A system and method for comprehensive utilization of waste heat in coking production process

Abstract

The present invention relates to a system and method for comprehensive utilization of waste heat in a coking production process, the system comprising a dry coke quenching waste heat recovery system and a raw coal gas waste heat recovery system; the dry coke quenching waste heat recovery system comprises a desalted water tank, a steam turbine generator set and a dry coke quenching boiler; the steam turbine generator set comprises a high-pressure cylinder, a medium-low-pressure cylinder and a generator connected in sequence; the dry coke quenching boiler comprises a boiler drum, and an economizer, a membrane water cooler and an evaporator, a primary reheater, a secondary reheater, a primary superheater and a secondary superheater arranged in the dry coke quenching boiler body from bottom to top; the raw coal gas waste heat recovery system comprises a first riser drum, a first riser heat exchanger, a second riser drum and a second riser heat exchanger; the present invention can maximize the utilization rate of coking waste heat and reduce the energy consumption per ton of coke in the enterprise; at the same time, ultra-high temperature and ultra-high pressure units are used for power generation to increase power generation, and the economic benefits and energy-saving and consumption-reducing effects are remarkable.

Description

Technical Field

[0001] The present invention relates to the technical field of waste heat recovery from coking production, and in particular to a system and method for comprehensive utilization of waste heat in a coking production process. Background Art

[0002] At present, the waste heat recovery measures commonly used by coking enterprises include waste heat recovery from raw coal gas and waste heat recovery from red coke. The waste heat recovery from raw coal gas utilizes the heat exchange of the coke oven riser to generate low-pressure saturated steam for use by low-pressure steam users, while the waste heat recovery from red coke utilizes the dry quenching boiler to generate high-temperature and high-pressure superheated steam for power generation by steam turbine generator sets. The two are relatively independent.

[0003] In order to further accelerate the transformation and upgrading of the coking industry, promote technological progress in the coking industry, improve the comprehensive utilization rate of resources and the level of energy conservation and environmental protection, and promote high-quality development of the coking industry. The present invention organically combines the two production process systems of waste heat recovery of raw coal gas and waste heat recovery of red coke. According to the waste heat utilization characteristics and waste heat steam parameters of each process system, and based on the energy utilization principle of "energy use according to quality, temperature matching, and cascade utilization", it avoids the occurrence of problems such as waste heat dissipation and high-parameter steam cooling and pressure reduction, maximizes the waste heat utilization rate, and reduces the energy consumption per ton of coke in the enterprise. Summary of the invention

[0004] The present invention provides a system and method for comprehensive utilization of waste heat in a coking production process, which can maximize the utilization rate of coking waste heat and reduce the energy consumption per ton of coke in the enterprise; at the same time, ultra-high temperature and ultra-high pressure units are used to generate electricity, thereby increasing the power generation, and achieving significant economic benefits and energy-saving and consumption-reducing effects.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A system for comprehensive utilization of waste heat in a coking production process, including a dry coke quenching waste heat recovery system; and also including a raw coal gas waste heat recovery system; the dry coke quenching waste heat recovery system includes a desalted water tank, a steam turbine generator set and a dry coke quenching boiler; the steam turbine generator set includes a high-pressure cylinder, a medium-low pressure cylinder and a generator connected in sequence; the dry coke quenching boiler includes a boiler drum, and an economizer, a membrane water cooler and an evaporator, a primary reheater, a secondary reheater, a primary superheater and a secondary superheater arranged in the dry coke quenching boiler body from bottom to top; the raw coal gas waste heat recovery system includes a first riser drum, a first riser heat exchanger, a second riser drum and a second riser heat exchanger; the specific structure is as follows:

[0007] The desalted water outlet of the desalted water tank is connected to the deoxygenated feed water pump, the feed water preheater and the deaerator in sequence through the desalted water outlet pipeline, wherein the feed water preheater is arranged at the circulating gas outlet of the dry coke quenching boiler; the deoxygenated water outlet of the deaerator is respectively connected to the inlet of the boiler feed water pump and the inlet of the drum feed water pump; the outlet of the boiler feed water pump is connected to the water inlet of the economizer in the dry coke quenching boiler; the water outlet of the economizer is connected to the water inlet of the boiler drum, and the water outlet of the boiler drum is connected to the steam-water mixture inlet of the boiler drum through the membrane water cooler and the evaporator, and the boiler The saturated steam outlet of the drum is connected to the steam inlet of the medium and high pressure cylinders of the steam turbine generator set through the primary superheater and the secondary superheater in turn; the steam outlet of the high pressure cylinder is connected to the primary reheater and the secondary reheater through the steam pipeline, and the secondary reheater is connected to the steam inlet of the medium and low pressure cylinders through the reheat steam pipeline; the steam outlet of the medium and low pressure cylinders is connected to the steam inlet of the condenser, and the condensate outlet of the condenser is connected to the condensate inlet of the desalted water tank through the condensate pipeline, and a condensate pump is provided on the condensate pipeline; the desalted water tank is also provided with a secondary desalted water inlet;

[0008] The outlet of the drum feed water pump is connected to the water inlet of the first drum of the riser, the water outlet of the first drum of the riser is connected to the steam-water mixture inlet of the first drum of the riser through a forced circulation pump and a first riser heat exchanger, the saturated steam outlet of the first drum of the riser is connected to the saturated steam inlet of the second drum of the riser through a second riser heat exchanger, and the superheated steam outlet of the second drum of the riser is connected to the steam pipe between the high-pressure cylinder and the primary reheater.

[0009] The deaerator is a medium-pressure deaerator, and the deaerator is provided with a steam inlet connected to a low-pressure steam pipeline network.

[0010] A reheat steam water spray desuperheater is arranged on the connecting pipe between the primary reheater and the secondary reheater.

[0011] A superheated steam water spray desuperheater is arranged on the connecting pipe between the primary superheater and the secondary superheater.

[0012] The feed water preheater is a radial heat exchange tube feed water preheater.

[0013] The CDQ boiler is an ultra-high temperature and ultra-high pressure CDQ boiler, with a rated steam temperature of 570°C and a rated steam pressure of 13.7 MPa.

[0014] The steam turbine generator set is an ultra-high temperature and ultra-high pressure coaxial steam turbine generator set with single reheat, with a rated steam temperature of 570°C, a rated steam pressure of 13.2MPa, a rated exhaust temperature of the high-pressure cylinder of 350°C, and a rated exhaust pressure of 2.8MPa.

[0015] The superheated steam outlet of the second steam drum of the riser is further connected to a low-pressure steam pipeline through a steam outlet pipeline, and a temperature and pressure reduction device is provided on the steam outlet pipeline.

[0016] A method for comprehensive utilization of waste heat in a coking production process comprises the following steps:

[0017] 1) The supplementary secondary demineralized water with a temperature of 25-30℃ supplied from the outside directly enters the demineralized water tank. After the exhaust steam from the low-pressure cylinder of the steam turbine generator set does work, it exchanges heat with the circulating cooling water through the condenser, and the condensed water with a temperature of 40-45℃ is generated and enters the demineralized water tank through the condensate pump. It is mixed with the supplementary secondary demineralized water in the demineralized water tank, and then is pressurized by the deaerator feed water pump and sent to the feed water preheater. After heating, the water temperature rises to 60℃-70℃ and enters the deaerator. After heating again, the water temperature rises to more than 120℃ and is sent out in two ways; one of which is pressurized by the boiler feed water pump and sent to the economizer in the dry coke quenching boiler, and the other is sent to the first drum of the riser by the drum feed water pump pressure boiler;

[0018] 2) The boiler feed water sent to the economizer is heated by the economizer to raise the water temperature to above 290°C before entering the boiler drum. The saturated temperature of the boiler water in the boiler drum is above 340°C. The boiler water enters the membrane water-cooled wall and evaporator through the downcomer, absorbs heat and vaporizes to form a steam-water mixture, which enters the boiler drum under the action of thermal pressure. The steam-water mixture is separated in the boiler drum by the steam-water separation device to produce saturated steam, and the saturated steam enters the primary superheater through the manifold; in the primary superheater, it exchanges heat with the high-temperature inert circulating gas to increase the steam temperature; after the steam temperature is adjusted to the set temperature by the hot steam spray water desuperheater, it enters the secondary superheater to exchange heat with the high-temperature inert circulating gas to increase the temperature, and finally the steam with a temperature of above 570°C all enters the high-pressure cylinder in the steam turbine generator set to generate electricity. After doing work, the high-pressure cylinder exhaust steam with a temperature of above 350°C and a pressure of above 2.8MPa is sent to the primary reheater in the dry coke quenching boiler;

[0019] 3) The drum feed water sent to the first drum of the riser is pressurized by a forced circulation pump and sent to the first drum of the riser. The saturated steam-water mixture produced enters the first drum of the riser. The steam-water mixture is separated by a steam-water separation device in the first drum of the riser to produce saturated steam. The saturated steam enters the second drum of the riser through a manifold. The steam is heat exchanged with the high-temperature raw coal gas in the second drum of the riser. The steam with a temperature of more than 350°C enters the second drum of the riser. The superheated steam with a temperature of more than 350°C and a pressure of more than 2.8MPa drawn out from the second drum of the riser is combined with the high-pressure cylinder exhaust steam and sent to the primary reheater in the dry coke quenching boiler.

[0020] 4) The combined superheated steam exchanges heat with the high-temperature inert circulating gas in the primary reheater to increase the steam temperature. After the steam temperature is adjusted to the set value by the reheat steam water spray desuperheater, it enters the secondary reheater to exchange heat with the high-temperature inert circulating gas to increase the temperature. Finally, the superheated steam with a temperature of more than 570°C enters the low-pressure cylinder in the steam turbine generator set to generate electricity.

[0021] When the CDQ boiler is in emergency maintenance condition, the superheated steam generated by the second drum of the riser is introduced into the low-pressure steam network through the temperature and pressure reduction device for use by low-pressure steam users.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) Taking into full consideration the regional layout, waste heat recovery methods and steam parameters of the two existing waste heat recovery systems in coking enterprises, the two waste heat recovery systems are organically combined. According to the energy utilization principle of "energy use according to quality, temperature matching, and cascade utilization", the problems of waste heat dissipation and high-parameter steam desuperheating and pressure reduction are avoided, and the waste heat utilization rate is maximized, the energy consumption per ton of coke in the enterprise is reduced, and the energy saving and consumption reduction effect is remarkable;

[0024] 2) Use ultra-high temperature and ultra-high pressure units to generate electricity, increase power generation, and achieve significant economic benefits;

[0025] 3) Use ultra-high temperature and ultra-high pressure dry quenching boilers to increase the reheater area and improve the utilization rate of high-grade parameter steam;

[0026] 4) The CDQ device and the coke oven riser device are laid out together and share a water supply system, thus achieving system optimization; shortening the distance between devices is beneficial to reducing the temperature drop and pressure drop of superheated steam. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a system for comprehensive utilization of waste heat in a coking production process according to the present invention.

[0028] In the figure: 1. Desalted water tank 2. High pressure cylinder 3. Medium and low pressure cylinder 4. Condenser 5. Condensate pump 6. Deaerator feed water pump 7. Feed water preheater 8. Deaerator 9. Boiler feed water pump 10. Economizer 11. Boiler drum 12. Membrane water wall and evaporator 13. Primary reheater 14. Reheated steam spray desuperheater 15. Secondary reheater 16. Primary superheater 17. Superheated steam spray desuperheater 18. Secondary superheater 19. Generator 20. Riser first drum 21. Forced circulation pump 22. First riser heat exchanger 23. Second riser heat exchanger 24. Riser second drum 25. Temperature reduction and pressure reduction 26. Drum feed water pump DETAILED DESCRIPTION

[0029] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0030] like Figure 1As shown, a comprehensive utilization system of waste heat in a coking production process of the present invention includes a dry coke quenching waste heat recovery system; and also includes a raw coal gas waste heat recovery system; the dry coke quenching waste heat recovery system includes a desalted water tank 1, a steam turbine generator set and a dry coke quenching boiler; the steam turbine generator set includes a high-pressure cylinder 2, a medium- and low-pressure cylinder 3 and a generator 19 connected in sequence; the dry coke quenching boiler includes a boiler drum 11, and an economizer 10, a membrane water cooler and an evaporator 12, a primary reheater 13, a secondary reheater 15, a primary superheater 16 and a secondary superheater 18 arranged in sequence in the dry coke quenching boiler body from bottom to top; the raw coal gas waste heat recovery system includes a first riser drum 20, a first riser heat exchanger 22, a second riser drum 24 and a second riser heat exchanger 23; the specific structure is as follows:

[0031] The deionized water outlet of the deionized water tank 1 is connected to the deoxygenated feed water pump 6, the feed water preheater 7 and the deaerator 8 in sequence through the deionized water outlet pipeline, wherein the feed water preheater 7 is arranged at the circulating gas outlet of the dry coke quenching boiler; the deoxygenated water outlet of the deaerator 8 is connected to the inlet of the boiler feed water pump 9 and the inlet of the drum feed water pump 26 respectively; the outlet of the boiler feed water pump 9 is connected to the water inlet of the economizer 10 in the dry coke quenching boiler; the water outlet of the economizer 10 is connected to the water inlet of the boiler drum 11, and the water outlet of the boiler drum 11 is connected to the steam-water mixture inlet of the boiler drum 11 through the membrane water cooler and the evaporator 12, and the boiler The saturated steam outlet of the boiler drum 11 is connected to the steam inlet of the medium and high pressure cylinder 2 of the steam turbine generator set through the primary superheater 16 and the secondary superheater 18 in sequence; the steam outlet of the high pressure cylinder 2 is connected to the primary reheater 13 and the secondary reheater 15 through a steam pipeline, and the secondary reheater 15 is connected to the steam inlet of the medium and low pressure cylinder 3 through a reheat steam pipeline; the steam outlet of the medium and low pressure cylinder 3 is connected to the steam inlet of the condenser 4, and the condensate outlet of the condenser 4 is connected to the condensate inlet of the desalted water tank 1 through a condensate pipeline, and a condensate pump 5 is provided on the condensate pipeline; the desalted water tank 1 is also provided with a secondary desalted water inlet;

[0032] The outlet of the drum feed water pump 26 is connected to the water inlet of the first drum 20 of the riser, the water outlet of the first drum 20 of the riser is connected to the steam-water mixture inlet of the first drum 20 of the riser through the forced circulation pump 21 and the first drum heat exchanger 22, the saturated steam outlet of the first drum 20 of the riser is connected to the saturated steam inlet of the second drum 24 of the riser through the second drum heat exchanger 23, and the superheated steam outlet of the second drum 24 of the riser is connected to the steam pipe between the high-pressure cylinder 2 and the primary reheater 13.

[0033] The deaerator 8 is a medium-pressure deaerator, and the deaerator 8 is provided with a steam inlet connected to a low-pressure steam pipeline network.

[0034] A reheat steam water spray desuperheater 14 is provided on the connecting pipe between the primary reheater 13 and the secondary reheater 15 .

[0035] A superheated steam water spray desuperheater 17 is provided on the connecting pipe between the primary superheater 16 and the secondary superheater 18 .

[0036] The feed water preheater 7 is a radial heat exchange tube feed water preheater.

[0037] The CDQ boiler is an ultra-high temperature and ultra-high pressure CDQ boiler, with a rated steam temperature of 570°C and a rated steam pressure of 13.7 MPa.

[0038] The steam turbine generator set is an ultra-high temperature and ultra-high pressure coaxial steam turbine generator set with single reheat, with a rated steam temperature of 570°C, a rated steam pressure of 13.2MPa, a rated exhaust temperature of the high-pressure cylinder of 350°C, and a rated exhaust pressure of 2.8MPa.

[0039] The superheated steam outlet of the second steam drum 24 of the riser is further connected to a low-pressure steam pipeline through a steam outlet pipeline, and a temperature and pressure reduction device 25 is provided on the steam outlet pipeline.

[0040] The working principle of the comprehensive utilization system of waste heat in the coking production process described in the present invention is as follows: desalted water is sent to the deaerator 8 after heat exchange in the feed water preheater 7, and the deoxygenated water with a temperature of 120°C after deoxygenation is divided into two paths, one of which is boiler feed water, which is sent to the high-pressure cylinder 2 of the steam turbine generator set to generate power by generating superheated steam with a temperature of about 570°C and a pressure of about 13.7MPa through the dry coke quenching boiler; the other path is drum feed water, which is sent to the high-pressure cylinder 2 of the steam turbine generator set to generate power by generating saturated steam with a temperature of about 236°C and a pressure of about 3.0MPa through the first riser heat exchanger 22, and the saturated steam is sent to the medium- and low-pressure cylinders 3 of the steam turbine generator set to generate power by generating superheated steam with a temperature of about 350°C and a pressure of about 2.8MPa through the second riser heat exchanger 23, and the exhaust steam of the medium- and high-pressure cylinder 2 of the steam turbine generator set with a temperature of about 350°C and a pressure of about 2.8MPa is merged into one path and enters the primary reheater 13 and the secondary reheater 15 of the dry coke quenching boiler for reheating, and the superheated steam with a temperature of about 570°C and a pressure of about 2.5MPa after reheating enters the medium- and low-pressure cylinders 3 of the steam turbine generator set to generate power.

[0041] The first riser heat exchanger 22 and the second riser heat exchanger 23 are provided on the coke oven riser, and both are in plurality.

[0042] A method for comprehensive utilization of waste heat in a coking production process comprises the following steps:

[0043] 1) The supplementary secondary demineralized water with a temperature of 25-30°C supplied from the outside directly enters the demineralized water tank 1. After the exhaust steam from the low-pressure cylinder 3 of the steam turbine generator set does work, it exchanges heat with the circulating cooling water through the condenser, and the condensed water with a temperature of 40-45°C is generated and enters the demineralized water tank 1 through the condensate pump 4. It is mixed with the supplementary secondary demineralized water in the demineralized water tank 1, and then is pressurized by the deaerator feed water pump 6 and sent to the feed water preheater 7. After heating, the water temperature rises to 60-70°C and enters the deaerator 8. After heating, the water temperature rises to more than 120°C and is sent out in two ways; one of which is pressurized by the boiler feed water pump 9 and sent to the economizer 10 in the dry coke quenching boiler, and the other is sent to the first steam drum 20 of the riser through the drum feed water pump 26 pressure boiler;

[0044] 2) The boiler feed water sent to the economizer 10 is heated by the economizer 10 to raise the water temperature to above 290°C before entering the boiler drum 11. The saturated temperature of the boiler water in the boiler drum 11 is above 340°C. The boiler water enters the membrane water-cooled wall and the evaporator 12 through the downcomer, absorbs heat and vaporizes to form a steam-water mixture, which enters the boiler drum 11 under the action of thermal pressure. The steam-water mixture is separated in the boiler drum 11 by the steam-water separation device to generate saturated steam, and the saturated steam enters the primary superheater 116 through the manifold; In the primary superheater 16, the steam exchanges heat with the high-temperature inert circulating gas to increase the steam temperature; after the steam temperature is adjusted to the set temperature by the hot steam spray water desuperheater 17, the steam enters the secondary superheater 18 to exchange heat with the high-temperature inert circulating gas to increase the temperature, and finally the steam with a temperature of more than 570°C all enters the high-pressure cylinder 2 in the steam turbine generator set to generate electricity. After doing work, the exhaust steam of the high-pressure cylinder 2 with a temperature of more than 350°C and a pressure of more than 2.8MPa is sent to the primary reheater 13 in the dry coke quenching boiler;

[0045] 3) The drum feed water sent to the first drum 20 of the riser is pressurized by the forced circulation pump 21 and sent to the first riser heat exchanger 22. The generated saturated steam-water mixture enters the first drum 20 of the riser. The steam-water mixture is separated by the steam-water separation device in the first drum 20 of the riser to generate saturated steam. The saturated steam enters the second drum 23 of the riser through the manifold. The steam is heat-exchanged with the high-temperature raw coal gas in the second drum 23. The steam with a temperature of more than 350°C enters the second drum 24 of the riser. The superheated steam with a temperature of more than 350°C and a pressure of more than 2.8MPa drawn out from the second drum 24 of the riser is combined with the exhaust steam of the high-pressure cylinder 2 and sent to the primary reheater 13 in the dry coke quenching boiler.

[0046] 4) The combined superheated steam exchanges heat with the high-temperature inert circulating gas in the primary reheater 13 to increase the steam temperature. After the steam temperature is adjusted to the set value by the reheated steam water spray desuperheater 14, it enters the secondary reheater 15 to exchange heat with the high-temperature inert circulating gas to increase the temperature. Finally, the superheated steam with a temperature of more than 570°C enters the low-pressure cylinder 3 in the steam turbine generator set to generate electricity.

[0047] When the CDQ boiler is in the accident maintenance condition, the superheated steam generated by the second steam drum 24 of the riser is incorporated into the low-pressure steam network through the temperature and pressure reduction device 25 for use by low-pressure steam users.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A system for comprehensive utilization of waste heat from a coking production process, comprising a coke dry quenching waste heat recovery system; characterized in that: It also includes a waste heat recovery system for raw coal gas; the waste heat recovery system for dry coke quenching includes a desalted water tank, a steam turbine generator set and a dry coke quenching boiler; the steam turbine generator set includes a high-pressure cylinder, a medium-low pressure cylinder and a generator connected in sequence; the dry coke quenching boiler includes a boiler drum, and an economizer, a membrane water cooler and an evaporator, a primary reheater, a secondary reheater, a primary superheater and a secondary superheater arranged in the dry coke quenching boiler body from bottom to top; the waste heat recovery system for raw coal gas includes a first riser drum, a first riser heat exchanger, a second riser drum and a second riser heat exchanger; the specific structure is as follows: The desalted water outlet of the desalted water tank is connected to the deoxygenated feed water pump, the feed water preheater and the deaerator in sequence through the desalted water outlet pipeline, wherein the feed water preheater is arranged at the circulating gas outlet of the dry coke quenching boiler; the deoxygenated water outlet of the deaerator is respectively connected to the inlet of the boiler feed water pump and the inlet of the drum feed water pump; the outlet of the boiler feed water pump is connected to the water inlet of the economizer in the dry coke quenching boiler; the water outlet of the economizer is connected to the water inlet of the boiler drum, and the water outlet of the boiler drum is connected to the steam-water mixture inlet of the boiler drum through the membrane water cooler and the evaporator, and the boiler The saturated steam outlet of the drum is connected to the steam inlet of the medium and high pressure cylinders of the steam turbine generator set through the primary superheater and the secondary superheater in turn; the steam outlet of the high pressure cylinder is connected to the primary reheater and the secondary reheater through the steam pipeline, and the secondary reheater is connected to the steam inlet of the medium and low pressure cylinders through the reheat steam pipeline; the steam outlet of the medium and low pressure cylinders is connected to the steam inlet of the condenser, and the condensate outlet of the condenser is connected to the condensate inlet of the desalted water tank through the condensate pipeline, and a condensate pump is provided on the condensate pipeline; the desalted water tank is also provided with a secondary desalted water inlet; The outlet of the drum feed water pump is connected to the water inlet of the first drum of the riser, the water outlet of the first drum of the riser is connected to the steam-water mixture inlet of the first drum of the riser through a forced circulation pump and a first riser heat exchanger, the saturated steam outlet of the first drum of the riser is connected to the saturated steam inlet of the second drum of the riser through a second riser heat exchanger, and the superheated steam outlet of the second drum of the riser is connected to the steam pipe between the high-pressure cylinder and the primary reheater.

2. A system for comprehensive utilization of waste heat in a coking production process according to claim 1, characterized in that: The deaerator is a medium-pressure deaerator, and the deaerator is provided with a steam inlet connected to a low-pressure steam pipeline network.

3. The system for comprehensive utilization of waste heat in a coking production process according to claim 1, characterized in that: A reheat steam water spray desuperheater is arranged on the connecting pipe between the primary reheater and the secondary reheater.

4. The system for comprehensive utilization of waste heat in a coking production process according to claim 1, characterized in that: A superheated steam water spray desuperheater is arranged on the connecting pipe between the primary superheater and the secondary superheater.

5. The system for comprehensive utilization of waste heat in a coking production process according to claim 1, characterized in that: The feed water preheater is a radial heat exchange tube feed water preheater.

6. The system for comprehensive utilization of waste heat in a coking production process according to claim 1, characterized in that: The CDQ boiler is an ultra-high temperature and ultra-high pressure CDQ boiler, with a rated steam temperature of 570°C and a rated steam pressure of 13.7 MPa.

7. The system for comprehensive utilization of waste heat in a coking production process according to claim 1, characterized in that: The steam turbine generator set is an ultra-high temperature and ultra-high pressure coaxial steam turbine generator set with single reheat, with a rated steam temperature of 570°C, a rated steam pressure of 13.2MPa, a rated exhaust temperature of the high-pressure cylinder of 350°C, and a rated exhaust pressure of 2.8MPa.

8. The system for comprehensive utilization of waste heat in a coking production process according to claim 1, characterized in that: The superheated steam outlet of the second steam drum of the riser is further connected to a low-pressure steam pipeline through a steam outlet pipeline, and a temperature and pressure reduction device is provided on the steam outlet pipeline.

9. A method for comprehensive utilization of waste heat from a coking production process based on the system of any one of claims 1 to 8, characterized in that: The steps include: 1) The supplementary secondary demineralized water with a temperature of 25-30℃ supplied from outside directly enters the demineralized water tank. After the exhaust steam from the low-pressure cylinders of the steam turbine generator set does work, it exchanges heat with the circulating cooling water through the condenser. The condensed water with a temperature of 40-45℃ is then pumped into the demineralized water tank through the condensate pump. It is mixed with the supplementary secondary demineralized water in the demineralized water tank and then pressurized and sent to the feed water preheater by the deaerator feed water pump. After being heated, the water temperature rises to 60℃-70℃ and enters the deaerator. After being heated again, the water temperature rises to above 120℃ and is sent out in two ways. One of them is pressurized by boiler feed water pump and sent to economizer in CDQ boiler, and the other is pressurized by drum feed water pump and sent to first drum of riser. 2) The boiler feed water sent to the economizer is heated to above 290℃ by the economizer and then enters the boiler drum. The saturated temperature of the boiler water in the boiler drum is above 340℃. The boiler water enters the membrane water-cooled wall and evaporator through the downcomer, absorbs heat and vaporizes to form a steam-water mixture, which enters the boiler drum under the action of thermal pressure. The steam-water mixture is separated in the boiler drum by the steam-water separation device to produce saturated steam. The saturated steam enters the primary superheater through the manifold; in the primary superheater, it exchanges heat with the high-temperature inert circulating gas to increase the steam temperature; after the steam temperature is adjusted to the set temperature by the hot steam spray water desuperheater, it enters the secondary superheater to exchange heat with the high-temperature inert circulating gas to increase the temperature. Finally, the steam with a temperature of above 570℃ all enters the high-pressure cylinder in the steam turbine generator set to generate electricity. After doing work, the high-pressure cylinder exhaust steam with a temperature of above 350℃ and a pressure of above 2.8MPa is sent to the primary reheater in the dry coke quenching boiler; 3) The drum feed water sent to the first drum of the riser is pressurized by a forced circulation pump and sent to the first drum of the riser. The saturated steam-water mixture produced enters the first drum of the riser. The steam-water mixture is separated by a steam-water separation device in the first drum of the riser to produce saturated steam. The saturated steam enters the second drum of the riser through a manifold. The steam is heat exchanged with the high-temperature raw coal gas in the second drum of the riser. The steam with a temperature of more than 350°C enters the second drum of the riser. The superheated steam with a temperature of more than 350°C and a pressure of more than 2.8MPa drawn out from the second drum of the riser is combined with the high-pressure cylinder exhaust steam and sent to the primary reheater in the dry coke quenching boiler. 4) The combined superheated steam exchanges heat with the high-temperature inert circulating gas in the primary reheater to increase the steam temperature. After the steam temperature is adjusted to the set value by the reheat steam water spray desuperheater, it enters the secondary reheater to exchange heat with the high-temperature inert circulating gas to increase the temperature. Finally, the superheated steam with a temperature of more than 570°C enters the low-pressure cylinder in the steam turbine generator set to generate electricity.

10. The method for comprehensive utilization of waste heat in a coking production process according to claim 9, characterized in that: When the CDQ boiler is in emergency maintenance condition, the superheated steam generated by the second drum of the riser is introduced into the low-pressure steam network through the temperature and pressure reduction device for use by low-pressure steam users.

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