Heat storage device in heat storage type compressed air energy storage system and energy storage and release method

Abstract

The invention discloses a heat storage device in a heat storage type compressed air energy storage system and an energy storage and release method. A working mode that a cold tank and a hot tank are shared is adopted, and energy savers are arranged between spherical tanks, so that fatigue damage generated by gas at the tops of the cold tank and the hot tank can be reduced, and energy loss generated by cold and hot mixing can be reduced; specifically, in the energy storage process of the heat storage device, low-temperature water enters another spherical tank after passing through an inverted tank pump and a compressor side heat exchange system in the energy storage and release heat exchange system, the low-temperature water absorbs heat on the compressor side and then is guided into the spherical tank, and steam in the spherical tank flows to an energy saver from a corresponding gas phase pipe; the water in the bypass pipe flows back into the spherical tank after heat exchange and condensation with bypass water flowing through the energy saver, fatigue damage caused by the fact that high-temperature gas in the spherical tank flows into other cold-state spherical tanks is avoided, meanwhile, the water in the bypass pipe flows back into the spherical tank after absorbing heat of the steam through the energy saver, and meanwhile the heat in the steam can be absorbed through the energy saver. And heat loss is avoided.

Description

Technical Field

[0001] The present invention belongs to the field of regenerative compressed air energy storage systems, and particularly relates to a heat storage device and a heat storage and release method in a regenerative compressed air energy storage system. Background Art

[0002] Compressed air energy storage is divided into three processes: compression, storage, and energy release. The required equipment includes air compressors, motors, generators, turbines, expanders, heat exchanger equipment, etc. Among them, air compressors and expanders are the core equipment. In terms of cost proportion, the compressors and expanders each account for about 20%, the heat storage and heat exchange device accounts for 15%-20%, the gas storage system accounts for 20%-30%, the plant land accounts for 10%, and the others account for 10%. The heat storage device is a key equipment in the energy storage system, and has a good market prospect.

[0003] The design of traditional regenerative compressed air energy storage systems is mostly of the double-tank type. The cold tank and the hot tank are independent structures, and their volumes are the same and not less than the heat storage capacity, that is, the total volume of the heat storage system is twice the energy storage capacity. However, with the increase in the scale capacity and duration of compressed air energy storage, the heat storage capacity increases linearly with the increase in heat storage power and heat storage time. The independent double-tank heat storage system of cold and hot tanks needs to double the heat storage volume, thus greatly increasing the tank volume, floor area, and construction and maintenance costs. A traditional 300MW compressed air energy storage power station needs to be equipped with 10 spherical tanks of 3000m 3 with a cost of about 140 million yuan.

[0004] If a working mode of sharing cold and hot tanks is adopted, such as Figure 3 , the number of spherical tanks will be reduced to 6, and the cost will be reduced by 56 million yuan, which is of great significance to the user side and the entire industry. In the traditional tank inversion mode, since the tops of the storage tanks are in a connected state, high-temperature gas will flow into the top of the low-temperature storage tank. On the one hand, it will cause fatigue damage to the equipment. On the other hand, the mixing of cold and heat will cause great energy loss and reduce the thermal efficiency of the system.

[0005] Analyzing the entire energy storage and release process, the No. 1 spherical tank is constantly at a low temperature of about 56°C, and the No. 6 spherical tank is constantly at a high temperature of about 224°C. The service lives of the No. 1 and No. 6 spherical tanks are relatively long; the No. 2-5 spherical tanks periodically bear temperature difference stresses and cause fatigue damage for a long time, and the service lives of the No. 2-5 spherical tanks are relatively short; the service life differences between different devices in the same device are relatively large, reducing the allowable service life of the entire device. Summary of the Invention

[0006] (1)Technical problems to be solved: For the heat storage process system of traditional compressed air energy storage, during the tank inversion process, since the top of the storage tank is in a connected state, high-temperature gas will flow into the top of the low-temperature storage tank. On the one hand, it will cause fatigue damage to the equipment and reduce the service life of the equipment. On the other hand, the mixing of hot and cold will cause great energy loss and reduce the thermal efficiency of the system. The present invention provides a heat storage device and a heat storage and release energy method in a regenerative compressed air energy storage system to solve the above problems.

[0007] (2) The technical solutions adopted by the present invention are as follows: A heat storage device in a regenerative compressed air energy storage system includes an inversion pump, a constant pressure water tank, a constant pressure water pump, a heat storage and release energy heat exchange system, 6 spherical tanks, and at least 5 economizers. Among them, 5 spherical tanks correspond to 5 economizers one by one, and the economizers are arranged on the tops of the corresponding spherical tanks. The tops of the 6 spherical tanks are connected by a gas phase pipe. The water outlets of the 6 spherical tanks are respectively connected to an outlet pipeline, and the water inlets of the 6 spherical tanks are respectively connected to an inlet pipeline. A valve two is arranged on the inlet pipeline. Each outlet pipeline is connected to the inlet end of the inversion pump. A valve three is arranged on the outlet pipeline. The outlet end of the inversion pump is connected to the heat storage and release energy heat exchange system. Each inlet pipeline is connected to the heat storage and release energy heat exchange system. The outlet end of the inversion pump is connected to at least 5 bypass pipes. The 5 bypass pipes correspond to the 5 economizers. The bypass pipe is connected to the medium inlet of the corresponding economizer. The medium outlet of the economizer is communicated with the corresponding spherical tank. A valve four is arranged on the bypass pipe. The gas phase pipe can exchange heat with the medium inside the economizer through the economizer. The bottom of one of the spherical tanks is connected to the constant pressure water tank through a constant pressure pipe. A regulating valve is arranged on the constant pressure pipe. The return water pipe of the constant pressure water tank is sequentially connected to the constant pressure water pump and the spherical tank.

[0008] Furthermore, the technical solution lies in that a valve five is arranged on the gas phase pipe between each spherical tank and the corresponding economizer, and the valve five is in an open state all the time.

[0009] A method for storing and releasing energy using a heat storage device in a regenerative compressed air energy storage system. The heat storage device has 6 spherical tanks, numbered 1 - 6 in sequence. The economizers corresponding to spherical tanks 2 - 6 are economizers 2 - 6 in sequence, and the bypass pipes corresponding to economizers 2 - 6 are bypass pipes 2 - 6 in sequence. The bottom of spherical tank 1 is connected to a constant pressure water tank. Before energy storage starts, the states of each spherical tank are as follows: spherical tanks 1 - 5 contain low - temperature water, spherical tank 6 is pre - filled with a part of high - temperature water at 224 °C, and there is a mixed gas of nitrogen and water vapor in spherical tanks 1 - 6 and the gas phase pipes. During the entire heat storage process and the energy storage and release process, the gas phase pressure in the system is detected in real - time. Since the change in the system temperature will affect the magnitude of the system pressure, the influence is overcome by draining and replenishing water in spherical tank 1 to ensure the constancy of the system pressure throughout the process. When the system pressure rises, the opening of the regulating valve between spherical tank 1 and the constant pressure water tank is adjusted to regulate the drainage volume to ensure the stability of the system pressure. When the system pressure drops, the constant pressure water pump between spherical tank 1 and the constant pressure water tank is used to control the replenishing water volume, thereby ensuring the stability of the system pressure.

[0010] The energy storage method of the heat storage device includes the following processes:

[0011] A1: Open valve three on the outlet pipeline of spherical tank 5, valve two on the inlet pipeline of spherical tank 6, and valve four on bypass pipe 6. Start the transfer pump so that the low - temperature water in spherical tank 5 enters spherical tank 6 after passing through the transfer pump and the compressor - side heat exchange system in the energy storage and release heat exchange system. The low - temperature water in spherical tank 5 absorbs the heat on the compressor side and then is introduced into spherical tank 6. Part of the low - temperature water remains in spherical tank 5, and the liquid level of spherical tank 6 rises. Moreover, the steam in spherical tank 6 flows from the corresponding gas phase pipe to economizer 6 and exchanges heat and condenses with the bypass water flowing through economizer 6 and then returns to spherical tank 6. The bypass water in economizer 6 comes from bypass pipe 6, and the transfer pump sends the water in spherical tank 5 to bypass pipe 6. After completion, close valve three on the outlet pipeline of spherical tank 5, valve two on the inlet pipeline of spherical tank 6, and valve four on bypass pipe 6, and turn off the transfer pump.

[0012] A2: Open Valve 3 on the outlet pipeline of Storage Tank 4, Valve 2 on the inlet pipeline of Storage Tank 5, and Valve 4 on the bypass pipeline 5. Start the transfer pump so that the low-temperature water in Storage Tank 4 enters Storage Tank 5 after passing through the transfer pump and the compressor-side heat exchange system in the energy storage and release heat exchange system. The low-temperature water in Storage Tank 4 absorbs the heat on the compressor side and then is introduced into Storage Tank 5, leaving some low-temperature water in Storage Tank 4. The liquid level of Storage Tank 5 rises, and the steam in Storage Tank 5 flows from the corresponding gas phase pipeline to the No. 5 energy saver, where it exchanges heat and condenses with the bypass water flowing through the No. 5 energy saver and then returns to Storage Tank 5. The bypass water in the No. 5 energy saver comes from the No. 5 bypass pipeline. The transfer pump sends the water in Storage Tank 4 to the No. 5 bypass pipeline. After completion, close Valve 3 on the outlet pipeline of Storage Tank 4, Valve 2 on the inlet pipeline of Storage Tank 5, and Valve 4 on the bypass pipeline 5, and turn off the transfer pump.

[0013] A3: Open Valve 3 on the outlet pipeline of Storage Tank 3, Valve 2 on the inlet pipeline of Storage Tank 4, and Valve 4 on the bypass pipeline 4. Start the transfer pump so that the low-temperature water in Storage Tank 3 enters Storage Tank 4 after passing through the transfer pump and the compressor-side heat exchange system in the energy storage and release heat exchange system. The low-temperature water in Storage Tank 3 absorbs the heat on the compressor side and then is introduced into Storage Tank 4, leaving some low-temperature water in Storage Tank 3. The liquid level of Storage Tank 4 rises, and the steam in Storage Tank 4 flows from the corresponding gas phase pipeline to the No. 4 energy saver, where it exchanges heat and condenses with the bypass water flowing through the No. 4 energy saver and then returns to Storage Tank 4. The bypass water in the No. 4 energy saver comes from the No. 4 bypass pipeline. The transfer pump sends the water in Storage Tank 3 to the No. 4 bypass pipeline. After completion, close Valve 3 on the outlet pipeline of Storage Tank 3, Valve 2 on the inlet pipeline of Storage Tank 4, and Valve 4 on the bypass pipeline 4, and turn off the transfer pump.

[0014] A4: Open Valve 3 on the outlet pipeline of Storage Tank 2, Valve 2 on the inlet pipeline of Storage Tank 3, and Valve 4 on the bypass pipeline 3. Start the transfer pump so that the low-temperature water in Storage Tank 2 enters Storage Tank 3 after passing through the transfer pump and the compressor-side heat exchange system in the energy storage and release heat exchange system. The low-temperature water in Storage Tank 2 absorbs the heat on the compressor side and then is introduced into Storage Tank 3, leaving some low-temperature water in Storage Tank 2. The liquid level of Storage Tank 3 rises, and the steam in Storage Tank 3 flows from the corresponding gas phase pipeline to the No. 3 energy saver, where it exchanges heat and condenses with the bypass water flowing through the No. 3 energy saver and then returns to Storage Tank 3. The bypass water in the No. 3 energy saver comes from the No. 3 bypass pipeline. The transfer pump sends the water in Storage Tank 2 to the No. 3 bypass pipeline. After completion, close Valve 3 on the outlet pipeline of Storage Tank 2, Valve 2 on the inlet pipeline of Storage Tank 3, and Valve 4 on the bypass pipeline 3, and turn off the transfer pump.

[0015] A5: Open Valve 3 on the outlet pipeline of Storage Tank 1, Valve 2 on the inlet pipeline of Storage Tank 2, and Valve 4 on the bypass pipeline 2. Start the transfer pump so that the low-temperature water in Storage Tank 1 enters Storage Tank 2 after passing through the transfer pump and the compressor-side heat exchange system in the energy storage and release heat exchange system. The low-temperature water in Storage Tank 1 absorbs the heat on the compressor side and then is introduced into Storage Tank 2, leaving some low-temperature water in Storage Tank 1. The liquid level of Storage Tank 2 rises, and the steam in Storage Tank 2 flows from the corresponding gas-phase pipeline to Energy Saver 2, where it exchanges heat and condenses with the bypass water flowing through Energy Saver 2 and then returns to Storage Tank 2. The bypass water in Energy Saver 2 comes from bypass pipeline 2, and the transfer pump sends the water in Storage Tank 1 to bypass pipeline 2. After completion, close Valve 3 on the outlet pipeline of Storage Tank 1, Valve 2 on the inlet pipeline of Storage Tank 2, and Valve 4 on the bypass pipeline 2, and then turn off the transfer pump.

[0016] Through the above processes A1 - A5, the heat energy on the compressor side in the energy storage and release heat exchange system is stored.

[0017] The energy release method of the heat storage device includes the following processes:

[0018] B1: Open Valve 3 on the outlet pipeline of Storage Tank 2, Valve 2 on the inlet pipeline of Storage Tank 1, and start the transfer pump so that the high-temperature water in Storage Tank 2 enters Storage Tank 1 after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in Storage Tank 2 is released to the expander side and then introduced into Storage Tank 1, leaving some high-temperature water in Storage Tank 2. The liquid level of Storage Tank 1 rises. After completion, close Valve 3 on the outlet pipeline of Storage Tank 2, Valve 2 on the inlet pipeline of Storage Tank 1, and the transfer pump.

[0019] B2: Open Valve 3 on the outlet pipeline of Storage Tank 3, Valve 2 on the inlet pipeline of Storage Tank 2, and Valve 4 on the bypass pipeline 2, and start the transfer pump so that the high-temperature water in Storage Tank 3 enters Storage Tank 2 after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in Storage Tank 3 is released to the expander side and then introduced into Storage Tank 2, leaving some high-temperature water in Storage Tank 3. The liquid level of Storage Tank 2 rises. After completion, close Valve 3 on the outlet pipeline of Storage Tank 3, Valve 2 on the inlet pipeline of Storage Tank 2, Valve 4 on the bypass pipeline 2, and the transfer pump.

[0020] B3: Open Valve 3 on the outlet pipeline of Storage Tank 4, Valve 2 on the inlet pipeline of Storage Tank 3, and Valve 4 on the bypass pipeline 3, and start the transfer pump so that the high-temperature water in Storage Tank 4 enters Storage Tank 3 after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in Storage Tank 4 is released to the expander side and then introduced into Storage Tank 3, leaving some high-temperature water in Storage Tank 4. The liquid level of Storage Tank 3 rises. After completion, close Valve 3 on the outlet pipeline of Storage Tank 4, Valve 2 on the inlet pipeline of Storage Tank 3, Valve 4 on the bypass pipeline 3, and the transfer pump.

[0021] B4: Open the valve three on the outlet pipeline of the No. 5 spherical tank, the valve two on the inlet pipeline of the No. 4 spherical tank, and the valve four on the No. 4 bypass pipe. Start the transfer pump so that the high-temperature water in the No. 5 spherical tank enters the No. 4 spherical tank after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in the No. 5 spherical tank is released to the expander side and then introduced into the No. 4 spherical tank. Leave part of the high-temperature water in the No. 5 spherical tank, and the liquid level of the No. 4 spherical tank rises. After completion, close the valve three on the outlet pipeline of the No. 5 spherical tank, the valve two on the inlet pipeline of the No. 4 spherical tank, the valve four on the No. 4 bypass pipe, and the transfer pump.

[0022] B5: Open the valve three on the outlet pipeline of the No. 6 spherical tank, the valve two on the inlet pipeline of the No. 5 spherical tank, and the valve four on the No. 5 bypass pipe. Start the transfer pump so that the high-temperature water in the No. 6 spherical tank enters the No. 5 spherical tank after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in the No. 6 spherical tank is released to the expander side and then introduced into the No. 5 spherical tank. Leave part of the high-temperature water in the No. 6 spherical tank, and the liquid level of the No. 5 spherical tank rises. After completion, close the valve three on the outlet pipeline of the No. 6 spherical tank, the valve two on the inlet pipeline of the No. 5 spherical tank, the valve four on the No. 5 bypass pipe, and the transfer pump.

[0023] Through the above processes B1 - B5, the release of thermal energy to the expander side in the energy storage and release heat exchange system is achieved.

[0024] (3) Due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows: The present invention adopts a working mode of sharing hot and cold tanks. By setting the energy saver between the spherical tanks, it can not only reduce the fatigue damage caused by the gas at the top of the hot and cold tanks, but also reduce the energy loss caused by the mixing of hot and cold. Specifically, during the energy storage process of the energy storage device, for example, the low-temperature water in the No. 5 spherical tank enters the No. 6 spherical tank after passing through the transfer pump and the compressor-side heat exchange system in the energy storage and release heat exchange system. The low-temperature water in the No. 5 spherical tank absorbs the heat from the compressor side and then is introduced into the No. 6 spherical tank. Leave part of the low-temperature water in the No. 5 spherical tank, and the liquid level of the No. 6 spherical tank rises. And the steam in the No. 6 spherical tank flows to the No. 6 energy saver through the corresponding gas phase pipe. During the energy storage stage, the bypass water flowing through the No. 6 energy saver is low-temperature water, so the steam can be condensed. And the nitrogen is supercooled and then enters the No. 5 tank, avoiding the high-temperature gas in the No. 6 spherical tank from entering other cold spherical tanks and causing fatigue damage. At the same time, the water in the No. 6 bypass pipe absorbs the heat of the steam through the No. 6 energy saver and then flows back into the No. 6 spherical tank. In the subsequent processes of the water in the No. 4 spherical tank flowing to the No. 5 spherical tank, the water in the No. 3 spherical tank flowing to the No. 4 spherical tank, the water in the No. 2 spherical tank flowing to the No. 3 spherical tank, and the water in the No. 1 spherical tank flowing to the No. 2 spherical tank, it can all avoid the high-temperature gas from entering other cold spherical tanks and causing fatigue damage, and at the same time can absorb the heat in the steam through the energy saver to avoid heat loss.

[0025] By connecting a constant-pressure water tank to the bottom of the No. 1 spherical tank, during the energy storage and release process, the gas-phase pressure in the system is detected in real time. Since the change in the system temperature will affect the system pressure, the influence is overcome by draining and replenishing water in the No. 1 spherical tank to ensure the constancy of the system pressure throughout the process. When the system pressure rises, the opening of the regulating valve between the No. 1 spherical tank and the constant-pressure water tank is adjusted to regulate the drainage volume, thereby ensuring the stability of the system pressure. When the system pressure drops, the constant-pressure water pump between the No. 1 spherical tank and the constant-pressure water tank is used to control the water replenishment volume, thereby ensuring the stability of the system pressure. For example, before the low-temperature water in the No. 5 spherical tank enters the No. 6 spherical tank after passing through the transfer pump and the compressor-side heat exchange system in the energy storage and release heat exchange system, the No. 6 spherical tank is pre-filled with hot water. The No. 6 spherical tank mainly contains a mixture of water vapor and nitrogen. After the high-temperature water enters the No. 6 spherical tank, new water vapor is generated. At the same time, as the liquid level rises, the water vapor enters the gas-phase pipe at the top of the No. 6 spherical tank and is condensed after passing through the energy saver, resulting in a decrease in the gas-phase pressure in the system. Therefore, it is necessary to use the constant-pressure water tank to replenish water to the No. 1 spherical tank to increase the gas-phase pressure in the system and ensure the constancy of the system pressure. After the water in the No. 4 spherical tank reaches the No. 5 spherical tank, since both the No. 5 and No. 6 spherical tanks contain high-temperature water, steam is generated, resulting in an increase in the gas-phase pressure in the system. Therefore, it is necessary to drain the water in the No. 1 spherical tank to the constant-pressure water tank to restore the pressure (the process of the water in the No. 3 spherical tank reaching the No. 4 spherical tank, the water in the No. 2 spherical tank reaching the No. 3 spherical tank, and the water in the No. 1 spherical tank reaching the No. 2 spherical tank is the same). During the energy release process, for example, the high-temperature water in the No. 2 spherical tank enters the No. 1 spherical tank after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in the No. 2 spherical tank is released to the expander side and then introduced into the No. 1 spherical tank, leaving some high-temperature water in the No. 2 spherical tank. Since the No. 2 spherical tank contains high-temperature water, high-temperature water vapor will be generated in the No. 2 spherical tank, resulting in an increase in the gas-phase pressure in the system. Therefore, it is necessary to drain the water in the No. 1 spherical tank to the constant-pressure water tank to restore the pressure. After the water in the No. 3 spherical tank reaches the No. 2 spherical tank, the No. 2 spherical tank changes from a hot state to a cold state, resulting in a decrease in the gas-phase pressure in the system. It is necessary to replenish water from the constant-pressure water tank to the No. 1 spherical tank to restore the pressure (the same is true for the water in the No. 4 spherical tank reaching the No. 3 spherical tank, the water in the No. 5 spherical tank reaching the No. 4 spherical tank, and the water in the No. 6 spherical tank reaching the No. 5 spherical tank).

[0026] During the energy release process, for example, when the water in the No. 3 spherical tank reaches the No. 2 spherical tank, since the low-temperature water enters the No. 2 spherical tank, the No. 2 spherical tank is at a low temperature, and the nitrogen in it is at a low temperature. As the liquid level in the No. 2 spherical tank rises, the nitrogen will enter other spherical tanks through the gas-phase pipe. However, the high-temperature water in the No. 3 spherical tank supplies the No. 2 energy saver, so the nitrogen will be heated by the energy saver, thus avoiding fatigue damage caused by the flow of low-temperature nitrogen to high-temperature spherical tanks.

[0027] During both the energy storage and release processes, during each backflow process, leaving a portion of water in the drained spherical tank can prevent the spherical tank from directly encountering water with a large temperature difference when replenishing water into the spherical tank, thereby avoiding fatigue damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 is Figure 1 a schematic diagram of the structure on the other side of the state shown;

[0030] Figure 3 is a diagram of the tank inversion in the prior art;

[0031] Figure 4 is a schematic diagram of the structure of the energy saver;

[0032] Figure 5 is a stress analysis diagram of the top of the cold tank after the hot tank steam enters the top of the cold tank without adding the energy saver during the energy storage stage;

[0033] Figure 6 is a stress analysis diagram of the top of the cold tank after the hot tank steam enters the top of the cold tank with the addition of the energy saver during the energy storage stage;

[0034] Figure 7 is a stress analysis diagram of the top of the cold tank after the nitrogen in the cold tank enters the top of the hot tank without adding the energy saver during the energy release stage;

[0035] Figure 8 is a stress analysis diagram of the top of the cold tank after the nitrogen in the cold tank enters the top of the hot tank with the addition of the energy saver during the energy release stage.

[0036] Reference numerals: SPH1, No. 1 spherical tank; SPH2, No. 2 spherical tank; SPH3, No. 3 spherical tank; SPH4, No. 4 spherical tank; SPH5, No. 5 spherical tank; SPH6, No. 6 spherical tank; E1, No. 1 energy saver 1; E2, No. 2 energy saver; E3, No. 3 energy saver; E4, No. 4 energy saver; E5, No. 5 energy saver; E6, No. 6 energy saver; P1, tank inversion pump; E7, compressor side heat exchange system; E8, expander side heat exchange system; P2, constant pressure water pump; C1, constant pressure water tank; Bypass-6, No. 6 bypass pipe; Bypass-5, No. 5 bypass pipe; Bypass-4, No. 5 bypass pipe; Bypass-3, No. 3 bypass pipe; Bypass-2, No. 2 bypass pipe; Bypass-1, No. 1 bypass pipe. DETAILED DESCRIPTION OF THE INVENTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0038] As Figures 1-8 shown. A heat storage device in a regenerative compressed air energy storage system includes an inverted tank pump P1, a constant pressure water tank C1, a constant pressure water pump P2, a heat storage and release heat exchange system, 6 spherical tanks, and 6 energy savers. The 6 spherical tanks and the 6 energy savers correspond to each other one by one, and the energy savers are arranged on the tops of the spherical tanks. The tops of the 6 spherical tanks are connected by a gas phase pipe. The water outlets of the 6 spherical tanks are respectively connected to an outlet pipeline, and the water inlets of the 6 spherical tanks are respectively connected to an inlet pipeline. A second valve is arranged on the inlet pipeline. Each outlet pipeline is connected to the water inlet end of the inverted tank pump P1, and a third valve is arranged on the outlet pipeline. The water outlet end of the inverted tank pump P1 is connected to the heat storage and release heat exchange system. Each inlet pipeline is connected to the heat storage and release heat exchange system. The water outlet end of the inverted tank pump P1 is connected to 6 bypass pipes. The 6 bypass pipes correspond to the 6 energy savers. The bypass pipes are connected to the medium inlets of the corresponding energy savers. The medium outlets of the energy savers are communicated with the corresponding spherical tanks. A fourth valve is arranged on the bypass pipes. The gas phase pipe can exchange heat with the medium inside the energy saver after passing through the energy saver. The bottom of one of the spherical tanks is connected to the constant pressure water tank C1 through a constant pressure pipe, and a regulating valve is arranged on the constant pressure pipe. The return water pipe of the constant pressure water tank C1 is successively connected to the constant pressure water pump P2 and the spherical tank. A fifth valve is arranged on the gas phase pipe between each spherical tank and the corresponding energy saver, and the fifth valve is in an open state all the time. The heat storage and release heat exchange system includes a compressor side heat exchange system E7 and an expander side heat exchange system E8. The water outlet end of the inverted tank pump P1 is respectively connected to the compressor side heat exchange system E7 and the expander side heat exchange system E8 through a branch pipeline, and valves are arranged before and after the compressor side heat exchange system E7 and the expander side heat exchange system E8 for switching between the two systems. A temperature detector is arranged on the pipeline after the gas phase pipe passes through the energy saver to detect the gas phase temperature after passing through the energy saver. The energy saver includes a closed shell, and two partition plates are arranged at both ends inside the shell. The two partition plates divide the internal space of the shell into three cavities. A plurality of tube bundles are directly arranged between the two partition plates. The tube bundles communicate the cavities at both ends of the shell. Nozzles one are arranged at both ends of the cavities at both ends of the shell, and the nozzles one are used for connecting the gas phase pipe. Nozzles two are arranged at both ends of the cavity in the middle of the shell, and the nozzles two are used for connecting the bypass pipes. Usage scenario of the No. 1 energy saver: After the heat storage is completed, the No. 1-5 spherical tanks are hot tanks. This process takes about 8 hours, which easily causes the temperature of the No. 1 spherical tank to continuously rise. Through the energy saver on the top of the No. 1 spherical tank, the low-temperature water in the No. 1 spherical tank is used to cool the gas on the top of the No. 1 spherical tank, which can reduce the temperature of the gas on the top of the No. 1 spherical tank, thereby preventing the system from overpressurizing.

[0039] A method for storing and releasing energy in a heat storage device of a regenerative compressed air energy storage system, characterized in that there are 6 spherical tanks in the heat storage device, which are successively numbered 1-6 spherical tanks SPH6. The corresponding economizers of the 1-6 spherical tanks SPH6 are successively numbered 1-6 economizers E6. The corresponding bypass pipes of the 1-6 economizers E6 are successively numbered 1-6 bypass pipes Bypass-6. The bottom of the 1st spherical tank SPH1 is connected to a constant pressure water tank C1. The states of each spherical tank before energy storage start: the 1-5th spherical tanks SPH5 are all filled with low-temperature water, the 6th spherical tank SPH6 is pre-filled with some high-temperature water at 224 °C, and there is a mixed gas of nitrogen and water vapor in the 1-6th spherical tanks SPH6 and the gas phase pipes. During the entire heat storage process, the heat storage temperature is 224 °C, the corresponding saturation pressure is 2.5 MPa, and the constant pressure is 2.6 MPa. During the energy storage and release process, the gas phase pressure in the system is detected in real time. Due to the change of the system temperature, it will affect the size of the system pressure. This influence is overcome by draining and replenishing water in the 1st spherical tank SPH1 to ensure the constancy of the system pressure throughout the process. When the system pressure rises, the opening of the regulating valve between the 1st spherical tank SPH1 and the constant pressure water tank C1 is adjusted to regulate the drainage volume to ensure the stability of the system pressure. When the system pressure drops, the constant pressure water pump P2 between the 1st spherical tank SPH1 and the constant pressure water tank C1 is used to control the replenishing water volume, thereby ensuring the stability of the system pressure.

[0040] The energy storage method of the heat storage device includes the following processes:

[0041] A1: Open the valve three on the outlet pipeline of the 5th spherical tank SPH5, the valve two on the inlet pipeline of the 6th spherical tank SPH6, and the valve four on the 6th bypass pipe Bypass-6. Start the transfer pump P1, so that the low-temperature water in the 5th spherical tank SPH5 enters the 6th spherical tank SPH6 after passing through the transfer pump P1 and the compressor side heat exchange system E7 in the energy storage and release heat exchange system. The low-temperature water in the 5th spherical tank SPH5 absorbs the heat on the compressor side and is introduced into the 6th spherical tank SPH6. Part of the low-temperature water remains in the 5th spherical tank SPH5. The liquid level of the 6th spherical tank SPH6 rises, and the steam in the 6th spherical tank SPH6 flows from the corresponding gas phase pipe to the 6th economizer E6, and exchanges heat and condenses with the bypass water flowing through the 6th economizer E6 and then returns to the 6th spherical tank SPH6. The bypass water in the 6th economizer E6 comes from the 6th bypass pipe Bypass-6. The transfer pump P1 sends the water in the 5th spherical tank SPH5 to the 6th bypass pipe Bypass-6. After completion, close the valve three on the outlet pipeline of the 5th spherical tank SPH5, the valve two on the inlet pipeline of the 6th spherical tank SPH6, and the valve four on the 6th bypass pipe Bypass-6, and turn off the transfer pump P1.

[0042] A2: Open Valve Three on the outlet pipeline of SPH4 in Ball Tank No. 4, Valve Two on the inlet pipeline of SPH5 in Ball Tank No. 5, and Valve Four on Bypass-4Bypass-5 of the No. 5 bypass pipeline. Start the transfer pump P1 so that the low-temperature water in SPH4 of Ball Tank No. 4 enters SPH5 of Ball Tank No. 5 after passing through the transfer pump P1 and the compressor-side heat exchange system E7 in the energy storage and release heat exchange system. The low-temperature water in SPH4 of Ball Tank No. 4 absorbs the heat on the compressor side and then is introduced into SPH5 of Ball Tank No. 5. Part of the low-temperature water remains in SPH4 of Ball Tank No. 4, the liquid level of SPH5 in Ball Tank No. 5 rises, and the steam in SPH5 of Ball Tank No. 5 flows from the corresponding gas phase pipeline to the No. 5 energy saver E5, and exchanges heat and condenses with the bypass water flowing through the No. 5 energy saver E5 and then returns to SPH5 of Ball Tank No. 5. The bypass water in the No. 5 energy saver E5 comes from Bypass-4Bypass-5 of the No. 5 bypass pipeline. The transfer pump P1 sends the water in SPH4 of Ball Tank No. 4 to Bypass-4Bypass-5 of the No. 5 bypass pipeline. After completion, close Valve Three on the outlet pipeline of SPH4 in Ball Tank No. 4, Valve Two on the inlet pipeline of SPH5 in Ball Tank No. 5, and Valve Four on Bypass-4Bypass-5 of the No. 5 bypass pipeline, and turn off the transfer pump P1.

[0043] A3: Open Valve Three on the outlet pipeline of SPH3 in Ball Tank No. 3, Valve Two on the inlet pipeline of SPH4 in Ball Tank No. 4, and Valve Four on the No. 4 bypass pipeline. Start the transfer pump P1 so that the low-temperature water in SPH3 of Ball Tank No. 3 enters SPH4 of Ball Tank No. 4 after passing through the transfer pump P1 and the compressor-side heat exchange system E7 in the energy storage and release heat exchange system. The low-temperature water in SPH3 of Ball Tank No. 3 absorbs the heat on the compressor side and then is introduced into SPH4 of Ball Tank No. 4. Part of the low-temperature water remains in SPH3 of Ball Tank No. 3, the liquid level of SPH4 in Ball Tank No. 4 rises, and the steam in SPH4 of Ball Tank No. 4 flows from the corresponding gas phase pipeline to the No. 4 energy saver E4, and exchanges heat and condenses with the bypass water flowing through the No. 4 energy saver E4 and then returns to SPH4 of Ball Tank No. 4. The bypass water in the No. 4 energy saver E4 comes from the No. 4 bypass pipeline. The transfer pump P1 sends the water in SPH3 of Ball Tank No. 3 to the No. 4 bypass pipeline. After completion, close Valve Three on the outlet pipeline of SPH3 in Ball Tank No. 3, Valve Two on the inlet pipeline of SPH4 in Ball Tank No. 4, and Valve Four on the No. 4 bypass pipeline, and turn off the transfer pump P1.

[0044] A4: Open Valve Three on the outlet pipeline of Spherical Tank 2 (SPH2), Valve Two on the inlet pipeline of Spherical Tank 3 (SPH3), and Valve Four on Bypass Pipe 3 (Bypass-3). Start the transfer pump P1 so that the low-temperature water in Spherical Tank 2 (SPH2) enters Spherical Tank 3 (SPH3) after passing through the transfer pump P1 and the compressor-side heat exchange system E7 in the energy storage and release heat exchange system. The low-temperature water in Spherical Tank 2 (SPH2) absorbs the heat on the compressor side and then is introduced into Spherical Tank 3 (SPH3). Part of the low-temperature water remains in Spherical Tank 2 (SPH2). The liquid level of Spherical Tank 3 (SPH3) rises, and the steam in Spherical Tank 3 (SPH3) flows from the corresponding gas-phase pipe to the No. 3 energy saver E3, where it exchanges heat and condenses with the bypass water flowing through the No. 3 energy saver E3 and then returns to Spherical Tank 3 (SPH3). The bypass water in the No. 3 energy saver E3 comes from Bypass Pipe 3 (Bypass-3). The transfer pump P1 sends the water in Spherical Tank 2 (SPH2) to Bypass Pipe 3 (Bypass-3). After completion, close Valve Three on the outlet pipeline of Spherical Tank 2 (SPH2), Valve Two on the inlet pipeline of Spherical Tank 3 (SPH3), and Valve Four on Bypass Pipe 3 (Bypass-3), and then turn off the transfer pump P1.

[0045] A5: Open Valve Three on the outlet pipeline of Spherical Tank 1 (SPH1), Valve Two on the inlet pipeline of Spherical Tank 2 (SPH2), and Valve Four on Bypass Pipe 2 (Bypass-2). Start the transfer pump P1 so that the low-temperature water in Spherical Tank 1 (SPH1) enters Spherical Tank 2 (SPH2) after passing through the transfer pump P1 and the compressor-side heat exchange system E7 in the energy storage and release heat exchange system. The low-temperature water in Spherical Tank 1 (SPH1) absorbs the heat on the compressor side and then is introduced into Spherical Tank 2 (SPH2). Part of the low-temperature water remains in Spherical Tank 1 (SPH1). The liquid level of Spherical Tank 2 (SPH2) rises, and the steam in Spherical Tank 2 (SPH2) flows from the corresponding gas-phase pipe to the No. 2 energy saver E2, where it exchanges heat and condenses with the bypass water flowing through the No. 2 energy saver E2 and then returns to Spherical Tank 2 (SPH2). The bypass water in the No. 2 energy saver E2 comes from Bypass Pipe 2 (Bypass-2). The transfer pump P1 sends the water in Spherical Tank 1 (SPH1) to Bypass Pipe 2 (Bypass-2). After completion, close Valve Three on the outlet pipeline of Spherical Tank 1 (SPH1), Valve Two on the inlet pipeline of Spherical Tank 2 (SPH2), and Valve Four on Bypass Pipe 2 (Bypass-2), and then turn off the transfer pump P1.

[0046] Through the above processes A1 - A5, the heat energy on the compressor side in the energy storage and release heat exchange system is stored.

[0047] The energy release method of the heat storage device includes the following processes:

[0048] B1: Open Valve 3 on the outlet pipeline of SPH2 of Ball Tank 2, Valve 2 on the inlet pipeline of SPH1 of Ball Tank 1, and start the transfer pump P1. Let the high-temperature water in SPH2 of Ball Tank 2 enter SPH1 of Ball Tank 1 through the transfer pump P1 and the expander-side heat exchange system E8 in the energy storage and release heat exchange system. The heat of the high-temperature water in SPH2 of Ball Tank 2 is released to the expander side and then introduced into SPH1 of Ball Tank 1. Leave some high-temperature water in SPH2 of Ball Tank 2. The liquid level of SPH1 of Ball Tank 1 rises. After completion, close Valve 3 on the outlet pipeline of SPH2 of Ball Tank 2, Valve 2 on the inlet pipeline of SPH1 of Ball Tank 1, and the transfer pump P1.

[0049] B2: Open Valve 3 on the outlet pipeline of SPH3 of Ball Tank 3, Valve 2 on the inlet pipeline of SPH2 of Ball Tank 2, and Valve 4 on Bypass-2. Start the transfer pump P1. Let the high-temperature water in SPH3 of Ball Tank 3 enter SPH2 of Ball Tank 2 through the transfer pump P1 and the expander-side heat exchange system E8 in the energy storage and release heat exchange system. The heat of the high-temperature water in SPH3 of Ball Tank 3 is released to the expander side and then introduced into SPH2 of Ball Tank 2. Leave some high-temperature water in SPH3 of Ball Tank 3. The liquid level of SPH2 of Ball Tank 2 rises. After completion, close Valve 3 on the outlet pipeline of SPH3 of Ball Tank 3, Valve 2 on the inlet pipeline of SPH2 of Ball Tank 2, Valve 4 on Bypass-2, and the transfer pump P1.

[0050] B3: Open Valve 3 on the outlet pipeline of SPH4 of Ball Tank 4, Valve 2 on the inlet pipeline of SPH3 of Ball Tank 3, and Valve 4 on Bypass-3. Start the transfer pump P1. Let the high-temperature water in SPH4 of Ball Tank 4 enter SPH3 of Ball Tank 3 through the transfer pump P1 and the expander-side heat exchange system E8 in the energy storage and release heat exchange system. The heat of the high-temperature water in SPH4 of Ball Tank 4 is released to the expander side and then introduced into SPH3 of Ball Tank 3. Leave some high-temperature water in SPH4 of Ball Tank 4. The liquid level of SPH3 of Ball Tank 3 rises. After completion, close Valve 3 on the outlet pipeline of SPH4 of Ball Tank 4, Valve 2 on the inlet pipeline of SPH3 of Ball Tank 3, Valve 4 on Bypass-3, and the transfer pump P1.

[0051] B4: Open Valve Three on the outlet pipeline of Storage Sphere SPH5, Valve Two on the inlet pipeline of Storage Sphere SPH4, and Valve Four on the bypass pipeline No. 4. Start the transfer pump P1 to allow the high-temperature water in Storage Sphere SPH5 to enter Storage Sphere SPH4 through the transfer pump P1 and the expander-side heat exchange system E8 in the energy storage and release heat exchange system. The heat of the high-temperature water in Storage Sphere SPH5 is released to the expander side and then introduced into Storage Sphere SPH4. Part of the high-temperature water remains in Storage Sphere SPH5, and the liquid level of Storage Sphere SPH4 rises. After completion, close Valve Three on the outlet pipeline of Storage Sphere SPH5, Valve Two on the inlet pipeline of Storage Sphere SPH4, Valve Four on the bypass pipeline No. 4, and the transfer pump P1.

[0052] B5: Open Valve Three on the outlet pipeline of Storage Sphere SPH6, Valve Two on the inlet pipeline of Storage Sphere SPH5, and Valve Four on the bypass pipeline Bypass-4Bypass-5. Start the transfer pump P1 to allow the high-temperature water in Storage Sphere SPH6 to enter Storage Sphere SPH5 through the transfer pump P1 and the expander-side heat exchange system E8 in the energy storage and release heat exchange system. The heat of the high-temperature water in Storage Sphere SPH6 is released to the expander side and then introduced into Storage Sphere SPH5. Part of the high-temperature water remains in Storage Sphere SPH6, and the liquid level of Storage Sphere SPH5 rises. After completion, close Valve Three on the outlet pipeline of Storage Sphere SPH6, Valve Two on the inlet pipeline of Storage Sphere SPH5, Valve Four on the bypass pipeline Bypass-4Bypass-5, and the transfer pump P1.

[0053] The heat energy is released to the expander side of the energy storage and release heat exchange system through the above processes B1 - B5.

[0054] During use, for example: V1 l The volume of liquid water in Storage Sphere SPH1 at a certain moment; V1g The volume of gas in Storage Sphere SPH1 at a certain moment; ΔV1 l For a single transfer process, the absolute value of the difference in the volume of liquid water in Storage Sphere SPH1; V2l The volume of liquid water in Storage Sphere SPH2 at a certain moment; V2g The volume of gas in Storage Sphere SPH2 at a certain moment; ΔV2 l For a single transfer process, the absolute value of the difference in the volume of liquid water in Storage Sphere SPH2; V3 l The volume of liquid water in Storage Sphere SPH3 at a certain moment; V3 g The volume of gas in Storage Sphere SPH3 at a certain moment; ΔV3 l For a single transfer process, the absolute value of the difference in the volume of liquid water in Storage Sphere SPH3; V4 l The volume of liquid water in Storage Sphere SPH4 at a certain moment; V4 g The volume of gas in Storage Sphere SPH4 at a certain moment; ΔV4l For a single tank inversion process, the absolute value of the difference in the volume of liquid water in spherical tank SPH4 No. 4; V5 l The volume of liquid water in spherical tank SPH5 No. 5 at a certain moment; V5g The volume of gas in spherical tank SPH5 No. 5 at a certain moment; ΔV5 l For a single tank inversion process, the absolute value of the difference in the volume of liquid water in spherical tank SPH5 No. 5; V6 l The volume of liquid water in spherical tank SPH6 No. 6 at a certain moment; V6 g The volume of gas in spherical tank SPH6 No. 6 at a certain moment; ΔV6 l For a single tank inversion process, the absolute value of the difference in the volume of liquid water in spherical tank SPH6 No. 6;

[0055] T1 is the temperature of spherical tank SPH1 No. 1; T2 is the temperature of spherical tank SPH2 No. 2; T3 is the temperature of spherical tank SPH3 No. 3; T4 is the temperature of spherical tank SPH4 No. 4; T5 is the temperature of spherical tank SPH5 No. 5; T6 is the temperature of spherical tank SPH6 No. 6;

[0056] P is the system constant pressure; P1 W Is the partial pressure of water vapor in spherical tank SPH1 No. 1, P1 N Is the partial pressure of nitrogen in spherical tank SPH1 No. 1; P2 W Is the partial pressure of water vapor in spherical tank SPH2 No. 2, P2 N Is the partial pressure of nitrogen in spherical tank SPH2 No. 2; P3 W Is the partial pressure of water vapor in spherical tank SPH3 No. 3, P3 N Is the partial pressure of nitrogen in spherical tank SPH3 No. 3; P4 W Is the partial pressure of water vapor in spherical tank SPH4 No. 4, P4 N Is the partial pressure of nitrogen in spherical tank SPH4 No. 4; P5 W Is the partial pressure of water vapor in spherical tank SPH5 No. 5, P5 N Is the partial pressure of nitrogen in spherical tank SPH5 No. 5; P6 W Is the partial pressure of water vapor in spherical tank SPH6 No. 6, P6 N Is the partial pressure of nitrogen in spherical tank SPH6 No. 6;

[0057] ρ1 w Is the density of liquid water in spherical tank SPH1 No. 1, ρ1 s Is the density of water vapor in spherical tank SPH1 No. 1, ρ1 N Is the density of nitrogen in spherical tank SPH1 No. 1; ρ2 w Is the density of liquid water in spherical tank SPH2 No. 2, ρ2 s Is the density of water vapor in spherical tank SPH2 No. 2, ρ2 N Is the density of nitrogen in spherical tank SPH2 No. 2; ρ3 w Is the density of liquid water in spherical tank SPH3 No. 3, ρ3s is the density of SPH3 water vapor in the No. 3 spherical tank, ρ3 N is the density of nitrogen in the No. 3 spherical tank SPH3; ρ4 w is the density of liquid water in the No. 4 spherical tank SPH4, ρ4 s is the density of SPH4 water vapor in the No. 4 spherical tank, ρ4 N is the density of nitrogen in the No. 4 spherical tank SPH4; ρ5 w is the density of liquid water in the No. 5 spherical tank SPH5, ρ5 s is the density of SPH5 water vapor in the No. 5 spherical tank, ρ5 N is the density of nitrogen in the No. 5 spherical tank SPH5; ρ6 w is the density of liquid water in the No. 6 spherical tank SPH6, ρ6 s is the density of SPH6 water vapor in the No. 6 spherical tank, ρ6 N is the density of nitrogen in the No. 6 spherical tank SPH6.

[0058] M d is the mass of water in the constant pressure water tank C1; M1 w is the mass of liquid water in the No. 1 spherical tank SPH1, M1 s is the mass of SPH1 water vapor in the No. 1 spherical tank, M1 N is the mass of nitrogen in the No. 1 spherical tank SPH1; M2 w is the mass of liquid water in the No. 2 spherical tank SPH2, M2 s is the mass of SPH2 water vapor in the No. 2 spherical tank, M2 N is the mass of nitrogen in the No. 2 spherical tank SPH2; M3 w is the mass of liquid water in the No. 3 spherical tank SPH3, M3 s is the mass of SPH3 water vapor in the No. 3 spherical tank, M3 N is the mass of nitrogen in the No. 3 spherical tank SPH3; M4 w is the mass of liquid water in the No. 4 spherical tank SPH4, M4 s is the mass of SPH4 water vapor in the No. 4 spherical tank, M4 N is the mass of nitrogen in the No. 4 spherical tank SPH4; M5 w is the mass of liquid water in the No. 5 spherical tank SPH5, M5 s is the mass of SPH5 water vapor in the No. 5 spherical tank, M5 N is the mass of nitrogen in the No. 5 spherical tank SPH5; M6 w is the mass of liquid water in the No. 6 spherical tank SPH6, M6 s is the mass of SPH6 water vapor in the No. 6 spherical tank, M6 N is the mass of nitrogen in the No. 6 spherical tank SPH6.

[0059] During the entire energy storage and release cycle, since nitrogen is neither emitted nor replenished, the nitrogen mass in the spherical tank system is conserved, i.e., M1 N +M2 N+ M3 N+ M4 N +M5 N+ M6 N = constant value. In addition, since the pressure of the entire system needs to be maintained close to a constant value, i.e., P1 W+ P1 N = P2 W+ P2 N = P3 W+ P3 N = P4 W+ P4 N = P5 W+ P5 N = P6 W+ P6 N = constant value. Regarding the constant pressure water tank C1 and the 6 spherical tanks as a system, the total mass of water is conserved, i.e., M d +M1 w +M1 s +M2 w +M2 s +M3 w +M3 s +M4 w +M4 s +M5 w +M5 s +M6 w +M6 s = constant value.

[0060] In the constant pressure device of the entire spherical tank heat storage system, it is set in the 1st spherical tank SPH1 (cold water tank). A constant pressure pipe is set at the bottom of the 1st spherical tank SPH1. The constant pressure system is equipped with 2 constant pressure water pumps P2 and 1 constant pressure water tank C1. The constant pressure water tank C1 is an atmospheric pressure water tank. The constant pressure water pump P2 operates with frequency conversion, one in operation and one in standby. During the entire heat storage process, the heat storage temperature is 224°C, and the corresponding saturation pressure is 2.5 MPa. Based on the requirement of no flashing and considering the economy of the device comprehensively, the constant pressure is 2.6 Mpa. The low-temperature water temperature range is 50 - 60°C, and the high-temperature water temperature range is 220 - 230°C.

[0061] During energy storage, the liquid level of the 1st - 5th spherical tanks SPH5 is 82%, and the low-temperature water is about 56°C. The liquid level of the 6th spherical tank SPH6 is 2%, and the high-temperature water is about 224°C. After the low-temperature water in the 5th spherical tank SPH5 is introduced into the 6th spherical tank SPH6, the 5th spherical tank SPH5 retains 2% of the low-temperature water, which is about 100°C, and the liquid level of the 6th spherical tank SPH6 rises. The specific determination method is that the liquid level change of the 6th spherical tank SPH6 is based on the initial and final liquid levels and density difference of the 5th spherical tank SPH5 (the density of water at 56°C is 986 kg / m3 , the density at 224 °C is 835 kg / m 3 , which is determined by the same mass), that is, ΔV6l × 835 = ΔV5l × 986, and ΔV6l = 96.4% can be obtained. Based on the liquid levels of SPH6 in spheres 2 - 6 and the temperatures of SPH6 in spheres 1 - 6 before and after the tank - emptying process, the temperatures of SPH6 in spheres 1 - 6 can be used to determine P1 w , P2 w , P3 w , P4 w , P5 w , P6 w , from the constraint equation “P1 W + P1 N = P2 W + P2 N = P3 W + P3 N = P4 W + P4 N = P5 W + P5 N = P6 W + P6 N = 2.6 MPa” described above, the nitrogen partial pressures P1 - 6 of each sphere can be further determined N . Then, combined with the gas volumes and densities of spheres 2 - 6, the nitrogen masses of SPH6 in spheres 2 - 6 can be determined. Combining with the nitrogen mass conservation equation “M1 N + M2 N + M3 N + M4 N + M5 N + M6 N = constant value”, the nitrogen mass of SPH1 in sphere 1 can be obtained. Combining with the gas temperature and nitrogen partial pressure of SPH1 in sphere 1, the nitrogen density of SPH1 in sphere 1 can be obtained, thereby determining the gas volume of SPH1 in sphere 1, and then obtaining the liquid - water volume of SPH1 in sphere 1. Thus, the liquid - water volumes and water - vapor volumes of SPH6 in spheres 1 - 6 have been determined. Combining with the water - vapor partial pressure and temperature described above, the densities of water vapor and liquid water can be determined, thereby determining the total mass of water in SPH6 in spheres 1 - 6. Combining with the water mass conservation equation “M d + M1 w + M1 s + M2 w + M2 s + M3 w + M3 s + M4 w + M4 s + M5 w + M5 s + M6w +M6 s = constant value", the mass of the constant pressure water tank C1 can be obtained; after the low-temperature water in the 4th spherical tank SPH4 is introduced into the 5th spherical tank SPH5, the liquid level of the 5th - 6th spherical tanks SPH6 is 94% high-temperature water, the remaining liquid level of the 4th spherical tank SPH4 is 2% low-temperature water, and the liquid levels of the 1st - 3rd are 93.97% low-temperature water; after the low-temperature water in the 3rd spherical tank SPH3 is introduced into the 4th spherical tank SPH4, the liquid levels of the 4th - 6th spherical tanks SPH6 are 94% high-temperature water, the remaining liquid level of the 3rd spherical tank SPH3 is 2% low-temperature water, and the liquid levels of the 1st - 2nd spherical tanks SPH2 are 92.42% low-temperature water; after the low-temperature water in the 2nd spherical tank SPH2 is introduced into the 3rd spherical tank SPH3, the liquid levels of the 3rd - 6th spherical tanks SPH6 are 94% high-temperature water, the remaining liquid level of the 2nd spherical tank SPH2 is 2% low-temperature water, and the liquid level of the 1st spherical tank SPH1 is 92.35% low-temperature water; after the low-temperature water in the 1st spherical tank SPH1 is heated and introduced into the 2nd spherical tank SPH2, the 2nd spherical tank SPH2 realizes the conversion from low-temperature water to high-temperature water, and the liquid level remains 2%. The remaining liquid level of the 1st spherical tank SPH1 is 15.13% low-temperature water, and the liquid levels of the 3rd - 6th spherical tanks SPH6 are 94% high-temperature water, completing an energy storage cycle. As Figure 5 and Figure 6 shown, during the energy storage stage, the steam in the hot tank enters the top of the cold tank, causing thermal shock damage to the top of the cold tank. After installing the economizer, this shock is mitigated. The stress intensity of the tank body is reduced from 202 MPa to 163 MPa, and the stress mitigation is obvious.

[0062] Energy release process:

[0063] During energy release, after the high-temperature water in the No. 2 spherical tank SPH2 is introduced into the No. 1 spherical tank SPH1, the liquid level of the No. 2 spherical tank SPH2 is 2% high-temperature water, the No. 1 spherical tank SPH1 is 18.2% low-temperature water, and the liquid levels of the No. 3-6 spherical tanks SPH6 are 94% high-temperature water. To maintain the system pressure constant, 965 t of low-temperature water needs to be discharged from the system to the constant-pressure water tank C1. Finally, the liquid level of the No. 1 spherical tank SPH1 increases from 15.13% to 18.2%. After the high-temperature water in the No. 3 spherical tank SPH3 is introduced into the No. 2 spherical tank SPH2, the liquid level of the No. 2 spherical tank SPH2 is 80% low-temperature water, the remaining liquid level of the No. 3 spherical tank SPH3 is 2% high-temperature water, and the liquid levels of the No. 4-6 spherical tanks SPH6 are 94% high-temperature water. To maintain the system pressure constant, 365 t of low-temperature water needs to be replenished from the constant-pressure water tank C1 to the system. Finally, the liquid level of the No. 1 spherical tank SPH1 increases from 18.2% to 30.3%. After the high-temperature water in the No. 4 spherical tank SPH4 is introduced into the No. 3 spherical tank SPH3, the liquid level of the No. 3 spherical tank SPH3 is 80% low-temperature water, the remaining liquid level of the No. 4 spherical tank SPH4 is 2% high-temperature water, and the liquid levels of the No. 5-6 spherical tanks SPH6 are 94% high-temperature water. To maintain the system pressure constant, 506 t of low-temperature water needs to be replenished from the constant-pressure water tank C1 to the system. Finally, the liquid level of the No. 1 spherical tank SPH1 increases from 30.3% to 50.23%. After the high-temperature water in the No. 5 spherical tank SPH5 is introduced into the No. 4 spherical tank SPH4, the liquid levels of the No. 2-4 spherical tanks SPH4 are 80% low-temperature water, the remaining liquid level of the No. 5 spherical tank SPH5 is 2% high-temperature water, and the liquid level of the No. 6 spherical tank SPH6 is 94% high-temperature water. To maintain the system pressure constant, 677 t of low-temperature water needs to be replenished from the constant-pressure water tank C1 to the system. Finally, the liquid level of the No. 1 spherical tank SPH1 increases from 50.23% to 70.15%. After the high-temperature water in the No. 6 spherical tank SPH6 is introduced into the No. 5 spherical tank SPH5, the liquid level of the No. 5 spherical tank SPH5 is 80% low-temperature water, the remaining liquid level of the No. 6 spherical tank SPH6 is 2% high-temperature water, and the remaining liquid levels of the No. 2-4 spherical tanks are 2% low-temperature water. To maintain the system pressure constant, 591 t of low-temperature water needs to be replenished from the constant-pressure water tank C1 to the system. Finally, the liquid level of the No. 1 spherical tank SPH1 increases from 70.15% to 90.08%, and thus an energy release cycle is completed.

[0064] During the energy storage and temperature rise process, for example, during the process of the No. 1 spherical tank SPH1 introducing into the No. 2 spherical tank SPH2, if the energy storage stops at this time, the nitrogen gas inside the No. 2 spherical tank SPH2 will be gradually heated. Without taking measures, it will cause the system overpressure to 4 Mpa. By setting an energy-saving device at the top of the spherical tank, cold water is taken from the No. 1 spherical tank SPH1 to cool the mixed steam of nitrogen and steam at the upper part of the No. 2 spherical tank SPH2. Since the steam condenses and the pressure drops, the gas circulation flow rate can be increased to ensure the anti-overpressure effect. The high-temperature nitrogen gas from the No. 2 spherical tank SPH2 is cooled by the energy-saving heat exchanger and then stored in the No. 1 spherical tank SPH1. In short, the energy-saving device is of great significance for the gas temperature control of the spherical tank system and the safe transfer of nitrogen during the energy storage and release process. As Figure 7 and Figure 8As shown, during the energy release stage, nitrogen in the cold tank enters the top of the hot tank, causing thermal shock damage to the top of the hot tank. After installing the energy saver, this shock is alleviated, and the stress intensity of the tank body is reduced from 204 MPa to 120 MPa, with obvious stress alleviation.

[0065] The above are only the preferred embodiments of the present invention.

Claims

1. A heat storage device in a regenerative compressed air energy storage system, characterized in that It includes a tank - emptying pump, a constant - pressure water tank, a constant - pressure water pump, a heat storage and release heat - exchange system, 6 spherical tanks, and at least 5 energy - savers. Among them, 5 spherical tanks correspond to 5 energy - savers one by one, and the energy - savers are arranged on the tops of the corresponding spherical tanks. The tops of the 6 spherical tanks are connected by a gas - phase pipe. The water outlets of the 6 spherical tanks are respectively connected to an outlet pipeline, and the water inlets of the 6 spherical tanks are respectively connected to an inlet pipeline. A second valve is arranged on the inlet pipeline. Each outlet pipeline is connected to the water inlet end of the tank - emptying pump, and a third valve is arranged on the outlet pipeline. The water outlet end of the tank - emptying pump is connected to the heat storage and release heat - exchange system. Each inlet pipeline is connected to the heat storage and release heat - exchange system. The water outlet end of the tank - emptying pump is connected to at least 5 bypass pipes. The 5 bypass pipes correspond to the 5 energy - savers. The bypass pipes are connected to the medium inlets of the corresponding energy - savers. The medium outlets of the energy - savers are communicated with the corresponding spherical tanks. A fourth valve is arranged on the bypass pipes. The gas - phase pipe can exchange heat with the medium inside the energy - saver when passing through the energy - saver. The bottom of one spherical tank is connected to the constant - pressure water tank through a constant - pressure pipe, and a regulating valve is arranged on the constant - pressure pipe. The return water pipe of the constant - pressure water tank is successively connected to the constant - pressure water pump and this spherical tank.

2. The heat storage device in a regenerative compressed air energy storage system according to claim 1, characterized in that, Valves five are arranged on the gas - phase pipes between the spherical tanks and the corresponding energy - savers.

3. A method for storing and releasing energy using the heat storage device in the regenerative compressed air energy storage system according to claim 1, characterized in that, The 6 spherical tanks of the heat storage device are successively the No. 1 - 6 spherical tanks. The energy - savers corresponding to the No. 2 - 6 spherical tanks are successively the No. 2 - 6 energy - savers. The bypass pipes corresponding to the No. 2 - 6 energy - savers are successively the No. 2 - 6 bypass pipes. The bottom of the No. 1 spherical tank is connected to the constant - pressure water tank. Before the start of heat storage, the states of each spherical tank are as follows: The No. 1 - 5 spherical tanks are all filled with low - temperature water, and the No. 6 spherical tank is pre - filled with part of high - temperature water at 224 °C. And there is a mixed gas of nitrogen and water vapor in the No. 1 - 6 spherical tanks and the gas - phase pipe. During the whole heat storage process and the heat storage and release process, the gas - phase pressure in the system is detected in real time. Due to the change of the system temperature, it will affect the size of the system pressure. This influence is overcome by draining and filling water in the No. 1 spherical tank to ensure the constancy of the system pressure during the whole process. When the system pressure rises, the opening degree of the regulating valve between the No. 1 spherical tank and the constant - pressure water tank is adjusted to regulate the drainage volume to ensure the stability of the system pressure. When the system pressure drops, the constant - pressure water pump between the No. 1 spherical tank and the constant - pressure water tank is used to control the water filling volume, thereby ensuring the stability of the system pressure. The energy - storage method of the heat storage device includes the following process: A1: Open the third valve on the outlet pipeline of the No. 5 spherical tank, the second valve on the inlet pipeline of the No. 6 spherical tank, and the fourth valve on the No. 6 bypass pipe. Start the tank - emptying pump, so that the low - temperature water in the No. 5 spherical tank enters the No. 6 spherical tank after passing through the tank - emptying pump and the compressor - side heat - exchange system in the heat storage and release heat - exchange system. The low - temperature water in the No. 5 spherical tank absorbs the heat on the compressor side and then is introduced into the No. 6 spherical tank. Part of the low - temperature water remains in the No. 5 spherical tank, and the liquid level of the No. 6 spherical tank rises. And the steam in the No. 6 spherical tank flows from the corresponding gas - phase pipe to the No. 6 energy - saver, and exchanges heat and condenses with the bypass water flowing through the No. 6 energy - saver and then flows back into the No. 6 spherical tank. The bypass water in the No. 6 energy - saver comes from the No. 6 bypass pipe, and the tank - emptying pump sends the water in the No. 5 spherical tank to the No. 6 bypass pipe. After completion, close the third valve on the outlet pipeline of the No. 5 spherical tank, the second valve on the inlet pipeline of the No. 6 spherical tank, and the fourth valve on the No. 6 bypass pipe, and turn off the tank - emptying pump. A2: Open Valve 3 on the outlet pipeline of Storage Tank 4, Valve 2 on the inlet pipeline of Storage Tank 5, and Valve 4 on the bypass pipeline 5. Start the transfer pump so that the low-temperature water in Storage Tank 4 enters Storage Tank 5 after passing through the transfer pump and the compressor-side heat exchange system in the energy storage and release heat exchange system. The low-temperature water in Storage Tank 4 absorbs the heat on the compressor side and then is introduced into Storage Tank 5, leaving some low-temperature water in Storage Tank 4. The liquid level of Storage Tank 5 rises, and the steam in Storage Tank 5 flows from the corresponding gas phase pipeline to the No. 5 energy saver, where it exchanges heat and condenses with the bypass water flowing through the No. 5 energy saver and then returns to Storage Tank 5. The bypass water in the No. 5 energy saver comes from the bypass pipeline 5. The transfer pump sends the water in Storage Tank 4 to the bypass pipeline 5. After completion, close Valve 3 on the outlet pipeline of Storage Tank 4, Valve 2 on the inlet pipeline of Storage Tank 5, and Valve 4 on the bypass pipeline 5, and turn off the transfer pump. A3: Open Valve 3 on the outlet pipeline of Storage Tank 3, Valve 2 on the inlet pipeline of Storage Tank 4, and Valve 4 on the bypass pipeline 4. Start the transfer pump so that the low-temperature water in Storage Tank 3 enters Storage Tank 4 after passing through the transfer pump and the compressor-side heat exchange system in the energy storage and release heat exchange system. The low-temperature water in Storage Tank 3 absorbs the heat on the compressor side and then is introduced into Storage Tank 4, leaving some low-temperature water in Storage Tank 3. The liquid level of Storage Tank 4 rises, and the steam in Storage Tank 4 flows from the corresponding gas phase pipeline to the No. 4 energy saver, where it exchanges heat and condenses with the bypass water flowing through the No. 4 energy saver and then returns to Storage Tank 4. The bypass water in the No. 4 energy saver comes from the bypass pipeline 4. The transfer pump sends the water in Storage Tank 3 to the bypass pipeline 4. After completion, close Valve 3 on the outlet pipeline of Storage Tank 3, Valve 2 on the inlet pipeline of Storage Tank 4, and Valve 4 on the bypass pipeline 4, and turn off the transfer pump. A4: Open Valve 3 on the outlet pipeline of Storage Tank 2, Valve 2 on the inlet pipeline of Storage Tank 3, and Valve 4 on the bypass pipeline 3. Start the transfer pump so that the low-temperature water in Storage Tank 2 enters Storage Tank 3 after passing through the transfer pump and the compressor-side heat exchange system in the energy storage and release heat exchange system. The low-temperature water in Storage Tank 2 absorbs the heat on the compressor side and then is introduced into Storage Tank 3, leaving some low-temperature water in Storage Tank 2. The liquid level of Storage Tank 3 rises, and the steam in Storage Tank 3 flows from the corresponding gas phase pipeline to the No. 3 energy saver, where it exchanges heat and condenses with the bypass water flowing through the No. 3 energy saver and then returns to Storage Tank 3. The bypass water in the No. 3 energy saver comes from the bypass pipeline 3. The transfer pump sends the water in Storage Tank 2 to the bypass pipeline 3. After completion, close Valve 3 on the outlet pipeline of Storage Tank 2, Valve 2 on the inlet pipeline of Storage Tank 3, and Valve 4 on the bypass pipeline 3, and turn off the transfer pump. A5: Open Valve 3 on the outlet pipeline of Storage Tank 1, Valve 2 on the inlet pipeline of Storage Tank 2, and Valve 4 on the bypass pipeline 2. Start the transfer pump so that the low-temperature water in Storage Tank 1 enters Storage Tank 2 after passing through the transfer pump and the compressor-side heat exchange system in the energy storage and release heat exchange system. The low-temperature water in Storage Tank 1 absorbs the heat on the compressor side and then is introduced into Storage Tank 2, leaving some low-temperature water in Storage Tank 1. The liquid level of Storage Tank 2 rises, and the steam in Storage Tank 2 flows from the corresponding gas-phase pipeline to Energy Saver 2, where it exchanges heat and condenses with the bypass water flowing through Energy Saver 2 and then returns to Storage Tank 2. The bypass water in Energy Saver 2 comes from bypass pipeline 2, and the transfer pump sends the water in Storage Tank 1 to bypass pipeline 2. After completion, close Valve 3 on the outlet pipeline of Storage Tank 1, Valve 2 on the inlet pipeline of Storage Tank 2, and Valve 4 on the bypass pipeline 2, and turn off the transfer pump. The heat energy on the compressor side in the energy storage and release heat exchange system is stored through the above processes A1 - A5. The energy release method of the heat storage device includes the following processes: B1: Open Valve 3 on the outlet pipeline of Storage Tank 2 and Valve 2 on the inlet pipeline of Storage Tank 1. Start the transfer pump so that the high-temperature water in Storage Tank 2 enters Storage Tank 1 after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in Storage Tank 2 is released to the expander side and then introduced into Storage Tank 1, leaving some high-temperature water in Storage Tank 2. The liquid level of Storage Tank 1 rises. After completion, close Valve 3 on the outlet pipeline of Storage Tank 2, Valve 2 on the inlet pipeline of Storage Tank 1, and the transfer pump. B2: Open Valve 3 on the outlet pipeline of Storage Tank 3, Valve 2 on the inlet pipeline of Storage Tank 2, and Valve 4 on the bypass pipeline 2. Start the transfer pump so that the high-temperature water in Storage Tank 3 enters Storage Tank 2 after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in Storage Tank 3 is released to the expander side and then introduced into Storage Tank 2, leaving some high-temperature water in Storage Tank 3. The liquid level of Storage Tank 2 rises. After completion, close Valve 3 on the outlet pipeline of Storage Tank 3, Valve 2 on the inlet pipeline of Storage Tank 2, Valve 4 on the bypass pipeline 2, and the transfer pump. B3: Open Valve 3 on the outlet pipeline of Storage Tank 4, Valve 2 on the inlet pipeline of Storage Tank 3, and Valve 4 on the bypass pipeline 3. Start the transfer pump so that the high-temperature water in Storage Tank 4 enters Storage Tank 3 after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in Storage Tank 4 is released to the expander side and then introduced into Storage Tank 3, leaving some high-temperature water in Storage Tank 4. The liquid level of Storage Tank 3 rises. After completion, close Valve 3 on the outlet pipeline of Storage Tank 4, Valve 2 on the inlet pipeline of Storage Tank 3, Valve 4 on the bypass pipeline 3, and the transfer pump. B4: Open Valve 3 on the outlet pipeline of Storage Tank 5, Valve 2 on the inlet pipeline of Storage Tank 4, and Valve 4 on the bypass pipeline of Storage Tank 4. Start the transfer pump so that the high-temperature water in Storage Tank 5 enters Storage Tank 4 after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in Storage Tank 5 is released to the expander side and then introduced into Storage Tank 4. Leave part of the high-temperature water in Storage Tank 5. The liquid level of Storage Tank 4 rises. After completion, close Valve 3 on the outlet pipeline of Storage Tank 5, Valve 2 on the inlet pipeline of Storage Tank 4, Valve 4 on the bypass pipeline of Storage Tank 4, and the transfer pump. B5: Open Valve 3 on the outlet pipeline of Storage Tank 6, Valve 2 on the inlet pipeline of Storage Tank 5, and Valve 4 on the bypass pipeline of Storage Tank 5. Start the transfer pump so that the high-temperature water in Storage Tank 6 enters Storage Tank 5 after passing through the transfer pump and the expander-side heat exchange system in the energy storage and release heat exchange system. The heat of the high-temperature water in Storage Tank 6 is released to the expander side and then introduced into Storage Tank 5. Leave part of the high-temperature water in Storage Tank 6. The liquid level of Storage Tank 5 rises. After completion, close Valve 3 on the outlet pipeline of Storage Tank 6, Valve 2 on the inlet pipeline of Storage Tank 5, Valve 4 on the bypass pipeline of Storage Tank 5, and the transfer pump. Through the above processes B1 - B5, the release of thermal energy to the expander side in the energy storage and release heat exchange system is achieved.

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