Coal gasification black water flash steam waste heat steam turbine gradient utilization system

Abstract

The invention relates to the technical field of coalification black water treatment, and particularly discloses a coal gasification black water flash steam waste heat steam turbine gradient utilization system which comprises a black water flash steam turbine module and a steam exhaust condensation module. The black water flash steam turbine module comprises a high-pressure flash evaporator, a low-pressure flash evaporator, a vacuum flash evaporator, a supplementary condensing steam turbine, a generator and a settling tank, and a water outlet of the vacuum flash evaporator is connected with the settling tank; the steam exhaust condensation module comprises an evaporative condenser and a condensate pump. Through the design of the scale scraping and water uniformizing piece, part of cooling water falling around the heat exchange coil from top to bottom falls on the water uniformizing plate to drive the water uniformizing plate to rotate, when the water uniformizing plate rotates, water on the water uniformizing plate is thrown out under the action of centrifugal force, cooling water without heat exchange can be uniformized to other heat exchange pipes for heat exchange, and the heat exchange efficiency is improved. Therefore, the cooling water flows more uniformly among the heat exchange coils, the utilization rate of the cooling water is improved, and the heat exchange efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of coal gasification black water treatment technology, and in particular to a coal gasification black water flash steam waste heat steam turbine cascade utilization system. Background Technology

[0002] Due to the need for cooling, coal gasification black water typically employs multi-stage flash evaporation for rapid cooling. This flash evaporation process generates a large amount of waste steam, which is commonly treated by condensing and cooling the black water using circulating cooling water. However, this method results in significant heat waste and requires substantial amounts of circulating cooling water. Furthermore, the production of this cooling water also consumes electricity and demineralized water, meaning this technological approach leads to a waste of both electricity and demineralized water.

[0003] Currently, there are mature technical routes for waste heat recovery from flash steam in gasification black water systems. One such route involves recovering waste heat from black water flash steam using an organic Rankine cycle. This technology reduces waste heat to some extent. However, it reduces system cycle efficiency through indirect heat exchange and requires additional heat exchangers for the black water flash steam and the organic working fluid, as well as the system needing to be charged with the organic working fluid. These factors contribute to the high cost of waste heat recovery power generation systems. Furthermore, to prevent working fluid leakage, the system requires significant maintenance and is very difficult to operate.

[0004] Another technical approach for recovering waste heat from flash steam in gasification black water is to use steam turbines to recover waste heat from each stage of flash steam for power generation. However, the system design of using separate steam turbines for each stage of flash steam is complex and requires high investment.

[0005] On the other hand, the steam after the waste heat of black water steam is used for power generation still needs to be condensed and circulated through a condenser. In traditional evaporative condensers, the spray structure is mostly located above the heat exchange coils. Since the heat exchange coils have multiple layers, the spray water flows from top to bottom. The upper heat exchange coils can be cooled more fully, while the lower heat exchange coils may not be cooled enough due to the reduction in the amount of spray water and the decrease in the flow velocity. This uneven cooling not only affects the overall heat exchange efficiency of the condenser, but may also cause some heat exchange coils to overheat, thereby shortening the service life of the condenser. Meanwhile, minerals and hardness components in the cooling water will crystallize on the surface of the heat exchange coil, forming scale. The presence of these oil films and scale not only increases thermal resistance and reduces the heat exchange efficiency of the heat exchange coil, but may also lead to a decline in the overall performance of the condenser, and even affect the stable operation of the refrigeration system.

[0006] Based on this, those skilled in the art have proposed a cascade utilization system for waste heat steam from flash steam of coal gasification black water, providing a new solution to the above-mentioned technical problems. Summary of the Invention

[0007] Therefore, it is necessary to provide a coal gasification black water flash steam waste heat steam turbine cascade utilization system to address the problems raised in the background technology.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The coal gasification black water flash steam waste heat steam turbine cascade utilization system specifically includes a black water flash steam turbine module and an exhaust steam condensation module; The black water flash steam turbine module includes a high-pressure flash evaporator, a low-pressure flash evaporator, a vacuum flash evaporator, a condensing steam turbine, a generator, and a settling tank. The outlet of the high-pressure flash evaporator is connected to the inlet of the low-pressure flash evaporator, the outlet of the low-pressure flash evaporator is connected to the inlet of the vacuum flash evaporator, the outlet of the vacuum flash evaporator is connected to the settling tank, the outlets of the high-pressure flash evaporator, the low-pressure flash evaporator, and the vacuum flash evaporator are all connected to the inlet of the condensing steam turbine, and the output end of the condensing steam turbine is connected to the input end of the generator. The exhaust steam condensation module includes an evaporative condenser and a condensate pump. The exhaust end of the condensing turbine is connected to the inlet end of the evaporative condenser, the output end of the evaporative condenser is connected to the input end of the condensate pump, and the output end of the condensate pump is connected to the settling tank.

[0009] Optionally, the evaporative condenser includes a condensing chamber and a liquid pump. An axial flow fan is installed on the top of the condensing chamber. A heat exchange mechanism is installed inside the condensing chamber. The heat exchange mechanism includes a heat exchange coil and a spray assembly. An air inlet grille is installed on the lower side wall of the condensing chamber. A liquid collection tank is installed at the bottom of the condensing chamber. The spray assembly is installed inside the condensing chamber and sprays heat exchange treatment onto the heat exchange coil. A water-distributing descaling component is installed on the straight tube of the heat exchange coil, and the water-distributing descaling component cleans the dirt on the heat exchange coil.

[0010] Optionally, the spray assembly includes a water delivery pipe connected to the output end of the infusion pump, the input end of the infusion pump being connected to the collection tank via a pipe, a plurality of distribution pipes being connected to the water delivery pipe, a plurality of spray pipes being connected to the distribution pipes, and a plurality of spray heads being evenly distributed around the outer periphery of the spray pipes.

[0011] Optionally, several spray pipes are disposed above the heat exchange coil. The water distribution and descaling assembly includes rotating connecting rings that are relatively sleeved on the straight pipe of the heat exchange coil. The rotating connecting rings are rotatably connected to the straight pipe of the heat exchange coil. Scaling and water distribution components are fixed on both sides between the two opposing rotating connecting rings. The inner wall of the scraping and water distribution component is in contact with the straight pipe of the heat exchange coil. The scraping and water distribution component extends outward from the side away from the straight pipe of the heat exchange coil to form a water distribution plate.

[0012] Optionally, the scale scraping and water equalization component has a hollow interior design. The scale scraping and water equalization component includes a scraper that fits against the outer wall of the straight tube of the heat exchange coil and a water-blocking arc plate located outside the scraper. The scraper and the water-blocking arc plate form a flow collection channel. The water equalization plate is fixed to the outside of the water-blocking arc plate. A water equalization cavity is provided on the inner side of the water equalization plate. A plurality of water equalization holes are opened on the side wall of the water equalization plate and on the side of the water equalization cavity away from the scraper.

[0013] Optionally, an installation groove is provided inside the water distribution cavity, and a filter plate adapted to it is inserted inside the installation groove. The filter plate has an arc-shaped cross-section, an opening on the side of the filter plate facing the flow collection channel, and the inner wall of the opening of the filter plate is flush with the inner wall of the water distribution cavity. The filter plate has a plurality of filter holes.

[0014] Optionally, a positioning ring is fixed to one end of the filter plate. An adjustment knob is rotatably and slidably connected to the end of the positioning ring away from the filter plate. An installation plate is rotatably connected to the inner side of the end of the adjustment knob near the positioning ring. A spring is provided between the installation plate and the positioning ring. The two ends of the spring are respectively connected to the installation plate and the positioning ring. The adjustment knob is threadedly connected to the scale scraping and water equalization component. Limiting strips are provided on both sides of the positioning ring. Limiting grooves that match the limiting strips are opened on the scale scraping and water equalization component.

[0015] Optionally, the heat exchange coil is designed as an elliptical tube with the major axis of its elliptical cross-section set in the vertical direction. Several spray pipes are inserted between four adjacent straight pipes of the heat exchange coil, and the spray heads are set in four groups along the axial direction of the straight pipes of the heat exchange coil, respectively facing the four adjacent straight pipes.

[0016] Optionally, a plurality of the spray pipes are inserted between two adjacent straight pipes above and below the heat exchange coil, and the spray heads are arranged in six groups along the axial direction of the straight pipes of the heat exchange coil, respectively facing the two adjacent straight pipes above and below the heat exchange coil and the straight pipes at its four corners: upper left, lower left, upper right, and lower right.

[0017] The water equalization and descaling component includes several connecting grooves opened along the axial direction of the heat exchange coil straight tube. The several connecting grooves are evenly distributed on the outer wall of the heat exchange coil straight tube. An installation strip is inserted into the inner side of the connecting groove. Several elastic silicone filaments are embedded on both sides of the top of the installation strip. In the natural state, the several elastic silicone filaments are attached to the outer wall of the heat exchange coil straight tube.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention, through the design of the scale scraping and water distribution component, allows some of the cooling water falling from top to bottom around the heat exchange coil to fall onto the water distribution plate, causing the water distribution plate to rotate. When the water distribution plate rotates, the water on it is thrown outwards under the action of centrifugal force, which can distribute the cooling water that has not been heat exchanged to other heat exchange tubes for heat exchange. This makes the flow of cooling water between the heat exchange coils more uniform, improves the utilization rate of cooling water, and thus improves the heat exchange efficiency.

[0019] 2. The present invention, through the design of filter plate, scraper and water baffle, when the scale scraping and water equalization component rotates, the scraper can scrape off the scale, crystals or oil film on the outer wall of the heat exchange coil, and send the scraped impurities into the water equalization chamber along the collection channel for collection and filtration, thereby ensuring the cleanliness of the heat exchange coil surface and improving heat exchange efficiency. On the other hand, the design of the scraper and the baffle plate can divide the cooling water falling on the surface of the heat exchange coil and the surrounding area into three parts. One part falls directly on the surface of the heat exchange coil for heat exchange, another part falls on the surface of the water distribution plate and is thrown out with its movement, and the third part enters between the scraper and the baffle plate and also exchanges heat with the heat exchange coil. To a certain extent, it plays the role of temporary water storage, increases the residence time of the cooling water on the surface of the heat exchange coil, and thus improves the heat exchange effect of the heat exchange coil.

[0020] 3. This invention uses a set of supplementary steam condensing steam turbines to recover the waste heat of multi-stage flash steam, simplifying the waste heat recovery system and reducing system investment. Attached Figure Description

[0021] To more clearly illustrate the solutions in this invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the coal gasification black water and flash steam waste heat steam turbine and waste heat cascade utilization system of the present invention. Figure 2 This is a schematic diagram of the evaporative condenser of the present invention; Figure 3 This is a schematic diagram of the internal structure of the condenser box of the present invention; Figure 4 This is a schematic diagram of the structure of the spray pipe of the present invention located between four straight pipes adjacent to the heat exchange coil; Figure 5 This is a schematic diagram of the structure of the spray pipe of the present invention located between two adjacent straight pipes above and below the heat exchange coil; Figure 6 This is a front view schematic diagram of the mounting strip and elastic silicone filament bundle of the present invention; Figure 7 This is a schematic diagram of the structure of the scale scraping and water equalization component and the heat exchange coil straight tube of the present invention; Figure 8 This is a schematic diagram of the rotating connecting ring and water distribution plate of the present invention. Figure 1 ; Figure 9 This is a schematic diagram of the rotating connecting ring and water distribution plate of the present invention. Figure 2 ; Figure 10 This is a schematic diagram of the scraper and water-blocking arc plate of the present invention; Figure 11 This is a schematic diagram of the structure of the filter plate of the present invention; Figure 12 This is a schematic diagram of the structure of the filter holes and water distribution holes of the present invention; Figure 13 This is a schematic diagram of the positioning ring and adjusting knob of the present invention; Figure 14 This is a schematic diagram of the structure of the limiting strip of the present invention.

[0023] The markings in the diagram are explained as follows: 1. Condensation box; 2. Axial flow fan; 3. Air inlet grille; 4. Infusion pump; 5. Water supply pipe; 6. Water distribution pipe; 7. Spray pipe; 8. Spray head; 9. Heat exchange coil; 10. Mounting strip; 11. Elastic silicone filament bundle; 12. Scaling and water distribution component; 13. Rotating connecting ring; 14. Water distribution plate; 15. Scraper; 16. Water baffle; 17. Filter plate; 18. Filter hole; 19. Water distribution hole; 20. Collection channel; 21. Water distribution chamber; 22. Positioning ring; 23. Limiting strip; 24. Adjusting knob; 25. Mounting plate; 26. Spring; 27. Limiting groove; 28. Mounting groove. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0025] Example 1 Please refer to Figure 1 The present invention provides a coal gasification black water flash steam waste heat steam turbine cascade utilization system, which includes a black water flash steam turbine module and an exhaust steam condensation module. The black water flash steam turbine module includes a high-pressure flash evaporator, a low-pressure flash evaporator, a vacuum flash evaporator, a condensing steam turbine, a generator, and a settling tank. The outlet of the high-pressure flash evaporator is connected to the inlet of the low-pressure flash evaporator, the outlet of the low-pressure flash evaporator is connected to the inlet of the vacuum flash evaporator, the outlet of the vacuum flash evaporator is connected to the settling tank, the outlets of the high-pressure flash evaporator, the low-pressure flash evaporator, and the vacuum flash evaporator are all connected to the inlet of the condensing steam turbine, and the output end of the condensing steam turbine is connected to the input end of the generator. The exhaust condensation module includes an evaporative condenser and a condensate pump. The exhaust end of the condensing turbine is connected to the inlet end of the evaporative condenser, the output end of the evaporative condenser is connected to the input end of the condensate pump, and the output end of the condensate pump is connected to the settling tank. When in use, the coal gasification black water first enters the high-pressure flash evaporator to produce high-pressure flash steam and high-flash black water. The high-flash black water then enters the low-pressure flash evaporator to produce low-pressure flash steam and low-flash black water. The low-flash black water then enters the vacuum flash evaporator to produce vacuum flash steam and true flash black water. The steam from the three-stage flash evaporation simultaneously enters the condensing turbine to perform work and drive the generator to generate electricity. The high-pressure flash steam is the main inlet steam of the condensing turbine, while the low-pressure flash steam and vacuum flash steam are the first and second stage make-up steam, respectively. The exhaust steam after performing work enters the evaporative condenser for condensation and cooling. Finally, the exhaust steam condensate is pressurized by the condensate pump and merges with the black water after vacuum flash evaporation, and is sent to the settling tank.

[0026] Example 2 Reference Figures 2-14 The evaporative condenser includes a condenser box 1 and a liquid pump 4. An axial flow fan 2 is installed on the top of the condenser box 1. A heat exchange mechanism is installed inside the condenser box 1. The heat exchange mechanism includes a heat exchange coil 9 and a spray assembly. An air inlet grille 3 is installed on the lower side wall of the condenser box 1. A liquid collection tank is installed at the bottom of the condenser box 1. The spray assembly is installed inside the condenser box 1 and sprays heat exchange treatment on the heat exchange coil 9. The water distribution and descaling component is installed on the straight tube of the heat exchange coil 9. The water distribution and descaling component cleans the scale on the heat exchange coil 9. When in use, the exhaust steam after the condensing turbine has done work enters the heat exchange coil 9 through the input end of the heat exchange coil 9, and after heat exchange in the evaporative condenser, it comes out from the output end of the heat exchange coil 9 and is sent to the settling tank by the condensate pump. The evaporation and condensation process is as follows: the liquid pump 4 delivers the cooling water in the liquid collection tank at the bottom of the condensation tank 1 to the inside of the spray assembly, and sprays it onto the heat exchange coil 9 for heat exchange treatment through the spray assembly. During this process, the axial flow fan 2 starts to draw air in from the air inlet grille 3, passes through the heat exchange mechanism, and is discharged from the top.

[0027] Reference Figure 2The spray assembly includes a water supply pipe 5 connected to the output end of the infusion pump 4. The input end of the infusion pump 4 is connected to the collection tank through a pipe. Several distribution pipes 6 are connected to the water supply pipe 5. Several spray pipes 7 are connected to the distribution pipes 6. Several spray heads 8 are evenly distributed on the outer periphery of the spray pipes 7. The distribution pipes 6 have several branches. The spray pipes 7 are connected to the branches of the distribution pipes 6. The infusion pump 4 draws coolant from the inside of the collection tank and delivers it to the inside of the spray pipes 7 through the water supply pipe 5 and the distribution pipes 6. The coolant is then sprayed out through the spray heads 8, so that the coolant falls onto the heat exchange coil 9 for heat exchange. Reference Figure 2-14 Several spray pipes 7 are positioned above the heat exchange coil 9. This is the traditional spray structure configuration for evaporative condensers. With the spray structure positioned above the heat exchange coil 9, cooling water flows from top to bottom. This design suffers from uneven cooling water flow, easily leading to uneven cooling. In this embodiment, the water equalization and descaling component includes rotating connecting rings 13 that are relatively sleeved on the straight tubes of the heat exchange coil 9. The rotating connecting rings 13 are rotatably connected to the straight tubes of the heat exchange coil 9. Scalding and water equalization components 12 are fixed on both sides between the two opposing rotating connecting rings 13. The scale scraping and water distribution component 12 is made of a material with good thermal conductivity. The inner wall of the scale scraping and water distribution component 12 is in contact with the straight tube of the heat exchange coil 9. The scale scraping and water distribution component 12 extends outward from the side away from the straight tube of the heat exchange coil 9 to form a water distribution plate 14. When the cooling water falls to the top of the water distribution plate 14, it will exert a certain force on it, causing it to rotate around the heat exchange coil 9. When it rotates, the water falling on the water distribution plate 14 will follow the rotation and be thrown outward under the action of centrifugal force. In this way, the vertically falling water can be transported to the heat exchange coil next to it, thereby achieving the effect of improving heat exchange efficiency. Reference Figure 8-14The internal design of the scale scraping and water distribution component 12 is hollow. The component includes a scraper 15 that fits against the outer wall of the straight tube of the heat exchange coil 9, and a baffle plate 16 located outside the scraper 15. The scraper 15 and the baffle plate 16 form a flow collection channel 20. A water distribution plate 14 is fixed to the outside of the baffle plate 16. A water distribution cavity 21 is provided inside the water distribution plate 14. Several water distribution holes are opened on the side wall of the water distribution plate 14 on the side away from the scraper 15 and located in the water distribution cavity 21. Through the design of the scraper 15, the baffle plate 16, and the water distribution plate 14, the cooling water falling around the heat exchange coil 9 can be divided into three parts. The first part falls directly onto the heat exchange coil 9. Heat exchange occurs on the outer wall of the heat exchange coil 9. The second part enters the manifold 20 and continues to contact the heat exchange coil 9 for heat exchange. Excess cooling water inside the manifold 20 can pass through the filter hole 18 and the water distribution hole 19 and then be thrown out with the water distribution plate 14, which greatly improves the utilization rate of cooling water. The third part falls directly onto the outside of the water distribution plate 14 and is thrown out onto the straight tubes of other heat exchange coils 9 as it moves, continuing to play a role in heat exchange. During the heat exchange process, the scraper 15 can scrape off the scale and oil film on the surface of the heat exchange coil 9 when it rotates, achieving a cleaning effect. Through a simple structural design, the effects of heat exchange, water distribution, and scale removal are achieved simultaneously. Reference Figure 8-14 An installation groove 28 is provided inside the water distribution chamber 21. A filter plate 17 that is compatible with it is inserted into the installation groove 28. The filter plate 17 has an arc-shaped cross-section and can rotate in the installation groove. The filter plate 17 has an opening on the side facing the collection channel 20, and the inner wall of the opening of the filter plate 17 is flush with the inner wall of the water distribution chamber 21. Several filter holes 18 are provided on the filter plate 17. Impurities scraped off by the scraper 15 will enter the inside of the water distribution chamber 21 through the collection channel 20 and then be filtered by the filter plate 17. At this time, the water distribution plate 14 plays the role of filtering and collecting impurities, effectively preventing impurities from falling back and re-attaching and forming scale after being scraped off.

[0028] Example 3 In the above embodiments, during long-term use, impurities may accumulate on the inside of the filter plate 17 due to its filtering effect. When the impurities accumulate to a certain extent, they may block the filter plate 17 and affect its function. Therefore, the filter plate 17 needs to be designed to be detachable.

[0029] Reference Figure 13-14A positioning ring 22 is fixed to one end of the filter plate 17. An adjusting knob 24 is rotatably and slidably connected to the end of the positioning ring 22 away from the filter plate 17. A mounting plate 25 is rotatably connected to the inner side of the adjusting knob 24 near the positioning ring 22. A spring 26 is provided between the mounting plate 25 and the positioning ring 22, with both ends of the spring 26 connected to the mounting plate 25 and the positioning ring 22 respectively. The adjusting knob 24 is threadedly connected to the scale scraping and water equalization component 12. Limiting strips 23 are provided on both sides of the positioning ring 22. Limiting grooves 27 that match the limiting strips 23 are provided on the scale scraping and water equalization component 12. The knob 24 is inserted into the inner side of the positioning ring 22 and can move within the positioning ring 22. However, it should be noted that the mounting plate 25 rotates inside the adjusting knob 24. Due to the connection of the spring 26, the adjusting knob 24 cannot be disengaged from the positioning ring 22. When it is necessary to disassemble the filter plate 17, first rotate the adjusting knob 24 to disengage it from the threaded connection with the scraper and water equalizer 12. Then pull the adjusting knob 24 to pull the filter plate 17 out a small section, so that the limiting strip 23 disengages from the limiting groove 27. Then rotate the filter plate 17 so that its opening faces upward to prevent it from being pulled out. During the process of removing the filter plate 17, impurities fall into the inner side of the water distribution chamber 21. The filter plate 17 can then be completely removed for cleaning. After cleaning, when installing the filter plate 17 into the scale scraping and water distribution component 12, first insert 17 into the inner side of the component 12, so that the limiting strip 23 is inserted into the inner side of the limiting groove 27. Then press and hold the adjustment knob 24 and rotate it to make it threadedly connected to the scale scraping and water distribution component 12, thereby fixing the filter plate 17 in place. It should be noted that when the limiting strip 23 is engaged with the limiting groove 27, the filter plate 17 opens... The opening faces the scraper 15, and the opening of the filter plate 17 is flush with the inner wall of the water distribution chamber 21 to facilitate the collection of impurities. On the other hand, it should be noted that in order to prevent the adjustment knob 24 from disengaging from the scraper and water distribution component 12 during long-term operation, a spring 26 is provided between the adjustment knob 24 and the positioning ring 22. When the adjustment knob 24 is screwed into the scraper and water distribution component 12 and its threaded connection is established, the spring 26 is in a compressed state, which generates an axial force on the adjustment knob 24, making the threaded connection between the adjustment knob 24 and the scraper and water distribution component 12 more stable.

[0030] Example 4 Reference Figure 3The heat exchange coil 9 is designed as an elliptical tube with the major axis of its elliptical cross-section set vertically. Several spray pipes 7 are installed between four adjacent straight pipes of the heat exchange coil 9. The spray heads 8 are set in four groups along the axial direction of the straight pipes of the heat exchange coil 9, facing the four adjacent straight pipes respectively. By placing the spray pipes 7 between the four adjacent straight pipes, each spray pipe sprays the straight pipes in four directions, thereby improving the spraying effect and making the contact between the cooling water and the heat exchange coils 9 of each layer more sufficient and uniform. In order to make the axial flow fan work better, make the airflow inside the condenser box 1 smoother, and reduce the obstruction of the airflow by the spray pipes 7, the heat exchange coil 9 is designed as an elliptical tube.

[0031] Example 4 In the above embodiments, the spray pipe 7 is placed between four straight pipes, which can effectively improve the spraying effect, but may affect the airflow to some extent. Therefore, this embodiment further optimizes embodiment three, referring to... Figure 4 Several spray pipes 7 are installed between two adjacent straight pipes of the heat exchange coil 9. The spray heads 8 are arranged in six groups along the axial direction of the straight pipes of the heat exchange coil 9, respectively facing the two adjacent straight pipes of the heat exchange coil 9 and the straight pipes at its four corners (upper left, lower left, upper right, and lower right). Setting the spray pipes 7 between the two adjacent straight pipes can improve the spraying effect while reducing the impact on the airflow.

[0032] Example 5 Reference Figure 5 The water-distributing descaling component includes several connecting grooves opened along the axial direction of the straight tube of the heat exchange coil 9. The connecting grooves are evenly distributed on the outer wall of the straight tube of the heat exchange coil 9. An installation strip 10 is inserted into the inner side of the connecting groove. Several elastic silicone filaments 11 are embedded on both sides of the top of the installation strip. In the natural state, the elastic silicone filaments 11 are attached to the outer wall of the straight tube of the heat exchange coil 9. It should be noted that the elastic silicone filaments 11 are made of high-temperature resistant material, so that the temperature of the surface of the heat exchange coil 9 will not damage the structure of the elastic silicone filaments 11. Through the design of the elastic silicone filaments 11, when the cooling water is sprayed onto the surface of the heat exchange coil 9, the elastic silicone filaments 11 will swing under the action of the water flow, thereby continuously brushing the wall of the heat exchange coil 9.

[0033] The specific working principle of the coal gasification black water flash steam waste heat steam turbine cascade utilization system provided by this invention is as follows: When in use, the coal gasification black water first enters the high-pressure flash evaporator to produce high-pressure flash steam and high-flash black water. The high-flash black water then enters the low-pressure flash evaporator to produce low-pressure flash steam and low-flash black water. The low-flash black water then enters the vacuum flash evaporator to produce vacuum flash steam and true flash black water. The steam from the three-stage flash evaporation simultaneously enters the condensing turbine to do work and drive the generator to generate electricity. The high-pressure flash steam is the main inlet steam of the condensing turbine, while the low-pressure flash steam and vacuum flash steam are the first and second stage make-up steam, respectively. The exhaust steam after doing work enters the evaporative condenser for condensation and cooling. Finally, the exhaust steam condensate is pressurized by the condensate pump and merged with the black water after vacuum flash evaporation and sent to the settling tank. The evaporation and condensation process is as follows: the liquid pump 4 delivers the cooling water in the liquid collection tank at the bottom of the condensation tank 1 to the inside of the spray assembly, and sprays it onto the heat exchange coil 9 through the spray assembly for heat exchange treatment. During this process, the axial flow fan 2 starts to draw air in from the air inlet grille 3, passes through the heat exchange mechanism, and is discharged from the top. During the evaporation and condensation process, the cooling water falling around the heat exchange coil 9 is divided into three parts by the scraper 15, the baffle plate 16 and the water distribution plate 14. The first part falls directly onto the outer wall of the heat exchange coil 9 for heat exchange. The second part enters the collection channel 20 and continues to contact the heat exchange coil 9 for heat exchange. The excess cooling water inside the collection channel 20 can pass through the filter hole 18 and the water distribution hole 19 and then be thrown out with the water distribution plate 14, which greatly improves the utilization rate of cooling water. The third part falls directly onto the outside of the water distribution plate 14 and is thrown out onto the straight tubes of other heat exchange coils 9 as it moves, continuing to play a role in heat exchange. During the heat exchange process, when the scraper 15 rotates, it can scrape off the scale and oil film on the surface of the heat exchange coil 9. The impurities scraped off by the scraper 15 will enter the inner side of the water distribution chamber 21 through the collection channel 20 and then be filtered by the filter plate 17. When the filter plate 17 needs to be disassembled, first rotate the adjustment knob 24 to disengage it from the scraper and water equalizer 12. Then pull the adjustment knob 24 to pull the filter plate 17 out a short distance, so that the limiting strip 23 disengages from the limiting groove 27. Then rotate the filter plate 17 so that its opening faces upward to prevent impurities from falling into the water equalizer 21 during the process of pulling out the filter plate 17. Then pull out the filter plate 17 completely to clean it. After cleaning, when the filter plate 17 needs to be installed into the scraper and water equalizer 12, first insert 17 into the inside of the scraper and water equalizer 12 so that the limiting strip 23 is inserted into the inside of the limiting groove 27. Then press and rotate the adjustment knob 24 to make it threadedly connected to the scraper and water equalizer 12, thereby fixing the filter plate 17 in place.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] Obviously, the embodiments described above are merely some embodiments of the present invention, not all embodiments. The accompanying drawings show preferred embodiments of the present invention, but do not limit the patent scope of the present invention. The present invention can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this invention.

Claims

1. A cascade utilization system for waste heat steam from flash steam in coal gasification black water, characterized in that, Includes a black water flash steam turbine module and an exhaust steam condensation module; The black water flash steam turbine module includes a high-pressure flash evaporator, a low-pressure flash evaporator, a vacuum flash evaporator, a condensing steam turbine, a generator, and a settling tank. The outlet of the high-pressure flash evaporator is connected to the inlet of the low-pressure flash evaporator, the outlet of the low-pressure flash evaporator is connected to the inlet of the vacuum flash evaporator, the outlet of the vacuum flash evaporator is connected to the settling tank, the outlets of the high-pressure flash evaporator, the low-pressure flash evaporator, and the vacuum flash evaporator are all connected to the inlet of the condensing steam turbine, and the output end of the condensing steam turbine is connected to the input end of the generator. The exhaust steam condensation module includes an evaporative condenser and a condensate pump. The exhaust end of the condensing turbine is connected to the inlet end of the evaporative condenser, the output end of the evaporative condenser is connected to the input end of the condensate pump, and the output end of the condensate pump is connected to the settling tank.

2. The coal gasification black water flash steam waste heat steam turbine cascade utilization system according to claim 1, characterized in that, The evaporative condenser includes a condenser box (1) and a liquid pump (4). An axial flow fan (2) is provided on the top of the condenser box (1). A heat exchange mechanism is provided inside the condenser box (1). The heat exchange mechanism includes a heat exchange coil (9) and a spray assembly. An air inlet grille (3) is provided on the lower side wall of the condenser box (1). A liquid collection tank is provided at the bottom of the condenser box (1). The spray assembly is located inside the condenser box (1) and sprays heat exchange treatment on the heat exchange coil (9). The water leveling and descaling component is installed on the straight pipe of the heat exchange coil (9) and cleans the scale on the heat exchange coil (9).

3. A cascade utilization system for waste heat steam from black water flash steam in coal gasification according to claim 2, characterized in that, The spray assembly includes a water delivery pipe (5) connected to the output end of the infusion pump (4), the input end of the infusion pump (4) is connected to the liquid collection tank through a pipe, a number of liquid distribution pipes (6) are connected to the water delivery pipe (5), a number of spray pipes (7) are connected to the liquid distribution pipes (6), and a number of spray heads (8) are evenly distributed on the outer periphery of the spray pipes (7).

4. A cascade utilization system for waste heat steam from flash steam of coal gasification black water according to claim 3, characterized in that, A plurality of spray pipes (7) are disposed above the heat exchange coil (9). The water equalization and descaling assembly includes a rotating connecting ring (13) that is sleeved on the straight pipe of the heat exchange coil (9). The rotating connecting ring (13) is rotatably connected to the straight pipe of the heat exchange coil (9). Scaling and water equalization components (12) are fixed on both sides between the two opposing rotating connecting rings (13). The inner wall of the scraping and water equalization component (12) is in contact with the straight pipe of the heat exchange coil (9). The scraping and water equalization component (12) extends outward from the side away from the straight pipe of the heat exchange coil (9) to form a water equalization plate (14).

5. A cascade utilization system for waste heat steam from flash steam of coal gasification black water according to claim 4, characterized in that, The internal design of the scale scraping and water equalization component (12) is hollow. The scale scraping and water equalization component (12) includes a scraper (15) that is in contact with the outer wall of the straight tube of the heat exchange coil (9) and a water baffle (16) located outside the scraper (15). The scraper (15) and the water baffle (16) form a flow collection channel (20). The water equalization plate (14) is fixed to the outside of the water baffle (16). The water equalization plate (14) has a water equalization cavity (21) on its inner side. Several water equalization holes are opened on the side wall of the water equalization plate (14) on the side away from the scraper (15) of the water equalization cavity (21).

6. A cascade utilization system for waste heat steam from flash steam of coal gasification black water according to claim 5, characterized in that, The water distribution cavity (21) has an installation groove (28) on its inner side. A filter plate (17) is inserted into the installation groove (28) and is adapted to it. The filter plate (17) has a circular arc design in cross section. The filter plate (17) has an opening on the side facing the flow collection channel (20). The inner wall of the opening of the filter plate (17) is flush with the inner wall of the water distribution cavity (21). The filter plate (17) has several filter holes (18).

7. A cascade utilization system for waste heat steam from flash steam of coal gasification black water according to claim 6, characterized in that, One end of the filter plate (17) is fixed with a positioning ring (22). The end of the positioning ring (22) away from the filter plate (17) is rotatably connected to an adjustment knob (24). The inner side of the adjustment knob (24) near the positioning ring (22) is rotatably connected to an installation plate (25). A spring (26) is provided between the installation plate (25) and the positioning ring (22). The two ends of the spring (26) are respectively connected to the installation plate (25) and the positioning ring (22). The adjustment knob (24) is threadedly connected to the scale scraping and water equalization component (12). Limiting strips (23) are provided on both sides of the positioning ring (22). A limiting groove (27) adapted to the limiting strip (23) is opened on the scale scraping and water equalization component (12).

8. A cascade utilization system for waste heat steam from black water flash steam in coal gasification according to claim 3, characterized in that, The heat exchange coil (9) is designed as an elliptical tube with the major axis of its elliptical cross section set in the vertical direction. Several spray pipes (7) are inserted between four adjacent straight pipes of the heat exchange coil (9). The spray heads (8) are set in four groups along the axial direction of the straight pipes of the heat exchange coil (9), and are respectively facing the four adjacent straight pipes.

9. A cascade utilization system for waste heat steam from flash steam of coal gasification black water according to claim 3, characterized in that, Several spray pipes (7) are installed between two adjacent straight pipes of the heat exchange coil (9). The spray heads (8) are arranged in six groups along the axial direction of the straight pipes of the heat exchange coil (9), respectively facing the two adjacent straight pipes of the heat exchange coil (9) and the straight pipes at its four corners: upper left, lower left, upper right, and lower right.

10. A cascade utilization system for waste heat steam from flash steam of coal gasification black water according to claim 8 or 9, characterized in that, The water equalization and descaling component includes several connecting grooves opened along the axial direction of the straight tube of the heat exchange coil (9). The several connecting grooves are evenly distributed on the outer wall of the straight tube of the heat exchange coil (9). An installation strip (10) is inserted into the inner side of the connecting groove. Several elastic silicone filaments (11) are embedded on both sides of the top of the installation strip. In the natural state, the several elastic silicone filaments (11) are attached to the outer wall of the straight tube of the heat exchange coil (9).

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