Pressurized slag discharging system and method for preventing slag accumulation in gasifier slag pool

Abstract

The invention discloses an under-pressure slag discharging system for preventing slag accumulation in a gasification furnace slag pool and an under-pressure slag discharging method for preventing slag accumulation in the gasification furnace slag pool, in the slag collecting process, whether a pull-down slag discharging program is started or stopped or not can be judged according to parameters such as current and liquid level, and slag is discharged through circulating diversion and high-pressure pull-down slag discharging. According to the device, accumulated slag enriched on the wall in the slag pool and the slag collecting tank is rapidly drained to the slag lock, so that the problem that the ash in the slag pool is agglomerated and hung on the wall is thoroughly solved, distortion of key process parameters such as liquid level and differential pressure caused by slag accumulation in the slag pool is avoided, reliable data support is provided for stable operation of the gasification furnace, and meanwhile, obstruction of accumulated slag to a synthetic gas flow channel can be eliminated; full-load operation of the gasification furnace is guaranteed, the yield of downstream products is prevented from being reduced, the long-period operation efficiency of the device is improved, a slag-water mixture can be prevented from entraining slag to enter a washing system, abrasion of pipelines and equipment is reduced, passive shutdown overhaul times are reduced, the service life of the equipment is prolonged, and maintenance and production loss cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of gasifier slag discharge, and more specifically to a pressurized slag discharge system and method for preventing slag accumulation in gasifier slag pools. Background Technology

[0002] Shell's coal gasification process is one of the most advanced coal gasification processes in the world. Classified by chemical engineering characteristics, Shell's coal gasification belongs to the fluidized bed gasification category. Pulverized coal and oxygen are introduced into the gasifier in a parallel flow under pressure, completing a series of physical and chemical processes such as heating, pyrolysis, combustion, and conversion within a very short time. The gasification produces syngas, primarily composed of CO and H2, which serves as the downstream feedstock for the production process.

[0003] The Shell dry coal gasification system adopted by Hulunbuir Jinxin Chemical Co., Ltd. mainly includes the following units: crushed coal pre-drying unit, pulverized coal drying unit, pulverized coal pressurized conveying unit, gasification unit, slag removal unit, wet washing unit, ash water treatment, and utilities. The slag removal process of the slag removal unit is as follows: Coal entering the furnace undergoes combustion and gasification reactions to produce slag. This slag is then introduced into the downstream quenching section in a high-temperature liquid state along with the crude coal gas. After quenching with 150℃, 5.4MPa quenching water, granular slag blocks are formed. These slag blocks settle by gravity in the slag pool, are crushed and guided by a bottom slag crusher, and then enter the slag lock. Within a fixed cycle, the slag lock utilizes slag discharge control to isolate and depressurize, discharging the slag-water mixture to a slag remover. The mixture is then drained by a scraper inside the machine and discharged to a slag truck, which transports it to a designated location.

[0004] However, during long-term operation of the gasifier, the slag morphology will change due to variations in the composition of the raw coal and different reaction conditions. A small amount of needle-shaped slag and stringy slag produced after the reaction will agglomerate and combine with a large amount of particulate slag, adhering to the inner wall of the slag pool. This slag cannot be discharged into the slag lock through the slag crusher, and long-term accumulation will cause slag buildup in the slag pool, thus leading to the following problems: 1. As the gasifier operates for longer periods, the amount of slag accumulated in the slag pit will also increase. A large amount of accumulated slag needs to be converted into... The changes in the material distribution and liquid level in the slag pool caused distortion of key process parameters such as the liquid level in the slag pool and the differential pressure in the furnace. 2. When the slag in the slag pool accumulates to a certain extent, it begins to obstruct the synthesis gas flow channel of the gasifier. The gas flow inside the gasifier is not smooth, which leads to the limited output of the gasifier and the inability to meet production needs, resulting in a decrease in the output of downstream products. 3. In the later stages of slag accumulation, the presence of a large amount of solid slag in the slag pit occupies the effective space of the slag pit, leading to a reduction in the total water volume. At this time, when the syngas passes through the slag pit, due to the lack of sufficient quench water for washing and cooling, it will carry quench water and slag into the subsequent washing system. Because of the high hardness of the slag, it will cause strong scouring and wear on the pipes and equipment of the washing system, exacerbating the wear and tear of the washing system, eventually leading to pipe and equipment wear-through and leakage, and the company will be forced to shut down for maintenance. Shutdown for maintenance not only interrupts production and causes economic losses due to production stoppage, but also requires a large investment of manpower and resources for equipment repair and replacement, further increasing the company's operating costs.

[0005] All of the above situations will seriously affect the long-term stable operation of the gasifier, and will have a significant impact on the company's product output, energy efficiency, and employee workload. Summary of the Invention

[0006] To address the aforementioned problems, the first objective of this invention is to provide a pressurized slag discharge system for preventing slag accumulation in gasification furnace slag pools, and the second objective of this invention is to provide a pressurized slag discharge method for preventing slag accumulation in gasification furnace slag pools.

[0007] The first objective of this invention is achieved by the following technical solution: A pressurized slag discharge system for preventing slag accumulation in a gasifier slag pool includes a gasifier, a slag pool, a slag crusher, a slag collection tank, a slag lock, a water supply tank, and a slag removal machine. The bottom end of the slag discharge pipe at the center of the bottom distribution plate of the gasifier is sealed to one end of the slag lowering pipe. The other end of the slag lowering pipe passes through the top of the slag pool and is placed inside the slag pool. The slag outlet of the slag pool is connected to the inlet of the slag crusher. The outlet of the slag crusher is sealed to one end of the slag collecting pipe. The other end of the slag collecting pipe passes through the top of the slag collecting tank and extends to the middle of the slag collecting tank. The slag outlet at the bottom of the slag collecting tank is connected to the slag inlet of the slag lock through a pipeline. The slag outlet of the slag lock is connected to the inlet of the slag removal machine through a pipeline. A valve #1 is provided on the pipeline connecting the slag outlet of the slag collecting tank and the slag inlet of the slag lock. A valve #2 is provided at the slag outlet of the slag lock. A water inlet is provided on the side wall of the slag lock, and the outlet of the water supply tank is connected to the water inlet through a water supply pipeline; a pressure relief port is provided on the top of the slag lock, and the pressure relief port is connected to the top of the water supply tank through a pressure relief pipeline; a No. 4 valve is provided on the water supply pipeline, a No. 3 valve is provided on the pressure relief pipeline, and an angle valve is provided at the outlet end of the pressure relief pipeline; The outlet of the water supply pipeline is connected to the inlet of the water supply tank through the pipeline, and a No. 5 valve is provided at the outlet of the water supply pipeline. A flow guide port is also provided on the side wall of the slag lock. The flow guide port is connected to the inlet of the slurry flow pump through a first flow guide pipeline. The outlet of the slurry flow pump is connected to the return port opened on the side wall of the slag collection tank through a second flow guide pipeline. A valve #6 is provided on the first flow guide pipeline and a valve #7 is provided on the second flow guide pipeline. The outlet of the high-pressure flushing water pipeline is connected to the guide port through a pressurization pipeline, and a valve #9 is installed on the pressurization pipeline.

[0008] Furthermore, it also includes a bypass pipeline, through which the inlet and outlet of the slurry diversion pump are connected, and an 8# valve is provided on the bypass pipeline.

[0009] Furthermore, a slag level sensor is installed in the slag pool, and a water supply tank level sensor and a water supply tank pressure sensor are installed in the water supply tank.

[0010] Furthermore, the water supply pipeline is also connected to the pressure relief port of the slag lock through a pressure relief flushing pipeline, and a pressure relief flushing valve is provided on the pressure relief flushing pipeline.

[0011] Furthermore, a slag collection tank pressure sensor is installed inside the slag collection tank, and a slag lock liquid level sensor and a slag lock pressure sensor are respectively installed inside the slag lock.

[0012] The second objective of this invention is achieved by the following technical solution: A pressurized slag discharge method for preventing slag accumulation in a gasification furnace slag pool includes the following steps: S1. Slag Collection: Open valve #1 and close valve #2 to allow the gasification ash produced in the gasifier to enter the slag pool through the slag discharge pipe. After contacting the quench water, the ash is cooled down and the water and slag mix to form coal slag water. After being cooled in the slag pool, the coal slag water is crushed by the slag crusher and enters the downstream slag collection tank. The coal slag water in the slag collection tank enters the slag lock for slag collection. At the same time, open valves #6 and #7, close valve #8, and the slurry diversion pump is in the start state; when the opening time of valve #1 reaches the preset slurry collection cycle, the slurry collection ends, and S2 is executed to control the slurry discharge. During the slag collection process, it is determined whether the conditions for starting the pull-down slag discharge are met. If they are met, the pull-down slag discharge program is started; if not, the pull-down slag discharge program is not started. S2, Sequential Slag Discharge: Close valve #1, open valve #3, and simultaneously open the pressure relief flushing valve. After depressurizing until the pressure inside the slag lock is less than 0.15MPa, close the pressure relief flushing valve, open valve #2 at the bottom of the slag lock to discharge slag, and then open valve #4 to flush the slag lock. Pour the slag / water mixture accumulated at the bottom of the slag lock into the slag remover. The slag remover uses its built-in scraper to remove the slag, drain it, and discharge it to the slag truck. When the opening time of valve #2 reaches the preset slag discharge cycle, close valve #2 to end slag discharge and proceed to S3, Pressurization. S3, Pressurization: Open valve #4 to fill the liquid level in the slag lock to full level, then close valve #4 and valve #3, and then open valve #9 to pressurize the slag lock. When the slag lock and the slag collection tank reach the same pressure, end the pressurization and execute S1, Slag Collection.

[0013] Furthermore, in S1, the slag collection, The conditions for starting the downward slag discharge are as follows: In the previous slag discharge cycle, the peak value of the working current of the slag remover was less than the preset current value; The liquid level in the slag pool is >45%; 40% > Liquid level in the replenishment tank > 20%; If all of the above conditions are met, the conditions for starting the slag discharge downwards are considered to be met; if any of the above conditions are not met, the conditions for starting the slag discharge downwards are considered not to be met. The slag discharge procedure is as follows: close valve #6, open valve #8, keep valve #7 open, and keep valve #5 closed. Open valve #3 and angle valve to quickly drain the slag accumulated on the wall of the slag pool and slag collection tank under high pressure. After passing through the slag lock, the excess slag water enters the water replenishment tank, and the accumulated ash slag is forcibly carried into the slag lock. During the slag discharge process, it is determined whether the slag discharge termination condition is met. If it is met, the slag discharge termination procedure is executed; otherwise, the slag discharge procedure continues.

[0014] Furthermore, the condition for ending the downward slag discharge is as follows: The pressure inside the water tank is >0.1 MPa; The liquid level in the water replenishment tank is >80%; The liquid level in the water replenishment tank has increased by 20% compared to before the slag discharge procedure was started; Valve #3 opens for at least 2 minutes; If any of the above conditions are met, the slag discharge termination condition is considered to be met; if none of the above conditions are met, the slag discharge termination condition is considered not met. The procedure for ending the slag discharge is as follows: close valve #3 and angle valve, delay for 2 seconds, then open valve #6 and close valve #8.

[0015] Furthermore, in step S3, during pressurization, when the liquid level in the water tank is lower than the preset low liquid level value, valve #5 is opened to replenish the water tank; when the liquid level in the water tank reaches the preset high liquid level value, valve #5 is closed to stop replenishing the liquid.

[0016] Advantages of this invention: During the slag collection process, the start and stop of the slag discharge procedure can be determined based on parameters such as current and liquid level. Through circulation guidance and high-pressure slag discharge, the slag accumulated and adhered to the walls of the slag pool and slag collection tank is quickly diverted to the slag lock, completely solving the problem of ash and slag agglomeration and adhesion in the slag pool. This avoids distortion of key process parameters such as liquid level and differential pressure caused by slag accumulation in the slag pool, providing reliable data support for the stable operation of the gasifier. At the same time, it can eliminate the obstruction of the synthesis gas flow channel by the accumulated slag, ensuring the full-load operation of the gasifier, avoiding a decrease in downstream product output, improving the long-term operating efficiency of the unit, and preventing the slag-water mixture from carrying slag into the washing system, reducing wear on pipelines and equipment, reducing the number of passive shutdowns for maintenance, extending equipment service life, and reducing maintenance and production loss costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system connection in Example 1.

[0018] In the diagram: 1. Gasifier; 2. Slag pit; 3. Slag crusher; 4. Slag collection tank; 5. Slag lock; 6. Water supply tank; 7. Slag removal machine; 8. Valve #1; 9. Valve #2; 10. Valve #3; 11. Valve #4; 12. Valve #5; 13. Valve #6; 14. Valve #7; 15. Valve #8; 16. Valve #9; 17. Angle valve; 18. Slurry diversion pump; 19. Pressure relief flushing valve; 20. Slag pit level sensor; 21. Water supply tank level sensor; 22. Water supply tank pressure sensor; 23. Slag collection tank pressure sensor; 24. Slag lock level sensor; 25. Slag lock pressure sensor; 26. High-pressure flushing water inlet pipeline; 27. Water supply inlet pipeline; 28. Slag drop pipe; 29. ​​Slag collection pipe; 30. Water supply pipeline; 31. Pressure relief pipeline; 32. First diversion pipeline; 33. Second diversion pipeline; 34. Bypass pipeline; 35. Pressure relief flushing pipeline; 36. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1 like Figure 1The pressurized slag discharge system shown includes a gasifier 1, a slag pool 2, a slag crusher 3, a slag collection tank 4, a slag lock 5, a water replenishment tank 6, and a slag removal machine 7. The bottom end of the slag discharge pipe 28 at the center of the bottom distribution plate of the gasifier 1 is sealed to one end of the slag discharge pipe 29. The other end of the slag discharge pipe 29 passes through the top of the slag pool 2 and is placed inside the slag pool 2. The slag outlet of the slag pool 2 is connected to the inlet of the slag crusher 3. The outlet of the slag crusher 3 is sealed to one end of the slag collection pipe 30. The other end of the slag collection pipe 30 passes through the top of the slag collection tank 4 and extends to the middle of the slag collection tank 4. The slag outlet at the bottom of the slag collection tank 4 is connected to the slag inlet of the slag lock 5 through a pipeline. The slag outlet of the slag lock 5 is connected to the inlet of the slag remover 7 through a pipeline. A valve 1#8 is installed on the pipeline connecting the slag outlet of the slag collection tank 4 and the slag inlet of the slag lock 5. A valve 2#9 is installed at the slag outlet of the slag lock 5. A water inlet is provided on the side wall of the slag lock 5, and the outlet of the water supply tank 6 is connected to the water inlet through the water supply pipeline 31. A pressure relief port is provided on the top of the slag lock 5, and the pressure relief port is connected to the top of the water supply tank 6 through the pressure relief pipeline 32. A valve 11 is provided on the water supply pipeline 31, a valve 10 is provided on the pressure relief pipeline 32, and an angle valve 17 is provided at the outlet end of the pressure relief pipeline 32 to facilitate the isolation operation of pipeline leakage caused by slag removal. In addition, a wear-resistant angle valve 17 and a matching wear-resistant pipeline are added after the valve 10, which simultaneously improves the wear resistance of the inner lining of the water supply tank 6, thereby effectively extending the service life of the pressure relief pipeline 32 and the equipment.

[0021] The outlet of the water supply pipeline 27 is connected to the inlet of the water supply tank 6 through the pipeline, and valve 12 is installed at the outlet of the water supply pipeline 27. A flow guide port is also provided on the side wall of the slag lock 5. The flow guide port is connected to the inlet of the slurry flow pump 18 through the first flow guide pipe 33. The outlet of the slurry flow pump 18 is connected to the return port opened on the side wall of the slag collection tank 4 through the second flow guide pipe 34. A valve 13 is provided on the first flow guide pipe 33 and a valve 14 is provided on the second flow guide pipe 34. The outlet of the high-pressure flushing water inlet pipeline 26 is connected to the guide port through the pressurization pipeline, and valve 16 (No. 9) is installed on the pressurization pipeline.

[0022] This embodiment also includes a bypass pipeline 35, through which the inlet and outlet of the slurry diversion pump 18 are connected, and an 8# valve 15 is provided on the bypass pipeline 35.

[0023] A slag level sensor 20 is installed in the slag pool 2, and a water supply tank level sensor 21 and a water supply tank pressure sensor 22 are installed in the water supply tank 6. The water supply pipeline 27 is also connected to the pressure relief port of the slag lock 5 through a pressure relief flushing pipeline 36, and a pressure relief flushing valve 19 is installed on the pressure relief flushing pipeline 36. A slag collection tank pressure sensor 23 is installed in the slag collection tank 4, and a slag lock level sensor 24 and a slag lock pressure sensor 25 are installed in the slag lock 5.

[0024] Example 2 A pressurized slag discharge method for preventing slag accumulation in slag pool 2 of gasifier 1, utilizing a pressurized slag discharge system for preventing slag accumulation in slag pool 2 of gasifier 1 provided in Example 1, includes the following steps: S1. Slag Collection: Open valve #1 (8) and close valve #2 (9) to allow the gasification ash produced in gasifier 1 to enter slag pool 2 through slag discharge pipe 28 and slag discharge pipe 29. After contacting the quench water, the ash is cooled down and the water and slag mix to form coal slag water. After being cooled in slag pool 2, the coal slag water is crushed by slag crusher 3 to form smaller particles, which facilitates uniform mixing with the liquid phase and increases its fluidity. The coal slag water in slag pool 4 enters slag lock 5 for slag collection. Simultaneously, valves 13 and 14 are opened, and valve 15 is closed. The slurry diversion pump 18 is started, creating a slurry flow between the slag collection tank 4 and the slag lock 5. The coal slag water in the slag lock 5 is drawn out through valve 13, pressurized by the slurry diversion pump 18, and then enters the bottom of the slag collection tank 4 through valve 14. The coal slag water circulates between the slag lock 5 and the slag collection tank 4. This flow allows the ash and slag to settle more quickly to the bottom of the slag collection tank 4 under the combined action of gravity and water flow, thereby increasing the concentration of ash and slag in the slag collection tank 4 and providing favorable conditions for subsequent slag discharge. When valve 8 is open for the preset slag collection cycle (25 minutes), slag collection ends, and S2, sequential slag discharge, is executed. During the slag collection process, it will also determine in real time whether the conditions for starting the pull-down slag discharge are met. If they are met, the pull-down slag discharge program will be started; if they are not met, the pull-down slag discharge program will not be started. The conditions for starting the slag discharge downwards are as follows: In the previous slag discharge cycle, the peak value of the working current of the slag remover 7 (collected by the AMC96L-E4 / KC multi-functional power meter of Acrel Electric Co., Ltd.) was less than the preset current value (12A). This is because the peak value of the working current of the slag remover 7 can reflect its working load. If the peak current is small, it means that the slag remover 7 encounters less resistance during the slag discharge process. There may be a lot of slag accumulated in the slag pool 2 or the slag collection tank 4, which has not been effectively discharged. The liquid level in slag tank 2 is >45%; 40% > Liquid level in water tank 6 > 20%; If all of the above conditions are met, the conditions for starting the slag discharge downwards are considered to be met; if any of the above conditions are not met, the conditions for starting the slag discharge downwards are considered not to be met. The slag discharge procedure is as follows: close valve 6#13, open valve 8#15, keep valve 7#14 open, and keep valve 5#12 closed. Open valve 3#10 and angle valve 17. At this time, since the slag collection tank 4, slag pool 2 and slag lock 5 are all under high pressure, and the water supply tank 6 is under normal pressure, the slag slurry is pulled down through the pressure relief pipeline 32, and the slag accumulated on the wall of the slag pool 2 and slag collection tank 4 is quickly diverted under high pressure. After passing through the slag lock 5, the excess slag water enters the water supply tank 6, and the accumulated ash slag is forcibly carried into the slag lock 5. During the slag discharge process, it is determined whether the slag discharge termination condition is met. If it is met, the slag discharge termination procedure is executed; otherwise, the slag discharge procedure continues.

[0025] The condition for ending the downward slag discharge is as follows: The pressure inside water tank 6 is >0.1 MPa; The liquid level in water tank 6 is >80%; The liquid level in water tank 6 has increased by 20% compared to before the slag discharge procedure was started; Valve #3 (10) should be open for at least 2 minutes. If any of the above conditions are met, the slag discharge termination condition is considered to be met; if none of the above conditions are met, the slag discharge termination condition is considered not met. The procedure for ending the slag discharge is as follows: close valve #3 (10) and angle valve #17, delay for 2 seconds, then open valve #6 (13) and close valve #8 (15).

[0026] S2, Smooth Slag Discharge: Close valve #1 (8) to isolate slag collection tank 4 from slag lock 5, preventing coal slag water in slag collection tank 4 from continuing to flow into slag lock 5 during slag discharge, thus affecting the slag discharge effect and system stability; open valve #3 (10) to discharge coal slag water into water supply tank 6 for pressure relief; simultaneously open pressure relief flushing valve #19, and after the pressure in slag lock 5 is less than 0.15 MPa, close pressure relief flushing valve #19, open valve #2 (9) at the bottom of slag lock 5 for slag discharge, and then open valve #4 (11) to flush slag lock 5, helping to clean the residual coal slag water and impurities in slag lock 5. Pour the slag / water mixture accumulated at the bottom of slag lock 5 into slag remover 7, which uses a built-in scraper to remove and drain the slag before discharging it to a slag truck for transport to a designated location; when valve #2 (9) has been open for the preset slag discharge cycle, close valve #2 (9) to end slag discharge and proceed to S3, Pressurization. S3, Pressurization: Open valve 4#11 to fill the liquid level in slag lock 5 to full level, then close valve 4#11 and valve 3#10, and then open valve 9#16 to pressurize slag lock 5. When slag lock 5 and slag collection tank 4 reach a pressure equalization state (pressure difference less than 0.5MPa), end the pressurization and execute S1, Slag Collection.

[0027] During the pressurization process, when the liquid level in the water replenishment tank 6 is lower than the preset low liquid level value (20%), valve 5#12 is opened to replenish the water replenishment tank 6; when the liquid level in the water replenishment tank 6 reaches the preset high liquid level value (100%), valve 5#12 is closed to stop replenishing the liquid.

[0028] In this embodiment, during the slag collection process, when the conditions for starting the pull-down slag discharge are met, the system quickly initiates the pull-down slag discharge procedure. High pressure is used to rapidly guide the accumulated slag adhering to the walls of the slag pool 2 and slag collection tank 4 to the slag lock 5, preventing slag buildup from obstructing the synthesis gas flow channel. This ensures the synthesis gas flow channel of the gasifier 1 remains unobstructed, allowing gas to flow smoothly, thereby increasing the output of the gasifier 1 and ensuring stable downstream product output. Taking Hulunbuir Jinxin Chemical Co., Ltd. as an example, after adopting this pressurized slag discharge system, the output of the gasifier 1 has significantly improved, downstream product output has been effectively guaranteed, and production efficiency has been greatly enhanced.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pressurized slag removal system for preventing slag buildup in a gasifier slag pool, characterized by, The system comprises a gasification furnace, a slag pool, a slag breaker, a slag collecting tank, a slag lock, a water supplementing tank and a slag grabber. The bottom end of the slag falling pipe in the center of the distribution plate of the bottom of the gasification furnace is sealingly connected with one end of the slag falling pipe, the other end of the slag falling pipe penetrates through the top of the slag pool and is arranged in the slag pool, the slag outlet of the slag pool is in communication with the inlet of the slag breaker, the outlet of the slag breaker is sealingly connected with one end of the slag collecting pipe, the other end of the slag collecting pipe penetrates through the top of the slag collecting tank and extends to the middle of the slag collecting tank, the slag outlet at the bottom of the slag collecting tank is in communication with the slag inlet of the slag lock through a pipeline, the slag outlet of the slag lock is in communication with the inlet of the slag grabber through a pipeline, a first valve is arranged on the pipeline in communication with the slag outlet of the slag collecting tank and the slag inlet of the slag lock, and a second valve is arranged at the slag outlet of the slag lock. A water supplementing opening is arranged on the side wall of the slag lock, the water outlet of the water supplementing tank is in communication with the water supplementing opening through a water supplementing pipeline, a pressure relief opening is arranged on the top of the slag lock, the pressure relief opening is in communication with the top of the water supplementing tank through a pressure relief pipeline, a fourth valve is arranged on the water supplementing pipeline, a third valve is arranged on the pressure relief pipeline, and an angle valve is arranged at the outlet end of the pressure relief pipeline. The water outlet end of the water supplementing water inlet pipeline is in communication with the water inlet of the water supplementing tank through a pipeline, and a fifth valve is arranged at the water outlet end of the water supplementing water inlet pipeline. A flow guide opening is further arranged on the side wall of the slag lock, the flow guide opening is in communication with the inlet of a slag slurry flow guide pump through a first flow guide pipeline, the outlet of the slag slurry flow guide pump is in communication with a backflow opening arranged on the side wall of the slag collecting tank through a second flow guide pipeline, a sixth valve is arranged on the first flow guide pipeline, and a seventh valve is arranged on the second flow guide pipeline. The water outlet end of the high-pressure flushing water inlet pipeline is in communication with the flow guide opening through a pressure charging pipeline, and a ninth valve is arranged on the pressure charging pipeline.

2. A pressurized slag tapping system for preventing slag accumulation in a gasifier slag pool according to claim 1, wherein A bypass pipeline is further arranged, the inlet of the slag slurry flow guide pump and the outlet of the slag slurry flow guide pump are in communication through the bypass pipeline, and an eighth valve is arranged on the bypass pipeline.

3. A pressurized slag tapping system for preventing slag accumulation in a gasifier slag pool according to claim 1, wherein A slag pool liquid level sensor is arranged in the slag pool, and a water supplementing tank liquid level sensor and a water supplementing tank pressure sensor are respectively arranged in the water supplementing tank.

4. A pressurized slag tapping system for preventing slag accumulation in a gasifier slag pool according to claim 3, wherein The water supplementing water inlet pipeline is further in communication with the pressure relief opening of the slag lock through a pressure relief flushing pipeline, and a pressure relief flushing valve is arranged on the pressure relief flushing pipeline.

5. A pressurized slag tapping system for preventing slag accumulation in a gasifier slag pool according to claim 1, wherein A slag collecting tank pressure sensor is arranged in the slag collecting tank, and a slag lock liquid level sensor and a slag lock pressure sensor are respectively arranged in the slag lock.

6. A method of pressure discharge of slag from a gasifier slag pool, characterized in that The system comprises the following steps: S1, collecting slag: opening the first valve, closing the second valve, and enabling the gasification ash generated in the gasification furnace to enter the slag pool through the slag falling pipe and the slag falling pipe, and after being in contact with the quenching water, the water and slag mixture is cooled and cooled, and the coal slag water after the slag pool is cooled is broken by the slag breaker, and the larger ash enters the downstream slag collecting tank; the coal slag water in the slag collecting tank enters the slag lock for slag collection; Meanwhile, the sixth valve and the seventh valve are opened, the eighth valve is closed, and the slag slurry flow guide pump is in a starting state; when the opening time of the first valve reaches the preset slag collection period, the slag collection is ended, and S2, the sequence control slag discharge is performed. In the slag collecting process, it is judged whether the start condition of the down-drawing slagging is met, if yes, the down-drawing slagging program is started, if not, the down-drawing slagging program is not started; S2, sequence control slagging: close 1# valve, open 3# valve; at the same time, open the pressure relief flushing valve, and after the pressure in the slag lock is less than 0.15 MPa, close the pressure relief flushing valve, open 2# valve at the bottom of the slag lock for slagging, then open 4# valve for flushing the slag lock, and the slag / water mixture accumulated at the bottom of the slag lock is poured into the slag extractor, and the slag extractor drains the slag through the built-in scraper and then discharges the slag to the slag transport vehicle; when the opening time of 2# valve reaches the preset slagging period, 2# valve is closed, the slagging is ended, and S3, pressure charging, is executed. In the S1, slag collecting, 7. A method of pressure discharge of slag from a gasifier slag pool according to claim 6, wherein The start condition of the down-drawing slagging is: In the last slagging period, the peak value of the working current of the slag extractor is less than the preset current value; The liquid level in the slag pool is greater than 45%; 40%> the liquid level in the water supplement tank > 20%; When all the above conditions are met, it is considered that the start condition of the down-drawing slagging is met; when any of the above conditions is not met, it is considered that the start condition of the down-drawing slagging is not met; The down-drawing slagging program is: close 6# valve, open 8# valve, keep 7# valve always open, and make 5# valve in the closed state, open 3# valve and the angle valve, the stored slag in the slag pool and the slag tank is quickly drained under the action of high pressure, and the excess slag water enters the water supplement tank after passing through the slag lock, and the accumulated ash slag is forced to enter the slag lock; In the down-drawing slagging process, it is judged whether the end condition of the down-drawing slagging is met, if yes, the down-drawing slagging end program is executed, if not, the down-drawing slagging program is continuously executed. The end condition of the down-drawing slagging is:

8. A method of pressure discharge of slag from a gasifier slag pool according to claim 7, wherein The pressure in the water supplement tank is greater than 0.1 MPa; The liquid level in the water supplement tank is greater than 80%; The liquid level in the water supplement tank rises by 20% compared with before the down-drawing slagging program is started; The opening time of 3# valve is greater than or equal to 2 min; When any of the above conditions is met, it is considered that the end condition of the down-drawing slagging is met; when all the above conditions are not met, it is considered that the end condition of the down-drawing slagging is not met; The down-drawing slagging end program is: close 3# valve and the angle valve, open 6# valve after 2 s, and close 8# valve. In the S3, pressure charging, when the liquid level in the water supplement tank is lower than the preset low liquid level value, 5# valve is opened to supplement the water in the water supplement tank; when the liquid level in the water supplement tank reaches the preset high liquid level value, 5# valve is closed to stop the water supplement.

9. A method of pressure discharge of slag from a gasifier slag pool according to claim 6, wherein ​

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