A mixed air distribution system and working method for a gas generator

Abstract

The present invention discloses a mixed air distribution system and working method for a gasifier, and belongs to the technical field of coal gasification. In view of the problems in the prior art that the carbon conversion rate of the gasifier is low and fly ash is difficult to recycle, the present invention provides a mixed air distribution system for a gasifier, which includes a low-temperature reaction zone and a high-temperature slag zone arranged in sequence from top to bottom at the bottom of the gasifier body, and a relaxation zone is arranged between the low-temperature reaction zone and the high-temperature slag zone, and the relaxation zone includes a steam inlet, which is connected to a steam distribution plate, and a plurality of steam nozzles are arranged on the steam distribution plate, and the high-temperature slag zone includes an ash return pipe connected to the steam distribution plate and an air intake pipe arranged outside the ash return pipe. The carbon conversion rate is greatly improved by recycling fly ash; and the working method of the mixed air distribution system for a gasifier described in the present invention is easy to operate and has low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal gasification, and more specifically, relates to a mixed air distribution system and a working method of a coal gasifier. Background Art

[0002] my country has rich coal resources, with predicted geological reserves exceeding 4.5 trillion tons. It is the world's largest coal producer, and coal resources still occupy an important position in my country's energy structure. How to use coal economically, cleanly and efficiently has become a major technical problem in coal utilization at this stage. At present, there are two types of clean coal gasification technology: circulating fluidized bed gasification technology and fluidized bed gasification technology. The advantages of circulating fluidized bed gasifiers are simple structure and stable system operation. At the same time, there are no pollutants such as tar and phenol water during the operation of fluidized bed gasifiers, which is a relatively clean coal gasification device. However, the operating temperature of fluidized bed gasifiers is generally low at 950℃, the carbon conversion rate of coal in the gasifier is low, and the fly ash has a high carbon content, generally about 50-70%; high carbon content fly ash is a solid waste that is difficult to handle. The advantages of fluidized bed gasifiers are high carbon conversion rate and no pollution such as tar and phenol water. However, the fluidized bed requires the addition of coal grinding, oxygen production, coal powder transportation and other equipment, which greatly increases the investment cost of the fluidized bed; the investment cost of a general fluidized bed is more than five times that of a fluidized bed of the same size; and the fly ash produced by both types of generators during the gasification process is difficult to utilize and has a low carbon conversion rate.

[0003] Corresponding improvements have also been made to address the above-mentioned problems, such as Chinese patent application number CN200810060269.3, which was published on September 24, 2008. The patent discloses a gas generator, particularly a gas distribution and water vapor integrated gas generator that can directly provide mist water into the furnace and generate high-temperature water vapor to enable solid fuel to be fully burned and effectively catalytically reacted. The gas generator comprises a furnace, a hopper, a flue, an air outlet pipe and a furnace bridge. The hopper, the flue and the air outlet pipe are arranged on the top of the furnace, and the furnace bridge is arranged at the bottom of the furnace. A high-pressure fan is arranged outside the furnace, and the high-pressure fan is connected to a nozzle arranged under the furnace bridge through an air inlet pipe. A gas distributor is arranged above the nozzle, and the gas distributor is arranged above the furnace bridge. A water inlet pipe is arranged at the bottom of the gas distributor, and the mouth of the water inlet pipe is opposite to the nozzle. A plurality of gas distribution holes are opened at the upper end of the gas distributor. The gas distributor is a device for producing water vapor. The device has a simple structure and is easy to use. Since a water volume control valve is provided on the water inlet pipe, the amount of water entering the nozzle can be manually controlled. The gasifier ensures the supply and control of water vapor. The efficiency of the gasifier is improved. The disadvantage of this patent is that the high-carbon fly ash generated during the conversion process in the furnace is difficult to handle and the cost is high.

[0004] Another example is Chinese patent application number CN200420011886.1, which was published on May 11, 2005. The patent discloses a mixed coal gas generator, which includes a furnace body consisting of a furnace top, an inner furnace body, and an outer furnace body. A water jacket is provided between the inner and outer furnace bodies. A water inlet and a steam outlet are provided on the water jacket. A stoker is provided on the furnace top of the furnace body. A gas outlet is provided on the furnace body. A rotating grate is provided at the lower part of the furnace body. The rotating grate is fixed in an ash pan. A steam inlet connected to the rotating grate is provided at the bottom of the ash pan. A steam outlet is provided on the water jacket and is connected to the steam inlet connected to the rotating grate. The characteristic of the mixed coal gas generator is that a heat receiving pipe connected to the water jacket is provided on the inner furnace body. Since a heat receiving pipe connected to the water jacket is provided on the inner furnace body of the mixed coal gas generator, the water heating area is increased, the steam output is increased, and the self-produced steam can meet the requirements of coal conversion into coal gas, thereby increasing the coal gas output. The shortcoming of this patent is that although it can effectively improve the conversion efficiency of coal, a large amount of fly ash is generated during the conversion process. Summary of the invention

[0005] 1. Problems to be solved

[0006] In view of the problems of low carbon conversion rate and difficulty in recycling fly ash in the prior art gasifier, the present invention provides a mixed air distribution system and working method for a gasifier. The mixed air distribution system for a gasifier of the present invention recycles the fly ash generated during the gasification process, greatly improving the overall carbon conversion rate of the gasifier; and the method of the present invention is easy to operate, does not require the addition of large-scale equipment, and saves production costs for enterprises.

[0007] 2. Technical solution

[0008] To solve the above problems, the present invention adopts the following technical solutions.

[0009] A mixed air distribution system for a coal gas generator includes a low-temperature reaction zone for raw coal to react and a high-temperature slag zone for fly ash to react, which are arranged in sequence from top to bottom at the bottom of the generator body. A relaxation zone is arranged between the low-temperature reaction zone and the high-temperature slag zone. The relaxation zone includes a steam inlet connected to a steam distribution plate, and a plurality of steam nozzles are arranged on the steam distribution plate. The high-temperature slag zone includes an ash return pipe connected to the steam distribution plate and an air intake pipe arranged outside the ash return pipe. The fly ash is recycled to improve the overall carbon conversion rate of the generator, greatly saving production costs.

[0010] Furthermore, the mitigation zone also includes a steam chamber, a steam inlet is arranged on one side of the steam chamber, and a steam distribution plate is arranged on the top of the steam chamber. The arrangement of the steam chamber can evenly distribute the steam from the steam nozzle, thereby improving the reaction efficiency of the steam.

[0011] Furthermore, the steam distribution plate is in a "V" shape, which is beneficial to the fluidity of the solid particles, so that they can fully contact with the steam and react fully.

[0012] Furthermore, the air intake pipe includes an intake pipe body, an air inlet arranged at the bottom of the intake pipe body, and an anti-backflow device arranged in the intake pipe body to prevent the backflow of solid particles and improve work efficiency.

[0013] Furthermore, the ash return pipe comprises an ash return pipe body connected to the anti-return material device, and an ash return pipe inlet is arranged on the ash return pipe body. The ash delivery process is complete and the operation is simple.

[0014] Furthermore, the anti-return material device comprises an upper baffle connected to the air inlet pipe body and a lower baffle connected to the ash return pipe body, so as to prevent the solid materials in the furnace from falling into the air inlet pipe.

[0015] Furthermore, the low temperature reaction zone includes a distribution plate body arranged at the bottom of the gasifier body, a plurality of hoods are arranged on the distribution plate body, and refractory materials are filled between two adjacent hoods, so that the low temperature reaction zone has high working efficiency and long service life of parts.

[0016] Furthermore, the hood is a mushroom-shaped hood or a bell-shaped hood, which has a simple structure and a wide range of applications.

[0017] A working method using the mixed air distribution system for a gasifier as described in any one of the above, comprising the following steps:

[0018] (1) The raw coal enters the low-temperature reaction zone in the gasifier body to react. The fly ash generated after the reaction is discharged from the gasifier body along with the coal gas, while the solid coal particles remain in the low-temperature reaction zone;

[0019] (ii) After the reaction, the fly ash is collected and enters the gasifier body through the ash return pipe, and air is added to the air inlet pipe at the same time. The air and fly ash react to form slag at the upper part of the air inlet pipe to form a high-temperature slag zone;

[0020] (iii) While step (ii) is being carried out, steam is added from the steam inlet, and the steam enters the gasifier body through the steam nozzles on the steam distribution plate. At this time, the solid coal particles in the low-temperature reaction zone and the slag in the high-temperature slag zone are converted into coal gas again.

[0021] Furthermore, the fly ash in the above step enters the gasifier body from the ash return pipe by pipeline pneumatic transportation. The transportation is centralized and efficient, and the fly ash is prevented from leaking into the external environment during the transportation process, thereby improving the cleanliness of the working environment.

[0022] 3. Beneficial effects

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention sequentially arranges a low-temperature reaction zone for gasification and slag discharge in the gasifier body from top to bottom, a high-temperature slag zone for slag reaction between fly ash and high-temperature air, and a buffer zone arranged between the two zones. The three zones together form an air distribution system. The buffer zone is arranged to convert the coal char particles in the low-temperature reaction zone and the slag in the high-temperature slag zone, realize the combination of high-temperature slag and solid slag discharge, and recycle the fly ash, thereby greatly improving the comprehensive conversion rate of coal gasification. The use of this system to produce 10,000 standard cubic meters of coal gas per hour can save 600 kg of raw coal, that is, compared with conventional coal gasifiers, it can save about 17% of raw coal per hour, and the economic benefit is very significant.

[0025] (2) The steam distribution plate of the present invention is connected in a "V" shape, which is conducive to the flow of solid coal particles in the low-temperature reaction zone and slag in the high-temperature reaction zone in the buffer zone, so that they can contact and react fully; the two inclined cone surfaces in the steam distribution plate are respectively at an angle of 30° to 50° with the axis of the steam distribution plate, which further facilitates the flow of solid particles; if the angle is too small, it is easy to make the overall height of the steam distribution plate too high, making it inconvenient to install; if the angle is too large, it is not easy for solid particles to flow on the steam distribution plate;

[0026] (3) The air intake pipe in the present invention includes an intake pipe body, which is a straight pipe, so as to facilitate the input of high-temperature air and make it input smoothly; the high-temperature air enters the gasifier body through the air inlet at the bottom of the intake pipe body, so that the high-temperature air enters from bottom to top, and the high-temperature air is not easy to disperse; the anti-return device in the intake pipe body prevents the solid particles in the gasifier body from returning, thereby improving its working efficiency;

[0027] (4) The anti-return device of the present invention increases the resistance to the flow of solid particles, preventing solid particles from falling into the lower part of the air inlet pipe body, causing particle accumulation and affecting the transportation of high-temperature air, which requires manual cleaning. On the other hand, when high-temperature air is transported, the high-temperature air in the air inlet pipe body can easily blow up the solid particles accumulated on the anti-return device for re-reaction, thereby improving the gas conversion rate.

[0028] (5) The low temperature zone in the present invention includes a distribution plate body arranged at the bottom of the gasifier body, which is used for the reaction between the raw coal and the gasifying agent. A plurality of wind caps are arranged on the distribution plate body. The arrangement of the wind caps avoids the deposition of solid coal particles, reduces the carbon loss of cold slag, and can evenly distribute the air; refractory materials are filled between two adjacent wind caps to avoid deformation of the distribution plate body during the reaction process, thereby further improving the service life of the air distribution plate body;

[0029] (6) The working method of the mixed air distribution system described in the present invention is easy to operate, does not require the addition of large equipment, and reduces the production cost of the enterprise. By recycling the fly ash generated in the gasification process into the gasifier body for another reaction, the carbon conversion rate in the entire generator is effectively improved, and the fly ash is recycled, which provides a solution to the treatment of fly ash. The fly ash enters the gasifier body through pipeline pneumatic transportation, which makes the fly ash transportation concentrated and efficient, avoids the dispersion of fly ash, and effectively improves the cleanliness of the working environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the present invention;

[0031] Figure 2 for Figure 1 Method diagram of Part A;

[0032] Figure 3 It is a schematic diagram of the structure of three zones of the present invention;

[0033] Figure 4 It is a schematic diagram of an outer ring uniform fluidization distribution device;

[0034] Figure 5 It is a schematic diagram of the working principle of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of the device to prevent material backflow.

[0036] In the figure: 1. Outer ring uniform fluidization distribution device; 11. Distribution plate body; 12. Wind hood; 13. Refractory material; 2. Steam distribution device; 21. Steam distribution plate; 22. Steam nozzle; 23. Steam chamber; 24. Steam inlet; 3. Air inlet pipe; 31. Inlet pipe body; 32. Anti-return material device; 321. Upper baffle plate; 322. Lower baffle plate; 33. Air inlet; 4. Ash return pipe; 41. Ash return pipe body; 42. Ash return pipe inlet; B. Low-temperature reaction zone; C. High-temperature slag zone; D. Relaxation zone. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with specific embodiments and drawings.

[0038] Example 1

[0039] like Figure 1 , Figure 2 , Figure 3 and Figure 5As shown, a mixed air distribution system for a coal gasifier comprises a low-temperature reaction zone for reacting raw coal and a high-temperature slag zone for reacting fly ash, which are arranged in sequence from top to bottom at the bottom of the generator body. Specifically, the low-temperature reaction zone mainly performs a gasification process of the raw coal and produces fly ash with a high carbon content in the gasification process. The fly ash produced in the process is discharged from the gasifier body together with the raw coal gas, and the solid coal particles that have not reacted completely are left in the low-temperature reaction zone; the high-temperature slag zone performs a slag reaction between fly ash and high-temperature air. The fly ash here is the fly ash discharged from the gasifier body that is collected and processed and then The steam inlet 24 is provided on the steam distribution plate 21, and a plurality of steam nozzles 22 are provided on the steam distribution plate 21. The steam distribution plate 21, the steam chamber 23 and the steam inlet 24 form a steam distribution device 2. More specifically, the steam inlet 24 is provided on one side of the steam chamber 23, and a steam distribution plate 21 is provided on the top of the steam chamber 23. The steam enters the steam chamber 23 through the steam inlet 24, and then enters the steam chamber 23 through the steam distribution plate 21. The steam chamber 23 is provided so that the steam is evenly distributed from the steam nozzle 22, thereby improving the reaction efficiency of the steam; the addition of steam isolates the high-temperature slag zone and the low-temperature reaction zone to a certain extent, thereby forming a buffer zone, in which the presence of steam enables the solid coal particles in the low-temperature reaction zone to be converted into the fly ash slag in the high-temperature slag zone, thereby improving the water-gas reaction and thus improving the carbon conversion rate in the gasifier body; the high-temperature slag zone includes an ash return pipe 4 connected to the lower end of the steam distribution plate 21 and an air inlet pipe 3 arranged outside the ash return pipe 4, and the air The medium in the air inlet pipe 3 is high-temperature air. The high-temperature air mentioned in the present invention refers to air with a temperature of 500-700°C; the high-temperature air reacts with the fly ash in the ash return pipe 4 at the upper part of the air inlet pipe 3, and a high-temperature slag zone is formed below the steam distribution plate 21; preferably, the ash return pipe 4 and the air inlet pipe 3 are coaxially arranged, and the coaxial arrangement can make the overall reaction have better uniformity; and the ash return pipe 4 and the air inlet pipe 3 are both arranged at the center position of the lower part of the steam distribution plate 21, so that the fly ash and steam are in more uniform and sufficient contact, which promotes the water-gas reaction and effectively improves the carbon conversion rate.

[0040] The mixed air distribution system for the coal gasifier of the present invention recycles the fly ash with high carbon content generated in the gasification reaction process by processing it and then feeding it back into the gasifier body. The system comprises a low-temperature reaction zone, a buffer zone and a high-temperature slag zone. The low-temperature reaction zone is used for gasification and slag discharge of raw coal, and the high-temperature slag zone is used for slag reaction between fly ash and high-temperature air. A buffer zone is provided between the two. On the one hand, the steam in the buffer zone can isolate the low-temperature reaction zone and the high-temperature slag zone to a certain extent, so that the temperature of the bottom of the entire gasifier will not be always in a high temperature state, which is easy to be damaged. On the other hand, the water in the buffer zone can prevent the low-temperature reaction zone from being easily damaged. Steam converts the coal char particles in the low-temperature reaction zone and the slag in the high-temperature slag zone, realizes the combination of high-temperature slag and solid slag discharge, improves the water-gas reaction and thus improves the carbon conversion rate of the gasifier; it has been measured that the use of the mixed air distribution system for the gasifier of the present invention to produce 10,000 standard cubic meters of coal gas per hour can save 600KG of raw coal, that is, compared with conventional gasifiers, about 17% of raw coal can be saved per hour, and the economic benefit is very significant; and it has changed the situation that the previous air distribution device can only carry out raw coal gasification reaction but not fly ash reaction, the overall structure is simple, and the manufacture and installation are convenient, which effectively improves the overall gasification efficiency.

[0041] Example 2

[0042] Basically the same as in Example 1, preferably, the steam distribution plate 21 is in a "V" shape, that is, the steam distribution plate 21 includes two inclined conical surfaces, and the two inclined conical surfaces are connected in a "V" shape, so that the steam distribution plate 21 has a certain slope, which can be beneficial to the flow of solid coal particles in the warm reaction zone and the slag in the high-temperature reaction zone in the buffer zone, so that they can contact and react with the steam fully, thereby improving the reaction efficiency; further, the two inclined conical surfaces in the steam distribution plate 21 are respectively at an angle of 30° to 50° with the axis of the steam distribution plate 21, which further facilitates the flow of solid particles. movement; if the angle is too small, it means that the cone of the inclined cone is too steep, resulting in a high overall height of the entire steam distribution plate 21, causing a waste of space; if the angle is too large, it means that the cone angle of the inclined cone is too gentle, and the material is not easy to flow on the steam distribution plate 21; the diameter of the steam nozzle 22 on the steam distribution plate 21 is 2 to 10 mm, and the direction of the steam nozzle 22 is horizontally inward. If the diameter of the steam nozzle 22 is too small, it is easy to cause blockage of solid particles and affect the reaction process; if the aperture is too large, the fly ash is easy to disperse, the contact with the solid particles is insufficient, and the reaction is not thorough.

[0043] Example 3

[0044] Basically the same as Example 1, preferably, the air intake pipe 3 includes an intake pipe body 31, and the intake pipe body 31 is a straight pipe, which is convenient for the input of high-temperature air and makes its input smooth; an expansion joint is provided at the lower part of the straight pipe to supplement the expansion of the intake pipe body 31, thereby increasing the service life of the intake pipe body 31; an air inlet 33 is provided at the bottom of the intake pipe body 31, and an anti-return device 32 is provided in the intake pipe body 31. The air inlet 33 is provided at the bottom of the intake pipe body 31. Because the air entering the intake pipe body 31 is high-temperature air, the inlet at the bottom can allow the high-temperature air to enter from bottom to top, and the high-temperature air does not Diversion is easy to occur, reducing heat loss; the anti-return material device 32 can effectively prevent the material from returning to the gasifier body, effectively improving work efficiency. Specifically, the ash return pipe 4 includes an ash return pipe body 41 connected to the anti-return material device 32, and an ash return pipe inlet 42 is arranged at the bottom of the ash return pipe body 41. The ash return pipe body 41 is also a straight pipe to ensure smooth fly ash transportation; and the lower part of the ash return pipe body 41 is welded and fixed to the air inlet pipe body 31 to ensure a stable connection between the two pipes; the anti-return material device 32 described in the present invention refers to a device that can prevent solid particles from falling when the air inlet pipe body 31 stops working;

[0045] like Figure 6As shown, in this embodiment, the anti-return material device 32 includes an upper baffle plate 321 connected to the air inlet pipe body 31 and a lower baffle plate 322 connected to the ash return pipe body 41. The upper baffle plate 321 and the lower baffle plate 322 are both truncated cone-shaped or funnel-shaped, which facilitates the solid particles remaining on the upper baffle plate 321 and the lower baffle plate 322 to be blown up by the high-temperature air. The structure is simple and easy to install and fix. Specifically, the truncated cone-shaped upper baffle plate 321 is welded and sealed with the air inlet pipe body 31, and there is a certain gap between the truncated cone-shaped upper baffle plate 321 and the ash return pipe body 41; the truncated cone-shaped lower baffle plate 322 is welded and sealed with the air inlet pipe body 31, and there is a certain gap between the truncated cone-shaped upper baffle plate 321 and the ash return pipe body 41; The baffle 322 is welded and sealed with the ash return pipe body 41, and there is a certain gap between the baffle 322 and the air inlet pipe body 31; the high-temperature air in the air inlet pipe body 31 must pass through these two gaps to enter the gasifier body; during the gasification reaction of the gasifier, it is inevitable that solid particles will fall into the air inlet pipe body 31. When the gasifier is in normal working condition, high-temperature air is always blown from bottom to top in the air inlet pipe body 31, so solid particles will not fall into the air inlet pipe body 31. However, when the furnace is stopped or the fire is suppressed, that is, the transportation of high-temperature air is stopped, , solid particles will fall into the air inlet pipe body 31 due to their own gravity. The upper and lower frustum-shaped baffles increase the resistance to the flow of solid particles, preventing solid particles from falling into the lower part of the air inlet pipe body 31 and causing too many particles to accumulate and cannot be easily blown up, requiring manual cleaning, thus saving labor costs; on the other hand, when high-temperature air is transported, the high-temperature air in the air inlet pipe body 31 can easily blow up the solid particles accumulated on the anti-return material device 32 for re-reaction, thereby improving the gas conversion rate; further, the upper The distance between the inner edge of the baffle 321 and the ash return pipe body 41 is smaller than the distance between the outer edge of the lower baffle 322 and the ash return pipe body 41. This arrangement can ensure that the solid particles in the upper baffle 321 can only fall into the lower baffle 322 instead of falling into the lower part of the air inlet pipe body 31, and the distance between the upper and lower baffles can be reasonably set according to the repose angle of the object so that the solid particles cannot slide from the lower baffle 322 to the lower part of the air inlet pipe body 31. The repose angle is the maximum angle at which the material can remain stationary when stacked in a natural state.

[0046] Example 4

[0047] Basically the same as in Example 1, preferably Figure 4As shown, the low-temperature reaction zone includes a distribution plate body 11 arranged at the bottom of the gasifier body, and a plurality of hoods 12 are arranged on the distribution plate body 11. The hoods 12 are arranged in a ring shape on the distribution plate body 11. The hoods 12 can avoid the deposition of solid coal particles, reduce the carbon loss of cold slag, improve the reaction efficiency, and evenly distribute the air; a refractory material 13 is filled between two adjacent hoods 12. The refractory material 13 is arranged to avoid deformation of the distribution plate body 11 during the reaction process, further improving the service life of the air distribution plate body 11; the distribution plate body 11, the hood 12 and the refractory material 13 together constitute an outer ring uniform fluidization distribution device 1, which makes the gasification reaction of the raw coal sufficient, improves the service life as a whole, and reduces the number of maintenance and replacement. Furthermore, the hood 12 is a mushroom head hood or a bell-shaped hood. This type of hood 12 can achieve even air distribution and has a simple structure and a wide range of applications.

[0048] Example 5

[0049] A working method using the mixed air distribution system for a gasifier as described in any one of the above embodiments 1-4 comprises the following steps:

[0050] (1) The raw coal enters the low-temperature reaction zone in the gasifier body to react. The fly ash generated after the reaction is discharged from the gasifier body along with the coal gas, while the solid coal particles remain in the low-temperature reaction zone;

[0051] (ii) After the reaction, the fly ash is collected and enters the gasifier body through the ash return pipe 4, and high-temperature air is added to the air intake pipe 3 at the same time. The high-temperature air and fly ash react to form slag at the upper part of the air intake pipe 3 to form a high-temperature slag zone; specifically, the fly ash enters the gasifier body from the ash return pipe 4 through pipeline pneumatic transportation, so that the fly ash is transported in a concentrated manner, the transportation efficiency is fast, the dispersion of the fly ash is avoided, and the cleanliness of the working environment is effectively improved;

[0052] (iii) While step (ii) is being carried out, steam is added from the steam inlet 24, and the steam enters the gasifier body through the steam nozzles 22 on the steam distribution plate 21. At this time, the solid coal particles in the low-temperature reaction zone and the slag in the high-temperature slag zone are converted into coal gas again.

[0053] The working method of the mixed air distribution system described in the present invention is easy to operate, does not require the addition of large equipment, and reduces the production cost of the enterprise. By recycling the fly ash generated in the gasification process into the gasifier body for another reaction, the carbon conversion rate in the entire generator is effectively improved, and the fly ash is recycled, which provides a solution to the treatment of fly ash; and effectively improves the overall carbon conversion rate in the gasifier, which has a high use value.

[0054] The examples described in the present invention are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should all fall within the protection scope of the present invention.

Claims

1. A mixed air distribution system for a gasifier, characterized in that: The invention comprises a low-temperature reaction zone, a relaxation zone and a high-temperature slag zone. The low-temperature reaction zone is used for raw coal gasification and slag removal. The high-temperature slag zone is used for fly ash and high-temperature air to react with slag. A relaxation zone is arranged between the two. The relaxation zone comprises a steam inlet (24). The steam inlet (24) is connected to a steam distribution plate (21). The steam distribution plate (21) is provided with a plurality of steam nozzles (22). The high-temperature slag zone comprises an ash return pipe (4) connected to the steam distribution plate (21) and an air intake pipe (3) arranged outside the ash return pipe (4). The ash return pipe (4) and the air intake pipe (3) are both arranged at the central position of the lower part of the steam distribution plate (21). The relaxation zone further comprises a steam chamber (23), a steam inlet (24) is arranged on one side of the steam chamber (23), and a steam distribution plate (21) is arranged on the top of the steam chamber (23); the steam distribution plate (21) is in a "V" shape; The air intake pipe (3) comprises an intake pipe body (31), an air inlet (33) arranged at the bottom of the intake pipe body (31), and an anti-return material device (32) arranged in the intake pipe body (31), wherein the anti-return material device (32) can prevent solid particles from falling when the intake pipe body (31) stops working; The low-temperature reaction zone comprises a distribution plate body (11) arranged at the bottom of the gasifier body, a plurality of wind caps (12) are arranged on the distribution plate body (11), a refractory material (13) is filled between two adjacent wind caps (12), and the distribution plate body (11), the wind caps (12) and the refractory material (13) together constitute an outer ring uniform fluidization distribution device (1).

2. A mixed air distribution system for a gasifier according to claim 1, characterized in that: The ash return pipe (4) comprises an ash return pipe body (41) connected to the anti-return material device (32), and an ash return pipe inlet (42) is provided on the ash return pipe body (41).

3. A mixed air distribution system for a gasifier according to claim 2, characterized in that: The anti-return material device (32) comprises an upper baffle (321) connected to the air inlet pipe body (31) and a lower baffle (322) connected to the ash return pipe body (41).

4. A mixed air distribution system for a gasifier according to claim 1, characterized in that: The hood (12) is a mushroom-shaped hood or a bell-shaped hood.

5. A working method using the mixed air distribution system for a gasifier as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: (i) The raw coal enters the low-temperature reaction zone in the gasifier body to react. The fly ash generated after the reaction is discharged from the gasifier body along with the coal gas, while the solid coal particles remain in the low-temperature reaction zone; (ii) After the reaction, the fly ash is collected and enters the gasifier body through the ash return pipe (4), and at the same time, air is added to the air inlet pipe (3), and the air and the fly ash react at the upper part of the air inlet pipe (3) to form slag to form a high-temperature slag zone; (iii) While step (ii) is being carried out, steam is added from the steam inlet (24), and the steam enters the gasifier body through the steam nozzle (22) on the steam distribution plate (21).

6. The working method of the mixed air distribution system of a gas generator according to claim 5, characterized in that: The fly ash in step (ii) enters the gasifier body from the ash return pipe (4) by means of pipeline pneumatic transportation.

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