Cold power station

Abstract

The invention relates to a cold power generation station, energy is stored by using liquefied gas produced by an air separation device, cold power generation is carried out by using the energy-stored liquefied gas, the energy storage type cold power generation station efficiently absorbs photovoltaic power and wind power or is used for valley shifting and peak filling of a power system, and the power station further has combined cooling and power supply capacity. And liquid oxygen, liquid nitrogen or high-purity nitrogen can be produced as a byproduct, and the expected social and economic benefits are obvious.

Description

Technical Field

[0001] The invention relates to a cold power plant, in particular to a cold power plant adopting air separation liquefied gas energy storage technology. Background Art

[0002] On September 22, 2020, my country formally proposed at the 75th United Nations General Assembly: strive to peak carbon dioxide emissions before 2030. Energy storage will participate as a core link and is an important guarantee for maintaining the stability of the power system.

[0003] Since photovoltaic and wind power generation are random and intermittent, and electricity has the characteristics of real-time balance of supply and demand and is difficult to store on a large scale, the large-scale grid-connected photovoltaic and wind power generation will aggravate the dual volatility and uncertainty on both the supply and demand sides of the power system, making system peak regulation difficult and bringing about a series of problems such as abandoned solar and wind power. Energy storage can smooth out the instability of photovoltaic and wind power generation and achieve a dynamic balance of electricity supply and demand.

[0004] In July 2024, the demand for electricity in the summer was strong, and the peak-valley electricity price difference continued to widen. In 17 provinces and regions, the peak-valley electricity price difference exceeded 0.7 yuan / kWh. The economic benefits of industrial and commercial energy storage projects were highlighted, and the economic benefits of peak-valley arbitrage were significantly improved. Even in the spring when electricity demand was relatively stable, in March there were still 16 regions with a peak-valley electricity price difference of more than 0.7 yuan / kWh, which effectively ensured the profitability stability of peak-valley arbitrage of industrial and commercial energy storage systems throughout the year.

[0005] The new energy power supply system will face problems such as mismatch between power supply and demand, and energy storage, virtual power plants, microgrids and other regulation methods are indispensable. Electricity is a dynamic process energy that is not easy to store. It is mainly achieved through the power grid to achieve simultaneous production, transmission and consumption. The role of new energy storage in promoting the development and consumption of new energy and the safe and stable operation of the power system is gradually emerging.

[0006] Liquid air energy storage (LAES) is a new type of energy storage technology that stores energy by liquefying air. This technology uses the "compression-expansion" process of air to cool the compressed air to a liquid state for storage, completing the conversion of electrical energy and pressure energy. Compared with traditional compressed air energy storage systems (CAES), liquefied air energy storage technology realizes the storage of electrical energy in the form of liquid air. In addition to the many application advantages of compressed air energy storage technology, this technology does not require large pressure storage containers, thus getting rid of the restrictions on its site selection and construction due to factors such as geographical location. The energy storage density of this method is 10 to 40 times that of compressed air energy storage. It can store more energy in smaller containers, is not restricted by geographical conditions, and has more flexible site selection.

[0007] Chinese patents such as 201210266701.0-High-pressure liquid air energy storage and release system, 201210266535.4-High-efficiency high-pressure liquid air energy storage and release system, etc., have conducted in-depth research on liquid compressed air energy storage (LAES) technology.

[0008] The key equipment of LAES technology, such as compressors, high-pressure gas storage tanks, cryogenic expanders, liquid pumps, expansion generators and other domestic equipment, has been relatively mature, and the industrial chain is mature. As the capacity of the energy storage system increases, the cost will tend to decrease, and it is expected that LAES technology will usher in a broader application prospect in the future.

[0009] Therefore, the liquid gas cooling power generation in LAES, the high-pressure and low-temperature gas phase fluid cooling power generation, and the low-pressure and low-temperature air energy storage cooling power generation technology are worthy of in-depth study. Summary of the invention

[0010] The purpose of the present invention is to provide an energy storage type cold power station, the cold power station is implemented as follows: When storing energy: The liquid gas in the low-pressure liquid storage tank 3 is used for energy storage, or the liquid gas in the low-pressure liquid storage tank 3 is pressurized by the high-pressure pump 4 and then enters the high-pressure liquid storage tank 5 for energy storage; When releasing energy: The liquid gas in the low-pressure liquid storage tank 3 or the high-pressure liquid storage tank 5 is discharged after passing through the first low-boiling-point working medium condenser 8, the gas turbine 20, and the second low-boiling-point working medium condenser 15. The first low-boiling-point working medium condenser 8 absorbs the cold released by the transported liquid gas, liquefies the gaseous low-temperature and low-boiling-point working medium separated by the gas-liquid separator 28, and the low-boiling-point working medium liquid enters the low-boiling-point working medium buffer tank 9. The high-temperature gaseous low-boiling-point working medium 14 discharged from the low-boiling-point working medium expander 12 is cooled by the No. 2 low-boiling-point working medium condenser 15, and the formed gas-liquid mixture enters the gas-liquid separator 28. The gaseous low-temperature low-boiling-point working medium separated by the gas-liquid separator 28 enters the No. 1 low-boiling-point working medium condenser 8, and the liquid separated by the gas-liquid separator 28 enters the low-boiling-point working medium buffer tank 9. The liquid low-boiling-point working medium in the low-boiling-point working medium buffer tank 9 is gasified by the low-boiling-point working medium circulation pump 10 and the low-boiling-point working medium evaporator 11, and the formed gaseous low-boiling-point working medium enters the low-boiling-point working medium expander 12 to expand and do work, driving the low-boiling-point working medium generator 13 to generate electricity, and the high-temperature gaseous low-boiling-point working medium 14 discharged from the low-boiling-point working medium generator 13 enters the second low-boiling-point working medium condenser 15 to absorb cold energy, and the formed gas-liquid mixture enters the gas-liquid separator 28, thereby forming a low-boiling-point working medium Rankine cycle loop; The high-pressure, low-temperature gas 19 coming out of the No. 1 low-boiling-point working fluid condenser 8 enters the gas turbine 20 to expand and do work, driving the gas turbine generator 21 to generate electricity. The low-pressure, low-temperature gas 24 discharged from the gas turbine 20 enters the No. 2 low-boiling-point working fluid condenser 15 to release the cold and then is discharged to become gaseous exhaust gas 16. The gaseous exhaust gas 16 can be used as a cold source for cold storage or air-conditioning systems.

[0011] The liquid gas is liquid air, liquid nitrogen, liquid oxygen, liquid argon, liquid oxygen-enriched air or liquid nitrogen-enriched air.

[0012] A gas liquefaction unit 2 is provided: air is passed through the air liquefaction unit 2 to produce liquid gas, which is sent to the low-pressure liquid storage tank 3 for energy storage; or air is passed through the air liquefaction unit 2 to produce liquid gas, which is sent to the low-pressure liquid storage tank 3, and the liquid gas in the low-pressure liquid storage tank 3 is pressurized by a high-pressure pump 4 and then enters the high-pressure liquid storage tank 5 for energy storage.

[0013] The air liquefaction unit 2 adopts the known air separation or oxygen generator principle, air compression liquefaction principle (such as distillation, etc.) to perform air liquefaction operation, such as 201310030247.3-An air separation device for isobaric separation of air to produce oxygen and nitrogen, 201310030923.7-An air separation device for isobaric separation of oxygen and nitrogen, etc., which provide a technical approach to produce liquid air. The air liquefaction unit 2 includes air compression and cooling processes, as well as air purification and purification processes.

[0014] The low-boiling-point working fluid in the above-mentioned low-boiling-point working fluid Rankine cycle loop has a boiling point of less than -10°C under standard atmospheric pressure. The low-boiling-point working fluid is a single-component or multi-component low-boiling-point medium, such as 201310029379.4-Steam Rankine-low-boiling-point working fluid Rankine combined cycle power generation device, 201310029377.5-Extraction type steam Rankine-low-boiling-point working fluid Rankine combined cycle power generation device, etc., which provides further description of the low-boiling-point working fluid.

[0015] The heating medium of the low-boiling-point working medium evaporator 11, such as the heat medium 17, can be selected from air or water at room temperature, a cooling medium of a cold storage, waste heat, etc. The liquid low-boiling-point working medium is heated in the low-boiling-point working medium evaporator 11 to vaporize the liquid low-boiling-point working medium. The cold medium 18 with a reduced temperature coming out of the low-boiling-point working medium evaporator 11 can be used as a cold source to supply cold to a cold storage or a cold energy seawater desalination system, etc.

[0016] A distillation unit is provided: the liquid gas coming out of the low-pressure liquid storage tank 3 enters the distillation unit after being pressurized by a hydraulic pump, and produces liquid oxygen and gaseous nitrogen output; A liquefaction unit is provided: the gaseous nitrogen produced from the distillation unit is passed through the liquefaction unit to produce liquid nitrogen.

[0017] The distillation unit is designed, installed and operated with reference to the distillation tower of the air separation device.

[0018] The liquefaction unit is realized by using a conventional compression refrigeration process or a low-temperature expansion machine process.

[0019] A low-pressure self-boosting device 25 is provided: one end of the low-pressure self-boosting device 25 is connected to the bottom liquid side of the low-pressure liquid storage tank 3 through a pipeline, and the other end is connected to the top gas side of the low-pressure liquid storage tank 3 through a pipeline; when the low-pressure and low-temperature liquid gas stored in the low-pressure liquid storage tank 3 releases energy, the pressure in the low-pressure liquid storage tank 3 decreases, and the low-pressure and low-temperature liquid gas in the low-pressure self-boosting device 25 is heated to be vaporized and enter the top gas space of the low-pressure liquid storage tank 3, thereby maintaining the pressure in the low-pressure liquid storage tank 3 stable.

[0020] A high-pressure self-boosting device 26 is provided: one end of the high-pressure self-boosting device 26 is connected to the bottom liquid side of the high-pressure liquid storage tank 5 through a pipeline, and the other end is connected to the top gas side of the high-pressure liquid storage tank 5 through a pipeline; when the high-pressure and low-temperature liquid gas stored in the high-pressure liquid storage tank 5 releases energy, the pressure in the high-pressure liquid storage tank 5 decreases, and the high-pressure and low-temperature liquid gas in the high-pressure self-boosting device 26 is heated to be vaporized and enter the top gas space of the high-pressure liquid storage tank 5, thereby maintaining the pressure in the high-pressure liquid storage tank 5 stable.

[0021] The low-pressure self-supercharger 25 or the high-pressure self-supercharger 26 is heated by ambient air, and a heater such as a metal coil or a finned tube may also be used. The heating medium preferably contains less water to avoid ice clogging of the heater due to improper operation.

[0022] When the high-pressure and low-temperature liquid gas in the high-pressure liquid storage tank 5 increases in pressure due to heat absorption, a pressure relief pipeline line 27 is provided: the gaseous gas discharged from the high-pressure liquid storage tank 5 enters the gas turbine 20 through the pressure relief valve 6 and the pressure relief pipeline 27 to expand and do work, and is discharged after recovering the cold energy.

[0023] The gas turbine 20 and the low-boiling-point working fluid expander 12 can be coaxially arranged, and in this case, the gas turbine generator 21 and the low-boiling-point working fluid generator 13 can be combined into a large generator.

[0024] A No. 1 recooling liquefier 7 is provided: the turbine exhaust gas 22 extracted from the gas turbine 20 absorbs the coldness of the liquid gas delivered from the high-pressure liquid storage tank 5 through the No. 1 recooling liquefier 7, and the generated liquid gas returns to the low-pressure liquid storage tank 3. The liquid gas delivered from the high-pressure liquid storage tank 5 enters the No. 1 low-boiling point working medium condenser 8 through the No. 1 recooling liquefier 7.

[0025] A No. 2 recooling liquefier 23 is provided: the turbine exhaust air 22 extracted from the gas turbine 20 absorbs the cold of the exhaust gas of the gas turbine 20 through the No. 2 recooling liquefier 23, and the generated low-pressure liquid gas returns to the low-pressure liquid storage tank 3, and the low-pressure and low-temperature gas 24 of the gas turbine 20 enters the No. 2 low-boiling-point working fluid condenser 15 through the No. 2 recooling liquefier 23.

[0026] Equipment and its systems, pipelines, instruments, valves, cold preservation, bypass facilities with regulating functions, etc. not described in the present invention are matched with reference to or in accordance with mature and reliable technologies in the well-known existing air separation processes.

[0027] The equipment and pipelines in the present invention adopt necessary heat recovery, cooling recovery, quality recovery and other measures.

[0028] Parts not mentioned in the present invention, such as safety accessories, automatic control, etc., are matched with existing well-known technologies, that is, existing mature, reliable and reasonable technical measures are applied to this device.

[0029] Compared with the prior art, the present invention has the following advantages: 1. Compared with the existing thermal power generation type compressed air energy storage power station, the present invention retains the advantages of the compressed air energy storage power station, and proposes a new energy storage type cold power station and its supporting optimization plan, which is a breakthrough in the traditional compressed air energy storage power generation technology. It can be used as a large energy storage power station and can also be used for carriers such as cars, ships or aircraft; 2. Compared with the prior art, the present invention can combine the characteristics of the energy storage type cold power station with abundant surplus cold energy, optimize with large cold storage, central air conditioning or the system using cold source for seawater desalination, or use it as the cold source of the regional centralized cooling system to realize the cogeneration of cold and electricity; 3. Compared with existing technologies, it can effectively absorb photovoltaic and wind power or be used for "shifting valleys and filling peaks" to optimize operation. The raw material is the extremely abundant source of ambient air, which is clean and environmentally friendly. It can also co-produce liquid oxygen, nitrogen and liquid nitrogen according to market demand, thereby improving the comprehensive advantages of cold power stations; 4. Compared with the existing technology, the gas turbine exhaust cooling liquefaction process is adopted, which matches the energy and quality and further optimizes the process settings; 5. The energy storage type cold power station of the present invention can be conveniently used as a distributed cold power station for use by people in wartime. As long as there is liquid air transported, the cold power generator set can be started using the backup power supply to provide power and cooling, and can provide high-quality air resources for breathing space in air defense facilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the process flow of a cold power station.

[0031] Figure 1In: 1-air, 2-air liquefaction unit, 3-low-pressure liquid storage tank, 4-high-pressure pump, 5-high-pressure liquid storage tank, 6-pressure relief valve, 7-No. 1 recooling liquefier, 8-No. 1 low-boiling-point working medium condenser, 9-low-boiling-point working medium buffer tank, 10-low-boiling-point working medium circulation pump, 11-low-boiling-point working medium evaporator, 12-low-boiling-point working medium expander, 13-low-boiling-point working medium generator, 14-high-temperature gaseous low-boiling-point working medium, 15-No. 2 low-boiling-point working medium condenser, 16-gaseous exhaust, 17-heat medium, 18-refrigerant, 19-high-pressure low-temperature gas, 20-gas turbine, 21-gas turbine generator, 22-gas turbine exhaust, 23-No. 2 recooling liquefier, 24-low-pressure low-temperature gas, 25-low-pressure self-boosting compressor, 26-high-pressure self-boosting compressor, 27-pressure relief pipeline, 28-gas-liquid separator. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Embodiment 1: like Figure 1 As shown, a cold power station, the implementation process of the power station is as follows: When storing energy: The air is passed through the air liquefaction unit 2 to produce liquid air, which is then sent to the low-pressure liquid storage tank 3. The liquid gas in the low-pressure liquid storage tank 3 is pressurized by the high-pressure pump 4 and then enters the high-pressure liquid storage tank 5 for energy storage. When releasing energy: The liquid air in the high-pressure liquid storage tank 5 is discharged after passing through the No. 1 low-boiling-point working medium condenser 8, the gas turbine 20, and the No. 2 low-boiling-point working medium condenser 15. The first low-boiling-point working medium condenser 8 absorbs the cold released by the delivered liquid air, liquefies the gaseous low-temperature and low-boiling-point working medium separated by the gas-liquid separator 28, and the low-boiling-point working medium liquid enters the low-boiling-point working medium buffer tank 9. The high-temperature gaseous low-boiling-point working medium 14 discharged from the low-boiling-point working medium expander 12 is cooled by the No. 2 low-boiling-point working medium condenser 15, and the formed gas-liquid mixture enters the gas-liquid separator 28. The gaseous low-temperature low-boiling-point working medium separated by the gas-liquid separator 28 enters the No. 1 low-boiling-point working medium condenser 8, and the liquid separated by the gas-liquid separator 28 enters the low-boiling-point working medium buffer tank 9. The liquid low-boiling-point working medium in the low-boiling-point working medium buffer tank 9 is gasified by the low-boiling-point working medium circulation pump 10 and the low-boiling-point working medium evaporator 11, and the formed gaseous low-boiling-point working medium enters the low-boiling-point working medium expander 12 to expand and do work, driving the low-boiling-point working medium generator 13 to generate electricity, and the high-temperature gaseous low-boiling-point working medium 14 discharged from the low-boiling-point working medium generator 13 enters the second low-boiling-point working medium condenser 15 to absorb cold energy, and the formed gas-liquid mixture enters the gas-liquid separator 28, thereby forming a low-boiling-point working medium Rankine cycle loop; The high-pressure, low-temperature gas 19 coming out of the No. 1 low-boiling-point working fluid condenser 8 enters the gas turbine 20 to expand and do work, driving the gas turbine generator 21 to generate electricity. The low-pressure, low-temperature gas 24 discharged from the gas turbine 20 enters the No. 2 low-boiling-point working fluid condenser 15 to release the cold and then is discharged to become gaseous exhaust gas 16. The gaseous exhaust gas 16 can be used as a cold source for cold storage or air-conditioning systems.

[0034] The air liquefaction unit 2 adopts the known air separation or oxygen generator principle, air compression liquefaction principle (such as distillation, etc.) to perform air liquefaction operation, such as 201310030247.3-An air separation device for isobaric separation of air to produce oxygen and nitrogen, 201310030923.7-An air separation device for isobaric separation of oxygen and nitrogen, etc., which provide a technical approach to produce liquid air. The air liquefaction unit 2 includes air compression and cooling processes, as well as air purification and purification processes.

[0035] The low-boiling-point working fluid in the above-mentioned low-boiling-point working fluid Rankine cycle loop has a boiling point of less than -10°C under standard atmospheric pressure. The low-boiling-point working fluid is a single-component or multi-component low-boiling-point medium, such as 201310029379.4-Steam Rankine-low-boiling-point working fluid Rankine combined cycle power generation device, 201310029377.5-Extraction type steam Rankine-low-boiling-point working fluid Rankine combined cycle power generation device, etc., which provides further description of the low-boiling-point working fluid.

[0036] The heating medium of the low-boiling-point working medium evaporator 11, such as the heat medium 17, can be selected from air or water at room temperature, a cooling medium of a cold storage, waste heat, etc. The liquid low-boiling-point working medium is heated in the low-boiling-point working medium evaporator 11 to vaporize the liquid low-boiling-point working medium. The cold medium 18 with a reduced temperature coming out of the low-boiling-point working medium evaporator 11 can be used as a cold source to supply cold to a cold storage or a cold energy seawater desalination system, etc.

[0037] A distillation unit is provided: the liquid gas coming out of the low-pressure liquid storage tank 3 enters the distillation unit after being pressurized by a hydraulic pump, and produces liquid oxygen and gaseous nitrogen output; A liquefaction unit is provided: the gaseous nitrogen produced from the distillation unit is passed through the liquefaction unit to produce liquid nitrogen.

[0038] The distillation unit is designed, installed and operated with reference to the distillation tower of the air separation device.

[0039] The liquefaction unit is realized by using a conventional compression refrigeration process or a low-temperature expansion machine process.

[0040] A low-pressure self-boosting device 25 is provided: one end of the low-pressure self-boosting device 25 is connected to the bottom liquid side of the low-pressure liquid storage tank 3 through a pipeline, and the other end is connected to the top gas side of the low-pressure liquid storage tank 3 through a pipeline; when the low-pressure and low-temperature liquid gas stored in the low-pressure liquid storage tank 3 releases energy, the pressure in the low-pressure liquid storage tank 3 decreases, and the low-pressure and low-temperature liquid gas in the low-pressure self-boosting device 25 is heated to be vaporized and enter the top gas space of the low-pressure liquid storage tank 3, thereby maintaining the pressure in the low-pressure liquid storage tank 3 stable.

[0041] A high-pressure self-boosting device 26 is provided: one end of the high-pressure self-boosting device 26 is connected to the bottom liquid side of the high-pressure liquid storage tank 5 through a pipeline, and the other end is connected to the top gas side of the high-pressure liquid storage tank 5 through a pipeline; when the high-pressure and low-temperature liquid gas stored in the high-pressure liquid storage tank 5 releases energy, the pressure in the high-pressure liquid storage tank 5 decreases, and the high-pressure and low-temperature liquid gas in the high-pressure self-boosting device 26 is heated to be vaporized and enter the top gas space of the high-pressure liquid storage tank 5, thereby maintaining the pressure in the high-pressure liquid storage tank 5 stable.

[0042] The low-pressure self-supercharger 25 or the high-pressure self-supercharger 26 is heated by ambient air, and a heater such as a metal coil or a finned tube may also be used. The heating medium preferably contains less water to avoid ice clogging of the heater due to improper operation.

[0043] When the high-pressure and low-temperature liquid gas in the high-pressure liquid storage tank 5 increases in pressure due to heat absorption, a pressure relief pipeline line 27 is provided: the gaseous gas discharged from the high-pressure liquid storage tank 5 enters the gas turbine 20 through the pressure relief valve 6 and the pressure relief pipeline 27 to expand and do work, and is discharged after recovering the cold energy.

[0044] The gas turbine 20 and the low-boiling-point working fluid expander 12 can be coaxially arranged, and in this case, the gas turbine generator 21 and the low-boiling-point working fluid generator 13 can be combined into a large generator.

[0045] A No. 1 recooling liquefier 7 is provided: the turbine exhaust gas 22 extracted from the gas turbine 20 absorbs the coldness of the liquid gas delivered from the high-pressure liquid storage tank 5 through the No. 1 recooling liquefier 7, and the generated liquid gas returns to the low-pressure liquid storage tank 3. The liquid gas delivered from the high-pressure liquid storage tank 5 enters the No. 1 low-boiling point working medium condenser 8 through the No. 1 recooling liquefier 7.

[0046] A No. 2 recooling liquefier 23 is provided: the turbine exhaust air 22 extracted from the gas turbine 20 absorbs the cold of the exhaust gas of the gas turbine 20 through the No. 2 recooling liquefier 23, and the generated low-pressure liquid gas returns to the low-pressure liquid storage tank 3, and the low-pressure and low-temperature gas 24 of the gas turbine 20 enters the No. 2 low-boiling-point working fluid condenser 15 through the No. 2 recooling liquefier 23.

[0047] Equipment and its systems, pipelines, instruments, valves, cold preservation, bypass facilities with regulating functions, etc. not described in the present invention are matched with reference to or in accordance with mature and reliable technologies in the well-known existing air separation processes.

[0048] The equipment and pipelines in the present invention adopt necessary heat recovery, cooling recovery, quality recovery and other measures.

[0049] Parts not mentioned in the present invention, such as safety accessories, automatic control, etc., are matched with existing well-known technologies, that is, existing mature, reliable and reasonable technical measures are applied to this device.

[0050] Although the present invention has been disclosed as above with preferred embodiments, they are not intended to limit the present invention. Anyone familiar with the art can make various changes or modifications without departing from the spirit and scope of the present invention, which also belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the definition of the claims of this application.

Claims

1. A cold power station, characterized in that: When storing energy: The liquid gas in the low-pressure liquid storage tank (3) is used for energy storage, or the liquid gas in the low-pressure liquid storage tank (3) is pressurized by the high-pressure pump (4) and then enters the high-pressure liquid storage tank (5) for energy storage; When releasing energy: The liquid gas in the low-pressure liquid storage tank (3) or the high-pressure liquid storage tank (5) is discharged after passing through the No. 1 low-boiling-point working medium condenser (8), the gas turbine (20), and the No. 2 low-boiling-point working medium condenser (15). The first low-boiling-point working medium condenser (8) absorbs the cold released by the delivered liquid gas, liquefies the gaseous low-temperature and low-boiling-point working medium separated by the gas-liquid separator (28), and the low-boiling-point working medium liquid enters the low-boiling-point working medium buffer tank (9). The high-temperature gaseous low-boiling-point working medium (14) discharged from the low-boiling-point working medium expander (12) is cooled by the second low-boiling-point working medium condenser (15), and the resulting gas-liquid mixture enters the gas-liquid separator (28). The gaseous low-temperature low-boiling-point working medium separated by the gas-liquid separator (28) enters the first low-boiling-point working medium condenser (8). The liquid low-boiling-point working medium separated by the gas-liquid separator (28) enters the low-boiling-point working medium buffer tank (9). The liquid low-boiling-point working medium in the low-boiling-point working medium buffer tank (9) is gasified by the low-boiling-point working medium circulation pump (10) and the low-boiling-point working medium evaporator (11), and the resulting gaseous low-boiling-point working medium enters the low-boiling-point working medium expander (12) to expand and perform work, driving the low-boiling-point working medium generator (13) to generate electricity. The high-temperature gaseous low-boiling-point working medium (14) discharged from the low-boiling-point working medium generator (13) enters the second low-boiling-point working medium condenser (15) to absorb cold energy, and the resulting gas-liquid mixture enters the gas-liquid separator (28), thereby forming a low-boiling-point working medium Rankine cycle loop. The high-pressure and low-temperature gas (19) coming out of the No. 1 low-boiling-point working medium condenser (8) enters the gas turbine (20) to expand and perform work, driving the gas turbine generator (21) to generate electricity. The low-pressure and low-temperature gas (24) discharged from the gas turbine (20) enters the No. 2 low-boiling-point working medium condenser (15) to release cold and then is discharged.

2. The cold power plant according to claim 1, characterized in that: The liquid gas is liquid air, liquid nitrogen, liquid oxygen, liquid argon, liquid oxygen-enriched air or liquid nitrogen-enriched air.

3. The cold power plant according to claim 1, characterized in that: An air liquefaction unit (2) is provided: air is passed through the air liquefaction unit (2) to produce liquid gas, which is then sent to a low-pressure liquid storage tank (3) for energy storage; or air is passed through the air liquefaction unit (2) to produce liquid gas, which is then sent to a low-pressure liquid storage tank (3); the liquid gas in the low-pressure liquid storage tank (3) is pressurized by a high-pressure pump (4) and then enters a high-pressure liquid storage tank (5) for energy storage.

4. The cold power plant according to claim 1, characterized in that: A distillation unit is provided: the liquid gas coming out of the low-pressure liquid storage tank (3) is pressurized by a hydraulic pump and then enters the distillation unit to produce liquid oxygen; the gaseous nitrogen produced by the distillation unit is produced by a liquefaction unit to produce liquid nitrogen.

5. The cold power plant according to claim 1, characterized in that: A low-pressure self-boosting device (25) is provided: one end of the low-pressure self-boosting device (25) is connected to the bottom liquid side of the low-pressure liquid storage tank (3) through a pipeline, and the other end is connected to the top gas side of the low-pressure liquid storage tank (3) through a pipeline; when the low-pressure and low-temperature liquid gas stored in the low-pressure liquid storage tank (3) releases energy, the pressure in the low-pressure liquid storage tank (3) decreases, and the low-pressure and low-temperature liquid gas in the low-pressure self-boosting device (25) is heated to be vaporized and enter the top gas space of the low-pressure liquid storage tank (3), thereby maintaining the pressure in the low-pressure liquid storage tank (3) stable.

6. The cold power plant according to claim 1, characterized in that: A high-pressure self-boosting device (26) is provided: one end of the high-pressure self-boosting device (26) is connected to the bottom liquid side of the high-pressure liquid storage tank (5) through a pipeline, and the other end is connected to the top gas side of the high-pressure liquid storage tank (5) through a pipeline; when the high-pressure and low-temperature liquid gas stored in the high-pressure liquid storage tank (5) releases energy, the pressure in the high-pressure liquid storage tank (5) decreases, and the high-pressure and low-temperature liquid gas in the high-pressure self-boosting device (26) is heated to be gasified and enter the top gas space of the high-pressure liquid storage tank (5), thereby maintaining the pressure in the high-pressure liquid storage tank (5) stable.

7. The cold power plant according to claim 1, characterized in that: The gaseous exhaust gas (16) coming out of the No. 2 low-boiling-point working medium condenser (15) is used as a cooling source for cooling.

8. The cold power plant according to claim 1, characterized in that: The refrigerant medium (18) coming out of the low-boiling-point working medium evaporator (11) is used as a cooling source.

9. The cold power plant according to claim 1, characterized in that: A first recooling liquefier (7) is provided: the gas turbine exhaust (22) extracted from the gas turbine (20) absorbs the cold of the liquid gas delivered from the high-pressure liquid storage tank (5) through the first recooling liquefier (7), and the generated liquid gas returns to the low-pressure liquid storage tank (3); the liquid gas delivered from the high-pressure liquid storage tank (5) enters the first low-boiling-point working medium condenser (8) through the first recooling liquefier (7).

10. The cold power plant according to claim 1, characterized in that: A second recooling liquefier (23) is provided: the turbine exhaust gas (22) extracted from the gas turbine (20) absorbs the cold energy of the exhaust gas of the gas turbine (20) through the second recooling liquefier (23), and the generated low-pressure liquid gas returns to the low-pressure liquid storage tank (3); the low-pressure and low-temperature gas (24) of the gas turbine (20) enters the second low-boiling-point working medium condenser (15) through the second recooling liquefier (23).

Images