Waste heat utilization device for pressurized gasification of pulverized coal

Abstract

The utility model discloses a waste heat utilization device for pressurized gasification of pulverized coal, which relates to the technical field of waste heat recovery and comprises a high-pressure flash tank, an exhaust port of the high-pressure flash tank is communicated with a gas inlet of a heat exchange tower through a pipeline I, a liquid outlet of the high-pressure flash tank is communicated with a liquid inlet of a low-pressure flash tank through a pipeline II, and a liquid outlet of the low-pressure flash tank is communicated with a gas outlet of a heat exchange tower through a pipeline II. An exhaust port of the low-pressure flash tank is communicated with an air inlet of an air supplementing tank through a fourth pipeline, an air supplementing port of the air supplementing tank is communicated with a first pipeline through a fifth pipeline, a pressure valve is installed in the fifth pipeline, and an air outlet of the air supplementing tank is communicated with a power generation mechanism through a sixth pipeline. The flash steam waste heat of the spaceflight pulverized coal pressurized gasification device is fully utilized, the operation stability of the gasification device is improved, the purpose of converting inferior steam energy into convenient energy is achieved, good economic benefits and social benefits are obtained, and the energy consumption of the whole plant is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of waste heat recovery, in particular to a waste heat utilization device for pressurized gasification of pulverized coal. Background Art

[0002] Coal pressurized gasification technology is a production technology. Pulverized coal pressurized gasification technology uses dry coal powder as raw material, pure oxygen and steam as gasification agents, pressurized gasification, and water-quenched rough scrubbing synthesis gas, which can improve energy conversion efficiency and reduce environmental pollution.

[0003] After the raw coal is cleaned, it is sent to the coal mill for crushing. At the same time, it is dried by heated low-pressure nitrogen to prepare qualified coal powder and store it in the silo. Most of the low-pressure nitrogen used for heating can be recycled. The coal powder in the silo is transported by low-pressure nitrogen and high-pressure nitrogen successively, and then enters the gasifier through the gasification nozzle. The gasifying agent oxygen and steam also enter the gasifier through the gasification nozzle, and react with the coal powder under high temperature and pressure. The high-temperature synthesis gas out of the gasifier is quenched and washed, and then merged into the synthesis gas pipeline of the gasification workshop. The molten ash is quenched and solidified in the quenching chamber of the gasifier, collected by the lock bucket, and discharged regularly. The black water from the washing tower is flashed in the second stage, and the water vapor and a part of the acid gas CO2, H2S dissolved in the black water are flashed out quickly. The flash gas is condensed and separated, and then treated together with the acid gas of the production system of the gasification plant. The flashed black water is cooled by the heat exchanger and discharged into the ditch, and then sent to the sewage treatment system of the production equipment of the gasification plant.

[0004] In the existing two-stage flash evaporation, the black water inside the high-pressure flash tank directly enters the vacuum flash tank for flash evaporation. The temperature and pressure of this part of black water are relatively high, so its energy can be fully utilized. In addition, the steam flashed out of the vacuum flash tank is recycled by cooling and condensing with circulating water. The heat is not fully utilized, and a large amount of circulating water is consumed, resulting in high energy consumption. Especially in summer when the circulating water temperature is high, the true flash system will have a positive pressure situation, which will be extremely unfavorable to the ash water sedimentation system. The turbidity of the ash water in the sedimentation tank often does not meet the index requirement of less than 30NTU. Long-term operation in this state will cause the deposition of ash slag outside the drainage, affecting the normal operation of the terminal water. The high fine ash content inside the gasification system will aggravate scaling, causing the quenching ring to be blocked, the downcomer to be burned, and the safe operation of the gasifier to be affected. For this reason, we propose a waste heat utilization device for pressurized gasification of pulverized coal. Utility Model Content

[0005] The technical problem to be solved by the utility model is to overcome the existing defects and provide a waste heat utilization device for pressurized pulverized coal gasification. After the black water flash evaporation is modified, the flash steam is used for power generation, which not only makes full use of the flash steam waste heat of the aerospace pulverized coal pressurized gasification device, but also improves the stability of the operation of the gasification device, realizes the purpose of converting inferior steam energy into convenient energy, achieves good economic and social benefits, and reduces the energy consumption of the whole plant, which can effectively solve the problems in the background technology.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a waste heat utilization device for pressurized gasification of pulverized coal, comprising a high-pressure flash tank, the high-pressure flash tank, the exhaust port of the high-pressure flash tank is connected to the air inlet of the heat exchange tower through pipeline one, the discharge port of the high-pressure flash tank is connected to the liquid inlet of the low-pressure flash tank through pipeline two, the exhaust port of the low-pressure flash tank is connected to the air inlet of the air replenishing tank through pipeline four, the air replenishing port of the air replenishing tank is connected to pipeline one through pipeline five, a pressure valve is installed inside the pipeline five, the air outlet of the air replenishing tank is connected to a power generation mechanism through pipeline six, the diameter of the pipeline four is larger than the diameter of the pipeline six, and the discharge port of the low-pressure flash tank is connected to a three-stage flash mechanism.

[0007] The air supply tank is designed so that when the output of low-pressure air generated in the low-pressure flash tank is too low, part of the high-pressure steam generated by the high-pressure flash tank is introduced to ensure the normal operation of the power generation mechanism. The diameter of the design pipeline four is larger than the diameter of the pipeline six, so that after the steam enters the air supply tank, the internal pressure of the air supply tank is increased, and the pressure valve cooperates with the opening and closing of the pipeline five to automatically introduce the high-pressure steam when needed, which is more convenient. When the control device is working, the black water is first transported into the high-pressure flash tank for high-pressure flash evaporation, and the generated high-pressure steam enters the heat exchange tower through the pipeline one for heat recovery. After recovery, The condensed water and non-condensable gas are treated in an environmentally friendly manner, the black water at the bottom of the high-pressure flash tank enters the low-pressure flash tank through pipeline two for low-pressure flash evaporation, the low-pressure steam generated by the low-pressure flash evaporation enters the air supply tank through pipeline four, and then enters the power generation mechanism through pipeline six for power generation, the remaining black water in the low-pressure flash tank enters the tertiary flash evaporation mechanism for subsequent treatment, when the steam generated by the low-pressure flash evaporation is insufficient, the air pressure in the air supply tank drops, causing the pressure valve to open, thereby connecting the air supply tank with pipeline one, so that part of the high-pressure steam in pipeline one enters the air supply tank for replenishment, thereby ensuring the normal operation of the power generation mechanism.

[0008] Furthermore, the power generation mechanism includes an ORC generator set, and the air outlet of the air supply tank is connected to the pipeline air inlet of the ORC generator set through a pipeline six.

[0009] The ORC generator set is designed so that low-pressure steam with lower temperature can be used for low-temperature power generation. When the low-pressure steam completes heat exchange in the ORC generator set, condensed water and non-condensable gas are generated. The non-condensable gas is discharged through the pipeline for subsequent environmental protection treatment, and the condensed water is discharged into the sedimentation tank.

[0010] Furthermore, the three-stage flash mechanism comprises a vacuum flash tank, the liquid discharge port of the low-pressure flash tank is connected to the liquid inlet of the vacuum flash tank through pipeline three, and the liquid discharge port of the vacuum flash tank is connected to the sedimentation tank.

[0011] The remaining black water is vacuum flashed by a vacuum flash tank, the generated steam is discharged into the atmosphere, and the remaining impurities are discharged into the sedimentation tank.

[0012] Furthermore, the waste heat utilization device also includes a rotating sleeve, the lower end of the pipe five extends to the interior of the air supply tank, the lower part of the outer surface of the pipe five is rotatably connected to the rotating sleeve, the outer surface of the rotating sleeve is fixedly connected to the mixing blades at an equal angle, and a rotating block is arranged inside the pipe five, which is located inside the air supply tank, and the outer surface of the rotating block is fixedly connected to the pneumatic blades at an equal angle, and the lower end of the rotating block is fixedly connected to the lower end of the rotating sleeve by a support rod.

[0013] The mixing blades are designed to automatically stir the mixed high-pressure steam, so that the high-pressure steam can be quickly mixed with the low-pressure steam for heat exchange, thereby making the gas temperature uniform. When the high-pressure steam enters the pipe five, it drives the pneumatic blades to rotate, thereby driving the rotating sleeve to rotate, and thus driving the mixing blades to rotate.

[0014] Furthermore, the waste heat utilization device also includes a filter, and the interior of the pipeline five is located at an upper position of the pressure valve and is fixedly connected to the filter.

[0015] The filter is designed to filter out the particulate impurities in the high-pressure steam to avoid pipeline blockage.

[0016] Compared with the prior art, the utility model has the following beneficial effects: the waste heat utilization device for pressurized gasification of pulverized coal has the following advantages:

[0017] 1. Design the air replenishment tank so that when the output of low-pressure air generated in the low-pressure flash tank is too low, part of the high-pressure steam generated by the high-pressure flash tank will be introduced to ensure the normal operation of the power generation mechanism;

[0018] 2. The diameter of the design pipeline 4 is larger than that of the pipeline 6, so that after the steam enters the air supply tank, the internal pressure of the air supply tank increases, and the pressure valve cooperates with the opening and closing of pipeline 5 to automatically introduce high-pressure steam when needed;

[0019] 3. Design mixing blades to automatically stir the mixed high-pressure steam, so that the high-pressure steam can quickly mix and exchange heat with the low-pressure steam, thereby making the gas temperature uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the utility model;

[0021] Figure 2 This is a schematic diagram of the structure of the gas supply tank of the utility model;

[0022] Figure 3 This is a schematic diagram of the internal structure of the gas replenishing tank of the utility model.

[0023] In the figure: 1 high-pressure flash tank, 2 pipeline one, 3 heat exchange tower, 4 pipeline two, 5 low-pressure flash tank, 6 pipeline three, 7 vacuum flash tank, 8 pipeline four, 9 air supply tank, 10 pipeline five, 11 pressure valve, 12 pipeline six, 13, ORC generator set, 14 rotating sleeve, 15 mixing fan blade, 16 pneumatic fan blade, 17 filter screen. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] See also Figure 1-3 The present embodiment provides a technical solution: a waste heat utilization device for pressurized gasification of pulverized coal, comprising a high-pressure flash tank 1, the exhaust port of the high-pressure flash tank 1 is connected to the air inlet of the heat exchange tower 3 through a pipeline 1 2, the liquid discharge port of the high-pressure flash tank 1 is connected to the liquid inlet of the low-pressure flash tank 5 through a pipeline 2 4, the exhaust port of the low-pressure flash tank 5 is connected to the air inlet of the air supply tank 9 through a pipeline 4 8, the air supply port of the air supply tank 9 is connected to the pipeline 1 2 through a pipeline 5 10, a pressure valve 11 is installed inside the pipeline 5 10, the air outlet of the air supply tank 9 is connected to the power generation mechanism through a pipeline 6 12, the diameter of the pipeline 4 8 is larger than the diameter of the pipeline 6 12, and the liquid discharge port of the low-pressure flash tank 5 is connected to the three-stage flash mechanism.

[0026] The air supply tank 9 is designed so that when the output of low-pressure air generated in the low-pressure flash tank 5 is too low, part of the high-pressure steam generated by the high-pressure flash tank 1 is introduced to ensure the normal operation of the power generation mechanism. The diameter of the design pipeline four 8 is larger than the diameter of the pipeline six 12, so that after the steam enters the interior of the air supply tank 9, the internal pressure of the air supply tank 9 is increased, thereby cooperating with the pressure valve 11 to open and close the pipeline five 10, so that the high-pressure steam is automatically introduced when needed, which is more convenient. When the control device is working, the black water is first transported into the high-pressure flash tank 1 for high-pressure flash evaporation, and the generated high-pressure steam enters the heat exchange tower 3 through the pipeline one 2 for heat recovery. After recovery The condensed water and non-condensable gas are treated in an environmentally friendly manner, the black water at the bottom of the high-pressure flash tank 1 enters the low-pressure flash tank 5 through the pipe 2 4 for low-pressure flash evaporation, the low-pressure steam generated by the low-pressure flash evaporation enters the air supply tank 9 through the pipe 4 8, and then enters the power generation mechanism through the pipe 6 12 for power generation, the remaining black water in the low-pressure flash tank 5 enters the tertiary flash evaporation mechanism for subsequent treatment, when the steam generated by the low-pressure flash evaporation is insufficient, the air pressure in the air supply tank 9 drops, causing the pressure valve 11 to open, thereby connecting the air supply tank 9 with the pipe 1 2, so that part of the high-pressure steam in the pipe 1 2 enters the air supply tank 9 for replenishment, thereby ensuring the normal operation of the power generation mechanism.

[0027] The power generation mechanism includes an ORC generator set 13, and the air outlet of the air supply tank 9 is connected to the pipeline air inlet of the ORC generator set 13 through a pipeline 6 12.

[0028] The ORC generator set 13 is designed so that low-pressure steam with a relatively low temperature can perform low-temperature power generation. When the low-pressure steam completes heat exchange in the ORC generator set 13, condensed water and non-condensable gas are generated. The non-condensable gas is discharged through a pipeline for subsequent environmental protection treatment, and the condensed water is discharged and enters a sedimentation tank.

[0029] The three-stage flash mechanism comprises a vacuum flash tank 7, the discharge port of the low-pressure flash tank 5 is connected to the liquid inlet of the vacuum flash tank 7 through a pipeline 3 6, and the discharge port of the vacuum flash tank 7 is connected to a sedimentation tank.

[0030] The remaining black water is subjected to vacuum flash evaporation in the vacuum flash tank 7, the generated steam is discharged into the atmosphere, and the remaining impurities are discharged into the sedimentation tank.

[0031] The waste heat utilization device also includes a rotating sleeve 14. The lower end of the pipe 5 10 extends to the interior of the air supply tank 9. The lower part of the outer surface of the pipe 5 10 is rotatably connected to the rotating sleeve 14. The outer surface of the rotating sleeve 14 is fixedly connected to the mixing blades 15 at an equal angle. A rotating block is arranged inside the pipe 5 10, and the outer surface of the rotating block is fixedly connected to the pneumatic blades 16 at an equal angle. The lower end of the rotating block is fixedly connected to the lower end of the rotating sleeve 14 at a fixed position through a support rod.

[0032] The mixing blades 15 are designed to automatically stir the mixed high-pressure steam, so that the high-pressure steam can quickly mix with the low-pressure steam for heat exchange, thereby making the gas temperature uniform. When the high-pressure steam enters the pipe 5 10, it drives the pneumatic blades 16 to rotate, thereby driving the rotating sleeve 14 to rotate, and thus driving the mixing blades 15 to rotate.

[0033] The waste heat utilization device also includes a filter screen 17, and the filter screen 17 is fixedly connected to the interior of the pipeline 5 10 at an upper position of the pressure valve 11.

[0034] The filter screen 17 is designed to filter out particulate impurities present in the high-pressure steam to avoid pipeline blockage.

[0035] The working principle of the waste heat utilization device for pressurized gasification of pulverized coal provided by the utility model is as follows:

[0036] First, the black water is transported to the high-pressure flash tank 1 for high-pressure flash evaporation, and the generated high-pressure steam enters the heat exchange tower 3 through the pipeline 1 2 for heat recovery. After recovery, the condensed water and non-condensable gas are treated for environmental protection. The black water at the bottom of the high-pressure flash tank 1 enters the low-pressure flash tank 5 through the pipeline 2 4 for low-pressure flash evaporation. The low-pressure steam generated by the low-pressure flash evaporation enters the air replenishment tank 9 through the pipeline 4 8, and then enters the ORC generator set 13 through the pipeline 6 12 for power generation. When the low-pressure steam completes the heat exchange in the ORC generator set 13, condensed water and non-condensable gas are generated. The non-condensable gas is discharged through the pipeline for subsequent environmental protection treatment. The condensed water is discharged and enters the sedimentation tank. The low-pressure flash tank 5 The remaining black water enters the vacuum flash tank 7 for vacuum flash evaporation of the remaining black water, and the generated steam is discharged into the atmosphere, and the remaining impurities are discharged into the sedimentation tank. When the steam generated by the low-pressure flash evaporation is insufficient, the air pressure in the air supply tank 9 drops, causing the pressure valve 11 to open, thereby connecting the air supply tank 9 with the pipeline 2, so that part of the high-pressure steam in the pipeline 2 enters the air supply tank 9 for replenishment, thereby ensuring the normal operation of the power generation mechanism. When the high-pressure steam enters the pipeline 5 10, it drives the pneumatic fan blades 16 to rotate, thereby driving the rotating sleeve 14 to rotate, thereby driving the mixing fan blades 15 to rotate, so that the high-pressure steam is quickly mixed with the low-pressure steam for heat exchange, so that the gas temperature is uniform.

[0037] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A waste heat utilization device for pressurized gasification of pulverized coal, characterized in that: The invention comprises a high-pressure flash tank (1), wherein the exhaust port of the high-pressure flash tank (1) is connected to the air inlet of a heat exchange tower (3) through a pipeline 1 (2), the liquid discharge port of the high-pressure flash tank (1) is connected to the liquid inlet of a low-pressure flash tank (5) through a pipeline 2 (4), the exhaust port of the low-pressure flash tank (5) is connected to the air inlet of an air supply tank (9) through a pipeline 4 (8), the air supply port of the air supply tank (9) is connected to the pipeline 1 (2) through a pipeline 5 (10), a pressure valve (11) is installed inside the pipeline 5 (10), the air outlet of the air supply tank (9) is connected to a power generation mechanism through a pipeline 6 (12), the diameter of the pipeline 4 (8) is larger than the diameter of the pipeline 6 (12), and the liquid discharge port of the low-pressure flash tank (5) is connected to a three-stage flash mechanism.

2. The waste heat utilization device for pressurized pulverized coal gasification according to claim 1, characterized in that: The power generation mechanism comprises an ORC generator set (13), and the gas outlet of the gas supply tank (9) is connected to the pipeline gas inlet of the ORC generator set (13) through a pipeline six (12).

3. The waste heat utilization device for pressurized pulverized coal gasification according to claim 1, characterized in that: The three-stage flash mechanism comprises a vacuum flash tank (7), the liquid discharge port of the low-pressure flash tank (5) is connected to the liquid inlet of the vacuum flash tank (7) through a pipeline three (6), and the liquid discharge port of the vacuum flash tank (7) is connected to a sedimentation tank.

4. The waste heat utilization device for pressurized pulverized coal gasification according to claim 1, characterized in that: The waste heat utilization device further comprises a rotating sleeve (14), the lower end of the pipe five (10) extends to the interior of the air supply tank (9), the lower portion of the outer surface of the pipe five (10) is rotatably connected to the rotating sleeve (14), the outer surface of the rotating sleeve (14) is fixedly connected to the mixing blades (15) at an equal angle, the interior of the pipe five (10) is provided with a rotating block located inside the air supply tank (9), the outer surface of the rotating block is fixedly connected to the pneumatic blades (16) at an equal angle, and the lower end of the rotating block is fixedly connected to the lower end of the rotating sleeve (14) at a fixed position via a support rod.

5. The waste heat utilization device for pressurized pulverized coal gasification according to claim 1, characterized in that: The waste heat utilization device further comprises a filter screen (17), and the filter screen (17) is fixedly connected to the interior of the pipeline five (10) at a position above the pressure valve (11).

Images