing the heating speed of the boiler heat transfer oil.

[0023] 7. Overall modular transportation, simple and convenient installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of a combustion chamber according to an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of the cross-sectional structure of the combustion chamber of an embodiment;

[0026] Figure 3 is a schematic diagram of the cross-sectional structure of the ash outlet of the embodiment;

[0027] Figure 4 2 is a schematic diagram of the first oil cooling tube spacing structure of the embodiment;

[0028] Figure 5 2 is a schematic diagram of the oil cooling tube spacing structure of the second embodiment;

[0029] Figure 6 Schematic diagram of the pin distribution structure on the first oil cooling tube of the embodiment;

[0030] Figure 7 Schematic diagram of the angle of the pins on the oil cooling tube of the embodiment;

[0031] Figure 8 It is a schematic diagram of the pin distribution structure on the second oil cooling tube of the embodiment. DETAILED DESCRIPTION

[0032] The present invention is further illustrated below in conjunction with specific examples. The examples are implemented based on the technical solutions of the present invention. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0033] like Figure 1 , Figure 2 and Figure 3As shown, a biomass gas organic heat carrier boiler combustion chamber includes a shell 1 and a burner 3. The shell 1 is in a rectangular shape as a whole. The furnace 2 is located in the shell 1. The shell 1 includes a first refractory layer 15, a second refractory layer 16, an ultra-heat-resistant insulation layer 17, a heat-resistant insulation layer 18 and an insulation layer 19. The first refractory layer 15 is located below the furnace 2 and is located at the innermost layer of the shell 1. The first refractory layer 15 is cast with concrete with a fire resistance of ≥1400°C. It is required to be tight and airtight, control the flame shape, prevent smoke from entering the external insulation layer, and damage the insulation and the outermost support. Steel structure, a furnace arch 21 is arranged in the shell 1, the furnace arch 21 is made of the same material as the first refractory layer 15, the furnace arch 21 is located above the furnace 2, the furnace 2 is between the first refractory layer 15 and the furnace arch 21, and the second refractory layer 16, the super heat-resistant thermal insulation layer 17, the heat-resistant thermal insulation layer 18 and the thermal insulation layer 19 are arranged on the side wall of the shell 1 from the inside to the outside. The second refractory layer 16 adopts high-alumina refractory bricks with a refractoriness of 1750 degrees Celsius, the super heat-resistant thermal insulation layer 17 adopts zirconium-containing ceramic fiber wool, the heat-resistant thermal insulation layer 18 is perlite concrete, and the thermal insulation layer 19 adopts thermal insulation rock wool board. The burner 3 is arranged at the front end of the shell 1. In this embodiment, the burner 3 adopts an existing gas burner, and the gas source adopts biomass gas. The biomass gas enters the furnace 2 through the burner 3 and burns. When the burner 3 is working, a flame is formed in the furnace 2. The high-temperature flue gas passes through the furnace arch 21 and the tail furnace wall 22 and passes through the boiler heating surface in turn, and is finally discharged into the atmosphere after being treated by environmental protection equipment.

[0034] like Figure 1 , Figure 2 and Figure 3As shown, the furnace arch 21 is arranged above the furnace 2, and the tail furnace wall 22 is arranged at the tail end of the furnace 2 and is located directly opposite to the flame. The tail furnace wall 22 is made of high-aluminum refractory bricks and concrete. It is built with high-aluminum refractory bricks and then poured with refractory concrete to form a whole with the brick wall. A plurality of first oil cooling pipes 41 arranged side by side are provided in the furnace arch 21. The first oil cooling pipes 41 are arranged horizontally. The plurality of first oil cooling pipes 41 are arranged at the tail end of the furnace arch 21. Both sides of the plurality of first oil cooling pipes 41 are connected to the side manifold 45. The side manifold 45 is arranged on both sides of the shell 1. An oil inlet pipe 43 connected to the first oil cooling pipe 41 is provided on the front end of the shell 1. The oil inlet pipe 43 is connected to the heat transfer oil pipeline of the organic heat carrier boiler. The heat transfer oil after heat exchange and cooling of the boiler first enters the side manifold 45 on the left side through the oil inlet pipe 43, and then enters the side manifold 45 on the right side after passing through the plurality of first oil cooling pipes 41. The heat transfer oil completes heat exchange with the refractory layer of the furnace arch 21 at the first oil cooling pipe 41, thereby reducing the temperature of the refractory layer at the furnace arch 21 and reducing the risk of collapse of the furnace arch 21. A plurality of second oil cooling pipes 42 are arranged side by side in the tail furnace wall 22. The second oil cooling pipes 42 are arranged vertically. The lower ends of the plurality of second oil cooling pipes 42 are connected to the bottom manifold 46. The upper ends of the plurality of second oil cooling pipes 42 are connected to the top manifold 47. The bottom manifold 46 is connected to the side manifold 45 on the right side. The heat transfer oil enters the bottom manifold 46 from the side manifold 45 on the right side, and then enters the top manifold 47 after passing through the plurality of second oil cooling pipes 42 upward. The heat transfer oil exchanges heat with the refractory layer of the tail furnace wall 22 at the second oil cooling pipes 42, thereby reducing the heat transfer of the tail furnace wall. 22 collapse risk, an oil outlet pipe connected with the second oil cooling pipe 42 is provided on the shell 1, the top manifold 47 is connected with the oil outlet pipe, the heat transfer oil enters the oil outlet pipe from the top manifold 47, the oil outlet pipe is connected with the heat transfer oil pipeline of the organic heat carrier boiler, the heat transfer oil is discharged from the oil outlet pipe to the shell 1 and returns to the high-temperature heating surface of the boiler to continue to circulate and absorb heat, the heat transfer oil passing through the first oil cooling pipe 41 and the second oil cooling pipe 42 is preheated while protecting the furnace arch 21 and the tail furnace wall 22, thereby improving the heat exchange rate of the heat transfer oil on the high-temperature heating surface of the boiler.

[0035] like Figure 4 and Figure 5 As shown, the outer diameter of the first oil cooling pipe 41 is D 1 The center distance between adjacent pipes in the plurality of first oil cooling pipes 41 is A, A≥2D 1 In this embodiment, A=2D 1 , to ensure the cooling effect, cool the furnace arch 21 and serve as the internal support structure of the furnace arch 21, effectively preventing the arch from collapsing. The first oil cooling pipe 41 is made of DN80 steel pipe. The diameter of the second oil cooling pipe 42 is D 2 The center distance between adjacent pipes in the plurality of second oil cooling pipes 42 is B, 3D 2 ≤B≤4D 2 In this embodiment, B = 3D 2To ensure the cooling effect, the second oil cooling pipe 42 in this embodiment is made of a DN50 steel pipe, which cools the tail furnace wall 22 and serves as an internal supporting structure of the tail furnace wall 22, thereby effectively preventing the collapse of the tail furnace wall 22.

[0036] like Figure 6 , Figure 7 and Figure 8 As shown, the fire-facing surfaces of the first oil cooling tube 41 and the second oil cooling tube 42 are connected with a plurality of pins 401, and the pins 401 are spaced apart along the axial direction of the oil cooling tubes (the first oil cooling tube 41 and the second oil cooling tube 42), and the extension lines of the pins 401 on the same plane pass through the center of the cross section of the oil cooling tube on the plane, and the adjacent pins 401 on the same plane form an angle α, α=45°. The fire-facing surfaces of the first oil-cooling pipe 41 and the second oil-cooling pipe 42 are cast with a refractory layer, and the thickness of the refractory layer on the fire-facing side is greater than or equal to 100 mm. Before casting the refractory layer, asbestos rope needs to be wrapped around the oil-cooling pipe to facilitate expansion. When the furnace arch 21 is cast, refractory concrete is cast on the first oil-cooling pipe 41, and the casting thickness on the fire-facing side is greater than or equal to 100 mm. After casting, the furnace arch 21 is formed, and the tail furnace wall 22 is first built with refractory bricks, and asbestos rope is wrapped around the second oil-cooling pipe 42, and then refractory concrete is cast and integrated with the brick wall to form the tail furnace wall 22.

[0037] like Figure 1 and Figure 2 As shown, a recirculating flue gas inlet pipe 5 is provided on the side wall of the shell 1, and the inlet end of the recirculating flue gas inlet pipe 5 is connected to the boiler flue gas outlet, and the outlet end of the recirculating flue gas inlet pipe 5 is communicated with the furnace 2, and the outlet end of the circulating flue gas inlet pipe 5 is connected to the side wall of the shell 1 near the front end, and the recirculating flue gas inlet pipe 5 includes a first flue gas inlet pipe 51 located on the right side of the shell 1 and a second flue gas inlet pipe 52 located on the left side of the shell 1, and the first flue gas inlet pipe 51 and the second flue gas inlet pipe 52 can be arranged in multiple groups, and the plane where the first flue gas inlet pipe 51 and the corresponding second flue gas inlet pipe 52 are located longitudinally cuts the flame in the furnace 2, and the smallest circle surrounding the flame on the longitudinal section of the flame is the first circle 201, and the first flue gas inlet pipe 51 and the upper end of the first circle 201 are at the same height, so that the extension line of the first flue gas inlet pipe 51 is tangent to the first circle 201, and the second flue gas inlet pipe 52 and the lower end of the first circle 201 are at the same height, so that the extension line of the second flue gas inlet pipe 52 is tangent to the first circle 201. During operation, biomass gas and combustion-supporting air are mixed in the burner 3 and then enter the furnace 2 through the burner 3 to burn. Part of the recycled flue gas extracted from the boiler flue gas outlet enters the furnace 2 from the recycled flue gas inlet pipe 5 on both sides to disturb the flame, forming a cyclone-like combustion, strengthening the disturbance in the furnace to facilitate the combustion of biomass gas, making the temperature field more uniform and avoiding local high temperature.

[0038] like Figure 1 and Figure 3As shown, the rear end of the shell 1 is provided with a secondary air nozzle 61, which penetrates the multi-layer structure of the shell 1 and the tail furnace wall 22 and is connected to the furnace 2. The secondary air nozzle 61 appropriately supplements air to assist combustion according to the oxygen content of the tail exhaust gas, so that the gas can be burned as much as possible while avoiding excessive cold air from entering, so as to maximize the thermal efficiency of the system. A butterfly valve (the butterfly valve is not shown in the figure, and the existing butterfly valve is used) is provided on the secondary air nozzle 61 and the recycled flue gas inlet pipe 5 to adjust the air volume. The front end of the shell 1 is provided with a tar air supply pipe 62, which penetrates the multi-layer structure of the shell 1 and is connected to the furnace 2. The tar air supply pipe 62 blows compressed air into the inside through the pipe every 24 hours, so that the tar leaking to the bottom of the burner 3 is lifted up and burned completely, and each blowing time is greater than 20 minutes. The bottom of the furnace 2 is in the shape of an inverted cone to form an ash collecting trough. An ash outlet 23 is provided on the side wall of the shell 1 near the tail end. The ash outlet 23 is connected to the ash collecting trough at the bottom of the furnace 2 to collect dust during equipment operation. It is convenient for personnel to clean and discharge ash when the furnace is shut down regularly. The ash collecting trough is in the shape of an inverted cone to reduce the accumulation of dust in the corners.

[0039] like Figure 1 and Figure 2 As shown, a smoke-proof wall 7 is arranged above the furnace arch 21. The smoke-proof wall 7 is located above the furnace arch 21 to prevent high-temperature flue gas from directly entering the convection tube bundle to release heat and cause safety accidents. The soot-blowing pipe 8 is cast in the smoke-proof wall 7. The soot-blowing pipe 8 includes a soot-blowing branch pipe 81. The outlet end of the soot-blowing branch pipe 81 faces the top wall of the furnace arch 21, and is used to blow soot on the top wall of the furnace arch 21, and blow the dust accumulated on the furnace arch 21 into the ash collecting trough at the bottom of the furnace 2. The inlet end of the soot-blowing pipe 8 is connected to the flue gas outlet of the boiler. The soot-blowing pipe 8 can use part of the recycled flue gas for soot-blowing, so as to avoid the situation that the oxygen content of the final exhaust gas increases and the boiler efficiency is reduced when air is used for soot-blowing. When the boiler is running, the excess ash can be scraped out through the ash outlet 23. When the boiler is shut down, the dust in the furnace is thoroughly cleaned and transported out of the boiler through the ash outlet 23.

[0040] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A biomass gas organic heat carrier boiler combustion chamber, characterized in that: The invention comprises a shell (1) in which a furnace (2) is arranged, a burner (3) arranged at the front end of the shell (1) and used to form a flame in the furnace (2), a furnace arch (21) arranged above the furnace (2), and a tail furnace wall (22) arranged at the tail end of the furnace (2), wherein a first oil cooling pipe (41) is arranged in the furnace arch (21), and a second oil cooling pipe (42) is arranged in the tail furnace wall (22).

2. The biomass gas organic heat carrier boiler combustion chamber according to claim 1, characterized in that: The shell (1) is provided with an oil inlet pipe (43) connected to the first oil cooling pipe (41), the second oil cooling pipe (42) is connected to the first oil cooling pipe (41), and the shell (1) is provided with an oil outlet pipe connected to the second oil cooling pipe (42).

3. The biomass gas organic heat carrier boiler combustion chamber according to claim 2 is characterized in that: A plurality of the first oil cooling tubes (41) are arranged side by side, the diameter of the first oil cooling tubes (41) is D1, and the center distance between adjacent tubes in the plurality of first oil cooling tubes (41) is A, wherein A≥2D1.

4. The biomass gas organic heat carrier boiler combustion chamber according to claim 2, characterized in that: A plurality of the second oil cooling tubes (42) are arranged side by side, the diameter of the second oil cooling tubes (42) is D2, the center distance between adjacent tubes in the plurality of second oil cooling tubes (42) is B, and 3D2≤B≤4D2.

5. The biomass gas organic heat carrier boiler combustion chamber according to claim 1, characterized in that: The fire-facing surfaces of the first oil cooling pipe (41) and the second oil cooling pipe (42) are both connected with pins (401).

6. The biomass gas organic heat carrier boiler combustion chamber according to claim 1, characterized in that: The side wall of the shell (1) is provided with a recirculating flue gas inlet pipe (5) connected to the furnace (2), and the recirculating flue gas inlet pipe (5) comprises a first flue gas inlet pipe (51) located on one side of the shell (1) and a second flue gas inlet pipe (52) located on the other side of the shell (1).

7. The biomass gas organic heat carrier boiler combustion chamber according to claim 6, characterized in that: The plane where the first smoke inlet pipe (51) and the second smoke inlet pipe (52) are located longitudinally cuts the flame in the furnace (2), and the smallest circle surrounding the flame on the longitudinal section of the flame is a first circle (201). The first smoke inlet pipe (51) and the upper end of the first circle (201) are at the same height, and the second smoke inlet pipe (52) and the lower end of the first circle (201) are at the same height.

8. The biomass gas organic heat carrier boiler combustion chamber according to claim 1, characterized in that: The rear end of the shell (1) is provided with a secondary air nozzle (61), and the front end of the shell (1) is provided with a tar air supply pipe (62).

9. The biomass gas organic heat carrier boiler combustion chamber according to claim 1, characterized in that: The shell (1) is provided with an ash outlet (23) which is in communication with the bottom of the furnace (2); the bottom of the furnace (2) is in the shape of an inverted cone.

10. The biomass gas organic heat carrier boiler combustion chamber according to claim 1, characterized in that: A smoke-isolating wall (7) is arranged above the furnace arch (21), a soot-blowing pipe (8) is arranged inside the smoke-isolating wall (7), and the soot-blowing pipe (8) comprises a soot-blowing branch pipe (81) facing the top wall of the furnace arch (21).

Images