Power generation and seawater desalination system and method based on dry quenching waste heat recovery

Abstract

This invention relates to a power generation and seawater desalination system and method based on waste heat recovery from dry quenching coke. In the power generation and seawater desalination system, the inert gas outlet of the dry quenching furnace is connected to a CO2 waste heat boiler. The inert gas in the dry quenching furnace, after absorbing heat from the red-hot coke, enters the CO2 waste heat boiler to exchange heat with S-CO2. The inert gas outlet of the CO2 waste heat boiler is connected to a first distillation desalination unit, and the inert gas outlet of the first distillation desalination unit is connected to the dry quenching furnace. The S-CO2 gas outlet of the CO2 waste heat boiler is connected to an S-CO2 power generation system and a reverse osmosis seawater desalination subsystem. The S-CO2 gas outlet of the S-CO2 power generation system is connected to a second distillation desalination unit, and the S-CO2 gas outlet of the second distillation desalination unit is connected to the S-CO2 power generation system, and the S-CO2 gas outlet of the S-CO2 power generation system is connected to the CO2 waste heat boiler. The reverse osmosis seawater desalination subsystem can convert the thermal energy of S-CO2 into pressure energy for pressurizing seawater, and can then process the pressurized seawater through a reverse osmosis membrane to produce fresh water. This fully utilizes waste heat, simultaneously generating electricity and desalinating seawater.

Description

Technical Field

[0001] This invention relates to the technical field of waste heat recovery and utilization, and in particular to a power generation and seawater desalination system and method based on dry quenching waste heat recovery. Background Technology

[0002] Seawater desalination technology is a crucial solution to the problem of limited freshwater resources. Traditional seawater desalination technologies rely on fossil fuels, resulting in high costs and CO2 emissions. Currently, over 120 countries worldwide have set carbon neutrality goals. To reduce costs and carbon emissions, developing and utilizing new energy seawater desalination technologies, primarily based on industrial waste heat, nuclear energy, and renewable energy, is an inevitable trend. Employing low-grade waste heat from industrial emissions and developing energy recovery technologies and equipment are effective ways to reduce seawater desalination costs and carbon emissions.

[0003] Currently, the 105,000 t / d MED seawater desalination project at the Zhejiang Zhoushan Green Petrochemical Base, the 45,000 t / d MED seawater desalination project at Hengli Petrochemical Dalian, and the 25,000 t / d MED seawater desalination project at Hebei Zongheng Group Fengnan Steel, all completed in 2018-2019, have adopted waste heat desalination technology. However, this waste heat desalination technology only utilizes the waste heat emitted by industrial emissions once. The remaining heat after the waste heat is released and condensed to desalinate the seawater is not fully utilized, resulting in a single heat source and low heat utilization rate. Furthermore, it is difficult to reduce water production costs. Summary of the Invention

[0004] The first technical problem to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a power generation and seawater desalination system and method based on dry quenching waste heat recovery. It solves the technical problems of current waste heat desalination technology that only utilizes industrial waste heat once, and the remaining heat after the waste heat is released and condensed to desalinate the seawater is not fully utilized. It also has the problems of single heat source and low heat utilization rate, as well as the difficulty in reducing water production costs.

[0006] Two technical solutions

[0007] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0008] In a first aspect, embodiments of the present invention provide a power generation and seawater desalination system based on dry quenching waste heat recovery, including a dry quenching furnace, a CO2 waste heat boiler, a first distillation desalination device, a second distillation desalination device, an S-CO2 power generation system, and a reverse osmosis seawater desalination subsystem;

[0009] The inert gas outlet of the dry quenching furnace is connected to a CO2 waste heat boiler, which contains S-CO2;

[0010] The inert gas outlet of the CO2 waste heat boiler is connected to the first distillation and desalination unit, and the inert gas outlet of the first distillation and desalination unit is connected to the dry quenching furnace.

[0011] The S-CO2 gas outlet of the CO2 waste heat boiler is connected to the S-CO2 power generation system and the reverse osmosis seawater desalination subsystem; the S-CO2 gas outlet of the S-CO2 power generation system is connected to the second distillation desalination unit, the S-CO2 gas outlet of the second distillation desalination unit is connected to the S-CO2 power generation system, and the S-CO2 gas outlet of S-CO2 power generation system B is connected to the CO2 waste heat boiler; the reverse osmosis seawater desalination subsystem can convert the thermal energy of S-CO2 into pressure energy for pressurizing seawater, and can produce fresh water from the pressurized seawater through a reverse osmosis membrane.

[0012] According to the present invention, a heat pump recovery module is also included;

[0013] Both the first and second distillation desalination units are multi-effect distillation desalination units; the steam outlets of both the first and second distillation desalination units are connected to a heat pump recovery module.

[0014] The secondary steam generated at the end of the first and second distillation desalination units enters the heat pump recovery module through the steam outlet and exchanges heat with the S-CO2 in the heat pump recovery module; the secondary steam in the heat pump recovery module condenses to form fresh water, and the S-CO2 in the heat pump recovery module, after absorbing heat, desalinates seawater and exchanges heat with the secondary steam again.

[0015] According to the present invention, the heat pump recovery module includes a third distillation desalination device, a throttling valve, a condenser, and a first compressor;

[0016] The third distillation desalination unit is a multi-effect distillation desalination unit;

[0017] The steam outlets of the first, second, and third distillation desalination units are all connected to a condenser. The secondary steam generated at the end of the first, second, and third distillation desalination units enters the condenser through the steam outlet and exchanges heat with S-CO2. The secondary steam in the condenser condenses to form fresh water.

[0018] The S-CO2 gas outlet of the condenser is connected to the first compressor, the S-CO2 gas outlet of the first compressor is connected to the third distillation and desalination unit, and the S-CO2 gas outlet of the third distillation and desalination unit is connected to the condenser through a pipeline with a throttling valve installed on the pipeline.

[0019] According to the present invention, it further includes a first vacuum regulating valve, a second vacuum regulating valve, a third vacuum regulating valve, and a vacuum pump;

[0020] The first vacuum regulating valve is installed on the first pressure regulating pipeline connecting the first distillation and desalination device and the vacuum pump;

[0021] The second vacuum regulating valve is installed on the second pressure regulating pipeline connecting the second distillation and desalination unit and the vacuum pump;

[0022] The third vacuum regulating valve is installed on the third pressure regulating pipeline connecting the third distillation and desalination unit and the vacuum pump;

[0023] According to the present invention, it also includes a freshwater heat exchanger and a concentrated water heat exchanger;

[0024] The freshwater outlets of both the first and second distillation desalination units are connected to a freshwater heat exchanger; the freshwater in the heat exchanger heats the seawater.

[0025] The concentrate outlets of both the first and second distillation desalination units are connected to a concentrate heat exchanger; the concentrate in the heat exchanger heats the seawater.

[0026] The seawater outlets of both the freshwater heat exchanger and the concentrated water heat exchanger are connected to the reverse osmosis seawater desalination subsystem.

[0027] According to the present invention, the reverse osmosis seawater desalination subsystem includes a first S-CO2 turbine, a high-pressure pump, and a reverse osmosis desalination membrane separation device;

[0028] The S-CO2 gas outlet of the CO2 waste heat boiler is connected to the first S-CO2 turbine, the S-CO2 turbine is connected to a high-pressure pump, and the high-pressure pump is installed on the seawater inlet pipe connected to the reverse osmosis desalination membrane separation device.

[0029] The S-CO2 entering the S-CO2 turbine drives the S-CO2 turbine to rotate, thereby driving the high-pressure pump to pressurize the seawater in the seawater inlet pipe. The pressurized seawater enters the reverse osmosis desalination membrane separation device and is processed into fresh water through the reverse osmosis membrane.

[0030] According to the present invention, the reverse osmosis seawater desalination subsystem further includes an energy recovery device;

[0031] The concentrate outlet of the reverse osmosis desalination membrane separation unit is connected to an energy recovery unit, which is used to collect the pressure energy of the concentrate discharged from the reverse osmosis desalination membrane separation unit.

[0032] According to the present invention, the S-CO2 power generation system includes a second S-CO2 turbine and a generator connected to the second S-CO2 turbine; the S-CO2 gas outlet of the CO2 waste heat boiler is connected to the second S-CO2 turbine, and the S-CO2 gas outlet of the second S-CO2 turbine is connected to a second distillation and desalination unit.

[0033] After absorbing heat, the S-CO2 enters the second S-CO2 turbine to drive its rotation, thereby generating electricity.

[0034] According to the present invention, the S-CO2 power generation system further includes a regenerator and a second compressor;

[0035] The S-CO2 gas outlet of the second S-CO2 turbine is connected to the regenerator. The S-CO2 discharged from the second S-CO2 turbine enters the regenerator to release heat. The S-CO2 gas outlet of the regenerator is connected to the second distillation desalination unit. The S-CO2 after releasing heat enters the second distillation desalination unit to release heat and desalinate seawater.

[0036] The S-CO2 gas outlet of the second distillation and desalination unit is connected to the second compressor. The S-CO2 gas outlet of the second compressor is connected to the regenerator. The S-CO2 gas outlet of the regenerator is connected to the CO2 waste heat boiler.

[0037] Secondly, the present invention also provides a method for power generation and seawater desalination based on a dry quenching waste heat recovery system, comprising the following steps:

[0038] S1: The inert gas that has absorbed the heat of the red-hot coke in the dry quenching furnace enters the CO2 waste heat boiler to exchange heat with S-CO2.

[0039] S2: The inert gas released after heat release in the CO2 waste heat boiler enters the first distillation and desalination unit through the inert gas outlet of the CO2 waste heat boiler to release heat, so that the seawater absorbs heat, evaporates and condenses into fresh water; the inert gas released after heat release enters the dry quenching furnace through the inert gas outlet of the first distillation and desalination unit to absorb heat again.

[0040] S2: After absorbing heat in the CO2 waste heat boiler, a portion of the S-CO2 enters the S-CO2 power generation system through the S-CO2 gas outlet of the CO2 waste heat boiler, converting the thermal energy of the S-CO2 into electrical energy; the S-CO2 that has done work and released heat enters the second distillation desalination unit through the S-CO2 gas outlet of the S-CO2 power generation system to release heat, causing seawater to absorb heat, evaporate, and condense into fresh water; the S-CO2 that has released heat enters the S-CO2 power generation system through the S-CO2 gas outlet of the second distillation desalination unit for heating and pressurization, and then enters the CO2 waste heat boiler again through the S-CO2 gas outlet of the S-CO2 power generation system to absorb heat again;

[0041] Another portion of the S-CO2 after heat absorption in the CO2 waste heat boiler enters the reverse osmosis seawater desalination subsystem through the S-CO2 gas outlet of the CO2 waste heat boiler. The reverse osmosis seawater desalination subsystem can convert the thermal energy of S-CO2 into pressure energy to pressurize seawater, and can produce fresh water from the pressurized seawater through the reverse osmosis membrane.

[0042] Three beneficial effects

[0043] The beneficial effects of this invention are as follows: The power generation and seawater desalination system and its recovery method based on waste heat recovery from dry quenching coke utilize the heat of coke obtained after coking in metallurgical enterprises at temperatures as high as 1000℃, simultaneously generating electricity and desalinating seawater, thus making full use of waste heat and providing freshwater to metallurgical enterprises located near the sea with large freshwater demand. Furthermore, this power generation and seawater desalination system uses supercritical carbon dioxide (S-CO2) at a temperature exceeding 31.3℃ and a pressure of 7.38 MPa, existing in a gas-liquid two-phase state, as the heat exchange medium, replacing water for heat exchange. This medium has superior fluidity and diffusivity compared to water, and its unit volume is smaller than that of water vapor. Combined with the overall power generation and seawater desalination system, it has the following advantages:

[0044] Using S-CO2 as the heat exchange circulating medium, this system fully utilizes the waste heat of red-hot coke to simultaneously generate electricity and desalinate seawater, enriching the product. Multiple heat sources enable low-cost seawater desalination. Inert gas absorbs heat and cools the 1000℃ red-hot coke in a dry quenching furnace, then exchanges heat with S-CO2 in a CO2 waste heat boiler, where the S-CO2 extracts the heat from the inert gas. The waste heat from the released inert gas is released through a first distillation desalination unit to evaporate and condense seawater into fresh water. A portion of the absorbed S-CO2 can sequentially generate electricity through an S-CO2 power generation system and desalinate seawater through a second distillation desalination unit. The remaining absorbed S-CO2 converts thermal energy into pressure energy for pressurizing seawater through a reverse osmosis seawater desalination subsystem, and the pressurized seawater can then be processed into fresh water via a reverse osmosis membrane. Therefore, the waste heat of the inert gas after cooling red-hot coke can be fully utilized, and power generation and seawater desalination can be carried out simultaneously, enriching the products of waste heat recovery and increasing production and efficiency. Simultaneously, the residual heat energy after the inert gas releases heat, the heat energy of S-CO2 after extracting heat from the inert gas, and the heat energy of S-CO2 after extracting heat from the inert gas and generating electricity can all be used for seawater desalination, realizing seawater desalination from multiple heat sources. Furthermore, the entire power generation and seawater desalination system uses S-CO2 and inert gas as heat exchange circulating media for recycling, without introducing other media such as water, thus eliminating the need for a water supply system and effectively reducing the cost of seawater desalination.

[0045] This invention shortens the seawater desalination process, reduces equipment costs and size. It innovatively uses inert gas and high-pressure S-CO2 directly introduced into the first and second distillation units, eliminating the intermediate process of converting low-grade heat sources into steam before they can enter the desalination units, a process common in traditional seawater desalination. Furthermore, using S-CO2 as the heat exchange medium instead of water eliminates the need for a feedwater system for a steam waste heat boiler, shortening the process, reducing equipment costs and thus water production costs, and decreasing equipment size. Moreover, because the unit volume of S-CO2 is smaller than that of water vapor, the power generation unit in this application is only 1 / 25 the size of a steam turbine unit. Simultaneously, using S-CO2 as the power generation medium eliminates the need to consider equipment oxidation and corrosion, removing the deaeration water supply pump station required in traditional dry quenching waste heat power generation systems, further reducing the overall equipment size.

[0046] This system reduces carbon emissions, consumes no water, produces water, and increases efficiency. By installing a CO2 waste heat boiler, using supercritical carbon dioxide (S-CO2) at a temperature exceeding 31.3℃ and a pressure of 7.38MPa, in a gas-liquid two-phase state, as the heat exchange medium, it extracts heat from the inert gases after absorbing the heat from red-hot coke. This heat can synergize with carbon capture and utilization technology (CCUS) to extract carbon-containing gases generated during coking and other production processes, forming S-CO2. The waste heat from the S-CO2 heat exchange is then used for seawater desalination and power generation, achieving carbon reduction, efficiency improvement, and environmental friendliness. Simultaneously, by using S-CO2 instead of water for heat exchange, no water resources are consumed, and the waste heat can be used to produce fresh water through a first and second distillation desalination unit, achieving increased water production efficiency.

[0047] The heat exchange efficiency is improved. As a heat exchange medium with a temperature exceeding 31.3℃ and a pressure of 7.38MPa that exists between gas and liquid phases, S-CO2 has better fluidity and diffusivity than water. By setting up a CO2 waste heat boiler and using S-CO2 as the heat exchange medium, the heat of the inert gas after absorbing the heat of the red-hot coke can be extracted. This fully utilizes the characteristics of S-CO2, such as its large specific heat capacity and strong radiative heat exchange capacity, thus improving the heat exchange efficiency for the inert gas.

[0048] The power generation efficiency is improved. Power generation is achieved by using S-CO2, which is in a high-temperature, high-pressure state after heat extraction from inert gas, i.e., employing the Reyton cycle power generation technology. Compared to steam Rankine cycle power generation technology, the S-CO2 in the Reyton cycle is in a supercritical state between the gas and liquid phases, which avoids changes in the working fluid phase, reduces the consumption of compression work, and significantly improves cycle efficiency, thereby increasing power generation efficiency. Therefore, the power generation efficiency of this application is 3-5% higher than that of traditional steam Rankine cycle power generation technology. Attached Figure Description

[0049] Figure 1This is a schematic diagram of the power generation and seawater desalination system based on dry quenching waste heat recovery according to the present invention.

[0050] [Explanation of Labels in the Attached Image]

[0051] A: Waste heat extraction subsystem: 11: CO2 waste heat boiler; 12: dust collector; 13: fan;

[0052] B: S-CO2 generator system; 21: Second S-CO2 turbine; 22: Generator; 23: Regenerator; 24: Second compressor;

[0053] C: Seawater distillation and desalination subsystem: 31: First distillation and desalination unit; 32: Second distillation and desalination unit; 33: Third distillation and desalination unit; 34: Throttling valve; 35: Condenser; 36: First compressor;

[0054] D: Reverse osmosis seawater desalination subsystem; 51: First S-CO2 turbine; 52: High-pressure pump; 53: Energy recovery device; 54: Reverse osmosis desalination membrane separation device; 55: Flow valve; 56: Seawater pretreatment device;

[0055] 61: First vacuum regulating valve; 62: Second vacuum regulating valve; 63: Third vacuum regulating valve; 64: Vacuum pump;

[0056] 71: Freshwater heat exchanger; 72: Concentrate heat exchanger;

[0057] 81a: First inert gas line; 81b: Second inert gas line; 81c: Inert gas loop; 82a: First S-CO2 line; 82b: Second S-CO2 line; 82c: Third S-CO2 line; 82d: First S-CO2 loop; 82e: Second S-CO2 loop; 82f: Third S-CO2 loop; 82g: Fourth S-CO2 line; 82h: Fourth S-CO2 loop; 82i: Fourth S-CO2 loop;

[0058] 83a: First seawater pipeline; 83b: Second seawater pipeline; 83c: Third seawater pipeline; 84: Secondary steam pipeline; 85a: First freshwater pipeline; 85b: Second freshwater pipeline; 85c: Third freshwater pipeline; 86a: First concentrated water pipeline; 86b: Second concentrated water pipeline; 86c: Third concentrated water pipeline; 86d: Third concentrated water pipeline. Detailed Implementation

[0059] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0060] See Figure 1This invention provides a power generation and seawater desalination system based on waste heat recovery from dry quenching coke, comprising a waste heat extraction subsystem A, a seawater distillation and desalination subsystem C, an S-CO2 power generation system B, and a reverse osmosis seawater desalination subsystem D. Waste heat extraction subsystem A includes a dry quenching furnace and a CO2 waste heat boiler 11. Seawater distillation and desalination subsystem C includes a first distillation and desalination unit 31 and a second distillation and desalination unit 32.

[0061] The inert gas outlet of the dry quenching furnace is connected to the CO2 waste heat boiler 11, which contains S-CO2. The inert gas in the dry quenching furnace, after absorbing the heat from the red-hot coke, enters the CO2 waste heat boiler 11 to exchange heat with the S-CO2.

[0062] The inert gas outlet of the CO2 waste heat boiler 11 is connected to the first distillation and desalination unit 31, and the inert gas outlet of the first distillation and desalination unit 31 is connected to the dry quenching furnace.

[0063] The S-CO2 gas outlet of the CO2 waste heat boiler 11 is connected to the S-CO2 power generation system B and the reverse osmosis seawater desalination subsystem D. The S-CO2 gas outlet of the S-CO2 power generation system B is connected to the second distillation desalination unit 32, the S-CO2 gas outlet of the second distillation desalination unit 32 is connected to the S-CO2 power generation system B, and the S-CO2 gas outlet of the S-CO2 power generation system B is connected to the CO2 waste heat boiler 11. The reverse osmosis seawater desalination subsystem D can convert the thermal energy of S-CO2 into pressure energy for pressurizing seawater, and can produce fresh water from the pressurized seawater through a reverse osmosis membrane.

[0064] Specifically, the power generation and seawater desalination method based on dry quenching waste heat recovery includes the following steps:

[0065] S1: The inert gas that has absorbed the heat from the red-hot coke in the dry quenching furnace enters the CO2 waste heat boiler 11 to exchange heat with S-CO2.

[0066] S2: The inert gas released from the CO2 waste heat boiler 11 enters the first distillation desalination unit 31 through the inert gas outlet of the CO2 waste heat boiler 11 to release heat, so that the seawater absorbs heat, evaporates, and condenses into fresh water. The inert gas released from the CO2 waste heat boiler 11 enters the dry quenching furnace through the inert gas outlet of the first distillation desalination unit 31 to absorb heat again.

[0067] S2: A portion of the S-CO2 that has absorbed heat in the CO2 waste heat boiler 11 enters the S-CO2 power generation system B through the S-CO2 gas outlet of the CO2 waste heat boiler 11, converting the thermal energy of the S-CO2 into electrical energy. The S-CO2 that has performed work and released heat enters the second distillation desalination unit 32 through the S-CO2 gas outlet of the S-CO2 power generation system B to release heat, causing seawater to absorb heat, evaporate, and condense into fresh water. The released heat S-CO2 then enters the S-CO2 power generation system B through the S-CO2 gas outlet of the second distillation desalination unit 32 for heating and pressurization, and then enters the CO2 waste heat boiler 11 again through the S-CO2 gas outlet of the S-CO2 power generation system B to absorb heat again.

[0068] Another portion of the S-CO2 after heat absorption in the CO2 waste heat boiler 11 enters the reverse osmosis seawater desalination subsystem D through the S-CO2 gas outlet of the CO2 waste heat boiler 11. The reverse osmosis seawater desalination subsystem D can convert the thermal energy of S-CO2 into pressure energy for pressurizing seawater, and can produce fresh water from the pressurized seawater through the reverse osmosis membrane.

[0069] This invention relates to a power generation and seawater desalination system and its recovery method based on waste heat recovery from dry quenching coke. It utilizes the heat from coke, which reaches temperatures as high as 1000°C, obtained after coking in metallurgical enterprises, to simultaneously generate electricity and desalinate seawater. This fully utilizes the waste heat from coke and provides freshwater to metallurgical enterprises located near the sea with high freshwater demand. The entire power generation and seawater desalination system utilizes waste heat from dry quenching coke. It employs a waste heat extraction subsystem A, an S-CO2 power generation subsystem B, a seawater distillation and desalination subsystem C, and a reverse osmosis seawater desalination subsystem D, achieving a combined design of dry quenching cooling, S-CO2 power generation, and seawater desalination. Supercritical carbon dioxide (S-CO2) at a temperature exceeding 31.3°C and a pressure of 7.38 MPa, existing in a gas-liquid two-phase state, is used as the heat exchange medium, replacing water. Utilizing the superior fluidity and diffusivity compared to water, and its smaller volume per unit area compared to water vapor, it offers the following advantages:

[0070] Using S-CO2 as the heat exchange circulating medium, the waste heat of red-hot coke is fully utilized to simultaneously generate electricity and desalinate seawater, enriching the product. Multiple heat sources enable low-cost seawater desalination. Inert gas absorbs heat and cools the 1000℃ red-hot coke in a dry quenching furnace, then exchanges heat with S-CO2 in a CO2 waste heat boiler, where the S-CO2 extracts the heat from the inert gas. The waste heat from the inert gas is released through the first distillation desalination unit 31 to evaporate and condense seawater into fresh water. A portion of the absorbed S-CO2 can sequentially generate electricity through the S-CO2 power generation system and desalinate seawater through the second distillation desalination unit 32. The remaining absorbed S-CO2 converts thermal energy into pressure energy for pressurizing seawater through the reverse osmosis seawater desalination subsystem D, and the pressurized seawater can be processed into fresh water through a reverse osmosis membrane. Therefore, the waste heat of the inert gas after cooling red-hot coke can be fully utilized, and power generation and seawater desalination can be carried out simultaneously, enriching the products of waste heat recovery and increasing production and efficiency. Simultaneously, the residual heat energy after the inert gas releases heat, the heat energy of S-CO2 after extracting heat from the inert gas, and the heat energy of S-CO2 after extracting heat from the inert gas and generating electricity can all be used for seawater desalination, realizing seawater desalination from multiple heat sources. Furthermore, the entire power generation and seawater desalination system uses S-CO2 and inert gas as heat exchange circulating media for recycling, without introducing other media such as water, thus eliminating the need for a water supply system and effectively reducing the cost of seawater desalination.

[0071] This invention shortens the seawater desalination process, reduces equipment costs and size. It innovatively uses inert gas and high-pressure S-CO2 directly introduced into the first and second distillation desalination units 31 and 32, eliminating the intermediate process of converting low-grade heat sources into steam before they can enter the desalination units, as is done in traditional seawater desalination processes. Furthermore, using S-CO2 as the heat exchange medium instead of water eliminates the need for a feedwater system for a steam waste heat boiler, shortening the process, reducing equipment costs and thus water production costs, and decreasing equipment size. Moreover, because the unit volume of S-CO2 is smaller than that of water vapor, the volume of the power generation unit in this application is only 1 / 25th that of a steam turbine unit. Simultaneously, using S-CO2 as the power generation medium eliminates the need to consider equipment oxidation and corrosion issues, removing the deaeration water supply pump station required in traditional dry quenching waste heat power generation systems, further reducing the overall equipment size.

[0072] This system reduces carbon emissions, consumes no water, produces water, and increases efficiency. By installing a CO2 waste heat boiler, using supercritical carbon dioxide (S-CO2) at a temperature exceeding 31.3℃ and a pressure of 7.38MPa, in a gas-liquid two-phase state, as the heat exchange medium, it extracts heat from the inert gases after absorbing the heat from red-hot coke. This heat can synergize with carbon capture and utilization technology (CCUS) to extract carbon-containing gases generated during coking and other production processes, forming S-CO2. The waste heat from the S-CO2 heat exchange is then used for seawater desalination and power generation, achieving carbon reduction, efficiency improvement, and environmental friendliness. Simultaneously, by using S-CO2 instead of water for heat exchange, no water resources are consumed, and the waste heat can be used to produce fresh water through a first and second distillation desalination unit, achieving increased water production efficiency.

[0073] The heat exchange efficiency is improved. As a heat exchange medium with a temperature exceeding 31.3℃ and a pressure of 7.38MPa that exists between gas and liquid phases, S-CO2 has better fluidity and diffusivity than water. By setting up a CO2 waste heat boiler and using S-CO2 as the heat exchange medium, the heat of the inert gas after absorbing the heat of the red-hot coke can be extracted. This fully utilizes the characteristics of S-CO2, such as its large specific heat capacity and strong radiative heat exchange capacity, thus improving the heat exchange efficiency for the inert gas.

[0074] The power generation efficiency is improved. Power generation is achieved by using S-CO2, which is in a high-temperature, high-pressure state after heat extraction from inert gas, i.e., employing the Reyton cycle power generation technology. Compared to steam Rankine cycle power generation technology, the S-CO2 in the Reyton cycle is in a supercritical state between the gas and liquid phases, which avoids changes in the working fluid phase, reduces the consumption of compression work, and significantly improves cycle efficiency, thereby increasing power generation efficiency. Therefore, the power generation efficiency of this application is 3-5% higher than that of traditional steam Rankine cycle power generation technology.

[0075] Preferably, the inert gas is N2.

[0076] Furthermore, under the action of the blower, inert gas is introduced into the dry quenching furnace.

[0077] The circulating gas cools the red-hot coke at approximately 1000°C in the dry quenching furnace. After being heated to 900-980°C, the circulating gas enters the CO2 waste heat boiler 11 to heat the S-CO2, causing the circulating gas temperature to drop to 160-170°C and the S-CO2 temperature to rise to approximately 850°C. The circulating gas, now at 160-170°C, is discharged from the CO2 waste heat boiler 11 into the first distillation desalination unit 31 to release heat, causing seawater to evaporate and condense into fresh water. The temperature of the released circulating gas drops to approximately 130°C and is then returned to the dry quenching furnace by the first distillation desalination unit 31 to cool the red-hot coke again.

[0078] Furthermore, the inert gas outlet of the dry quenching furnace is connected to the CO2 waste heat boiler 11 via a first inert gas pipeline 81a. The inert gas outlet of the CO2 waste heat boiler 11 is connected to the first distillation and desalination unit 31 via a second inert gas pipeline 81b. The inert gas outlet of the first distillation and desalination unit 31 is connected to the dry quenching furnace via an inert gas circuit 81c.

[0079] The S-CO2 gas outlet of the CO2 waste heat boiler 11 is connected to the S-CO2 power generation system B and the reverse osmosis seawater desalination subsystem D via the first S-CO2 pipeline 82a. The S-CO2 gas outlet of the S-CO2 power generation system B is connected to the second distillation desalination unit 32 via the third S-CO2 pipeline 82c. The S-CO2 gas outlet of the second distillation desalination unit 32 is connected to the S-CO2 power generation system B via the first S-CO2 loop 82d. The S-CO2 gas outlet of the S-CO2 power generation system B is connected to the CO2 waste heat boiler 11 via the third S-CO2 loop 82f.

[0080] Furthermore, a dust collector 12 and a fan 13 are sequentially installed on the second inert gas pipeline 81b along the flow direction of the inert gas. The inert gas discharged from the CO2 waste heat boiler 11 is sent into the first distillation and desalination unit 31 by the fan 13 after being purged by the dust collector 12.

[0081] Furthermore, the S-CO2 power generation system B includes a second S-CO2 turbine 21 and a generator 22 connected to the second S-CO2 turbine 21.

[0082] The S-CO2 gas outlet of the S-CO2 waste heat boiler 11 is connected to the second S-CO2 turbine 21, and the S-CO2 gas outlet of the second S-CO2 turbine 21 is connected to the second distillation and desalination unit 32.

[0083] After absorbing heat, the S-CO2 at a temperature of approximately 850°C enters the second S-CO2 turbine 21 to drive the second S-CO2 turbine 21 to rotate, thereby driving the generator 22 to generate electricity, thus realizing the conversion of the thermal energy of S-CO2 after extracting heat from the inert gas into electrical energy.

[0084] Furthermore, the S-CO2 power generation system B also includes a regenerator 23 and a second compressor 24.

[0085] The S-CO2 gas outlet of the second S-CO2 turbine 21 is connected to the regenerator 23. The S-CO2 gas outlet of the regenerator 23 is connected to the second distillation and desalination unit 32. The S-CO2 gas outlet of the second distillation and desalination unit 32 is connected to the second compressor 24. The S-CO2 gas outlet of the second compressor 24 is connected to the regenerator 23. The S-CO2 gas outlet of the regenerator 23 is connected to the CO2 waste heat boiler 11.

[0086] The S-CO2 discharged from the second S-CO2 turbine 21 enters the regenerator 23 to release heat. The S-CO2 after releasing heat enters the second distillation and desalination unit 32 to release heat and desalinate seawater. The S-CO2 discharged from the second distillation and desalination unit 32 is pressurized by the second compressor 24 and heated by the regenerator 23 in sequence, and then enters the CO2 waste heat boiler 11 again to absorb heat.

[0087] Specifically, the S-CO2 gas outlet of the S-CO2 waste heat boiler 11 is connected to the second S-CO2 turbine 21 via the first S-CO2 pipeline 82a. The S-CO2 gas outlet of the second S-CO2 turbine 21 is connected to the regenerator 23 via the second S-CO2 pipeline 82b. The S-CO2 gas outlet of the regenerator 23 is connected to the second distillation and desalination unit 32 via the third S-CO2 pipeline 82c. The S-CO2 gas outlet of the second distillation and desalination unit 32 is connected to the second compressor 24 via the first S-CO2 circuit 82d. The S-CO2 gas outlet of the second compressor 24 is connected to the regenerator 23 via the second S-CO2 circuit 82e. The S-CO2 gas outlet of the regenerator 23 is connected to the CO2 waste heat boiler 11 via the third S-CO2 circuit 82f.

[0088] Furthermore, the reverse osmosis seawater desalination subsystem D includes a first S-CO2 turbine 51, a high-pressure pump 52, and a reverse osmosis desalination membrane separation device 54.

[0089] The S-CO2 gas outlet of the CO2 waste heat boiler 11 is connected to the first S-CO2 turbine 51. The S-CO2 turbine is connected to the high-pressure pump 52, which is installed on the seawater inlet pipe connected to the reverse osmosis desalination membrane separation device 54.

[0090] The S-CO2 entering the S-CO2 turbine drives the turbine to rotate, which in turn drives the high-pressure pump 52 to pressurize the seawater in the seawater inlet pipe. This improves the thermal energy conversion efficiency of the S-CO2, eliminating the need for external functional devices and reducing seawater desalination costs. The pressurized seawater then enters the reverse osmosis desalination membrane separation unit 54, where it passes through the reverse osmosis membrane to produce fresh water. The reverse osmosis membrane is capable of allowing solvents to pass through. The pressurized seawater overcomes the pressure of the reverse osmosis membrane and passes through to form fresh water, which is then discharged, leaving behind concentrated water with a higher salt content.

[0091] Furthermore, the reverse osmosis seawater desalination subsystem D also includes an energy recovery device 53.

[0092] The concentrate outlet of the reverse osmosis desalination membrane separation unit 54 is connected to the energy recovery unit 53. The energy recovery unit 53 is used to collect the pressure energy of the concentrate in the concentrated state discharged from the reverse osmosis desalination membrane separation unit 54, so as to make full use of the energy of the entire power generation and seawater desalination system.

[0093] Specifically, the S-CO2 gas outlet of the CO2 waste heat boiler 11 is connected to the first S-CO2 turbine 51 via the first S-CO2 pipeline 82a. The second seawater pipeline 83b is connected to the reverse osmosis desalination membrane separation device 54 to supply seawater to the reverse osmosis desalination membrane separation device 54. The high-pressure pump 52 and the energy recovery device 53 are sequentially arranged on the second seawater pipeline 83b in the direction of seawater flow.

[0094] More specifically, the second seawater pipeline 83b connects to the seawater inlet of the energy recovery device 53, and the seawater outlet of the energy recovery device 53 connects to the reverse osmosis desalination membrane separation device 54 via the third seawater pipeline 83c. The concentrate outlet of the reverse osmosis desalination membrane separation device 54 connects to the energy recovery device 53 via the second concentrate pipeline 86b. The concentrate outlet of the energy recovery device 53 discharges the concentrated water collected by pressure energy through the third concentrate pipeline 86c. The fresh water produced by the reverse osmosis desalination membrane separation device 54 is discharged through the second fresh water pipeline 85b.

[0095] Specifically, the permeation seawater desalination subsystem D also includes a flow valve 55 and a seawater pretreatment unit 56, which are sequentially arranged on the second seawater pipeline 83b in the direction of coastal water flow. The flow valve 55 is used to control the flow rate of seawater supplied to the permeation seawater desalination subsystem D. The seawater pretreatment unit 56 is used to filter impurities in the seawater.

[0096] Furthermore, it also includes a freshwater heat exchanger 71 and a concentrated water heat exchanger 72.

[0097] The freshwater outlets of both the first distillation desalination unit 31 and the second distillation desalination unit 32 are connected to a freshwater heat exchanger 71. The freshwater in the freshwater heat exchanger 71 heats seawater. The concentrate outlets of both the first distillation desalination unit 31 and the second distillation desalination unit 32 are connected to a concentrate heat exchanger 72. The concentrate in the concentrate heat exchanger 72 heats seawater. The seawater outlets of both the freshwater heat exchanger 71 and the concentrate heat exchanger 72 are connected to the reverse osmosis seawater desalination subsystem D.

[0098] The suitable operating temperature for seawater in the reverse osmosis seawater desalination subsystem D is 5-35℃. By utilizing the waste heat from the freshwater and concentrate produced by the first and second distillation units 31 and 32, the seawater is preheated to the optimal operating temperature for the reverse osmosis membrane of the subsystem D, where the membrane flux is at its best. This replaces the need for additional heating equipment, allowing for more efficient use of system heat energy, reduced costs, and smaller equipment size. It is particularly suitable for utilizing waste heat from seawater during winter or when ambient temperatures are low.

[0099] Specifically, the freshwater outlets of both the first distillation desalination unit 31 and the second distillation desalination unit 32 are connected to the freshwater heat exchanger 71 via the first freshwater pipeline 85a. The concentrated water outlets of both the first distillation desalination unit 31 and the second distillation desalination unit 32 are connected to the concentrated water heat exchanger 72 via the first concentrated water pipeline 86a.

[0100] More specifically, the first seawater pipeline 83a connects the seawater inlets of the freshwater heat exchanger 71 and the concentrate heat exchanger 72 to introduce seawater into them. The freshwater outlet of the freshwater heat exchanger 71 discharges freshwater through the third freshwater pipeline 85c. The concentrate outlet of the concentrate heat exchanger 72 discharges concentrate through the third concentrate pipeline 86d. The seawater outlets of both the freshwater heat exchanger 71 and the concentrate heat exchanger 72 are connected to the permeate seawater desalination subsystem D through the second seawater pipeline 83b to introduce preheated seawater into the permeate seawater desalination subsystem D.

[0101] Furthermore, both the first distillation desalination unit 31 and the second distillation desalination unit 32 are single-effect or multi-effect distillation desalination units. The single-effect distillation desalination unit includes an evaporator, which acts as a heat pump condenser, supplying higher-temperature heat energy to the seawater to cause it to evaporate.

[0102] Preferably, both the first distillation desalination unit 31 and the second distillation desalination unit 32 are multi-effect distillation desalination units, and the seawater distillation desalination subsystem C further includes a heat pump recovery module. The steam outlets of both the first distillation desalination unit 31 and the second distillation desalination unit 32 are connected to the heat pump recovery module.

[0103] The multi-effect distillation desalination device includes multiple evaporators. The first-effect evaporator acts as a heat pump condenser, supplying high-temperature heat energy to the seawater to make it evaporate. The steam generated by the first-effect evaporator is then transported to the second-effect evaporator as a heat source for the evaporator. In the second-effect evaporator, the steam is condensed into fresh water while the circulating seawater in that effect is evaporated. This process continues, with each effect connected to the next. The secondary steam generated in the last effect enters the heat pump recovery module, which then transfers heat to the heat pump recovery module to form a cycle.

[0104] Specifically, the secondary steam generated at the end of the first distillation desalination unit 31 and the second distillation desalination unit 32 enters the heat pump recovery module through the steam outlet and exchanges heat with the S-CO2 in the heat pump recovery module. The secondary steam in the heat pump recovery module condenses to form fresh water, and the S-CO2 in the heat pump recovery module, after absorbing heat, desalinates the seawater and exchanges heat with the secondary steam again.

[0105] By setting up a heat pump recovery module, the heat of the secondary water vapor generated at the end of the first distillation and desalination unit 31 and the second distillation and desalination unit 32 can be recovered to distill seawater and desalinate it, thereby further improving the utilization rate of waste heat from dry quenching. Moreover, the seawater desalination process does not use water cooling, resulting in significant water saving.

[0106] Specifically, the heat pump recovery module includes a third distillation desalination unit 33, a throttle valve 34, a condenser 35, and a first compressor 36.

[0107] The third distillation and desalination unit 33 is a multi-effect distillation and desalination unit.

[0108] The steam outlets of the first distillation desalination unit 31, the second distillation desalination unit 32, and the third distillation desalination unit 33 are all connected to the condenser 35. The secondary steam generated at the end of the process by the first distillation desalination unit 31, the second distillation desalination unit 32, and the third distillation desalination unit 33 enters the condenser 35 through the steam outlet and exchanges heat with S-CO2. The secondary steam in the condenser 35 condenses to form fresh water.

[0109] The S-CO2 gas outlet of the condenser 35 is connected to the first compressor 36, the S-CO2 gas outlet of the first compressor 36 is connected to the third distillation and desalination unit 33, and the S-CO2 gas outlet of the third distillation and desalination unit 33 is connected to the condenser 35 through a pipeline, on which a throttle valve 34 is installed.

[0110] The heat pump recovery module utilizes S-CO2 to extract the heat from the secondary steam generated at the end of the first distillation desalination unit 31, the second distillation desalination unit 32, and the third distillation desalination unit 33. The extracted S-CO2 is then used for exothermic distillation to desalinate seawater. Furthermore, the secondary steam can also be converted into fresh water after exothermic distillation, thereby improving the utilization rate of waste heat from dry quenching and increasing the output of seawater desalination.

[0111] Specifically, the steam outlets of the first distillation desalination unit 31, the second distillation desalination unit 32, and the third distillation desalination unit 33 are all connected to the condenser 35 via a secondary steam pipeline 84. The S-CO2 gas outlet of the condenser 35 is connected to the first compressor 36 via a fourth S-CO2 circuit 82h. The S-CO2 gas outlet of the first compressor 36 is connected to the third distillation desalination unit 33 via a fourth S-CO2 circuit 82i. The S-CO2 gas outlet of the third distillation desalination unit 33 is connected to the condenser 35 via a fourth S-CO2 pipeline 82g. A throttling valve 34 is installed on the fourth S-CO2 pipeline 82g.

[0112] Furthermore, this power generation and seawater desalination system also includes a first vacuum regulating valve 61, a second vacuum regulating valve 62, a third vacuum regulating valve 63, and a vacuum pump 64.

[0113] The first vacuum regulating valve 61 is installed on the first pressure regulating line connecting the first distillation and desalination device 31 and the vacuum pump 64. The second vacuum regulating valve 62 is installed on the second pressure regulating line connecting the second distillation and desalination device 32 and the vacuum pump 64. The third vacuum regulating valve 63 is installed on the third pressure regulating line connecting the third distillation and desalination device 33 and the vacuum pump 64. The first vacuum regulating valve 61, the second vacuum regulating valve 62, and the third vacuum regulating valve 63 respectively regulate the pressure in the first distillation and desalination device 31, the second distillation and desalination device 32, and the third distillation and desalination device 33 to suit different operating temperatures, and can be adjusted to negative or positive pressure, which is maintained by the vacuum pump 20.

[0114] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0115] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A power generation and seawater desalination system based on waste heat recovery from dry quenching coke oven gas, characterized in that, It includes a dry quenching furnace, a CO2 waste heat boiler (11), a first distillation desalination unit (31), a second distillation desalination unit (32), an S-CO2 power generation system (B), and a reverse osmosis seawater desalination subsystem (D); The inert gas outlet of the dry quenching furnace is connected to the CO2 waste heat boiler (11), which contains S-CO2; The inert gas outlet of the CO2 waste heat boiler (11) is connected to the first distillation desalination device (31), and the inert gas outlet of the first distillation desalination device (31) is connected to the dry quenching furnace. The S-CO2 gas outlet of the CO2 waste heat boiler (11) is connected to the S-CO2 power generation system (B) and the reverse osmosis seawater desalination subsystem (D); the S-CO2 gas outlet of the S-CO2 power generation system (B) is connected to the second distillation desalination device (32), the S-CO2 gas outlet of the second distillation desalination device (32) is connected to the S-CO2 power generation system (B), and the S-CO2 gas outlet of the S-CO2 power generation system (B) is connected to the CO2 waste heat boiler (11); the reverse osmosis seawater desalination subsystem (D) can convert the thermal energy of S-CO2 into pressure energy for pressurizing seawater, and can produce fresh water from the pressurized seawater through a reverse osmosis membrane.

2. The power generation and seawater desalination system based on dry quenching waste heat recovery as described in claim 1, characterized in that, It also includes a heat pump recovery module; Both the first distillation desalination device (31) and the second distillation desalination device (32) are multi-effect distillation desalination devices; The steam outlets of the first distillation desalination device (31) and the second distillation desalination device (32) are both connected to the heat pump recovery module; The secondary steam generated at the end of the first distillation desalination device (31) and the second distillation desalination device (32) enters the heat pump recovery module through the steam outlet and exchanges heat with the S-CO2 in the heat pump recovery module; the secondary steam in the heat pump recovery module condenses to form fresh water, and the S-CO2 in the heat pump recovery module, after absorbing heat, desalinates seawater by releasing heat and exchanges heat with the secondary steam again.

3. The power generation and seawater desalination system based on dry quenching waste heat recovery as described in claim 2, characterized in that, The heat pump recovery module includes a third distillation desalination device (33), a throttle valve (34), a condenser (35), and a first compressor (36). The third distillation desalination device (33) is a multi-effect distillation desalination device; The steam outlets of the first distillation desalination device (31), the second distillation desalination device (32), and the third distillation desalination device (33) are all connected to the condenser (35); the secondary steam generated at the end of the first distillation desalination device (31), the second distillation desalination device (32), and the third distillation desalination device (33) enters the condenser (35) through the steam outlet and exchanges heat with the S-CO2, and the secondary steam in the condenser (35) condenses to form the fresh water; The S-CO2 gas outlet of the condenser (35) is connected to the first compressor (36), the S-CO2 gas outlet of the first compressor (36) is connected to the third distillation desalination device (33), and the S-CO2 gas outlet of the third distillation desalination device (33) is connected to the condenser (35) through a pipeline, on which the throttle valve (34) is installed.

4. The power generation and seawater desalination system based on dry quenching waste heat recovery as described in claim 3, characterized in that, It also includes a first vacuum regulating valve (61), a second vacuum regulating valve (62), a third vacuum regulating valve (63), and a vacuum pump (64). The first vacuum regulating valve (61) is installed on the first pressure regulating pipeline connecting the first distillation and desalination device (31) and the vacuum pump (64); The second vacuum regulating valve (62) is installed on the second pressure regulating pipeline connecting the second distillation desalination device (32) and the vacuum pump (64); The third vacuum regulating valve (63) is installed on the third pressure regulating pipeline connecting the third distillation and desalination device (33) and the vacuum pump (64).

5. The power generation and seawater desalination system based on dry quenching waste heat recovery as described in claim 1, characterized in that, It also includes a freshwater heat exchanger (71) and a concentrated water heat exchanger (72); The freshwater outlets of the first distillation desalination device (31) and the second distillation desalination device (32) are both connected to the freshwater heat exchanger (71); the freshwater in the freshwater heat exchanger (71) heats the seawater. The concentrated water outlets of the first distillation desalination device (31) and the second distillation desalination device (32) are both connected to the concentrated water heat exchanger (72); the concentrated water in the concentrated water heat exchanger (72) heats the seawater; The seawater outlets of both the freshwater heat exchanger (71) and the concentrated water heat exchanger (72) are connected to the reverse osmosis seawater desalination subsystem (D).

6. The power generation and seawater desalination system based on dry quenching waste heat recovery as described in claim 1, characterized in that, The reverse osmosis seawater desalination subsystem (D) includes a first S-CO2 turbine (51), a high-pressure pump (52), and a reverse osmosis desalination membrane separation device (54). The S-CO2 gas outlet of the CO2 waste heat boiler (11) is connected to the first S-CO2 turbine (51), the S-CO2 turbine is connected to the high-pressure pump (52), and the high-pressure pump (52) is installed on the seawater inlet pipe connected to the reverse osmosis desalination membrane separation device (54). The S-CO2 entering the S-CO2 turbine drives the S-CO2 turbine to rotate, thereby driving the high-pressure pump (52) to pressurize the seawater in the seawater inlet pipe. The pressurized seawater enters the reverse osmosis desalination membrane separation device (54) and is processed into fresh water through the reverse osmosis membrane.

7. The power generation and seawater desalination system based on dry quenching waste heat recovery as described in claim 6, characterized in that, The reverse osmosis seawater desalination subsystem (D) also includes an energy recovery device (53); The concentrate outlet of the reverse osmosis desalination membrane separation device (54) is connected to the energy recovery device (53), which is used to collect the pressure energy of the concentrate discharged from the reverse osmosis desalination membrane separation device (54).

8. The power generation and seawater desalination system based on dry quenching waste heat recovery as described in claim 1, characterized in that, The S-CO2 power generation system (B) includes a second S-CO2 turbine (21) and a generator (22) connected to the second S-CO2 turbine (21); the S-CO2 gas outlet of the CO2 waste heat boiler (11) is connected to the second S-CO2 turbine (21), and the S-CO2 gas outlet of the second S-CO2 turbine (21) is connected to the second distillation desalination unit (32). After absorbing heat, the S-CO2 enters the second S-CO2 turbine (21) to drive the second S-CO2 turbine (21) to rotate, thereby driving the generator (22) to generate electricity.

9. The power generation and seawater desalination system based on dry quenching waste heat recovery as described in claim 8, characterized in that, The S-CO2 power generation system (B) also includes a regenerator (23) and a second compressor (24); The S-CO2 gas outlet of the second S-CO2 turbine (21) is connected to the regenerator (23), and the S-CO2 discharged by the second S-CO2 turbine (21) enters the regenerator (23) to release heat; the S-CO2 gas outlet of the regenerator (23) is connected to the second distillation desalination device (32), and the S-CO2 after releasing heat enters the second distillation desalination device (32) to release heat to desalinate seawater; the S-CO2 gas outlet of the second distillation desalination device (32) is connected to the second compressor (24), the S-CO2 gas outlet of the second compressor (24) is connected to the regenerator (23), and the S-CO2 gas outlet of the regenerator (23) is connected to the CO2 waste heat boiler (11).

10. A power generation and seawater desalination method based on a dry quenching waste heat recovery system as described in any one of claims 1-9, characterized in that, Includes the following steps: S1: The inert gas that has absorbed the heat of the red-hot coke in the dry quenching furnace enters the CO2 waste heat boiler (11) to exchange heat with S-CO2; S2: The inert gas that has released heat in the CO2 waste heat boiler (11) enters the first distillation desalination device (31) through the inert gas outlet of the CO2 waste heat boiler (11) to release heat, so that the seawater absorbs heat, evaporates and condenses into fresh water; the inert gas that has released heat enters the dry quenching furnace through the inert gas outlet of the first distillation desalination device (31) to absorb heat again. S2: A portion of the S-CO2 after absorbing heat in the CO2 waste heat boiler (11) enters the S-CO2 power generation system (B) through the CO2 gas outlet of the CO2 waste heat boiler (11), converting the thermal energy of the S-CO2 into electrical energy; the S-CO2 after doing work and releasing heat enters the second distillation desalination device (32) through the CO2 gas outlet of the S-CO2 power generation system (B) to release heat, so that seawater absorbs heat, evaporates and condenses into fresh water; the S-CO2 after releasing heat enters the S-CO2 power generation system (B) through the S-CO2 gas outlet of the second distillation desalination device (32) to be heated and pressurized, and then enters the CO2 waste heat boiler (11) again through the S-CO2 gas outlet of the S-CO2 power generation system (B) to absorb heat again; Another portion of the S-CO2 after heat absorption in the CO2 waste heat boiler (11) enters the reverse osmosis seawater desalination subsystem (D) through the CO2 gas outlet of the CO2 waste heat boiler (11). The reverse osmosis seawater desalination subsystem (D) can convert the thermal energy of the S-CO2 into pressure energy to pressurize seawater, and can produce fresh water from the pressurized seawater through a reverse osmosis membrane.

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