A coking system waste heat recovery and comprehensive utilization power generation system and method

Abstract

The present invention relates to the comprehensive waste heat recovery and utilization in the field of coking engineering technology, and specifically to a coking system waste heat recovery and comprehensive utilization power generation system and method, which is characterized by at least comprising a coke oven gas boiler, a dry coke quenching boiler, a gas riser waste heat boiler, a coke oven flue gas waste heat boiler, an atmospheric deaerator, a high-pressure deaerator, a high-pressure boiler feed water pump, a steam turbine high-pressure cylinder, a steam turbine low-pressure cylinder, a generator, a condenser, a condensate pump, a condensate tank, a deaerator feed water pump, and a low-pressure boiler feed water pump; the coke oven gas boiler and the dry coke quenching boiler are connected to the steam turbine high-pressure cylinder through the coke oven gas steam outlet pipeline and the dry coke quenching boiler steam outlet pipeline respectively, and the high-temperature and ultra-high-pressure steam generated by the coke oven gas boiler and the dry coke quenching boiler is discharged after expanding and working in the steam turbine high-pressure cylinder. It improves the thermal efficiency of the waste heat and waste energy utilization of the coking system and effectively promotes energy saving and consumption reduction.

Description

Technical Field

[0001] The invention relates to comprehensive waste heat recovery and utilization in the technical field of coking engineering, and specifically to a coking system waste heat recovery and comprehensive utilization power generation system and method. Background Art

[0002] The coking system waste heat recovery and comprehensive utilization power generation system will eventually effectively convert the waste heat and waste energy generated by various production links in the coking industry into electrical energy, which can significantly reduce the energy consumption of the enterprise and bring great economic benefits.

[0003] The coking process in the coking industry is a relatively complete energy conversion process, which produces a variety of secondary energy sources of different qualities. The high-temperature hot exhaust gas discharged from the coke oven flue, the high-temperature raw gas in the coke oven riser, the high-temperature circulating gas of the dry coke quenching system and the coke oven gas, a by-product of coking, etc., these secondary energy sources almost account for all the available secondary energy in the coking industry.

[0004] The heat energy of coke oven flue gas and raw coal gas from riser pipes is currently basically recovered by heat exchange in waste heat boilers to produce low-pressure saturated steam. However, the low-pressure saturated steam produced has low thermal energy quality and small quantity and has not been effectively utilized. The total amount of coke oven gas, a by-product of the coking process, is not large. The investment in building a gas-fired power generation project alone is high and the payback period is long. The price of coke oven gas for external municipal use is low due to factors such as high dust content and long transportation distance. Therefore, there has been no mature utilization plan for coke oven gas. The recovery plan for high-temperature circulating gas in the dry coke quenching system is relatively mature, and the dry coke quenching boiler is used to generate steam for power generation.

[0005] The waste heat recovery and comprehensive utilization power generation system of the coking system uses the principle of cascade utilization of thermal energy to effectively utilize thermal energy of different grades in appropriate locations. First, low-pressure steam with low-grade thermal energy is used to heat the boiler feed water to remove dissolved oxygen in the feed water; then high-temperature and ultra-high-pressure steam with high-grade thermal energy is used to drive the generator with high efficiency and high parameter steam turbine to generate electricity. In the waste heat recovery and comprehensive utilization power generation system of the coking system, low-grade thermal energy and low-pressure steam are efficiently utilized in the deaerator. There is no conversion between different forms of energy and no loss of cold source. All thermal energy is completely transferred to the boiler feed water; high-temperature and ultra-high-pressure steam with high-grade thermal energy is concentrated for high-parameter steam turbine generator sets to generate electricity, and the thermal energy grade of steam is no longer reduced for other uses. The thermal efficiency of this system is greatly improved compared with the original waste heat recovery systems used separately.

[0006] The higher the initial parameters of the circulating medium used for power generation, the higher the energy carried per unit mass of the medium, and the higher the efficiency of the system. The steam used for water deoxygenation does not have high requirements for parameters, as long as the total amount of heat energy contained meets the standard. Therefore, in the process of waste heat recovery and utilization of coking systems, it is not required that the waste heat recovery at each point has multifunctionality. It is necessary to comprehensively consider the heat energy level recovered at each point for comprehensive and efficient utilization.

[0007] As waste heat and waste energy recovery solutions in various production links of the coking industry are becoming increasingly perfect, the coking system waste heat recovery and comprehensive utilization power generation system is now ready for implementation. Summary of the invention

[0008] The purpose of the present invention is to provide a system and method for comprehensive utilization of waste heat recovery from a coking system to generate electricity, so as to further improve the thermal efficiency of waste heat recovery from various production heat exchange processes in the coking system and effectively promote energy conservation and consumption reduction.

[0009] The technical scheme of the present invention is: a coking system waste heat recovery and comprehensive utilization power generation system, which is characterized by: at least comprising a coke oven gas boiler, a dry coke quenching boiler, a gas riser waste heat boiler, a coke oven flue gas waste heat boiler, an atmospheric deaerator, a high-pressure deaerator, a high-pressure boiler feed pump, a turbine high-pressure cylinder, a turbine low-pressure cylinder, a generator, a condenser, a condensate pump, a condensate tank, a deaerator feed pump, and a low-pressure boiler feed pump; the coke oven gas boiler and the dry coke quenching boiler are connected to the turbine high-pressure cylinder through the coke oven gas steam outlet pipeline and the dry coke quenching boiler steam outlet pipeline respectively, and the high-temperature and ultra-high-pressure steam generated by the coke oven gas boiler and the dry coke quenching boiler expands in the turbine high-pressure cylinder and does work and is discharged;

[0010] The high-pressure cylinder of the steam turbine is connected to the coke oven gas boiler through the high-pressure cylinder exhaust pipeline of the steam turbine. The steam discharged from the high-pressure cylinder of the steam turbine is reheated in the reheater of the coke oven gas boiler and then supplied to the outside.

[0011] The coke oven gas boiler is connected to the low-pressure cylinder of the steam turbine through the reheat steam pipeline. The reheat steam expands in the low-pressure cylinder of the steam turbine and does work before being discharged.

[0012] The high-pressure cylinder and the low-pressure cylinder of the steam turbine are connected to the generator through a shaft. The high-pressure cylinder and the low-pressure cylinder of the steam turbine convert the thermal energy of the steam into mechanical energy. The mechanical energy is transmitted to the generator through the shaft. The generator converts the mechanical energy into electrical energy.

[0013] The low-pressure cylinder of the steam turbine is connected to the condenser through an exhaust pipeline, the condenser is connected to the condensate pump through a condensate pipeline, and the condensate pump is connected to the condensate tank through a condensate pump outlet pipeline;

[0014] The condensate tank is connected to the inlet pipeline of the deaerator feed pump through the inlet pipeline of the deaerator feed pump; the deaerator feed pump has two output pipelines, one of which is from the deaerator feed pump to the high-pressure deaerator through the high-pressure deaerator water inlet pipeline, and the other is from the atmospheric deaerator water inlet pipeline to the top of the atmospheric deaerator; the atmospheric deaerator water inlet pipeline is connected to the atmospheric deaerator;

[0015] The steam discharged from the low-pressure cylinder of the steam turbine condenses into condensate in the condenser. The condensate is pressurized by the condensate pump and sent to the condensate tank. The condensate tank stores the condensate and a desalted water pipeline is set as supplementary water. The condensate in the condensate tank is pressurized by the boiler deaerator feed water pump and sent to the high-pressure deaerator and atmospheric deaerator for deoxidation.

[0016] The high-pressure deaerator is connected to the high-pressure boiler feed water pump through the high-pressure deaerator outlet pipeline. The outlet of the high-pressure boiler feed water pump is divided into two routes, one route is connected to the coke oven gas boiler through the coke oven gas boiler feed water pipeline, and the other route is connected to the dry coke quenching boiler through the dry coke quenching boiler feed water pipeline;

[0017] After the dissolved oxygen in the boiler feed water is removed in the high-pressure deaerator, it is pressurized by the high-pressure boiler feed water pump and sent to the coke oven gas boiler and the dry coke quenching boiler for heat exchange. The high-pressure boiler feed water is heated in the coke oven gas boiler and the dry coke quenching boiler to become high-temperature ultra-high-pressure steam and supplied externally.

[0018] The atmospheric deaerator is connected to the low-pressure boiler feed water pump through the atmospheric deaerator outlet water pipeline. The outlet of the low-pressure boiler feed water pump is divided into two routes, one route is connected to the gas riser waste heat boiler through the gas riser waste heat boiler feed water pipeline, and the other route is connected to the coke oven flue gas waste heat boiler through the coke oven flue gas waste heat boiler feed water pipeline; the gas riser waste heat boiler and the coke oven flue gas waste heat boiler feed water are pressurized by the low-pressure boiler feed water pump after the dissolved oxygen in the water is removed in the atmospheric deaerator and then sent to the gas riser waste heat boiler and the coke oven flue gas waste heat boiler for heat exchange respectively. The low-pressure boiler feed water is heated in the gas riser waste heat boiler and the coke oven flue gas waste heat boiler to become low-pressure saturated steam and supplied externally.

[0019] The coke oven flue gas waste heat boiler and the coal gas riser waste heat boiler are operated in parallel, and low-pressure feed water enters the coke oven flue gas waste heat boiler and the coal gas riser waste heat boiler for heat exchange to generate low-pressure saturated steam. The low-pressure saturated steam generated by the coke oven flue gas waste heat boiler and the coal gas riser waste heat boiler is merged into the low-pressure saturated steam mother pipe through the steam outlet pipeline. The low-pressure saturated steam mother pipe is respectively connected to the high-pressure deaerator steam inlet pipeline and the low-pressure deaerator steam inlet pipeline. The low-pressure saturated steam from the coke oven flue gas waste heat boiler and the coal gas riser waste heat boiler is used as deoxidation heating steam to enter the two deaerators for heat exchange with condensate.

[0020] The coke oven gas waste heat boiler and the dry coke quenching boiler are operated in parallel, and the high-temperature and ultra-high-pressure steam of the coke oven gas waste heat boiler and the dry coke quenching boiler are merged to the inlet of the high-pressure cylinder of the steam turbine through the outlet pipeline. The steam after doing work in the high-pressure cylinder returns to the coke oven gas boiler reheater through the high-pressure cylinder exhaust pipeline to be overheated again. The reheated steam after reheating enters the low-pressure cylinder through the reheat steam pipeline to do work. The high-pressure cylinder and the low-pressure cylinder are used to receive the high-temperature and ultra-high-pressure steam of the coke oven gas boiler and the dry coke quenching boiler, and convert the thermal energy of the steam into mechanical energy, and at the same time drive the generator, and the generator converts the mechanical energy into electrical energy.

[0021] The steam discharged from the low-pressure cylinder of the steam turbine is condensed into water through the condenser, and the condensed water in the condenser is transported to the condensed water tank for storage through the condensed water pump, and the condensed water in the condensed water tank is transported to the high-pressure deaerator and the atmospheric deaerator through the deaerator feed water pump. The high-pressure deaerator and the atmospheric deaerator are operated in parallel, and the condensed water is heated by the high-pressure deaerator and the atmospheric deaerator to remove the dissolved oxygen in the water. The high-pressure boiler feed water pump transports the deoxygenated water in the high-pressure deaerator as high-pressure feed water to the coke oven gas boiler and the dry coke quenching waste heat boiler for heat exchange, and the low-pressure boiler feed water pump drains the deoxygenated water in the atmospheric deaerator as low-pressure feed water to the coke oven flue gas waste heat boiler and the gas riser waste heat boiler for heat exchange.

[0022] A method for comprehensive utilization of waste heat recovery and power generation in a coking system, comprising at least a coke oven gas boiler, a dry coke quenching boiler, a gas riser waste heat boiler, a coke oven flue gas waste heat boiler, an atmospheric deaerator, a high-pressure deaerator, a high-pressure boiler feed pump, a steam turbine high-pressure cylinder, a steam turbine low-pressure cylinder, a generator, a condenser, a condensate pump, a condensate tank, a deaerator feed pump, and a low-pressure boiler feed pump; the coke oven gas boiler and the dry coke quenching boiler are respectively connected to the steam turbine high-pressure cylinder 8 through pipelines, and the coke oven gas boiler 1 and the dry quenching boiler are respectively connected to the steam turbine high-pressure cylinder 8 through pipelines. The high-temperature and ultra-high-pressure steam generated by the coke boiler expands in the high-pressure cylinder of the steam turbine and then is discharged after doing work; the high-pressure cylinder of the steam turbine and the low-pressure cylinder of the steam turbine are connected to the generator through shafts, and the high-pressure cylinder of the steam turbine and the low-pressure cylinder of the steam turbine convert the thermal energy of the steam into mechanical energy, which is transmitted to the generator through the shaft, and the generator converts the mechanical energy into electrical energy; the low-pressure cylinder of the steam turbine is connected to the condenser through the exhaust pipeline, the condenser is connected to the condensate pump through the condensate pipeline, and the condensate pump is connected to the condensate tank through the condensate pump outlet pipeline.

[0023] The specific steps are as follows:

[0024] 1) The water in the condensate tank is pressurized by the deaerator feed pump and enters the high-pressure deaerator and the atmospheric deaerator respectively;

[0025] 2) The saturated steam in the low-pressure saturated steam main pipe is used as the heating steam source for the high-pressure deaerator and the atmospheric deaerator 5 to enter the deaerator to heat the deaerator water;

[0026] 3) The deoxygenated water in the high-pressure deaerator is pressurized by the high-pressure boiler feed water pump and then sent to the coke oven gas boiler and the dry coke quenching boiler for heat exchange;

[0027] 4) The deoxygenated water in the atmospheric deaerator is pressurized by the low-pressure boiler feed water pump and then sent to the coke oven flue gas waste heat boiler and the coal gas riser waste heat boiler for heat exchange;

[0028] 5) High-pressure boiler feed water generates high-temperature and ultra-high-pressure superheated steam after heat exchange in the coke oven gas boiler and the dry coke quenching boiler;

[0029] 6) Low-pressure feed water generates low-pressure saturated steam after heat exchange in the coke oven flue gas waste heat boiler and the coal gas riser waste heat boiler;

[0030] 7) High-temperature super-high steam enters the high-pressure cylinder of the steam turbine to do work and then discharges low-parameter superheated steam;

[0031] 8) The low-parameter superheated steam discharged from the high-pressure cylinder of the steam turbine enters the coke oven gas boiler for reheating;

[0032] 9) After being reheated by the coke oven gas boiler, the high temperature steam enters the low pressure cylinder of the steam turbine to perform work;

[0033] 10) High-temperature super-high-pressure steam and high-temperature reheated steam expand and perform work in the high-pressure cylinder and low-pressure cylinder of the steam turbine respectively, driving the generator connected through the rotating shaft to generate electricity;

[0034] 11) The exhaust steam from the low-pressure cylinder of the steam turbine is recovered through the condenser as condensate, which is pressurized by the condensate pump and then sent to the condensate tank.

[0035] Compared with the prior art, the effects of the present invention are:

[0036] The present invention adopts high temperature and ultra-high pressure parameters. Due to the improvement in efficiency, when recovering the same amount of waste heat and waste energy, the high temperature and ultra-high pressure parameter unit can generate more electricity than the high temperature and high pressure unit. Under the condition of basically the same operating cost, the factory has increased economic benefits; by using waste heat boilers to produce low-pressure saturated steam for use as deaerator steam, the steam heat recovery efficiency of the entire waste heat recovery system is improved, and the comprehensive energy consumption of the factory is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be further described below in conjunction with the accompanying drawings of the embodiments:

[0038] Figure 1 This is a schematic diagram of the process flow of recovering and comprehensively utilizing waste heat from a coking system for power generation according to an embodiment of the present invention.

[0039] In the figure: 1. Coke oven gas boiler, 2. CDQ boiler, 3. Gas riser waste heat boiler, 4. Coke oven flue gas waste heat boiler, 5. Atmospheric deaerator, 6. High-pressure deaerator, 7. High-pressure boiler feed pump, 8. Steam turbine high-pressure cylinder, 9. Steam turbine low-pressure cylinder, 10. Generator, 11. Condenser, 12. Condensate pump, 13. Condensate tank, 14. Deaerator feed pump, 15. Low-pressure boiler feed pump, 16. Coke oven gas steam outlet pipeline, 17. CDQ boiler steam outlet pipeline, 18. Steam turbine high-pressure cylinder exhaust pipeline, 19. Reheat steam pipeline, 20. Steam turbine low-pressure exhaust pipeline, 21. Condensate pipeline, 22. Condensate pump Outlet pipeline, 23. Deaerator feed pump inlet pipeline, 24. High-pressure deaerator inlet pipeline, 25. Atmospheric deaerator inlet pipeline, 26. Atmospheric deaerator outlet pipeline, 27. Gas riser waste heat boiler feed pipeline, 28. Coke oven flue gas waste heat boiler feed pipeline, 29. Coke oven flue gas waste heat boiler low-pressure saturated steam outlet pipeline, 30. Gas riser waste heat boiler low-pressure saturated steam outlet pipeline, 31. Low-pressure saturated steam main pipe, 32. High-pressure deaerator steam inlet pipeline, 33. Atmospheric deaerator steam inlet pipeline, 34. High-pressure deaerator outlet pipeline, 35. Coke oven gas boiler feed pipeline, 36. CDQ boiler feed pipeline. DETAILED DESCRIPTION

[0040] like Figure 1 As shown, a coking system waste heat recovery and comprehensive utilization power generation system at least includes a coke oven gas boiler 1, a coke dry quenching boiler 2, a gas riser waste heat boiler 3, a coke oven flue gas waste heat boiler 4, an atmospheric deaerator 5, a high-pressure deaerator 6, a high-pressure boiler feed water pump 7, a steam turbine high-pressure cylinder 8, a steam turbine low-pressure cylinder 9, a generator 10, a condenser 11, a condensate pump 12, a condensate tank 13, a deaerator feed water pump 14, and a low-pressure boiler feed water pump 15; the coke oven gas boiler 1 and the coke dry quenching boiler 2 are connected to the steam turbine high-pressure cylinder 8 through a coke oven gas steam outlet pipeline 16 and a coke dry quenching boiler steam outlet pipeline 17, respectively, and the high-temperature and ultra-high-pressure steam generated by the coke oven gas boiler 1 and the coke dry quenching boiler 2 expands in the steam turbine high-pressure cylinder 8 and then is discharged;

[0041] The high-pressure cylinder 8 of the steam turbine is connected to the coke oven gas boiler 1 through the high-pressure cylinder exhaust pipe 18 of the steam turbine. The steam exhausted from the high-pressure cylinder 8 of the steam turbine is reheated in the reheater of the coke oven gas boiler 1 and then supplied to the outside.

[0042] The coke oven gas boiler 1 is connected to the low-pressure cylinder 9 of the steam turbine through the reheat steam pipeline 19. The reheat steam expands in the low-pressure cylinder 9 of the steam turbine and performs work before being discharged.

[0043] The high-pressure cylinder 8 and the low-pressure cylinder 9 of the steam turbine are connected to the generator 10 through a shaft. The high-pressure cylinder 8 and the low-pressure cylinder 9 of the steam turbine convert the thermal energy of the steam into mechanical energy. The mechanical energy is transmitted to the generator 10 through the shaft. The generator 10 converts the mechanical energy into electrical energy.

[0044] The low-pressure cylinder 9 of the steam turbine is connected to the condenser 11 through the low-pressure exhaust pipe 20 of the steam turbine, the condenser 11 is connected to the condensate pump 12 through the condensate pipe 21, and the condensate pump 12 is connected to the condensate tank 13 through the condensate pump outlet pipe 22;

[0045] The condensate tank 13 is connected to the inlet pipeline of the deaerator feed water pump 14 through the deaerator feed water pump inlet pipeline 23; the deaerator feed water pump 14 has two output pipelines, one of which is through the high-pressure deaerator 6 water inlet pipeline 24 to the high-pressure deaerator 6, and the other is through the water inlet pipeline 25 to the top of the atmospheric deaerator 5; the atmospheric deaerator water inlet pipeline 25 is connected to the atmospheric deaerator 5;

[0046] The steam discharged from the low-pressure cylinder 9 of the steam turbine is condensed into condensate in the condenser 11. The condensate is pressurized by the condensate pump 12 and sent to the condensate tank 13. The condensate tank stores the condensate and is provided with a desalted water pipeline as supplementary water. The condensate in the condensate tank 13 is pressurized by the low-pressure boiler feed water pump 15 and sent to the high-pressure deaerator 6 and the atmospheric deaerator 5 for deoxidation.

[0047] The high-pressure deaerator 6 is connected to the high-pressure boiler feed water pump 7 through the high-pressure deaerator outlet water pipeline 34. The outlet of the high-pressure boiler feed water pump 7 is divided into two paths, one of which is connected to the coke oven gas boiler 1 through the coke oven gas boiler feed water pipeline 35, and the other is connected to the dry quenching boiler 2 through the dry quenching boiler feed water pipeline 36.

[0048] After the dissolved oxygen in the boiler feed water is removed in the high-pressure deaerator 6, the boiler feed water is pressurized by the high-pressure boiler feed water pump 7 and sent to the coke oven gas boiler 1 and the dry coke quenching boiler 2 for heat exchange. The high-pressure boiler feed water is heated in the coke oven gas boiler 1 and the dry coke quenching boiler 2 to become high-temperature ultra-high-pressure steam and supplied externally.

[0049] The atmospheric deaerator 5 is connected to the low-pressure boiler feed water pump 15 through the atmospheric deaerator outlet water pipeline 26. The outlet of the low-pressure boiler feed water pump 15 is divided into two paths, one of which is connected to the gas riser waste heat boiler 3 through the gas riser waste heat boiler feed water pipeline 27, and the other is connected to the coke oven flue gas waste heat boiler 4 through the coke oven flue gas waste heat boiler feed water pipeline 28.

[0050] After the dissolved oxygen in the boiler feed water is removed in the atmospheric deaerator 5, the boiler feed water is pressurized by the low-pressure boiler feed water pump 15 and is respectively sent to the coal gas riser waste heat boiler 3 and the coke oven flue gas waste heat boiler 4 for heat exchange. The low-pressure boiler feed water is heated in the coal gas riser waste heat boiler 3 and the coke oven flue gas waste heat boiler 4 to become low-pressure saturated steam and supplied externally.

[0051] The coke oven flue gas waste heat boiler 4 and the coal gas riser waste heat boiler 3 are operated in parallel, and low-pressure feed water enters the coke oven flue gas waste heat boiler 4 and the coal gas riser waste heat boiler 3 for heat exchange to generate low-pressure saturated steam. The low-pressure saturated steam generated by the coke oven flue gas waste heat boiler 4 and the coal gas riser waste heat boiler 3 is merged into the low-pressure saturated steam mother pipe through the steam outlet pipeline. The low-pressure saturated steam mother pipe is respectively connected to the high-pressure deaerator steam inlet pipeline and the low-pressure deaerator steam inlet pipeline. The low-pressure saturated steam from the coke oven flue gas waste heat boiler and the coal gas riser waste heat boiler is used as deoxidation heating steam to enter the two deaerators for heat exchange with condensate.

[0052] The coke oven flue gas waste heat boiler 4 is operated in parallel with the dry coke quenching boiler 2. The high-temperature and ultra-high-pressure steam of the coke oven flue gas waste heat boiler 4 and the dry coke quenching boiler 2 are merged to the inlet of the high-pressure cylinder of the steam turbine through the outlet pipeline. The steam after doing work in the high-pressure cylinder returns to the coke oven gas boiler reheater through the high-pressure cylinder exhaust pipeline to be overheated again. The reheated steam after reheating enters the low-pressure cylinder through the reheat steam pipeline to do work. The high-pressure cylinder and the low-pressure cylinder are used to receive the high-temperature and ultra-high-pressure steam of the coke oven gas boiler and the dry coke quenching boiler, and convert the thermal energy of the steam into mechanical energy, and at the same time drive the generator, and the generator converts the mechanical energy into electrical energy.

[0053] The steam discharged from the low-pressure cylinder 9 of the steam turbine is condensed into water through the condenser 11. The condensed water in the condenser 11 is transported to the condensed water tank 13 for storage through the condensed water pump 12. The condensed water in the condensed water tank 13 is transported to the high-pressure deaerator 6 and the atmospheric deaerator 5 through the deaerator feed water pump 14. The high-pressure deaerator 6 and the atmospheric deaerator 5 are operated in parallel. The condensed water is heated by the high-pressure deaerator 6 and the atmospheric deaerator 5 to remove dissolved oxygen in the water. The high-pressure boiler feed water pump 7 transports the deoxygenated water in the high-pressure deaerator 6 as high-pressure feed water to the coke oven gas boiler 1 and the dry coke quenching boiler 2 for heat exchange. The low-pressure boiler feed water pump 15 drains the deoxygenated water in the atmospheric deaerator 5 as low-pressure feed water to the coke oven flue gas waste heat boiler 4 and the coal gas riser waste heat boiler 3 for heat exchange.

[0054] like Figure 1As shown, a method for comprehensive utilization of waste heat recovery and power generation in a coking system at least comprises a coke oven gas boiler 1, a coke dry quenching boiler 2, a gas riser waste heat boiler 3, a coke oven flue gas waste heat boiler 4, an atmospheric deaerator 5, a high-pressure deaerator 6, a high-pressure boiler feed water pump 7, a steam turbine high-pressure cylinder 8, a steam turbine low-pressure cylinder 9, a generator 10, a condenser 11, a condensate pump 12, a condensate tank 13, a deaerator feed water pump 14, and a low-pressure boiler feed water pump 15; the coke oven gas boiler 1 and the coke dry quenching boiler 2 are respectively connected to the steam turbine high-pressure cylinder 8 through pipelines, and the coke oven gas boiler 1 and the coke dry quenching boiler 2 are respectively connected to the steam turbine high-pressure cylinder 8 through pipelines. The high-temperature and ultra-high-pressure steam generated by the boiler 2 expands in the high-pressure cylinder 8 of the steam turbine and then is discharged after doing work; the high-pressure cylinder 8 of the steam turbine and the low-pressure cylinder 9 of the steam turbine are connected to the generator 10 through a shaft, and the high-pressure cylinder 8 of the steam turbine and the low-pressure cylinder 9 of the steam turbine convert the thermal energy of the steam into mechanical energy, which is transmitted to the generator 10 through the shaft, and the generator 10 converts the mechanical energy into electrical energy; the low-pressure cylinder 9 of the steam turbine is connected to the condenser 11 through the exhaust pipe 20, and the condenser 11 is connected to the condensate pump 12 through the condensate pipe 21, and the condensate pump 12 is connected to the condensate tank 13 through the condensate pump outlet pipe 22.

[0055] The specific steps are as follows:

[0056] The water in the condensate tank 13 is pressurized by the deaerator feed water pump 14 and enters the high-pressure deaerator 6 and the atmospheric deaerator 5 respectively;

[0057] The saturated steam in the low-pressure saturated steam main pipe 31 is used as the heating steam source of the high-pressure deaerator 6 and the atmospheric deaerator 5 to enter the deaerator to heat the deaerator water;

[0058] The deoxygenated water in the high-pressure deaerator 6 is pressurized by the high-pressure boiler feed water pump 7 and then fed to the coke oven gas boiler 1 and the dry coke quenching boiler 2 for heat exchange;

[0059] The deoxygenated water in the atmospheric deaerator 5 is pressurized by the low-pressure boiler feed water pump 15 and then sent to the coke oven flue gas waste heat boiler 4 and the coal gas riser waste heat boiler 3 for heat exchange;

[0060] The high-pressure boiler feed water generates superheated steam with high temperature and ultra-high pressure parameters after heat exchange in the coke oven gas boiler 1 and the dry coke quenching boiler 2;

[0061] The low-pressure feed water generates low-pressure saturated steam after heat exchange in the coke oven flue gas waste heat boiler 4 and the coal gas riser waste heat boiler 3;

[0062] High-temperature super-high steam enters the high-pressure cylinder 8 of the steam turbine and performs work, and then discharges low-parameter superheated steam;

[0063] The high-pressure cylinder 8 of the steam turbine discharges low-parameter superheated steam and enters the coke oven gas boiler 1 for reheating;

[0064] After being reheated by the coke oven gas boiler 1, the high temperature steam enters the low pressure cylinder 9 of the steam turbine to perform work;

[0065] The high-temperature super-high-pressure steam and the high-temperature reheated steam expand and perform work in the high-pressure cylinder 8 and the low-pressure cylinder 9 of the steam turbine respectively, driving the generator 10 connected through the rotating shaft to generate electricity;

[0066] The exhaust steam from the low-pressure cylinder 9 of the steam turbine is recovered as condensate through the condenser 11 and is pressurized by the condensate pump 12 and then sent to the condensate tank 13.

[0067] Compared with the prior art, the effects of the present invention are:

[0068] The present invention adopts high temperature and ultra-high pressure parameters. Due to the improvement in efficiency, when recovering the same amount of waste heat and waste energy, the high temperature and ultra-high pressure parameter unit can generate more electricity than the high temperature and high pressure unit. Under the condition of basically the same operating cost, the factory has increased economic benefits; by using waste heat boilers to produce low-pressure saturated steam for use as deaerator steam, the steam heat recovery efficiency of the entire waste heat recovery system is improved, and the comprehensive energy consumption of the factory is reduced.

Claims

1. A coking system waste heat recovery and comprehensive utilization power generation system, characterized by: The invention at least comprises a coke oven gas boiler (1), a dry coke quenching boiler (2), a gas riser waste heat boiler (3), a coke oven flue gas waste heat boiler (4), an atmospheric deaerator (5), a high-pressure deaerator (6), a high-pressure boiler feed water pump (7), a steam turbine high-pressure cylinder (8), a steam turbine low-pressure cylinder (9), a generator (10), a condenser (11), a condensate pump (12), a condensate tank (13), a deaerator feed water pump (14), and a low-pressure boiler feed water pump (15); the coke oven gas boiler (1) and the dry coke quenching boiler (2) are connected to the steam turbine high-pressure cylinder (8) via a coke oven gas steam outlet pipeline (16) and a dry coke quenching boiler steam outlet pipeline (17), respectively; the high-temperature and ultra-high-pressure steam generated by the coke oven gas boiler (1) and the dry coke quenching boiler (2) expands in the steam turbine high-pressure cylinder (8) and performs work before being discharged; The steam turbine high-pressure cylinder (8) is connected to the coke oven gas boiler (1) via a steam turbine high-pressure cylinder exhaust pipe (18), and the steam exhausted from the steam turbine high-pressure cylinder (8) is reheated in a reheater of the coke oven gas boiler (1) and then supplied to the outside; The coke oven gas boiler (1) is connected to the low-pressure cylinder (9) of the steam turbine via a reheat steam pipeline (19), and the reheat steam expands in the low-pressure cylinder (9) of the steam turbine and performs work before being discharged; The high-pressure cylinder (8) and the low-pressure cylinder (9) of the steam turbine are connected to the generator (10) via a shaft. The high-pressure cylinder (8) and the low-pressure cylinder (9) of the steam turbine convert the thermal energy of the steam into mechanical energy. The mechanical energy is transmitted to the generator (10) via the shaft. The generator (10) converts the mechanical energy into electrical energy. The low-pressure cylinder (9) of the steam turbine is connected to the condenser (11) via an exhaust pipe (20), the condenser (11) is connected to the condensate pump (12) via a condensate pipe (21), and the condensate pump (12) is connected to the condensate tank (13) via a condensate pump outlet pipe (22); The condensate tank (13) is connected to the inlet pipeline of the deaerator feed pump (14) through the inlet pipeline (23) of the deaerator feed pump; the deaerator feed pump (14) has two output pipelines, one of which is through the high-pressure deaerator water inlet pipeline (24) of the high-pressure deaerator (6) to the high-pressure deaerator (6), and the other is through the atmospheric deaerator water inlet pipeline (25) to the top of the atmospheric deaerator (5); the atmospheric deaerator water inlet pipeline (25) is connected to the atmospheric deaerator (5); The steam discharged from the low-pressure cylinder (9) of the steam turbine is condensed into condensate in the condenser (11). The condensate is pressurized by the condensate pump (12) and sent to the condensate tank (13). The condensate tank stores the condensate and is provided with a desalted water pipeline as supplementary water. The condensate in the condensate tank (13) is pressurized by the boiler deaerator feed water pump (14) and sent to the high-pressure deaerator (6) and the atmospheric deaerator (5) for deoxidation. The high-pressure deaerator (6) is connected to the high-pressure boiler feed water pump (7) through the high-pressure deaerator outlet water pipeline (34); the outlet of the high-pressure boiler feed water pump (7) is divided into two paths, one of which is connected to the coke oven gas boiler (1) through the coke oven gas boiler feed water pipeline (35), and the other is connected to the dry coke quenching boiler (2) through the dry coke quenching boiler feed water pipeline (36); After the dissolved oxygen in the boiler feed water is removed in the high-pressure deaerator (6), the boiler feed water is pressurized by the high-pressure boiler feed water pump (7) and then respectively sent to the coke oven gas boiler (1) and the dry coke quenching boiler (2) for heat exchange. The high-pressure boiler feed water is heated in the coke oven gas boiler (1) and the dry coke quenching boiler (2) to become high-temperature ultra-high-pressure steam and is supplied externally; The atmospheric deaerator (5) is connected to the low-pressure boiler feed water pump (15) through the atmospheric deaerator outlet water pipeline (26). The outlet of the low-pressure boiler feed water pump (15) is divided into two paths, one of which is connected to the gas riser waste heat boiler (3) through the gas riser waste heat boiler feed water pipeline (27), and the other is connected to the coke oven flue gas waste heat boiler (4) through the coke oven flue gas waste heat boiler feed water pipeline (28). The feed water of the gas riser waste heat boiler (3) and the coke oven flue gas waste heat boiler (4) is pressurized by the low-pressure boiler feed water pump (15) after the dissolved oxygen in the water is removed in the atmospheric deaerator (5) and then respectively sent to the gas riser waste heat boiler (3) and the coke oven flue gas waste heat boiler (4) for heat exchange. The low-pressure boiler feed water is heated in the gas riser waste heat boiler (3) and the coke oven flue gas waste heat boiler (4) to become low-pressure saturated steam and supplied externally.

2. According to claim 1, a coking system waste heat recovery and comprehensive utilization power generation system is characterized by: The coke oven flue gas waste heat boiler (4) and the coal gas riser waste heat boiler (3) are operated in parallel, and low-pressure feed water enters the coke oven flue gas waste heat boiler (4) and the coal gas riser waste heat boiler (3) for heat exchange to generate low-pressure saturated steam. The low-pressure saturated steam generated by the coke oven flue gas waste heat boiler (4) and the coal gas riser waste heat boiler (3) is combined into a low-pressure saturated steam main pipe through a steam outlet pipeline. The low-pressure saturated steam main pipe is respectively connected to a high-pressure deaerator steam inlet pipeline and a low-pressure deaerator steam inlet pipeline. The low-pressure saturated steam from the coke oven flue gas waste heat boiler and the coal gas riser waste heat boiler is used as deoxidation heating steam to enter the two deaerators for heat exchange with condensate.

3. The coking system waste heat recovery and comprehensive utilization power generation system according to claim 1 is characterized by: The coke oven flue gas waste heat boiler (4) and the dry coke quenching boiler (2) are operated in parallel, and the high-temperature and ultra-high-pressure steam of the coke oven flue gas waste heat boiler (4) and the dry coke quenching boiler (2) are combined to the inlet of the high-pressure cylinder of the steam turbine through the outlet pipeline. The steam after doing work in the high-pressure cylinder is returned to the coke oven gas boiler reheater through the high-pressure cylinder exhaust pipeline to be overheated again. The reheated steam after reheating enters the low-pressure cylinder through the reheat steam pipeline to do work. The high-pressure cylinder and the low-pressure cylinder are used to receive the high-temperature and ultra-high-pressure steam of the coke oven gas boiler and the dry coke quenching boiler, and convert the thermal energy of the steam into mechanical energy, and at the same time drive the generator, and the generator converts the mechanical energy into electrical energy.

4. The coking system waste heat recovery and comprehensive utilization power generation system according to claim 1 is characterized by: The steam discharged from the low-pressure cylinder (9) of the steam turbine is condensed into water through the condenser (11). The condensed water in the condenser (11) is transported to the condensed water tank (13) for storage through the condensed water pump (12). The condensed water in the condensed water tank (13) is transported to the high-pressure deaerator (6) and the atmospheric deaerator (5) through the deaerator feed water pump (14). The high-pressure deaerator (6) and the atmospheric deaerator (5) are operated in parallel. The condensed water is transported to the high-pressure deaerator (13) and the atmospheric deaerator (5). The high-pressure boiler feed water pump (7) transports the deoxygenated water in the high-pressure deaerator (6) as high-pressure feed water to the coke oven gas boiler (1) and the dry coke quenching boiler (2) for heat exchange, and the low-pressure boiler feed water pump (15) drains the deoxygenated water in the atmospheric deaerator (5) as low-pressure feed water to the coke oven flue gas waste heat boiler (4) and the coal gas riser waste heat boiler (3) for heat exchange.

5. A method for power generation based on the waste heat recovery and comprehensive utilization power generation system of the coking system according to any one of claims 1 to 4, which specifically works in the following steps: 1) The water in the condensate tank is pressurized by the deaerator feed pump and enters the high-pressure deaerator and the atmospheric deaerator respectively; 2) The saturated steam in the low-pressure saturated steam main pipe is used as the heating steam source for the high-pressure deaerator and the atmospheric deaerator to enter the deaerator to heat the deaerator water; 3) The deoxygenated water in the high-pressure deaerator is pressurized by the high-pressure boiler feed water pump and then sent to the coke oven gas boiler and the dry coke quenching boiler for heat exchange; 4) The deoxygenated water in the atmospheric deaerator is pressurized by the low-pressure boiler feed water pump and then sent to the coke oven flue gas waste heat boiler and the coal gas riser waste heat boiler for heat exchange; 5) High-pressure boiler feed water generates high-temperature and ultra-high-pressure superheated steam after heat exchange in the coke oven gas boiler and the dry coke quenching boiler; 6) Low-pressure feed water generates low-pressure saturated steam after heat exchange in the coke oven flue gas waste heat boiler and the coal gas riser waste heat boiler; 7) High-temperature super-high steam enters the high-pressure cylinder of the steam turbine to do work and then discharges low-parameter superheated steam; 8) The low-parameter superheated steam discharged from the high-pressure cylinder of the steam turbine enters the coke oven gas boiler for reheating; 9) After being reheated by the coke oven gas boiler, the high temperature steam enters the low pressure cylinder of the steam turbine to perform work; 10) High-temperature super-high-pressure steam and high-temperature reheated steam expand and perform work in the high-pressure cylinder and low-pressure cylinder of the steam turbine respectively, driving the generator connected through the rotating shaft to generate electricity; 11) The exhaust steam from the low-pressure cylinder of the steam turbine is recovered through the condenser as condensate, which is pressurized by the condensate pump and sent to the condensate tank.

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