Carbon dioxide power cycle system and method with polytropic combined supply and poly-medium energy storage

Abstract

The present application belongs to the technical field of comprehensive energy utilization, and relates to a carbon dioxide power cycle system method for multi-energy combined supply and multi-medium energy storage, comprising a gas storage bin, a first compressor, a first heat exchanger, a liquid storage tank, an evaporator, a turbine, a molten salt circulation unit, a water circulation unit, a solar light and heat unit, a steam supply unit and a cold supply unit. The present application can maximize the absorption of a large amount of waste heat in the energy storage process by increasing the high-quality heat in the molten salt circulation absorption energy storage process and the low-quality heat in the water circulation absorption energy storage process. Meanwhile, the circulating water in the hot water tank is continuously heated by the solar energy and the high-quality heat of the molten salt in the energy storage process, so that the circulating water becomes steam which is continuously supplied to the user for 24 hours. The cold energy in the carbon dioxide after expansion and work is used to supply cold or make ice to the user, so that the multi-energy combined supply of electric energy, steam and cold energy can be realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of comprehensive energy utilization, and relates to a carbon dioxide power cycle system and method for multi-energy supply and multi-medium energy storage. BACKGROUND

[0002] As a key support for solving the intermittency of renewable energy power generation, large-scale energy storage technology has attracted widespread attention in recent years. Among them, the energy storage system using carbon dioxide as the working medium has the advantages of high density, high efficiency and environmental friendliness, and has gradually become one of the research hotspots in the field of energy storage.

[0003] At present, the existing carbon dioxide energy storage system includes a gas storage bin, a compressor, a heat exchanger, a liquid storage tank, an evaporator and a turbine connected in sequence. During energy storage, the carbon dioxide in the gas storage bin enters the compressor, the electric energy generated by renewable energy power generation drives the compressor to operate, the carbon dioxide is compressed, the compressed carbon dioxide enters the heat exchanger to be cooled to obtain liquid carbon dioxide which is stored in the liquid storage tank. During energy release, the liquid carbon dioxide enters the evaporator to be evaporated and then enters the turbine to expand and do work to drive the generator to generate electricity, and the carbon dioxide after expansion and work is returned to the gas storage bin for storage.

[0004] However, the existing carbon dioxide energy storage system has many defects. Firstly, a large amount of waste heat generated during the energy storage process is not effectively recovered, resulting in low energy utilization rate. Secondly, only electric energy can be output during the energy release process, which cannot meet the demand for multi-energy supply such as steam and cold energy in industrial production or people's livelihood, and is difficult to adapt to diversified energy consumption scenarios. SUMMARY

[0005] The purpose of the present application is to provide a carbon dioxide power cycle system and method for multi-energy supply and multi-medium energy storage, which can recover a large amount of waste heat during energy storage and perform multi-energy supply such as electric energy, steam and cold energy during energy release, thereby improving the energy utilization rate and adapting to diversified energy consumption scenarios.

[0006] To achieve the above purpose, the technical scheme provided by the present application is as follows:

[0007] The carbon dioxide power cycle system for multi-energy supply and multi-medium energy storage comprises a gas storage bin, a first compressor, a first heat exchanger, a liquid storage tank, an evaporator and a turbine connected in sequence, and further comprises:

[0008] The molten salt circulation unit comprises a low-temperature salt tank and a first high-temperature salt tank, the outlet of the low-temperature salt tank is connected with the first inlet of the first heat exchanger, the inlet of the first high-temperature salt tank is connected with the first outlet of the first heat exchanger, and the low-temperature salt tank stores molten salt, which enters the first heat exchanger to absorb the heat generated by the compressed carbon dioxide and then enters the first high-temperature salt tank for storage;

[0009] The water circulation unit comprises a back cooler and a hot water tank, the back cooler is connected with the first heat exchanger and the liquid storage tank respectively, the first inlet of the back cooler is used for introducing circulating water, the first outlet of the back cooler is connected with the inlet of the hot water tank, and the circulating water is stored in the hot water tank after absorbing the residual heat of compressed carbon dioxide.

[0010] The solar light heat unit is connected with the low-temperature salt tank and is used for heating molten salt by using solar energy.

[0011] The steam supply unit comprises an evaporator, the first inlet of the evaporator is connected with the outlet of the first high-temperature salt tank and the solar light heat unit respectively, the first inlet of the evaporator is connected with the outlet of the hot water tank, and the circulating water in the hot water tank is heated into steam by the molten salt in the first high-temperature salt tank and the molten salt of the solar light heat unit and is continuously supplied to users.

[0012] The cooling supply unit comprises a first refrigeration device, the first refrigeration device is connected with the turbine and the gas storage bin respectively, the first inlet of the first refrigeration device is used for introducing circulating water, and the circulating water absorbs the cold quantity in the carbon dioxide after expansion work to supply cooling or make ice to users.

[0013] The application also has the characteristics that:

[0014] The solar light heat unit comprises:

[0015] The light heat tower is connected with the outlet of the low-temperature salt tank.

[0016] The second high-temperature salt tank is connected with the outlet of the light heat tower, and the outlet of the second high-temperature salt tank is connected with the first inlet of the evaporator.

[0017] The hot water tank and the evaporator are connected with a booster pump, the inlet of the booster pump is connected with the outlet of the hot water tank, the outlet of the booster pump is connected with the first inlet of the evaporator, and the booster pump is used for pressurizing the circulating water entering the evaporator.

[0018] The evaporator and the turbine are connected with a first heater, the first inlet of the first heater is connected with the first outlet of the evaporator, the first outlet of the first heater is connected with the inlet of the turbine, and the second inlet of the first heater is connected with the outlet of the hot water tank.

[0019] The back cooler and the liquid storage tank are connected with a condenser, the first inlet of the condenser is connected with the second outlet of the back cooler, the first outlet of the condenser is connected with the inlet of the liquid storage tank, and the second inlet of the condenser is used for introducing circulating water.

[0020] The first heat exchanger is connected with the post-cooler in sequence with the second compressor and the second heat exchanger, the first inlet of the second heat exchanger is connected with the outlet of the low-temperature salt tank, the first outlet of the second heat exchanger is connected with the inlet of the first high-temperature salt tank, the first refrigeration device is connected with the gas storage room in sequence with the second heater, the second turbine and the second refrigeration device, the first inlet of the second heater is connected with the outlet of the hot water tank, and the first inlet of the second refrigeration device is used for introducing circulating water.

[0021] The carbon dioxide power cycle method comprises the following steps:

[0022] The normal-temperature and normal-pressure carbon dioxide in the gas storage room enters the first compressor to be compressed to obtain high-temperature and high-pressure carbon dioxide, the high-temperature and high-pressure carbon dioxide enters the first heat exchanger to exchange heat with the molten salt from the low-temperature salt tank, the molten salt is stored in the first high-temperature salt tank after being heated, the high-temperature and high-pressure carbon dioxide becomes medium-temperature and high-pressure carbon dioxide and enters the post-cooler to exchange heat with the circulating water, the circulating water is stored in the hot water tank after being heated, the medium-temperature and high-pressure carbon dioxide becomes normal-temperature and high-pressure carbon dioxide and is condensed into liquid low-temperature and high-pressure carbon dioxide which is stored in the liquid storage tank;

[0023] The molten salt in the low-temperature salt tank enters the light-heat tower, the molten salt is heated by solar energy, and the heated molten salt is stored in the second high-temperature salt tank;

[0024] The circulating water in the hot water tank is pressurized by the booster pump and enters the evaporator, is continuously heated by the molten salt in the first high-temperature salt tank and the second high-temperature salt tank, becomes steam with a certain pressure, and continuously supplies steam to the user;

[0025] The liquid low-temperature and high-pressure carbon dioxide in the liquid storage tank is evaporated into normal-temperature and high-pressure carbon dioxide, enters the first heater to exchange heat with the circulating water from the hot water tank, becomes medium-temperature and high-pressure carbon dioxide, enters the first turbine to expand and do work to drive the generator to generate electricity, becomes low-temperature and normal-pressure carbon dioxide, enters the first refrigeration device to exchange heat with the circulating water, becomes normal-temperature and normal-pressure carbon dioxide and is stored in the gas storage room, and the circulating water absorbs cold energy to supply cold or make ice to the user.

[0026] The temperature of the high-temperature and high-pressure carbon dioxide is 250-300 DEG C, the pressure is 5-7 MPa, the temperature of the medium-temperature and high-pressure carbon dioxide is 200-250 DEG C, the pressure is 5-7 MPa, the temperature of the liquid low-temperature and high-pressure carbon dioxide is 0-20 DEG C, the pressure is 5-7 MPa, the temperature of the steam with a certain pressure is 200-250 DEG C, the pressure is 0.1-2 MPa, and the temperature of the low-temperature and normal-pressure carbon dioxide is -10-0 DEG C.

[0027] The carbon dioxide power cycle system and method with multi-energy supply and multi-medium energy storage of the application has the following advantages:

[0028] The application can absorb the large amount of waste heat in the energy storage process to the greatest extent by increasing the high-quality heat in the molten salt circulation absorption energy storage process and the low-quality heat in the water circulation absorption energy storage process, and can continuously supply the circulating water in the hot water tank with steam for 24 hours by using the solar energy to heat the molten salt and the molten salt with high-quality heat in the absorption energy storage process, and can supply the user with cold or ice by using the cold in the carbon dioxide after expansion and work in the energy release process, so that the multi-energy supply of electric energy, steam and cold can be realized, the energy utilization rate is improved, and diversified energy consumption scenarios are adapted. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the application.

[0030] Figure 2 It is a schematic diagram of the two-stage compression and two-stage turbine structure of the application.

[0031] Figure 3 It is a schematic diagram of the overall process of the application.

[0032] REFERENCE NUMERALS:

[0033] 1, gas storage warehouse, 2, first control valve, 3, first compressor, 4, first heat exchanger, 5, after-cooler, 6, condenser, 7, liquid storage tank, 8, second control valve, 9, evaporator, 10, first heater, 11, first turbine, 12, first refrigerator, 13, hot water tank, 14, third control valve, 15, fourth control valve, 16, booster pump, 17, evaporator, 18, first high-temperature salt tank, 19, second high-temperature salt tank, 20, photo-thermal tower, 21, low-temperature salt tank, 22, fifth control valve, 23, sixth control valve, 24, seventh control valve, 25, eighth control valve, 26, second compressor, 27, second heat exchanger, 28, second heater, 29, second turbine, 30, second refrigerator. DETAILED DESCRIPTION

[0034] The technical solutions in the present application will be clearly and exhaustively described below with reference to the drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " represents the meaning of "or", for example, A / B can represent A or B: "and / or" in the text is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist together, and B exists alone, and in addition, in the description of the embodiments of the present application, "multiple" means two or more than two. The following terms "first" "second" are only for description purposes, and cannot be understood as implying or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first" "second" can be explicitly or implicitly include one or more features.

[0035] As Figure 1As shown, the present application provides a carbon dioxide power cycle system for multi-energy supply and multi-medium energy storage, which comprises a gas storage warehouse 1, a first compressor 3, a first heat exchanger 4, a liquid storage tank 7, an evaporator 9 and a first turbine 11 connected in sequence, and further comprises a molten salt circulation unit, a water circulation unit, a solar photothermal unit, a steam supply unit and a cooling supply unit. The molten salt circulation unit comprises a low-temperature salt tank 21 and a first high-temperature salt tank 18. The outlet of the low-temperature salt tank 21 is connected with the first inlet of the first heat exchanger 4, and the inlet of the first high-temperature salt tank 18 is connected with the first outlet of the first heat exchanger 4. The low-temperature salt tank 21 stores molten salt. The molten salt absorbs the heat generated by compressed carbon dioxide in the first heat exchanger 4 and is then stored in the first high-temperature salt tank 18. The water circulation unit comprises a post-cooler 5 and a hot water tank 13. The post-cooler 5 is connected with the first heat exchanger 4 and the liquid storage tank 7 respectively. The first inlet of the post-cooler 5 is used to introduce circulating water. The first outlet of the post-cooler 5 is connected with the inlet of the hot water tank 13. The circulating water absorbs the residual heat of compressed carbon dioxide in the post-cooler 5 and is then stored in the hot water tank 13. The solar photothermal unit is connected with the low-temperature salt tank 21. The solar photothermal unit is used to heat the molten salt by using solar energy. The steam supply unit is used to continuously heat the circulating water in the hot water tank 13 by using the molten salt in the first high-temperature salt tank 18 and the solar photothermal unit, so that the circulating water becomes steam and is continuously supplied to users. The cooling supply unit is used to supply cooling or make ice to users by using the cold energy in the carbon dioxide after expansion work. The present application can maximize the absorption of a large amount of waste heat in the energy storage process by increasing the molten salt circulation to absorb high-quality heat in the energy storage process and increasing the water circulation to absorb low-quality heat in the energy storage process. At the same time, the circulating water in the hot water tank 13 is continuously heated to become steam for 24 hours by using the molten salt heated by solar energy and the high-quality heat in the energy storage process, and the cold energy in the carbon dioxide after expansion work in the energy release process is used to supply cooling or make ice to users, so that the present application can supply electricity, steam and cold energy, which not only improves the utilization rate of energy, but also adapts to diversified energy consumption scenarios.

[0036] As shown in Figure 1 , the solar photothermal unit comprises a photothermal tower 20 and a second high-temperature salt tank 19. The inlet of the photothermal tower 20 is connected with the outlet of the low-temperature salt tank 21, and the inlet of the second high-temperature salt tank 19 is connected with the outlet of the photothermal tower 20. The outlet of the second high-temperature salt tank 19 is connected with the first inlet of the evaporator 17.

[0037] As shown in Figure 1 , a booster pump 16 is arranged between the hot water tank 13 and the evaporator 17. The inlet of the booster pump 16 is connected with the outlet of the hot water tank 13, and the outlet of the booster pump 16 is connected with the first inlet of the evaporator 17. The booster pump 16 is used to pressurize the circulating water entering the evaporator 17, so that the circulating water becomes steam with a certain pressure.

[0038] As shown in Figure 1 The first heater 10 is arranged between the evaporator 9 and the first turbine 11, the first inlet of the first heater 10 is connected with the first outlet of the evaporator 9, the first outlet of the first heater 10 is connected with the inlet of the first turbine 11, the second inlet of the first heater 10 is connected with the outlet of the hot water tank 13, the recycled water stored in the hot water tank 13 is used to heat the evaporated carbon dioxide, so as to improve the inlet temperature of the first turbine 11.

[0039] As shown in Figure 1 The condenser 6 is arranged between the after-cooler 5 and the liquid storage tank 7, the first inlet of the condenser 6 is connected with the second outlet of the after-cooler 5, the first outlet of the condenser 6 is connected with the inlet of the liquid storage tank 7, and the second inlet of the condenser 6 is used to introduce recycled water.

[0040] As shown in Figure 2 According to the principle of "temperature matching and cascade utilization" of the total energy system, the second compressor 26 and the second heat exchanger 27 are sequentially connected between the first heat exchanger 4 and the after-cooler 5, the first inlet of the second heat exchanger 27 is connected with the outlet of the low-temperature salt tank 21, the first outlet of the second heat exchanger 27 is connected with the inlet of the first high-temperature salt tank 18, the second heater 28, the second turbine 29 and the second refrigerator 30 are sequentially connected between the first refrigerator 12 and the gas storage warehouse 1, the first inlet of the second heater 28 is connected with the outlet of the hot water tank 13, the first inlet of the second refrigerator 30 is used to introduce recycled water, through the arrangement of two-stage compression and two-stage turbine, a double-stage energy release link of main expansion work and secondary residual energy recovery is formed, which is beneficial to improve the energy utilization efficiency of the whole system, increase the diversity of output and ensure the stability of system operation.

[0041] As shown in Figure 1 , Figure 2 The outlet of the gas storage warehouse 1 is provided with the first control valve 2, the outlet of the liquid storage tank 7 is provided with the second control valve 8, the inlet of the booster pump 16 is provided with the third control valve 14, the second inlet of the first heater 10 is provided with the fourth control valve 15, the inlet of the light heat tower 20 is provided with the fifth control valve 22, the first inlet of the first heat exchanger 4 is provided with the sixth control valve 23, the outlet of the first high-temperature salt tank 18 is provided with the seventh control valve 24, and the outlet of the second high-temperature salt tank 19 is provided with the eighth control valve 25.

[0042] As shown in Figure 3 The carbon dioxide power cycle method of multi-energy combined supply and multi-medium energy storage adopts the above-mentioned system, and comprises the following steps:

[0043] The normal temperature and pressure carbon dioxide in the gas storage 1 enters the first compressor 3 to be compressed to obtain high temperature and pressure carbon dioxide, the high temperature and pressure carbon dioxide enters the first heat exchanger 4 to exchange heat with the molten salt from the low temperature salt tank 21, the molten salt is stored in the first high temperature salt tank 18 after being heated, the high temperature and pressure carbon dioxide becomes medium temperature and pressure carbon dioxide which enters the after-cooler 5 to exchange heat with the circulating water, the circulating water is stored in the hot water tank 13 after being heated, the medium temperature and pressure carbon dioxide becomes normal temperature and pressure carbon dioxide which is condensed into liquid low temperature and pressure carbon dioxide and is stored in the liquid storage tank 7.

[0044] The molten salt in the low temperature salt tank 21 enters the light heat tower 20, the molten salt is heated by solar energy, and the heated molten salt is stored in the second high temperature salt tank 19.

[0045] The circulating water in the hot water tank 13 is pressurized by the booster pump 16 and enters the evaporator 17, and is continuously heated by the molten salt in the first high temperature salt tank 18 and the second high temperature salt tank 19, the pressurized circulating water becomes steam with a certain pressure, and continuously supplies steam to the user.

[0046] The liquid low temperature and pressure carbon dioxide in the liquid storage tank 7 is evaporated into normal temperature and pressure carbon dioxide which enters the first heater 10 to exchange heat with the circulating water from the hot water tank 13, the normal temperature and pressure carbon dioxide becomes medium temperature and pressure carbon dioxide which enters the first turbine 11 to expand and do work to drive the generator to generate electricity, the medium temperature and pressure carbon dioxide becomes low temperature and pressure carbon dioxide which enters the first refrigeration device 12 to exchange heat with the circulating water, the low temperature and pressure carbon dioxide becomes normal temperature and pressure carbon dioxide which is stored in the gas storage 1, and the circulating water absorbs cold energy to supply cold to the user or make ice.

[0047] The temperature of the high temperature and pressure carbon dioxide is 250-300℃, the pressure is 5-7MPa, the temperature of the medium temperature and pressure carbon dioxide is 200-250℃, the pressure is 5-7MPa, the pressure of the normal temperature and pressure carbon dioxide is 5-7MPa, the temperature of the liquid low temperature and pressure carbon dioxide is 0-20℃, the pressure is 5-7MPa, the temperature of the steam with a certain pressure is 200-250℃, the pressure is 0.1-2MPa, and the temperature of the low temperature and pressure carbon dioxide is -10-0℃.

[0048] Working principle:

[0049] During energy storage, the normal temperature and pressure carbon dioxide in the storage bin 1 enters the first compressor 3, the first compressor 3 is driven by the electric energy generated by renewable energy power generation, the normal temperature and pressure carbon dioxide is compressed by the first compressor 3 to obtain high temperature and pressure carbon dioxide, the high temperature and pressure carbon dioxide enters the first heat exchanger 4 to exchange heat with the molten salt from the low temperature salt tank 21, the molten salt is stored in the first high temperature salt tank 18 after being heated, the high temperature and pressure carbon dioxide becomes medium temperature and pressure carbon dioxide and enters the after-cooler 5 to exchange heat with the circulating water from the water pool, the circulating water is stored in the hot water tank 13 after being heated, the medium temperature and pressure carbon dioxide becomes normal temperature and pressure carbon dioxide, the normal temperature and pressure carbon dioxide enters the condenser 6 to exchange heat with the circulating water from the water pool, the normal temperature and pressure carbon dioxide becomes low temperature and pressure liquid carbon dioxide after being condensed and is stored in the liquid storage tank 7, and the circulating water after heat exchange is discharged into the water pool.

[0050] The molten salt in the low temperature salt tank 21 enters the light heat tower 20, the molten salt is heated by solar energy, and the molten salt after being heated is stored in the second high temperature salt tank 19.

[0051] The circulating water in the hot water tank 13 is pressurized by the booster pump 16 and enters the evaporator 17, the circulating water is heated by the molten salt in the first high temperature salt tank 18 for 16 hours in the daytime, and the circulating water is heated by the molten salt in the second high temperature salt tank 19 for 8 hours at night, so that the pressurized circulating water becomes steam with a certain pressure, and the steam is continuously supplied to the user for 24 hours.

[0052] During energy release, the low temperature and pressure liquid carbon dioxide in the liquid storage tank 7 enters the evaporator 9 to exchange heat with the circulating water from the water pool, the low temperature and pressure liquid carbon dioxide becomes normal temperature and pressure carbon dioxide after being evaporated, the circulating water after heat exchange is discharged into the water pool, the low temperature and pressure liquid carbon dioxide becomes normal temperature and pressure carbon dioxide, the normal temperature and pressure carbon dioxide enters the first heater 10 to exchange heat with the circulating water from the hot water tank 13, the circulating water is discharged into the water pool after being cooled, the normal temperature and pressure carbon dioxide becomes medium temperature and pressure carbon dioxide and enters the first turbine 11 to expand and do work to drive the generator to generate electricity, the medium temperature and pressure carbon dioxide becomes low temperature and pressure carbon dioxide and enters the first refrigeration device 12 to exchange heat with the circulating water from the water pool, the low temperature and pressure carbon dioxide becomes normal temperature and pressure carbon dioxide and is stored in the storage bin 1, and the circulating water absorbs cold energy to supply cold to the user or make ice.

[0053] The multi-energy combined supply and multi-medium energy storage carbon dioxide power cycle system and method of the application have the following advantages:

[0054] Firstly, the present application has the energy storage peak clipping and valley filling function, can balance the power supply and demand fluctuation, realizes the multi-medium coordinated energy storage and the flexible supply of electricity, heat, cold and other various energies, and does not need to introduce other independent cycles, greatly simplifies the system structure, improves the system compactness, reduces the equipment investment and operation cost, reduces the system floor area, further enhances the economic practicability, and at the same time, the electricity, heat and cold cogeneration architecture and the multi-medium energy storage technology can effectively suppress the power supply and demand fluctuation, convert the intermittent energy input into multi-form stable energy output, and improve the response ability of the system to energy supply and demand changes.

[0055] Secondly, the present application realizes the deep coupling and intelligent regulation and control of carbon dioxide energy storage and solar thermal unit, gets rid of the dependence on fossil energy, uses carbon dioxide compression heat to ensure steam supply in the energy storage stage, combines solar heat in the energy release stage, realizes 24-hour uninterrupted steam supply, does not need to consume fossil energy in the whole process, reduces carbon emissions, has the advantages of low carbon and environmental protection and economy, meets the green development demand, and meets the continuous steam scene of industry, heating and the like.

[0056] Thirdly, the present application can realize sustainable steam supply, uses carbon dioxide compression heat to heat molten salt for 16 hours in the daytime, outputs steam with specified parameters, uses the molten salt heated by solar heat and the circulating water in the hot water tank to exchange heat for 8 hours in the evening, and outputs steam with specified parameters. This setting greatly reduces the total demand for solar energy, thereby reducing the mirror field construction area, reducing the mirror field equipment procurement and installation cost, reducing the land occupation and later maintenance cost, controlling the initial investment cost of the system, and improving the overall economy of the system.

[0057] Fourthly, the steam parameter range in the present application is large, and the application scenarios are wide. When there is solar radiation, the light heat tower heats the molten salt to provide sufficient heat for steam generation, and high-parameter steam with high temperature and high pressure can be output to meet the harsh demands of high-end manufacturing and high-efficiency power generation. When there is no sun, the energy storage system heat can still stably output steam meeting the basic energy demand, and flexibly cope with different field steam parameter requirements.

[0058] Fifthly, the present application constructs a multi-energy fusion, cascade utilization and closed loop circulation technical system aiming at the deficiencies of traditional energy systems in energy conversion efficiency, supply and demand adaptability and low carbon, realizes the collaborative optimization of energy utilization flexibility, economy and environmental protection, uses carbon dioxide as the closed loop circulation working medium to avoid working medium leakage pollution, replaces part of the traditional fossil energy with solar energy to reduce carbon emissions, and has no direct emission of pollutants in the operation process, meets the low-carbon green development trend, and provides technical support for energy system upgrading.

[0059] It is to be understood that the present application is described by way of example only, and that modifications or alterations can be made to the features and embodiments described without departing from the spirit and scope of the application. In addition, modifications can be made to the features and embodiments described to accommodate specific situations and materials without departing from the spirit and scope of the application. Accordingly, the application is not limited to the specific embodiments disclosed herein, but rather, the scope of the application includes all embodiments falling within the scope of the claims.

Claims

1. A carbon dioxide power cycle system with multi-energy supply and multi-media energy storage, comprising a gas storage tank (1), a first compressor (3), a first heat exchanger (4), an aftercooler (5), a condenser (6), a liquid storage tank (7), a first evaporator (9), a first heater (10), a first turbine (11), and a first refrigerator (12) connected in sequence, characterized in that, Also includes: The molten salt circulation unit includes a low-temperature salt tank (21) and a first high-temperature salt tank (18). The outlet of the low-temperature salt tank (21) is connected to the first inlet of the first heat exchanger (4), and the inlet of the first high-temperature salt tank (18) is connected to the first outlet of the first heat exchanger (4). Molten salt is stored in the low-temperature salt tank (21). The molten salt enters the first heat exchanger (4) to absorb the heat generated by the compression of carbon dioxide and then enters the first high-temperature salt tank (18) for storage. The water circulation unit includes an aftercooler (5) and a hot water tank (13). The aftercooler (5) is connected to the first heat exchanger (4) and the liquid storage tank (7) respectively. The first inlet of the aftercooler (5) is used to introduce circulating water. The first outlet of the aftercooler (5) is connected to the inlet of the hot water tank (13). After the circulating water enters the aftercooler (5), it absorbs the remaining heat from the compressed carbon dioxide and then enters the hot water tank (13) for storage. A solar thermal unit is connected to a low-temperature salt tank (21) to heat molten salt using solar energy; The steam supply unit is used to continuously heat the circulating water in the hot water tank (13) by using the molten salt in the first high-temperature salt tank (18) and the solar thermal unit, so that the circulating water is turned into steam and continuously supplied to the user. Cooling unit, used to provide cooling or make ice to users by utilizing the cooling energy in carbon dioxide after expansion and work; The solar thermal unit includes: The inlet of the solar thermal tower (20) is connected to the outlet of the low-temperature salt tank (21); The inlet of the second high-temperature salt tank (19) is connected to the outlet of the solar thermal tower (20), and the outlet of the second high-temperature salt tank (19) is connected to the steam supply unit. The steam supply unit includes: The first inlet of the second evaporator (17) is connected to the outlet of the first high-temperature salt tank (18) and the outlet of the second high-temperature salt tank (19), respectively, and the second inlet of the second evaporator (17) is connected to the outlet of the hot water tank (13); A first heater (10) is provided between the first evaporator (9) and the first turbine (11). The first inlet of the first heater (10) is connected to the first outlet of the first evaporator (9), the first outlet of the first heater (10) is connected to the inlet of the first turbine (11), and the second inlet of the first heater (10) is connected to the outlet of the hot water tank (13).

2. The carbon dioxide power cycle system with multi-energy supply and multi-media energy storage according to claim 1, characterized in that, The cooling unit includes: The first refrigerator (12) is connected to the first turbine (11) and the gas storage chamber (1) respectively. The first inlet of the first refrigerator (12) is used to introduce circulating water and use the circulating water to absorb the cold energy in the carbon dioxide after expansion and work to supply cooling or make ice to users.

3. The carbon dioxide power cycle system with multi-energy supply and multi-media energy storage according to claim 2, characterized in that, A booster pump (16) is provided between the hot water tank (13) and the second evaporator (17). The inlet of the booster pump (16) is connected to the outlet of the hot water tank (13), and the outlet of the booster pump (16) is connected to the first inlet of the second evaporator (17). The booster pump (16) is used to pressurize the circulating water entering the second evaporator (17).

4. The carbon dioxide power cycle system with multi-energy supply and multi-media energy storage according to claim 1, characterized in that, A condenser (6) is provided between the aftercooler (5) and the liquid storage tank (7). The first inlet of the condenser (6) is connected to the second outlet of the aftercooler (5), and the first outlet of the condenser (6) is connected to the inlet of the liquid storage tank (7). The second inlet of the condenser (6) is used to introduce circulating water.

5. The carbon dioxide power cycle system with multi-energy supply and multi-media energy storage according to claim 1, characterized in that, A second compressor (26) and a second heat exchanger (27) are connected in sequence between the first heat exchanger (4) and the aftercooler (5). The first inlet of the second heat exchanger (27) is connected to the outlet of the low-temperature salt tank (21), and the first outlet of the second heat exchanger (27) is connected to the inlet of the first high-temperature salt tank (18). A second heater (28), a second turbine (29), and a second refrigerator (30) are connected in sequence between the first refrigerator (12) and the gas storage chamber (1). The first inlet of the second heater (28) is connected to the outlet of the hot water tank (13), and the first inlet of the second refrigerator (30) is used to introduce circulating water.

6. A carbon dioxide power cycle method combining multiple energy sources and multi-media energy storage, characterized in that, The system described in claim 3 includes the following steps: The ambient temperature and pressure carbon dioxide in the gas storage chamber (1) enters the first compressor (3) for compression to obtain high temperature and high pressure carbon dioxide. The high temperature and high pressure carbon dioxide enters the first heat exchanger (4) to exchange heat with molten salt from the low temperature salt tank (21). After the molten salt is heated, it enters the first high temperature salt tank (18) for storage. The high temperature and high pressure carbon dioxide becomes medium temperature and high pressure carbon dioxide and enters the aftercooler (5) to exchange heat with circulating water. After the circulating water is heated, it enters the hot water tank (13) for storage. The medium temperature and high pressure carbon dioxide becomes ambient temperature and high pressure carbon dioxide and condenses into liquid low temperature and high pressure carbon dioxide, which enters the liquid storage tank (7) for storage. Molten salt in low-temperature salt tank (21) enters solar thermal tower (20) to heat the molten salt using solar energy. The heated molten salt is then stored in the second high-temperature salt tank (19). The circulating water in the hot water tank (13) is pressurized by the booster pump (16) and enters the second evaporator (17). It is continuously heated by the molten salt in the first high temperature salt tank (18) and the second high temperature salt tank (19). The pressurized circulating water becomes steam with a certain pressure and continuously supplies steam to the user. The low-temperature high-pressure carbon dioxide in the liquid storage tank (7) evaporates and becomes room-temperature high-pressure carbon dioxide, which enters the first heater (10) and exchanges heat with the circulating water from the hot water tank (13). The room-temperature high-pressure carbon dioxide becomes medium-temperature high-pressure carbon dioxide and enters the first turbine (11) to expand and do work to drive the generator to generate electricity. The medium-temperature high-pressure carbon dioxide becomes low-temperature normal-pressure carbon dioxide and enters the first refrigerator (12) to exchange heat with the circulating water. The low-temperature normal-pressure carbon dioxide becomes room-temperature normal-pressure carbon dioxide and enters the gas storage chamber (1) for storage. The circulating water absorbs the cold energy and supplies cooling or ice making to the user.

7. The carbon dioxide power cycle method with multi-energy supply and multi-media energy storage according to claim 6, characterized in that, The high-temperature high-pressure carbon dioxide has a temperature of 250℃~300℃ and a pressure of 5MPa~7MPa; the medium-temperature high-pressure carbon dioxide has a temperature of 200℃~250℃ and a pressure of 5MPa~7MPa; the liquid low-temperature high-pressure carbon dioxide has a temperature of 0℃~20℃ and a pressure of 5MPa~7MPa; the steam with a certain pressure has a temperature of 200℃~250℃ and a pressure of 0.1MPa~2MPa; and the low-temperature atmospheric pressure carbon dioxide has a temperature of -10℃~0℃.

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