CO2-based power generation, refrigeration and hot steam supply system and use method thereof

Abstract

According to the power generation, refrigeration and hot steam supply system based on CO2, steam is generated by recycling waste heat of high-temperature CO2 behind a turbine, the function of a refrigeration compressor is achieved through an ejector, meanwhile, a separator is introduced into a refrigeration system to separate non-condensable impurity gas, and therefore the purity of CO2 is improved; steam generated in the steam generator flows to a steam user, and chilled water generated in the CO2 evaporator is used for cold supply. The CO2 power generation cycle and the refrigeration cycle are deeply coupled through the ejector, high-temperature CO2 is used for preparing steam to achieve heat supply, power is provided for the refrigeration cycle, the comprehensive utilization rate of system energy is increased, and the operation cost can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power engineering and engineering thermal physics, and is specifically a method based on CO 2 Power generation, refrigeration and hot steam supply system and use method thereof. Background Art

[0002] Currently, CO 2 As a natural working fluid, it has been widely used in power generation, refrigeration and heating. 2 The system has the advantages of high power generation efficiency and small size, and is regarded as a power generation technology that can replace the steam Rankine cycle in the future. However, in existing thermal power plants, the supply of high-temperature and high-pressure steam is often achieved by directly extracting steam from the steam turbine, which is not suitable for CO 2 It is difficult to directly implement in power generation systems. 2 The refrigeration system has been verified by engineering, and academia and industry have proposed a variety of CO 2 Refrigeration system.

[0003] Comparative document CN110486968B discloses a method based on CO 2 The cooling and power cogeneration system with supercritical CO 2 Brayton cycle power generation system, transcritical CO 2 Cyclic refrigeration system. The CO of the supercritical Brayton cycle and the transcritical refrigeration cycle in the present invention 2 At the high temperature inlet of the low temperature regenerator, it is mixed with high pressure and low temperature CO 2 Heat exchange, and in CO 2 The cooler is cooled to the near-critical region and divided into two parts, one part CO 2 The compressor of the supercritical Brayton cycle system increases the pressure, and absorbs heat in the regenerator and heater to generate high-temperature and high-pressure CO 2 , and generates electricity in the expander; the other part of CO 2 The liquid flowing into the cooler of the transcritical refrigeration cycle system continues to be cooled to a liquid state below the critical temperature, and then evaporates and cools in the evaporator through the temperature and pressure reduction of the expansion valve. 2 The cooler converts supercritical CO 2 Cycle and transcritical CO 2 The cycle coupling realizes heat recovery and cooling heat rejection of the power generation system and refrigeration system. " However, in existing thermal power generation systems, steam comes from steam extraction from steam turbines, while in CO 2 How to generate steam in power generation system has not been solved; CO 2 In the system of power generation and refrigeration coupling, the refrigeration compressor still needs to boost the pressure, which consumes a lot of power. How to use the high pressure of the power generation system to drive the CO2 The refrigeration cycle still needs to be solved; CO 2 Thermal systems inevitably incorporate N 2 , O 2 It is necessary to install a removal device to increase the CO 2 purity.

[0004] Therefore, a CO-based 2 A power generation, refrigeration and hot steam supply system and a method of using the same are provided to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to inject CO 2 The power generation cycle is deeply coupled with the refrigeration cycle, utilizing high temperature CO 2 The production of steam can realize heat supply and provide power for the refrigeration cycle, which not only improves the comprehensive utilization rate of system energy, but also greatly reduces the operating cost. 2 A power generation, refrigeration and hot steam supply system and a method of using the same are provided to solve the problems raised in the background technology.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a CO 2 Power generation, refrigeration and hot steam supply systems, including CO 2 The boiler outlet is connected to the turbine inlet; the turbine outlet is connected to the heat fluid side inlet of the regenerator, the heat fluid side outlet of the regenerator is connected to the heat fluid side inlet of the steam generator, the heat fluid side outlet of the steam generator is connected to the cooler inlet, the cooler outlet is divided into interface 1 and interface 2, the interface 1 is connected to the high pressure side of the ejector; the interface 2 is connected to the gas-liquid separator inlet, the gas-liquid separator outlet is connected to the CO 2 The reservoir inlet connection, the CO 2 The liquid storage tank outlet is connected to the evaporator inlet, the evaporator outlet is connected to the ejector low pressure side, the ejector outlet is connected to the compressor inlet, the compressor outlet is connected to the regenerator cold fluid side inlet, and the regenerator cold fluid side outlet is connected to the boiler inlet.

[0007] Preferably, the cold fluid side inlet of the steam generator is connected to a heating softened water source, and the cold fluid side outlet of the steam generator is connected to a steam user through a valve.

[0008] Preferably, the cooling medium side inlet of the evaporator is connected to a water source, and the cooling medium side outlet of the evaporator is a refrigerated water outlet.

[0009] Preferably, an exhaust valve for releasing non-condensable impurity gases is provided on one side of the gas-liquid separator.

[0010] Preferably, the CO of the boiler 2 The outlet temperature ranges from 500℃ to 650℃.

[0011] Preferably, a diverter valve is provided between the first interface and the high-pressure side of the injector, and a throttle valve is provided between the second interface and the gas-liquid separator.

[0012] Preferably, a first valve is provided on the pipeline between the boiler outlet and the turbine inlet, a second valve is provided on the pipeline between the turbine outlet and the hot fluid side inlet of the regenerator, a third valve is provided on the pipeline between the hot fluid side outlet of the regenerator and the hot fluid side inlet of the steam generator, a fourth valve is provided on the pipeline between the hot fluid side outlet of the steam generator and the cooler inlet, a fifth valve is provided on the pipeline between the compressor outlet and the cold fluid side inlet of the regenerator, a sixth valve is provided between the cold fluid side outlet of the regenerator and the boiler inlet, and the gas-liquid separator outlet is connected to the CO 2 A seventh valve is provided on the pipeline between the liquid storage tank inlet and the CO 2 An eighth valve is arranged on the pipeline between the outlet of the liquid storage tank and the inlet of the evaporator.

[0013] Preferably, a first air valve is provided on the pipeline between the evaporator outlet and the low-pressure side of the ejector, and a second air valve is provided on the pipeline between the ejector outlet and the compressor inlet.

[0014] In addition, the present invention also discloses a method based on CO 2 The method for using the power generation, refrigeration and hot steam supply system includes the following processes: S1: CO 2 After the boiler is heated up, it enters the turbine through the first valve, and the high-temperature CO 2 Drive the turbine to generate electricity; S2: Turbine outlet CO 2 Entering the regenerator through the second valve, high temperature CO 2 From the hot fluid side to the cold fluid side of the regenerator, CO 2 Release heat; S3: Through the third valve, the heat exchanger hot fluid outlet CO 2 Entering the steam generator to release heat to the heating softened water; S4: Through the fourth valve, CO 2 Entering the cooler, after cooling, the output forms two streams of CO 2 ; S5: One CO 2 As the high-pressure fluid enters the high-pressure inlet of the injector from interface 1 through the diverter valve, the other CO 2After passing through the throttle valve from interface 2, the pressure and temperature are reduced in the gas-liquid separator to form gas-liquid two-phase. The non-condensable gas can be discharged through the exhaust valve in the gas-liquid separator. 2 Then CO flows in through the seventh valve 2 Fluid storage tank; S6: Through the eighth valve, CO 2 Liquid CO at the outlet of the storage tank 2 After entering the evaporator, it absorbs heat in the evaporator and evaporates into gas, generating cold at the same time; S7: After the first gas valve, the evaporated CO 2 Flowing into the low-pressure inlet of the ejector, it is 2 Injection pressurization, thereby mixing to form medium-pressure CO 2 ; S8: Medium pressure CO 2 After being pressurized by the compressor, the CO enters the cold fluid side and the hot fluid side of the regenerator. 2 Heat exchange; S9: Through the sixth valve, CO 2 The cold fluid side outlet of the regenerator flows back into the boiler, completing the entire power generation cycle.

[0015] Furthermore, in S3, the softened water absorbs heat in the steam generator to generate steam, and the generated steam flows to the steam user, and the chilled water generated in the evaporator in S6 is used for cooling supply.

[0016] The present invention has the following beneficial effects: 1. The present invention utilizes CO 2 The waste heat from the power generation cycle generates hot steam, which is then used to complete the CO 2 Refrigeration, using turbine post-CO 2 Pressure injection refrigeration CO 2 , not only realizes the supply of a variety of energy products, but also improves the energy utilization efficiency of the system; 2. The present invention is in CO 2 The gas-liquid separator is cleverly introduced into the refrigeration system to remove the non-condensable gas in the system, which can greatly improve the CO 2 purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the connection of the circulation system of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: See also Figure 1 , a CO-based 2 Power generation, refrigeration and hot steam supply systems, including CO 2The boiler 1 is connected to the inlet of the turbine 3; the outlet of the turbine 3 is connected to the inlet of the heat fluid side of the regenerator 5; the outlet of the heat fluid side of the regenerator 5 is connected to the inlet of the heat fluid side of the steam generator 7; the outlet of the heat fluid side of the steam generator 7 is connected to the inlet of the cooler 9; the outlet of the cooler 9 is divided into an interface 1 9.1 and an interface 2 9.2; the interface 1 9.1 is connected to the high pressure side of the ejector 11; the interface 2 9.2 is connected to the inlet of the gas-liquid separator 17; the outlet of the gas-liquid separator 17 is connected to the CO 2 The inlet of the liquid storage tank 19 is connected to the CO 2 The outlet of the liquid storage tank 19 is connected to the inlet of the evaporator 21, the outlet of the evaporator 21 is connected to the low-pressure side of the ejector 11, the outlet of the ejector 11 is connected to the inlet of the compressor 13, the outlet of the compressor 13 is connected to the inlet of the cold fluid side of the regenerator 5, and the outlet of the cold fluid side of the regenerator 5 is connected to the inlet of the boiler 1.

[0019] Preferably, the cold fluid side inlet of the steam generator 7 is connected to a heating softened water source, and the cold fluid side outlet of the steam generator 7 is connected to a steam user 25 through a valve 24 .

[0020] Preferably, the cooling medium side inlet of the evaporator 21 is connected to a water source, and the cooling medium side outlet of the evaporator 21 is a refrigerated water outlet.

[0021] Preferably, an exhaust valve 23 for releasing non-condensable impurity gases is provided on one side of the gas-liquid separator 17. 2 When the concentration is low, the exhaust valve 23 can be opened to discharge the non-condensable gas to increase the CO 2 purity.

[0022] Preferably, the CO of the boiler 1 2 The outlet temperature ranges from 500℃ to 650℃.

[0023] Preferably, a diverter valve 10 is provided between the first interface 9.1 and the high-pressure side of the ejector 11, and a throttle valve 16 is provided between the second interface 9.2 and the gas-liquid separator 17.

[0024] Preferably, a first valve 2 is provided on the pipeline between the outlet of the boiler 1 and the inlet of the turbine 3, a second valve 4 is provided on the pipeline between the outlet of the turbine 3 and the inlet of the hot fluid side of the regenerator 5, a third valve 6 is provided on the pipeline between the outlet of the hot fluid side of the regenerator 5 and the inlet of the hot fluid side of the steam generator 7, a fourth valve 8 is provided on the pipeline between the outlet of the hot fluid side of the steam generator 7 and the inlet of the cooler 9, a fifth valve 14 is provided on the pipeline between the outlet of the compressor 13 and the inlet of the cold fluid side of the regenerator 5, a sixth valve 15 is provided between the outlet of the cold fluid side of the regenerator 5 and the inlet of the boiler 1, and the outlet of the gas-liquid separator 17 is connected to the CO 2A seventh valve 18 is provided on the pipeline between the inlet and outlet of the liquid storage tank 19. 2 An eighth valve 20 is provided on the pipeline between the outlet of the liquid storage tank 19 and the inlet of the evaporator 21 .

[0025] Preferably, a first air valve 22 is provided on the pipeline between the outlet of the evaporator 21 and the low-pressure side of the ejector 11 , and a second air valve 12 is provided on the pipeline between the outlet of the ejector 11 and the inlet of the compressor 13 .

[0026] In addition, the present invention also discloses a method based on CO 2 The method for using the power generation, refrigeration and hot steam supply system includes the following processes: S1: CO 2 After being heated in boiler 1, it enters turbine 3 through first valve 2, and the high temperature CO 2 Drive turbine 3 to generate power; S2: Turbine 3 outlet CO 2 Entering the regenerator 5 through the second valve 4, the high temperature CO 2 In the regenerator 5, the hot fluid side is transferred to the cold fluid side CO 2 Release heat; S3: Through the third valve 6, the hot fluid outlet CO of the regenerator 5 2 Entering the steam generator 7 to release heat to the heating softened water; S4: Through the fourth valve 8, CO 2 Entering cooler 9, after cooling, the output forms two streams of CO 2 ; S5: One CO 2 As the high-pressure fluid enters the high-pressure inlet of the injector 11 through the diverter valve 10 from the interface 1, the other CO 2 From the interface 2 9.2, after passing through the throttle valve 16, the pressure and temperature are reduced in the gas-liquid separator 17 to form gas-liquid two-phase. The non-condensable gas can be discharged through the exhaust valve 23 in the gas-liquid separator 17. 2 Then CO flows in through the seventh valve 18 2 Liquid storage tank 19; S6: Through the eighth valve 20, CO 2 Liquid CO at the outlet of liquid storage tank 19 2 After entering the evaporator 21, it absorbs heat in the evaporator 21 and evaporates into gas, generating cold energy at the same time; S7: The evaporated CO passes through the first gas valve 22. 2 Flowing into the low-pressure inlet of the ejector 11, the high-pressure CO 2 Injection pressurization, thereby mixing to form medium-pressure CO 2 ; S8: Medium pressure CO 2After being pressurized by compressor 13, CO enters the cold fluid side and the hot fluid side of regenerator 5. 2 Heat exchange; S9: Through the sixth valve 15, CO 2 The cold fluid flows back into the boiler 1 from the outlet of the regenerator 5, completing the whole power generation cycle.

[0027] Furthermore, in S3, the softened water absorbs heat in the steam generator 7 to generate steam, and the generated steam flows to the steam user, and the chilled water generated in the evaporator 21 in S6 is used for cooling supply.

[0028] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A CO2-based power generation, refrigeration and hot steam supply system, comprising a boiler (1) filled with CO2, characterized in that: The outlet of the boiler (1) is connected to the inlet of the turbine (3); the outlet of the turbine (3) is connected to the inlet of the heat fluid side of the regenerator (5); the outlet of the heat fluid side of the regenerator (5) is connected to the inlet of the heat fluid side of the steam generator (7); the outlet of the heat fluid side of the steam generator (7) is connected to the inlet of the cooler (9); the outlet of the cooler (9) is divided into an interface 1 (9.1) and an interface 2 (9.2); the interface 1 (9.1) is connected to the high pressure side of the ejector (11); the interface 2 (9.2) is connected to the high pressure side of the ejector (11); The inlet of the gas-liquid separator (17) is connected, the outlet of the gas-liquid separator (17) is connected to the inlet of the CO2 liquid storage tank (19), the outlet of the CO2 liquid storage tank (19) is connected to the inlet of the evaporator (21), the outlet of the evaporator (21) is connected to the low-pressure side of the ejector (11), the outlet of the ejector (11) is connected to the inlet of the compressor (13), the outlet of the compressor (13) is connected to the inlet of the cold fluid side of the regenerator (5), and the outlet of the cold fluid side of the regenerator (5) is connected to the inlet of the boiler (1).

2. A CO2-based power generation, refrigeration and hot steam supply system according to claim 1, characterized in that: The cold fluid side inlet of the steam generator (7) is connected to a heating softened water source, and the cold fluid side outlet of the steam generator (7) is connected to a steam user (25) via a valve (24).

3. A CO2-based power generation, refrigeration and hot steam supply system according to claim 1, characterized in that: The cooling medium side inlet of the evaporator (21) is connected to a water source, and the cooling medium side outlet of the evaporator (21) is a refrigerated water outlet.

4. A CO2-based power generation, refrigeration and hot steam supply system according to claim 1, characterized in that: An exhaust valve (23) for releasing non-condensable impurity gas is provided on one side of the gas-liquid separator (17).

5. A CO2-based power generation, refrigeration and hot steam supply system according to claim 1, characterized in that: The CO2 outlet temperature of the boiler (1) is in the range of 500°C to 650°C.

6. A CO2-based power generation, refrigeration and hot steam supply system according to claim 1, characterized in that: A flow divider valve (10) is provided between the first interface (9.1) and the high-pressure side of the ejector (11), and a throttle valve (16) is provided between the second interface (9.2) and the gas-liquid separator (17).

7. A CO2-based power generation, refrigeration and hot steam supply system according to claim 1, characterized in that: A first valve (2) is provided on the pipeline between the outlet of the boiler (1) and the inlet of the turbine (3); a second valve (4) is provided on the pipeline between the outlet of the turbine (3) and the inlet of the hot fluid side of the regenerator (5); a third valve (6) is provided on the pipeline between the outlet of the hot fluid side of the regenerator (5) and the inlet of the hot fluid side of the steam generator (7); a fourth valve (8) is provided on the pipeline between the outlet of the hot fluid side of the steam generator (7) and the inlet of the cooler (9); a fifth valve (14) is provided on the pipeline between the outlet of the compressor (13) and the inlet of the cold fluid side of the regenerator (5); a sixth valve (15) is provided between the outlet of the cold fluid side of the regenerator (5) and the inlet of the boiler (1); a seventh valve (18) is provided on the pipeline between the outlet of the gas-liquid separator (17) and the inlet of the CO2 liquid storage tank (19); and an eighth valve (20) is provided on the pipeline between the outlet of the CO2 liquid storage tank (19) and the inlet of the evaporator (21).

8. A CO2-based power generation, refrigeration and hot steam supply system according to claim 1, characterized in that: A first air valve (22) is provided on the pipeline between the outlet of the evaporator (21) and the low-pressure side of the ejector (11), and a second air valve (12) is provided on the pipeline between the outlet of the ejector (11) and the inlet of the compressor (13).

9. A method for using a CO2-based power generation, refrigeration and hot steam supply system according to any one of claims 1 to 8, characterized in that: It includes the following processes: S1: After being heated in the boiler (1), CO2 enters the turbine (3) through the first valve (2). The high-temperature CO2 drives the turbine (3) to generate electricity; S2: CO2 at the outlet of the turbine (3) enters the regenerator (5) through the second valve (4), and the high-temperature CO2 releases heat to the CO2 on the cold fluid side of the regenerator (5); S3: Through the third valve (6), the hot fluid outlet CO2 of the regenerator (5) enters the steam generator (7) to release heat to the heating softened water; S4: CO2 enters the cooler (9) through the fourth valve (8), and after cooling, is output to form two streams of CO2; S5: One stream of CO2 as a high-pressure fluid enters the high-pressure inlet of the ejector (11) from the first interface (9.1) through the diverter valve (10), and the other stream of CO2 enters the second interface (9.2) through the throttle valve (16) and is then reduced in pressure and temperature in the gas-liquid separator (17) to form a gas-liquid two-phase system. The non-condensable gas can be discharged from the gas-liquid separator (17) through the exhaust valve (23), and the CO2 flows into the CO2 storage tank (19) through the seventh valve (18); S6: After the liquid CO2 at the outlet of the CO2 storage tank (19) enters the evaporator (21) through the eighth valve (20), it absorbs heat in the evaporator (21) and evaporates into gas, while generating cold energy; S7: The evaporated CO2 flows into the low-pressure inlet of the ejector (11) through the first gas valve (22), and is injected and pressurized by the high-pressure CO2, thereby mixing to form medium-pressure CO2; S8: The medium-pressure CO2 is pressurized by the compressor (13) and enters the regenerator (5) to exchange heat between the CO2 on the cold fluid side and the CO2 on the hot fluid side; S9: CO2 flows back into the boiler (1) from the outlet on the cold fluid side of the regenerator (5) through the sixth valve (15), completing the entire power generation cycle.

10. The method for using a CO2-based power generation, refrigeration and hot steam supply system according to claim 9, characterized in that: In S3, the softened water absorbs heat in the steam generator (7) to generate steam, and the generated steam flows to the steam user. The chilled water generated in the evaporator (21) in S6 is used for cold supply.

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