Combined energy storage device system and operation method thereof

Abstract

The invention relates to a combined energy storage device system and an operation method thereof. The combined energy storage device system comprises a compressed air energy storage unit, a first cooling pressure regulating unit, a compressed carbon dioxide energy storage unit and a pumped storage unit. A high-pressure air outlet of the compressed air energy storage unit is connected with a high-pressure air storage through a cooler of the first cooling pressure regulating unit; the low-pressure carbon dioxide gas storage is connected with the compressed carbon dioxide energy storage unit, and a high-pressure carbon dioxide outlet of the compressed carbon dioxide energy storage unit is connected with the liquid carbon dioxide gas storage. According to the combined energy storage device system, space sharing of the high-pressure air storage and the lower reservoir is achieved in the underground gas-liquid co-containing cavity, and sharing of the low-pressure carbon dioxide storage and the upper reservoir is achieved in the overground gas-liquid co-containing cavity. The space utilization rate of the system can be improved, and stable operation of the system is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of power storage, and in particular to a combined energy storage device system and an operation method thereof. Background Art

[0002] With the deepening of energy transformation, my country's power industry is gradually transforming to a new power system represented by wind and solar energy. New energy power generation, mainly wind power and photovoltaic power, has significant randomness, intermittency and volatility, which poses challenges to the safe and stable operation of the power system.

[0003] In order to ensure the safety and stable operation of the new power system, energy storage is one of the key technologies to be developed. At present, the mainstream long-term energy storage technology routes mainly include: pumped storage, compressed air storage and compressed carbon dioxide (CO 2 ) energy storage, etc. These technical routes all require a large space. For example, pumped storage requires a huge upper reservoir and lower reservoir, compressed air storage requires a high-pressure gas storage, and compressed CO 2 Energy storage requires a low-pressure, large-volume gas storage facility, etc. At the same time, during the process of storing and releasing energy, the compressed air energy storage unit operates under variable operating conditions, which puts forward wide operating condition requirements for equipment design, making the design more difficult; 2 Energy storage requires some means of inflation and deflation to maintain constant pressure operation of the system.

[0004] Therefore, how to improve the utilization rate of the gas storage space, achieve stable operation of the system, and improve the system efficiency is a technical problem that needs to be solved in this field. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a combined energy storage device system and an operating method thereof. Compared with the prior art, the combined energy storage device system provided by the present invention couples pumped storage, compressed air energy storage and carbon dioxide energy storage, which can improve the space utilization rate of the system and achieve stable operation of the system.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a combined energy storage device system, the combined energy storage device system comprising a compressed air energy storage unit, a first cooling and pressure regulating unit, a compressed carbon dioxide energy storage unit and a pumped storage unit;

[0008] The pumped storage unit comprises an above-ground gas-liquid co-accommodating chamber and an underground gas-liquid co-accommodating chamber, wherein the above-ground gas-liquid co-accommodating chamber comprises, from top to bottom, a low-pressure carbon dioxide gas storage reservoir and an upper water reservoir, and the underground gas-liquid co-accommodating chamber comprises, from top to bottom, a high-pressure air gas storage reservoir and a lower water reservoir;

[0009] The high-pressure air outlet of the compressed air energy storage unit is connected to the high-pressure air storage reservoir via the cooler of the first cooling and pressure regulating unit;

[0010] The low-pressure carbon dioxide gas storage reservoir is connected to a compressed carbon dioxide energy storage unit, and a high-pressure carbon dioxide outlet of the compressed carbon dioxide energy storage unit is connected to a liquid carbon dioxide gas storage reservoir.

[0011] In the combined energy storage device system provided by the present invention, by coupling the pumped storage unit, the compressed air storage unit and the compressed carbon dioxide storage unit, the upper water reservoir of the pumped storage is shared with the low-pressure carbon dioxide storage reservoir, and the lower water reservoir of the pumped storage is shared with the high-pressure air storage reservoir, thereby improving the space utilization rate of the system.

[0012] Preferably, the compressed air energy storage unit includes at least 2 levels of compressed air modules, for example, it can be 2 levels, 3 levels or 4 levels, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0013] Preferably, the compressed air module includes an electric motor, a compressor and a first heat exchange device, the electric motor is connected to the power input end of the compressor, the high-pressure air outlet of the compressor is connected to the heat source inlet of the first heat exchange device at this stage, the heat source outlet of the first heat exchange device is connected to the compressor of the next stage compressed air module, and the heat source outlet of the last first heat exchange device along the air flow is connected to the cooler.

[0014] Preferably, the cold source inlet of the first heat exchange device is connected to the heat storage cold tank via a heat storage cold pump, and the cold source outlet of the first heat exchange device is connected to the heat storage hot tank.

[0015] Preferably, the first cooling and pressure regulating unit comprises a circulation pump, a cooler and a first radiator.

[0016] Preferably, the first cooling and pressure regulating unit includes a first cooling path.

[0017] Preferably, in the first cooling path, the outlet of the circulation pump is connected to the cold source inlet of the cooler, the cold source outlet of the cooler is connected to the first radiator, and the outlet of the first radiator is connected to the inlet of the circulation pump.

[0018] Preferably, the first cooling and pressure regulating unit further includes a first pressure regulating path.

[0019] Preferably, in the first pressure regulating path, the inlet of the circulating pump is connected to the upper water reservoir, the outlet of the circulating pump is connected to the cold source inlet of the cooler, the cold source outlet of the cooler is connected to the first radiator, and the outlet of the first radiator is connected to the upper water reservoir.

[0020] Preferably, the pumped storage unit further comprises an integrated electric and power generating turbine.

[0021] Preferably, the lower reservoir is connected to the upper reservoir via an integrated electric and power generation turbine.

[0022] Preferably, elastic air membranes are respectively arranged between the low-pressure carbon dioxide gas storage reservoir and the upper water reservoir and between the high-pressure air gas storage reservoir and the lower water reservoir.

[0023] Preferably, the compressed carbon dioxide energy storage unit includes at least 2 levels of compressed carbon dioxide modules, for example, it can be 2 levels, 3 levels or 4 levels, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, the compressed carbon dioxide module includes an electric motor, a compressor and a second heat exchange device, the electric motor is connected to the power input end of the compressor, the high-pressure carbon dioxide outlet of the compressor is connected to the heat source inlet of the second heat exchange device of this stage, and the heat source outlet of the second heat exchange device is connected to the compressor of the next stage compressed carbon dioxide module.

[0025] Preferably, the compressed carbon dioxide energy storage unit also includes a third heat exchange device. In the compressed carbon dioxide energy storage unit, the heat source outlet of the last second heat exchange device along the carbon dioxide flow is connected to the heat source inlet of the third heat exchange device, and the heat source outlet of the third heat exchange device is connected to the liquid carbon dioxide gas storage reservoir.

[0026] Preferably, the cold source inlet of the second heat exchange device is connected to the heat storage cold tank via a heat storage cold pump, and the cold source outlet of the second heat exchange device is connected to the heat storage hot tank.

[0027] Preferably, the combined energy storage device system further includes a compressed air energy release unit.

[0028] Preferably, the compressed air energy release unit includes a generator and at least one level of compressed air energy release module, for example, it can be level 1, level 2, level 3 or level 4, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable. The generator is connected to the power output end of the compressed air energy release module.

[0029] Preferably, the compressed air energy release module includes a turbine and a fourth heat exchange device, the turbines of adjacent compressed air energy release modules are coaxially connected in series, the cold source outlet of the fourth heat exchange device is connected to the turbine of this stage, the cold source inlet of the fourth heat exchange device is connected to the turbine of the previous stage compressed air energy release module, and the cold source inlet of the first fourth heat exchange device along the air flow is connected to the high-pressure air storage reservoir.

[0030] Preferably, the heat source inlet of the fourth heat exchange device is connected to the heat storage hot tank via a heat storage heat pump, and the heat source outlet of the fourth heat exchange device is connected to the heat storage cold tank.

[0031] Preferably, the combined energy storage device system also includes a compressed carbon dioxide energy release unit.

[0032] Preferably, the compressed carbon dioxide energy release unit includes a generator and at least one level of compressed carbon dioxide energy release module, for example, it can be level 1, level 2, level 3 or level 4, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable. The generator is connected to the power output end of the compressed carbon dioxide energy release module.

[0033] Preferably, the compressed carbon dioxide energy release module includes a turbine and a fifth heat exchange device, the turbines of adjacent compressed carbon dioxide energy release modules are coaxially connected in series, the cold source outlet of the fifth heat exchange device is connected to the turbine of this stage, and the cold source inlet of the fifth heat exchange device is connected to the turbine of the previous stage compressed carbon dioxide energy release module.

[0034] Preferably, the compressed carbon dioxide energy release unit also includes a sixth heat exchange device. In the compressed carbon dioxide energy release unit, the cold source inlet of the first fifth heat exchange device along the carbon dioxide flow is connected to the cold source outlet of the sixth heat exchange device, and the cold source inlet of the sixth heat exchange device is connected to the liquid carbon dioxide gas storage reservoir.

[0035] Preferably, the heat source inlet of the fifth heat exchange device is connected to the heat storage hot tank via a heat storage heat pump, and the heat source outlet of the fifth heat exchange device is connected to the heat storage cold tank.

[0036] Preferably, the gas outlet of the compressed carbon dioxide energy release unit along the carbon dioxide flow toward the last turbine is connected to a low-pressure carbon dioxide gas storage reservoir.

[0037] Preferably, the combined energy storage device system further includes a second cooling and voltage regulating unit.

[0038] Preferably, the second cooling and pressure regulating unit comprises a second radiator, a cooling cold tank, a cooling cold pump, a cooling hot tank and a cooling hot pump.

[0039] Preferably, the second cooling and pressure regulating unit includes a second cooling path, a second pressure regulating path, a third pressure regulating path and a fourth pressure regulating path.

[0040] Preferably, in the second cooling path, the outlet of the cooling tank is connected to the second radiator via a cooling pump, and the outlet of the second radiator is connected to the cooling tank.

[0041] Preferably, in the second pressure regulating path, the upper water reservoir is connected to the inlet of the cooling cold pump, the outlet of the cooling cold pump is connected to the second radiator, and the outlet of the second radiator is connected to the upper water reservoir.

[0042] Preferably, in the third pressure regulating path, the upper water reservoir is connected to the inlet of the cooling cold pump, and the outlet of the cooling cold pump is connected to the cooling hot tank.

[0043] Preferably, in the fourth pressure regulating path, the outlet of the cooling hot tank is connected to the upper water reservoir via a cooling heat pump, and the outlet of the upper water reservoir is connected to the cooling cold tank.

[0044] Preferably, the cold source inlet of the third heat exchange device in the compressed carbon dioxide energy storage unit is connected to the cooling cold tank via a cooling cold pump, and the cold source outlet of the third heat exchange device is connected to the cooling hot tank.

[0045] Preferably, the heat source inlet of the sixth heat exchange device in the compressed carbon dioxide energy release unit is connected to the cooling hot tank via a cooling heat pump, and the heat source outlet of the sixth heat exchange device is connected to the cooling cold tank.

[0046] In a second aspect, the present invention provides an operating method of the combined energy storage device system according to the first aspect of the present invention, the operating method comprising the following steps:

[0047] In the energy storage mode, the compressed air energy storage unit draws air from the environment and compresses it to obtain high-pressure air; the high-pressure air is cooled by the first cooling and pressure regulating unit and then enters the high-pressure air storage reservoir in the underground gas-liquid co-containing chamber for storage; the carbon dioxide in the low-pressure carbon dioxide storage reservoir in the above-ground gas-liquid co-containing chamber is compressed by the compressed carbon dioxide energy storage unit to obtain high-pressure carbon dioxide, and the high-pressure carbon dioxide enters the liquid carbon dioxide storage reservoir for storage.

[0048] As a preferred technical solution of the second aspect of the present invention, the operating method comprises the following steps:

[0049] Energy storage mode: When the power consumption is low, the compressor of the compressed air module in the compressed air energy storage unit draws air from the environment for compression. The high-pressure air obtained by each stage of the compressed air module exchanges heat with the heat storage medium in the first heat exchange device and stores the heat. The high-pressure air at the outlet of the first heat exchange device in the last stage of the compressed air module enters the cooler for cooling. The cooled high-pressure air enters the high-pressure air storage reservoir in the underground gas-liquid co-containing chamber for storage. At this time, a pressure difference is generated on both sides of the elastic air membrane in the underground gas-liquid co-containing chamber. Under the combined action of the pressure difference and the turbine, the water in the lower reservoir Water is pressed into the upper reservoir, causing a pressure difference on both sides of the elastic air film in the gas-liquid co-containing chamber on the ground. Under the action of the pressure difference, the carbon dioxide in the low-pressure carbon dioxide gas storage reservoir enters the compressed carbon dioxide energy storage unit and is compressed by the compressor of the compressed carbon dioxide module. The high-pressure carbon dioxide obtained by each stage of the compressed carbon dioxide module exchanges heat with the heat storage medium in the second heat exchange device and stores the heat. The high-pressure carbon dioxide at the outlet of the second heat exchange device in the last stage of the compressed carbon dioxide module enters the third heat exchange device for cooling and liquefaction, and the liquefied carbon dioxide enters the liquid carbon dioxide gas storage reservoir;

[0050] Energy release mode: When the power consumption peaks, the compressed carbon dioxide energy release unit extracts liquid carbon dioxide from the liquid carbon dioxide gas storage reservoir, and the liquid carbon dioxide enters the sixth heat exchange device and is evaporated into a gaseous state. The gaseous carbon dioxide is heated into a high-temperature gas in the fifth heat exchange device of each stage of the compressed carbon dioxide energy release module, and the high-temperature gas drives the turbine to generate electricity. The outlet gas of the turbine in the last stage of the compressed carbon dioxide energy release module enters the low-pressure carbon dioxide gas storage reservoir for storage; at this time, a pressure difference is generated on both sides of the elastic air film in the above-ground gas-liquid co-containing chamber. Under the action of the pressure difference, the water in the upper reservoir is pressed into the lower reservoir, driving the turbine to generate electricity, and a pressure difference is generated on both sides of the elastic air film in the underground gas-liquid co-containing chamber. Under the action of the pressure difference, the high-pressure air in the high-pressure air storage reservoir enters the compressed air energy release unit, and is heated into a high-temperature gas in the fourth heat exchange device of each stage of the compressed air energy release module. The high-temperature gas drives the turbine to generate electricity, and the outlet gas of the turbine in the last stage of the compressed air energy release module is discharged into the environment;

[0051] In the energy storage mode and / or energy release mode, the first cooling pressure regulating unit and / or the second cooling pressure regulating unit are used to regulate the pressure of the upper reservoir and the lower reservoir. When the pressure of the upper reservoir is too high, the regulation method includes any one of the first pressure regulating path, the second pressure regulating path or the third pressure regulating path, or a combination of at least two of them. When the first pressure regulating path and / or the second pressure regulating path are used, the water in the upper reservoir enters the first radiator and / or the second radiator respectively for cooling and reducing pressure, and then returns to the upper reservoir, so that the pressure in the upper reservoir is reduced; when the third pressure regulating path is used, the water in the upper reservoir enters the third heat exchange device through the cooling cold pump to be heated, and then enters the cooling hot tank for storage, so that the water volume in the upper reservoir is reduced, thereby reducing the pressure of the upper reservoir; when the pressure of the upper reservoir is too low, the fourth pressure regulating path is used for regulation, and the water in the cooling hot tank enters the upper reservoir through the cooling heat pump, so that the upper reservoir is heated and the water volume is increased, thereby increasing the pressure of the upper reservoir, and the water in the upper reservoir is selectively discharged into the cooling cold tank until the pressure of the upper reservoir and the lower reservoir are balanced.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] (1) In the combined energy storage device system and its operation method provided by the present invention, a compressed air energy storage unit and a compressed carbon dioxide energy storage unit are connected through a pumped storage unit, so that the upper reservoir of the pumped storage can be shared with the low-pressure carbon dioxide storage reservoir, and the lower reservoir of the pumped storage can be shared with the high-pressure air storage reservoir, thereby improving the space utilization rate of the system.

[0054] (2) The combined energy storage device system and its operation method provided by the present invention use the pumped storage unit as a link and utilize the pressure difference between the upper reservoir and the water reservoir to maintain a constant pressure on the high-pressure side of the compressed air energy storage unit and the low-pressure side of the carbon dioxide energy storage unit, thereby achieving stable operation of the system.

[0055] (3) In the combined energy storage device system and its operation method provided by the present invention, constant pressure and temperature control are performed through the first cooling and pressure regulating unit and the second cooling and pressure regulating unit, the temperature requirement of the compressed air energy storage unit entering the high-pressure air storage reservoir is controlled, the pressure and temperature of the upper reservoir are regulated, the coordination and stability of the pumped storage unit and the compressed carbon dioxide energy storage unit are ensured, and the stable operation of the system is further maintained.

[0056] (4) In the combined energy storage device system and its operation method provided by the present invention, both the upper reservoir and the lower reservoir are closed systems, which can further reduce the evaporation of water in the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A schematic structural diagram of a combined energy storage device system provided in a specific embodiment of the present invention;

[0058] Among them, 1-above-ground gas-liquid co-containing chamber; 2-underground gas-liquid co-containing chamber; 3-low-pressure carbon dioxide gas storage; 4-upper water reservoir; 5-high-pressure air gas storage; 6-lower water reservoir; 7-cooler; 8-third heat exchange device; 9-motor; 10-compressor; 11-first heat exchange device; 12-heat storage cold pump; 13-heat storage cold tank; 14-heat storage hot tank; 15-circulating pump; 16-first radiator; 17-electric and power generation integrated turbine; 18-elastic air membrane; 19-second heat exchange device; 20-second radiator; 21-cooling cold tank; 22-cooling hot tank; 23-sixth heat exchange device; 24-generator; 25-turbine; 26-fourth heat exchange device; 27-heat storage heat pump; 28-fifth heat exchange device; 29-liquid carbon dioxide gas storage; 30-cooling cold pump; 31-cooling heat pump. DETAILED DESCRIPTION

[0059] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0060] It should be understood that, in the description of the present invention, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0061] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0063] In one embodiment, the present invention provides a combined energy storage device system, such as Figure 1 As shown, the combined energy storage device system includes a compressed air energy storage unit, a first cooling and pressure regulating unit, a compressed carbon dioxide energy storage unit and a pumped storage unit;

[0064] The pumped storage unit comprises an above-ground gas-liquid co-accommodating chamber 1 and an underground gas-liquid co-accommodating chamber 2, wherein the above-ground gas-liquid co-accommodating chamber 1 comprises a low-pressure carbon dioxide gas storage reservoir 3 and an upper water reservoir 4 from top to bottom, and the underground gas-liquid co-accommodating chamber 2 comprises a high-pressure air gas storage reservoir 5 and a lower water reservoir 6 from top to bottom;

[0065] The high-pressure air outlet of the compressed air energy storage unit is connected to the high-pressure air storage reservoir 5 via the cooler 7 of the first cooling and pressure regulating unit;

[0066] The low-pressure carbon dioxide gas storage reservoir 3 is connected to a compressed carbon dioxide energy storage unit, and a high-pressure carbon dioxide outlet of the compressed carbon dioxide energy storage unit is connected to a liquid carbon dioxide gas storage reservoir 29 .

[0067] In the combined energy storage device system provided by the present invention, by coupling the pumped storage unit, the compressed air storage unit and the compressed carbon dioxide storage unit, the upper water reservoir 4 of the pumped storage is shared with the low-pressure carbon dioxide storage reservoir 3, and the lower water reservoir 6 of the pumped storage is shared with the high-pressure air storage reservoir 5, thereby improving the space utilization rate of the system.

[0068] In the present invention, water is used as the cooling medium in the cooler 7 and the third heat exchange device 8, and the temperature is generally ≤25°C.

[0069] In some of the embodiments, the compressed air energy storage unit includes at least two levels of compressed air modules.

[0070] In some embodiments, the compressed air module includes an electric motor 9, a compressor 10 and a first heat exchange device 11, the electric motor 9 is connected to the power input end of the compressor 10, the high-pressure air outlet of the compressor 10 is connected to the heat source inlet of the first heat exchange device 11 of this stage, the heat source outlet of the first heat exchange device 11 is connected to the compressor 10 of the next stage compressed air module, and the heat source outlet of the last first heat exchange device 11 along the air flow is connected to the cooler 7.

[0071] In the present invention, the motor 9 drives the compressor 10 to compress the air to generate high-pressure air. The high-pressure air is cooled in the first heat exchange device 11 and the heat storage medium in the first cooling device is heated. The high-pressure air is then cooled by the cooler 7.

[0072] In some embodiments, the cold source inlet of the first heat exchange device 11 is connected to the heat storage cold tank 13 via the heat storage cold pump 12, and the cold source outlet of the first heat exchange device 11 is connected to the heat storage hot tank 14.

[0073] In the present invention, the heat storage medium in the first heat exchange device 11 comes from the cold heat storage tank 13 , and enters the hot heat storage tank 14 for storage after being heated in the first heat exchange device 11 .

[0074] In some embodiments, the first cooling and pressure regulating unit includes a circulation pump 15 , a cooler 7 and a first radiator 16 .

[0075] In some embodiments, the first cooling and pressure regulating unit includes a first cooling path.

[0076] In some embodiments, in the first cooling path, the outlet of the circulation pump 15 is connected to the cold source inlet of the cooler 7, the cold source outlet of the cooler 7 is connected to the first radiator 16, and the outlet of the first radiator 16 is connected to the inlet of the circulation pump 15.

[0077] The first cooling path provided by the present invention is used for circulating cooling of high-pressure air, specifically: the cooler 7 cools the high-pressure air, the heated medium in the cooler 7 enters the first radiator 16 for heat dissipation, and then is pumped back into the cooler 7 through the circulation pump 15, thereby realizing the recycling of the cooling medium (generally water).

[0078] In some embodiments, the first cooling and pressure regulating unit further includes a first pressure regulating path.

[0079] In some embodiments, in the first pressure regulating path, the inlet of the circulating pump 15 is connected to the upper water reservoir 4, the outlet of the circulating pump 15 is connected to the cold source inlet of the cooler 7, the cold source outlet of the cooler 7 is connected to the first radiator 16, and the outlet of the first radiator 16 is connected to the upper water reservoir 4.

[0080] In the first pressure regulating path provided by the present invention, when the pressure of the upper water reservoir 4 is too high, water from the upper water reservoir 4 is pumped into the cooler 7 through the circulating pump 15, and then enters the first radiator 16 for cooling and reducing pressure. The cooled water returns to the upper water reservoir 4, thereby reducing the pressure of the upper water reservoir 4.

[0081] In some of the embodiments, the pumped storage unit further includes an electric and power generating integrated turbine 17 .

[0082] In some of the embodiments, the lower reservoir 6 is connected to the upper reservoir 4 via an integrated electric and power generation turbine 17 .

[0083] In some of the embodiments, elastic air membranes 18 are respectively arranged between the low-pressure carbon dioxide gas storage reservoir 3 and the upper water reservoir 4 and between the high-pressure air gas storage reservoir 5 and the lower water reservoir 6 .

[0084] In the present invention, gaseous low-pressure carbon dioxide is stored in a low-pressure carbon dioxide gas storage reservoir 3, and liquid high-pressure carbon dioxide is stored in a liquid carbon dioxide gas storage reservoir 29 (generally a pressure vessel). The low-pressure carbon dioxide gas storage reservoir 3 (i.e., the gas chamber) and the upper water reservoir 4 (i.e., the water chamber) are shared in the gas-liquid co-containing chamber 1 on the ground, which can generally be formed by natural depressions or artificial excavations, wherein water and carbon dioxide are separated by an elastic gas membrane 18, and the pressures on both sides are the same. The whole is in a closed state except for the connecting pipes, with the gas chamber at the top and the water chamber at the bottom. In the present invention, the lower water reservoir 6 (water chamber) and the high-pressure air gas storage reservoir 5 (gas chamber) are shared in the underground gas-liquid co-containing chamber 2, and the middle is also separated by an elastic gas membrane 18, and the pressures on both sides are the same. The whole is in a closed state except for the connecting pipes, with the gas chamber at the top and the water chamber at the bottom.

[0085] In the present invention, the pressure of the low-pressure carbon dioxide gas storage reservoir 3 and the upper water reservoir 4 is the same, generally maintained slightly higher than the atmospheric pressure, for example, generally 0.102MPa, and the temperature is the ambient temperature. The pressure of the high-pressure air gas storage reservoir 5 and the lower water reservoir 6 can be adjusted according to the local geographical conditions and the underground depth, and the pressure range is 3-20MPa, preferably 10MPa, and the temperature is the underground temperature. In the present invention, the pressure of the liquid carbon dioxide gas storage reservoir 29 is generally 7MPa, and the temperature is preferably 28°C.

[0086] In some of the embodiments, the compressed carbon dioxide energy storage unit includes at least two stages of compressed carbon dioxide modules.

[0087] In the present invention, the number of stages of the compressed air module and the compressed carbon dioxide module can be selected as needed. When the number of stages is small (such as less than four stages), molten salt or heat transfer oil can be used as the heat storage medium. When molten salt is used, the preferred applicable temperature range is 170-390°C, and when heat transfer oil is used, the preferred applicable temperature range is 100-390°C. When the number of stages exceeds four, medium-temperature water heat storage can be used, and the preferred temperature range is 100-200°C. In some embodiments, the compressed carbon dioxide module includes a motor 9, a compressor 10, and a second heat exchange device 19, wherein the motor 9 is connected to the power input end of the compressor 10, the high-pressure carbon dioxide outlet of the compressor 10 is connected to the heat source inlet of the second heat exchange device 19 of this stage, and the heat source outlet of the second heat exchange device 19 is connected to the compressor 10 of the next stage of the compressed carbon dioxide module.

[0088] In the present invention, when low-pressure carbon dioxide enters the compressed carbon dioxide module, the compressor 10 compresses the carbon dioxide under the drive of the motor 9 to obtain high-pressure carbon dioxide. After each stage of compression, it is cooled in the second heat exchange device 19 and finally cooled by the third heat exchange device 8.

[0089] In some embodiments, the compressed carbon dioxide energy storage unit also includes a third heat exchange device 8. In the compressed carbon dioxide energy storage unit, the heat source outlet of the last second heat exchange device 19 along the carbon dioxide flow is connected to the heat source inlet of the third heat exchange device 8, and the heat source outlet of the third heat exchange device 8 is connected to the liquid carbon dioxide gas storage reservoir 29.

[0090] In some embodiments, the cold source inlet of the second heat exchange device 19 is connected to the heat storage cold tank 13 via the heat storage cold pump 12 , and the cold source outlet of the second heat exchange device 19 is connected to the heat storage hot tank 14 .

[0091] In the present invention, the heat storage medium in the second heat exchange device 19 comes from the heat storage cold tank 13, is transported to the second heat exchange device 19 through the heat storage cold pump 12, and returns to the heat storage hot tank 14 after heat exchange in the second heat exchange device 19.

[0092] In some of the embodiments, the combined energy storage device system further includes a compressed air energy release unit.

[0093] In some of the embodiments, the compressed air energy release unit includes a generator 24 and at least one compressed air energy release module, and the generator 24 is connected to the power output end of the compressed air energy release module.

[0094] In some of the embodiments, the compressed air energy release module includes a turbine 25 and a fourth heat exchange device 26, the turbines 25 of adjacent compressed air energy release modules are coaxially connected in series, the cold source outlet of the fourth heat exchange device 26 is connected to the turbine 25 of this stage, the cold source inlet of the fourth heat exchange device 26 is connected to the turbine 25 of the previous stage compressed air energy release module, and the cold source inlet of the first fourth heat exchange device 26 along the air flow is connected to the high-pressure air storage reservoir 5.

[0095] In the present invention, the compressed air enters the compressed air energy release module and is heated into high-temperature gas by the fourth heat exchange device 26, and then drives the turbine 25 to generate electricity, and the gas after power generation is discharged through the air outlet.

[0096] In some embodiments, the heat source inlet of the fourth heat exchange device 26 is connected to the heat storage tank 14 via the heat storage heat pump 27 , and the heat source outlet of the fourth heat exchange device 26 is connected to the heat storage tank 13 .

[0097] In the present invention, the heat storage medium of the fourth heat exchange device 26 comes from the heat storage tank 14, is transported to the fourth heat exchange device 26 by the heat storage heat pump 27, and the heat storage medium after heat exchange in the fourth heat exchange device 26 returns to the heat storage tank 13.

[0098] In some of the embodiments, the combined energy storage device system further includes a compressed carbon dioxide energy release unit.

[0099] In some of the embodiments, the compressed carbon dioxide energy release unit includes a generator 24 and at least one compressed carbon dioxide energy release module, and the generator 24 is connected to the power output end of the compressed carbon dioxide energy release module.

[0100] In some of the embodiments, the compressed carbon dioxide energy release module includes a turbine 25 and a fifth heat exchange device 28, the turbines 25 of adjacent compressed carbon dioxide energy release modules are coaxially connected in series, the cold source outlet of the fifth heat exchange device 28 is connected to the turbine 25 of this stage, and the cold source inlet of the fifth heat exchange device 28 is connected to the turbine 25 of the previous stage compressed carbon dioxide energy release module.

[0101] In some embodiments, the compressed carbon dioxide energy release unit also includes a sixth heat exchange device 23. In the compressed carbon dioxide energy release unit, the cold source inlet of the first fifth heat exchange device 28 along the carbon dioxide flow is connected to the cold source outlet of the sixth heat exchange device 23, and the cold source inlet of the sixth heat exchange device 23 is connected to the liquid carbon dioxide storage reservoir 29.

[0102] In some embodiments, the heat source inlet of the fifth heat exchange device 28 is connected to the heat storage hot tank 14 via the heat storage heat pump 27 , and the heat source outlet of the fifth heat exchange device 28 is connected to the heat storage cold tank 13 .

[0103] In some of the embodiments, the gas outlet of the compressed carbon dioxide energy release unit along the carbon dioxide flow toward the last turbine 25 is connected to the low-pressure carbon dioxide gas storage reservoir 3.

[0104] In the present invention, liquid carbon dioxide is gasified by the sixth heat exchange device 23, and then heated into high-temperature gas in the compressed carbon dioxide energy release module to drive the turbine 25 to generate electricity, and finally obtain low-pressure carbon dioxide and store it in the low-pressure carbon dioxide gas storage reservoir 3. In the present invention, the heat storage medium of the fifth heat exchange device 28 comes from the heat storage hot tank 14, is transported to the fifth heat exchange device 28 through the heat storage heat pump 27, and returns to the heat storage cold tank 13 after the heat exchange in the fifth heat exchange device 28 is completed.

[0105] In some of the embodiments, the combined energy storage device system further includes a second cooling and voltage regulating unit.

[0106] In some embodiments, the second cooling and pressure regulating unit includes a second radiator 20 , a cooling cold tank 21 , a cooling cold pump 30 , a cooling hot tank 22 and a cooling hot pump 31 .

[0107] In some embodiments, the second cooling and pressure regulating unit includes a second cooling path, a second pressure regulating path, a third pressure regulating path, and a fourth pressure regulating path.

[0108] In some embodiments, in the second cooling path, the outlet of the cooling tank 21 is connected to the second radiator 20 via the cooling pump 30 , and the outlet of the second radiator 20 is connected to the cooling tank 21 .

[0109] In some embodiments, in the second pressure regulating path, the upper water reservoir 4 is connected to the inlet of the cooling cold pump 30 , the outlet of the cooling cold pump 30 is connected to the second radiator 20 , and the outlet of the second radiator 20 is connected to the upper water reservoir 4 .

[0110] In some of the embodiments, in the third pressure regulating path, the upper water reservoir 4 is connected to the inlet of the cooling cold pump 30 , and the outlet of the cooling cold pump 30 is connected to the cooling hot tank 22 .

[0111] In some of the embodiments, in the fourth pressure regulating path, the outlet of the cooling hot tank 22 is connected to the upper water reservoir 4 via the cooling heat pump 31 , and the outlet of the upper water reservoir 4 is connected to the cooling cold tank 21 .

[0112] In some embodiments, the cold source inlet of the third heat exchange device 8 in the compressed carbon dioxide energy storage unit is connected to the cooling cold tank 21 via the cooling cold pump 30, and the cold source outlet of the third heat exchange device 8 is connected to the cooling hot tank 22.

[0113] In some embodiments, the heat source inlet of the sixth heat exchange device 23 in the compressed carbon dioxide energy release unit is connected to the cooling hot tank 22 via the cooling heat pump 31, and the heat source outlet of the sixth heat exchange device 23 is connected to the cooling cold tank 21.

[0114] In the present invention, the first cooling and pressure regulating unit and the second cooling and pressure regulating unit can not only realize the cooling of high-pressure gas, but also can be used to regulate the pressure of the upper reservoir 4 and the lower reservoir 6 to keep the pressure constant. When the pressure of the upper reservoir 4 is too high, the first pressure regulating path, the second pressure regulating path and the third pressure regulating path are used for regulation. In the first pressure regulating path and the second pressure regulating path, the water in the upper reservoir 4 is controlled to pass through the first radiator 16 or the second radiator 20 for cooling and pressure reduction, and then returns to the upper reservoir 4, thereby reducing the pressure of the upper reservoir 4. In the present invention, in the third pressure regulating path, the water in the upper reservoir 4 enters the third heat exchange device 8 through the cooling cold pump 30 to be heated, and then enters the cooling hot tank 22 for storage, so that the amount of water in the upper reservoir 4 is reduced, thereby reducing the pressure of the upper reservoir 4. In the present invention, when the pressure of the upper water reservoir 4 is too low, the fourth pressure regulating path is used for regulation, and the water in the cooling hot tank 22 enters the upper water reservoir 4 through the cooling heat pump 31, so that the temperature of the upper water reservoir 4 is increased and the water volume is increased, thereby increasing the pressure of the upper water reservoir 4, and the water in the upper reservoir 4 is selectively discharged into the cooling cold tank 21 until the pressure of the upper water reservoir 4 and the lower water reservoir 6 are balanced.

[0115] In the present invention, the cooling medium in the cooling tank 21 in the second cooling path is sent to the second radiator 20 through the cooling pump 30, is further cooled to the required temperature in the second radiator 20, and then returns to the cooling tank 21, so as to be further adjusted to the required temperature when the temperature of the working fluid in the cooling tank 21 cannot meet the process requirements.

[0116] In another specific embodiment, the present invention provides an operating method of a combined energy storage device system in a specific embodiment, the operating method comprising the following steps:

[0117] In the energy storage mode, the compressed air energy storage unit draws air from the environment and compresses it to obtain high-pressure air; the high-pressure air is cooled by the first cooling and pressure regulating unit and then enters the high-pressure air storage reservoir 5 of the underground gas-liquid co-containing chamber 2 for storage; the carbon dioxide in the low-pressure carbon dioxide storage reservoir 3 of the above-ground gas-liquid co-containing chamber 1 is compressed by the compressed carbon dioxide energy storage unit to obtain high-pressure carbon dioxide, and the high-pressure carbon dioxide enters the liquid carbon dioxide storage reservoir 29 for storage.

[0118] In some embodiments, the operating method comprises the following steps:

[0119] Energy storage mode: When the power consumption is low, the compressor 10 of the compressed air module in the compressed air energy storage unit draws air from the environment for compression. The high-pressure air obtained by each stage of the compressed air module exchanges heat with the heat storage medium in the first heat exchange device 11 and stores the heat. The high-pressure air at the outlet of the first heat exchange device 11 in the last stage of the compressed air module enters the cooler 7 for cooling. The cooled high-pressure air enters the high-pressure air storage reservoir 5 in the underground gas-liquid co-containing chamber 2 for storage. At this time, a pressure difference is generated on both sides of the elastic air membrane 18 in the underground gas-liquid co-containing chamber 2. Under the combined action of the pressure difference and the turbine, the water in the lower reservoir 6 is It is pressed into the upper water reservoir 4, so that a pressure difference is generated on both sides of the elastic air film 18 in the gas-liquid co-containing chamber 1 on the ground. Under the action of the pressure difference, the carbon dioxide in the low-pressure carbon dioxide gas storage reservoir 3 enters the compressed carbon dioxide energy storage unit and is compressed by the compressor 10 of the compressed carbon dioxide module. The high-pressure carbon dioxide obtained by each stage of the compressed carbon dioxide module exchanges heat with the heat storage medium in the second heat exchange device 19 and stores the heat. The high-pressure carbon dioxide at the outlet of the second heat exchange device 19 in the last stage of the compressed carbon dioxide module enters the third heat exchange device 8 for cooling and liquefaction, and the liquefied carbon dioxide enters the liquid carbon dioxide gas storage reservoir 29;

[0120] Energy release mode: When the power consumption peaks, the compressed carbon dioxide energy release unit extracts liquid carbon dioxide from the liquid carbon dioxide gas storage reservoir 29, and the liquid carbon dioxide enters the sixth heat exchange device 23 and is evaporated into gas. The gaseous carbon dioxide is heated into high-temperature gas in the fifth heat exchange device 28 of each stage of the compressed carbon dioxide energy release module. The high-temperature gas drives the turbine 25 to generate electricity. The outlet gas of the turbine 25 in the last stage of the compressed carbon dioxide energy release module enters the low-pressure carbon dioxide gas storage reservoir 3 for storage; at this time, the elastic gas in the gas-liquid co-containment chamber 1 on the ground A pressure difference is generated on both sides of the membrane 18. Under the action of the pressure difference, the water in the upper reservoir 4 is pressed into the lower reservoir 6, driving the turbine to generate electricity. In addition, a pressure difference is generated on both sides of the elastic air membrane 18 in the underground gas-liquid co-containing chamber 2. Under the action of the pressure difference, the high-pressure air in the high-pressure air storage reservoir 5 enters the compressed air energy release unit and is heated into high-temperature gas in the fourth heat exchange device 26 of each stage of the compressed air energy release module. The high-temperature gas drives the turbine 25 to generate electricity. The outlet gas of the turbine 25 in the last stage of the compressed air energy release module is discharged into the environment.

[0121] In the energy storage mode and / or energy release mode, the first cooling pressure regulating unit and / or the second cooling pressure regulating unit are used to regulate the pressure of the upper reservoir 4 and the lower reservoir 6. When the pressure of the upper reservoir 4 is too high, the regulation method includes any one of the first pressure regulating path, the second pressure regulating path or the third pressure regulating path, or a combination of at least two of them. When the first pressure regulating path and / or the second pressure regulating path are used, the water in the upper reservoir 4 enters the first radiator 16 and / or the second radiator 20 respectively to cool down and reduce the pressure, and then returns to the upper reservoir 4, so that the pressure in the upper reservoir 4 is reduced; When the third pressure regulating path is adopted, the water in the upper water reservoir 4 enters the third heat exchange device 8 through the cooling cold pump 30 to be heated, and then enters the cooling hot tank 22 for storage, so that the water volume of the upper water reservoir 4 is reduced, thereby reducing the pressure of the upper water reservoir 4; when the pressure of the upper water reservoir 4 is too low, the fourth pressure regulating path is adopted for regulation, and the water in the cooling hot tank 22 enters the upper water reservoir 4 through the cooling heat pump 31, so that the upper water reservoir 4 is heated and the water volume is increased, thereby increasing the pressure of the upper water reservoir 4, and the water in the upper reservoir 4 is selectively discharged into the cooling cold tank 21 until the pressure of the upper reservoir 4 and the lower reservoir 6 are balanced.

[0122] In summary, the combined energy storage device system and its operating method provided by the present invention realize sharing by adopting an above-ground gas-liquid co-containing chamber and an underground gas-liquid co-containing chamber, coupling pumped storage, compressed air energy storage and compressed carbon dioxide energy storage, thereby improving the space utilization of the system while realizing the operation of the system under stable working conditions and improving the system efficiency.

[0123] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A combined energy storage device system, characterized in that: The combined energy storage device system includes a compressed air energy storage unit, a first cooling and pressure regulating unit, a compressed carbon dioxide energy storage unit and a pumped storage unit; The pumped storage unit comprises an above-ground gas-liquid co-accommodating chamber and an underground gas-liquid co-accommodating chamber, wherein the above-ground gas-liquid co-accommodating chamber comprises, from top to bottom, a low-pressure carbon dioxide gas storage reservoir and an upper water reservoir, and the underground gas-liquid co-accommodating chamber comprises, from top to bottom, a high-pressure air gas storage reservoir and a lower water reservoir; The high-pressure air outlet of the compressed air energy storage unit is connected to the high-pressure air storage reservoir via the cooler of the first cooling and pressure regulating unit; The low-pressure carbon dioxide gas storage reservoir is connected to a compressed carbon dioxide energy storage unit, and a high-pressure carbon dioxide outlet of the compressed carbon dioxide energy storage unit is connected to a liquid carbon dioxide gas storage reservoir.

2. The combined energy storage device system according to claim 1, characterized in that: The compressed air energy storage unit includes at least two levels of compressed air modules; Preferably, the compressed air module comprises an electric motor, a compressor and a first heat exchange device, the electric motor is connected to the power input end of the compressor, the high-pressure air outlet of the compressor is connected to the heat source inlet of the first heat exchange device of this stage, the heat source outlet of the first heat exchange device is connected to the compressor of the next stage compressed air module, and the heat source outlet of the last first heat exchange device along the air flow is connected to the cooler; Preferably, the cold source inlet of the first heat exchange device is connected to the heat storage cold tank via a heat storage cold pump, and the cold source outlet of the first heat exchange device is connected to the heat storage hot tank.

3. The combined energy storage device system according to claim 1 or 2, characterized in that: The first cooling and pressure regulating unit comprises a circulation pump, a cooler and a first radiator; Preferably, the first cooling and pressure regulating unit comprises a first cooling path; Preferably, in the first cooling path, the outlet of the circulation pump is connected to the cold source inlet of the cooler, the cold source outlet of the cooler is connected to the first radiator, and the outlet of the first radiator is connected to the inlet of the circulation pump; Preferably, the first cooling and pressure regulating unit further comprises a first pressure regulating path; Preferably, in the first pressure regulating path, the inlet of the circulating pump is connected to the upper water reservoir, the outlet of the circulating pump is connected to the cold source inlet of the cooler, the cold source outlet of the cooler is connected to the first radiator, and the outlet of the first radiator is connected to the upper water reservoir.

4. The combined energy storage device system according to any one of claims 1 to 3, characterized in that: The pumped storage unit also includes an electric and power generation integrated water turbine; Preferably, the lower reservoir is connected to the upper reservoir via an electric and power generation integrated turbine; Preferably, elastic air membranes are respectively arranged between the low-pressure carbon dioxide gas storage reservoir and the upper water reservoir and between the high-pressure air gas storage reservoir and the lower water reservoir.

5. The combined energy storage device system according to any one of claims 1 to 4, characterized in that: The compressed carbon dioxide energy storage unit includes at least two stages of compressed carbon dioxide modules; Preferably, the compressed carbon dioxide module comprises an electric motor, a compressor and a second heat exchange device, the electric motor is connected to the power input end of the compressor, the high-pressure carbon dioxide outlet of the compressor is connected to the heat source inlet of the second heat exchange device of the current stage, and the heat source outlet of the second heat exchange device is connected to the compressor of the next stage compressed carbon dioxide module; Preferably, the compressed carbon dioxide energy storage unit further comprises a third heat exchange device, in which the heat source outlet of the last second heat exchange device along the flow of carbon dioxide is connected to the heat source inlet of the third heat exchange device, and the heat source outlet of the third heat exchange device is connected to the liquid carbon dioxide gas storage reservoir; Preferably, the cold source inlet of the second heat exchange device is connected to the heat storage cold tank via a heat storage cold pump, and the cold source outlet of the second heat exchange device is connected to the heat storage hot tank.

6. The combined energy storage device system according to any one of claims 1 to 5, characterized in that: The combined energy storage device system also includes a compressed air energy release unit; Preferably, the compressed air energy release unit comprises a generator and at least one compressed air energy release module, and the generator is connected to the power output end of the compressed air energy release module; Preferably, the compressed air energy release module comprises a turbine and a fourth heat exchange device, the turbines of adjacent compressed air energy release modules are coaxially connected in series, the cold source outlet of the fourth heat exchange device is connected to the turbine of the current stage, the cold source inlet of the fourth heat exchange device is connected to the turbine of the previous stage compressed air energy release module, and the cold source inlet of the first fourth heat exchange device along the air flow is connected to the high-pressure air storage reservoir; Preferably, the heat source inlet of the fourth heat exchange device is connected to the heat storage hot tank via a heat storage heat pump, and the heat source outlet of the fourth heat exchange device is connected to the heat storage cold tank.

7. The combined energy storage device system according to any one of claims 1 to 6, characterized in that: The combined energy storage device system also includes a compressed carbon dioxide energy release unit; Preferably, the compressed carbon dioxide energy release unit comprises a generator and at least one compressed carbon dioxide energy release module, and the generator is connected to the power output end of the compressed carbon dioxide energy release module; Preferably, the compressed carbon dioxide energy release module comprises a turbine and a fifth heat exchange device, the turbines of adjacent compressed carbon dioxide energy release modules are coaxially connected in series, the cold source outlet of the fifth heat exchange device is connected to the turbine of the current stage, and the cold source inlet of the fifth heat exchange device is connected to the turbine of the previous stage compressed carbon dioxide energy release module; Preferably, the compressed carbon dioxide energy release unit further comprises a sixth heat exchange device, in which the cold source inlet of the first fifth heat exchange device along the carbon dioxide flow direction is connected to the cold source outlet of the sixth heat exchange device, and the cold source inlet of the sixth heat exchange device is connected to the liquid carbon dioxide gas storage reservoir; Preferably, the heat source inlet of the fifth heat exchange device is connected to the heat storage tank via a heat storage heat pump, and the heat source outlet of the fifth heat exchange device is connected to the heat storage tank; Preferably, the gas outlet of the compressed carbon dioxide energy release unit along the carbon dioxide flow toward the last turbine is connected to a low-pressure carbon dioxide gas storage reservoir.

8. The combined energy storage device system according to any one of claims 1 to 7, characterized in that: The combined energy storage device system also includes a second cooling and voltage regulating unit; Preferably, the second cooling and pressure regulating unit comprises a second radiator, a cooling cold tank, a cooling cold pump, a cooling hot tank and a cooling hot pump; Preferably, the second cooling and pressure regulating unit comprises a second cooling path, a second pressure regulating path, a third pressure regulating path and a fourth pressure regulating path; Preferably, in the second cooling path, the outlet of the cooling tank is connected to the second radiator via a cooling pump, and the outlet of the second radiator is connected to the cooling tank; Preferably, in the second pressure regulating path, the upper water reservoir is connected to the inlet of the cooling pump, the outlet of the cooling pump is connected to the second radiator, and the outlet of the second radiator is connected to the upper water reservoir; Preferably, in the third pressure regulating path, the upper water reservoir is connected to the inlet of the cooling cold pump, and the outlet of the cooling cold pump is connected to the cooling hot tank; Preferably, in the fourth pressure regulating path, the outlet of the cooling hot tank is connected to the upper water reservoir via a cooling heat pump, and the outlet of the upper water reservoir is connected to the cooling cold tank; Preferably, the cold source inlet of the third heat exchange device in the compressed carbon dioxide energy storage unit is connected to the cooling cold tank via a cooling cold pump, and the cold source outlet of the third heat exchange device is connected to the cooling hot tank; Preferably, the heat source inlet of the sixth heat exchange device in the compressed carbon dioxide energy release unit is connected to the cooling hot tank via a cooling heat pump, and the heat source outlet of the sixth heat exchange device is connected to the cooling cold tank.

9. An operating method of a combined energy storage device system according to any one of claims 1 to 8, characterized in that: The operation method comprises the following steps: In the energy storage mode, the compressed air energy storage unit draws air from the environment and compresses it to obtain high-pressure air; the high-pressure air is cooled by the first cooling and pressure regulating unit and then enters the high-pressure air storage reservoir in the underground gas-liquid co-containing chamber for storage; the carbon dioxide in the low-pressure carbon dioxide storage reservoir in the above-ground gas-liquid co-containing chamber is compressed by the compressed carbon dioxide energy storage unit to obtain high-pressure carbon dioxide, and the high-pressure carbon dioxide enters the liquid carbon dioxide storage reservoir for storage.

10. The operating method according to claim 9, characterized in that: The operation method comprises the following steps: Energy storage mode: When the power consumption is low, the compressor of the compressed air module in the compressed air energy storage unit draws air from the environment for compression. The high-pressure air obtained by each stage of the compressed air module exchanges heat with the heat storage medium in the first heat exchange device and stores the heat. The high-pressure air at the outlet of the first heat exchange device in the last stage of the compressed air module enters the cooler for cooling. The cooled high-pressure air enters the high-pressure air storage reservoir in the underground gas-liquid co-containing chamber for storage. At this time, a pressure difference is generated on both sides of the elastic air membrane in the underground gas-liquid co-containing chamber. Under the combined action of the pressure difference and the turbine, the water in the lower reservoir Water is pressed into the upper reservoir, causing a pressure difference on both sides of the elastic air film in the gas-liquid co-containing chamber on the ground. Under the action of the pressure difference, the carbon dioxide in the low-pressure carbon dioxide gas storage reservoir enters the compressed carbon dioxide energy storage unit and is compressed by the compressor of the compressed carbon dioxide module. The high-pressure carbon dioxide obtained by each stage of the compressed carbon dioxide module exchanges heat with the heat storage medium in the second heat exchange device and stores the heat. The high-pressure carbon dioxide at the outlet of the second heat exchange device in the last stage of the compressed carbon dioxide module enters the third heat exchange device for cooling and liquefaction, and the liquefied carbon dioxide enters the liquid carbon dioxide gas storage reservoir; Energy release mode: When the power consumption peaks, the compressed carbon dioxide energy release unit extracts liquid carbon dioxide from the liquid carbon dioxide gas storage reservoir, and the liquid carbon dioxide enters the sixth heat exchange device and is evaporated into a gaseous state. The gaseous carbon dioxide is heated into a high-temperature gas in the fifth heat exchange device of each stage of the compressed carbon dioxide energy release module, and the high-temperature gas drives the turbine to generate electricity. The outlet gas of the turbine in the last stage of the compressed carbon dioxide energy release module enters the low-pressure carbon dioxide gas storage reservoir for storage; at this time, a pressure difference is generated on both sides of the elastic air film in the above-ground gas-liquid co-containing chamber. Under the action of the pressure difference, the water in the upper reservoir is pressed into the lower reservoir, driving the turbine to generate electricity, and a pressure difference is generated on both sides of the elastic air film in the underground gas-liquid co-containing chamber. Under the action of the pressure difference, the high-pressure air in the high-pressure air storage reservoir enters the compressed air energy release unit, and is heated into a high-temperature gas in the fourth heat exchange device of each stage of the compressed air energy release module. The high-temperature gas drives the turbine to generate electricity, and the outlet gas of the turbine in the last stage of the compressed air energy release module is discharged into the environment; In the energy storage mode and / or energy release mode, the first cooling pressure regulating unit and / or the second cooling pressure regulating unit are used to regulate the pressure of the upper reservoir and the lower reservoir. When the pressure of the upper reservoir is too high, the regulation method includes any one of the first pressure regulating path, the second pressure regulating path or the third pressure regulating path, or a combination of at least two of them. When the first pressure regulating path and / or the second pressure regulating path are used, the water in the upper reservoir enters the first radiator and / or the second radiator respectively for cooling and reducing pressure, and then returns to the upper reservoir, so that the pressure in the upper reservoir is reduced; when the third pressure regulating path is used, the water in the upper reservoir enters the third heat exchange device through the cooling cold pump to be heated, and then enters the cooling hot tank for storage, so that the water volume in the upper reservoir is reduced, thereby reducing the pressure of the upper reservoir; when the pressure of the upper reservoir is too low, the fourth pressure regulating path is used for regulation, and the water in the cooling hot tank enters the upper reservoir through the cooling heat pump, so that the upper reservoir is heated and the water volume is increased, thereby increasing the pressure of the upper reservoir, and the water in the upper reservoir is selectively discharged into the cooling cold tank until the pressure of the upper reservoir and the lower reservoir are balanced.

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