Compressed air energy storage heat recovery system and method

Abstract

The invention belongs to the technical field of energy recovery, and discloses a compressed air energy storage heat recovery system and method.The compressed air energy storage heat recovery system comprises a heat storage tank, an expansion assembly, a first heat supply valve, a second heat supply valve, a heat exchange assembly, a heat release mechanism and a heat storage mechanism; the heat exchange assembly is connected to the other ends of the first heat supply valve and the second heat supply valve, the input end of the heat release assembly is connected to the hot side of the heat storage tank, the output end of the heat release assembly is connected to one end of the heat release valve, the other end of the heat release valve is connected to the cold side of the heat storage tank, and the input end of the heat storage assembly is connected to one end of the heat storage valve. The output end of the heat storage assembly is connected to the hot side of the heat storage tank, the other end of the heat storage valve is connected to the cold side of the heat storage tank, energy storage and heat supply of the compressed air energy storage heat recovery system are achieved, the comprehensive utilization rate of energy and the heat storage efficiency are improved, and the feasibility of thermocline heat storage of the heat storage tank is enhanced. It is guaranteed that only cold water exists in the heat storage tank before next energy charging and discharging circulation.

Description

Technical Field

[0001] The present invention relates to the field of energy recovery technology, and in particular to a compressed air energy storage heat recovery system and method. Background Art

[0002] The development of the power system is characterized by a high proportion of renewable energy and a high proportion of power electronic equipment, which requires a large amount of energy storage support. New energy storage technologies such as compressed air energy storage and liquefied air energy storage are receiving widespread attention. The development of new energy storage technology routes has brought about an urgent need for pressurized water heat storage applications.

[0003] At present, in compressed air energy storage systems, pressurized water heat storage mainly has two forms: separate storage of hot and cold and storage of hot and cold. The amount of heat stored in the water in the thermocline layer cannot be directly adapted to the usage scenario. In addition, the maximum temperature of normal pressure water heat storage does not exceed 100°C, and the maximum temperature of pressurized water heat storage is usually between 180 and 220°C. The pressurized thermocline layer has more heat that cannot be directly used than the normal pressure thermocline layer. In a compressed air energy storage system, if the heat storage temperature is designed to be 200°C at high temperature and 40°C at low temperature, the temperature range of the thermocline layer is 64 to 176°C. The temperature in the thermocline layer deviates greatly from the rated operating conditions of the compressed air energy storage system. If hot water is stored in the thermocline layer, the efficiency of the compressed air energy storage system is too low at this time, and the main equipment may not be able to operate normally, resulting in the heat in the thermocline layer being unable to be used and causing energy waste.

[0004] Therefore, there is an urgent need for a compressed air energy storage heat recovery system and method to solve the above problems. Summary of the invention

[0005] According to one aspect of the present invention, the present invention provides a compressed air energy storage heat recovery system, which realizes energy storage and heat supply of the compressed air energy storage heat recovery system, improves the comprehensive energy utilization rate and heat storage efficiency, and enhances the feasibility of heat storage in the inclined temperature layer of the heat storage tank. It is ensured that only cold water exists in the heat storage tank before the next charge and discharge cycle.

[0006] In order to solve the above problems existing in the prior art, the present invention adopts the following technical solutions:

[0007] A compressed air energy storage heat recovery system, comprising:

[0008] a thermal storage tank having a cold side and a hot side;

[0009] An expansion assembly connected to the cold side of the heat storage tank, the expansion assembly is used to maintain the liquid level of the heat storage tank during the charging and discharging process;

[0010] a first heating valve, one end of which is connected to the hot side of the heat storage tank;

[0011] a second heating valve, one end of which is connected to the cold side of the heat storage tank;

[0012] a heat exchange assembly connected to the other end of the first heating valve and the second heating valve;

[0013] A heat release mechanism, comprising a heat release valve and a heat release component, wherein the input end of the heat release component is connected to the hot side of the heat storage tank, the output end of the heat release component is connected to one end of the heat release valve, and the other end of the heat release valve is connected to the cold side of the heat storage tank;

[0014] The heat storage mechanism comprises a heat storage valve and a heat storage component, wherein the input end of the heat storage component is connected to one end of the heat storage valve, the output end of the heat storage component is connected to the hot side of the heat storage tank, and the other end of the heat storage valve is connected to the cold side of the heat storage tank.

[0015] Preferably, the heat release component includes a heat release device and a heat release pump, the input end of the heat release device is connected to the hot side of the heat storage tank, the output end of the heat release device is connected to the input end of the heat release pump, and the output end of the heat release pump is connected to the heat release valve.

[0016] Preferably, the heat storage assembly comprises a heat storage device and a heat storage pump, the input end of the heat storage pump is connected to the heat storage valve, the output end of the heat storage pump is connected to the input end of the heat storage device, and the output end of the heat storage device is connected to the hot side of the heat storage tank.

[0017] Preferably, the expansion assembly comprises an expansion tank, an expansion constant pressure pump and an expansion valve, the expansion constant pressure pump and the expansion valve are arranged in parallel, the input end of the expansion constant pressure pump is connected to the expansion tank, the output end of the expansion constant pressure pump is connected to the cold side of the heat storage tank, the input end of the expansion valve is connected to the cold side of the heat storage tank, and the output end of the expansion valve is connected to the expansion tank.

[0018] Preferably, the heat exchange component comprises a heat exchanger and a radiator, the heat exchanger and the radiator are arranged in parallel, the heat exchanger is used for external heat supply, and the radiator is used for heat dissipation of the heat storage tank.

[0019] Preferably, the compressed air energy storage heat recovery system also includes an air storage component and a heating component, the air storage component is connected to the heating component, the air storage component and the heating component are both connected between the heat release mechanism and the heat storage mechanism, the air storage component is used to pressurize and cool the air, and the heating component is used to heat and pressurize the air.

[0020] Preferably, the gas storage component includes a compressor, a cooler and a gas storage tank, the heating component includes a heater and a turbine, the compressor is connected to the cooler, the cooler is connected to the gas storage tank, the gas storage tank is connected to the heater, and the heater is connected to the turbine.

[0021] According to another aspect of the present invention, a compressed air energy storage heat recovery method is provided. Through the implementation of the above-mentioned compressed air energy storage heat recovery system, the compressed air energy storage heat recovery system has a heat storage state and a heat release state. The compressed air energy storage heat recovery method includes:

[0022] S100: when storing heat, opening the heat storage valve, closing the heat release valve, the first heating valve and the second heating valve; when releasing heat, opening the heat release valve, closing the heat storage valve, the first heating valve and the second heating valve;

[0023] S200: When storing heat, a portion of cold water flows out of the cold side of the heat storage tank, and the cold water flows into the hot side of the heat storage tank after being heated by the heat storage component. At the same time, another portion of cold water flows out of the cold side of the heat storage tank, and the cold water flows into the expansion component. The heat storage is completed. When releasing heat, a portion of hot water flows out of the hot side of the heat storage tank, and the hot water flows into the cold side of the heat storage tank after being dissipated by the heat release component. At the same time, the expansion component replenishes cold water to the cold side of the heat storage tank.

[0024] S300: When releasing heat, the first heating valve is opened and the heat release valve is closed. When the outlet water temperature of the heat storage tank reaches the lower limit of the heating temperature, the heat exchange component performs heat exchange on the heat storage tank, and heat release is completed.

[0025] Preferably, in the compressed air energy storage heat recovery method, when storing heat, the expansion valve is opened, the expansion constant pressure pump is closed, and the cold water in the heat storage tank flows into the expansion tank through the expansion valve; when releasing heat, the expansion valve is closed, the expansion constant pressure pump is opened, and the cold water in the expansion tank flows into the heat storage tank through the expansion constant pressure pump.

[0026] Preferably, in the compressed air energy storage heat recovery method S200, when storing heat, the gas storage component is started, and the compressed air energy storage heat recovery system completes charging, and when releasing heat, the heating component is started, and the compressed air energy storage heat recovery system completes releasing.

[0027] The beneficial effects of the present invention are:

[0028] The present invention provides a compressed air energy storage heat recovery system, wherein an expansion component is connected to the cold side of a heat storage tank, the expansion component is used to maintain the liquid level of the heat storage tank during the charging and discharging process, one end of a first heat supply valve is connected to the hot side of the heat storage tank, one end of a second heat supply valve is connected to the cold side of the heat storage tank, and a heat exchange component is connected to the other end of the first heat supply valve and the second heat supply valve. The heat release mechanism includes a heat release valve and a heat release component, the input end of the heat release component is connected to the hot side of the heat storage tank, the output end of the heat release component is connected to one end of the heat release valve, and the other end of the heat release valve is connected to the cold side of the heat storage tank. The heat storage mechanism includes a heat storage valve and a heat storage component, the input end of the heat storage component is connected to one end of the heat storage valve, the output end of the heat storage component is connected to the hot side of the heat storage tank, and the other end of the heat storage valve is connected to the cold side of the heat storage tank. When storing heat, the heat storage valve is opened, the heat release valve, the first heat supply valve and the second heat supply valve are closed, a portion of cold water flows out of the cold side of the heat storage tank, and the cold water flows into the hot side of the heat storage tank after being heated by the heat storage component. At the same time, another part of cold water flows out of the cold side of the heat storage tank, and the cold water is discharged into the expansion component to maintain the liquid level height and the pressure in the heat storage tank, and complete the heat storage of the pressurized inclined temperature layer compressed air energy storage heat recovery system. When releasing heat, open the heat release valve, close the heat storage valve, the first heating valve and the second heating valve, and a part of hot water flows out of the hot side of the heat storage tank. The hot water flows into the cold side of the heat storage tank after heat dissipation by the heat release component. At the same time, the expansion component replenishes cold water to the cold side of the heat storage tank, maintains the liquid level and the pressure in the heat storage tank, opens the first heating valve, and closes the heat release valve. When the outlet water temperature of the heat storage tank reaches the lower limit of the heating temperature, the heat exchange component performs heat exchange on the heat storage tank, and completes the heat release of the pressurized inclined temperature layer compressed air energy storage heat recovery system. Solve the problem that the heat of the pressurized water inclined temperature layer cannot be utilized, improve the comprehensive utilization rate of energy, and enhance the feasibility of heat storage in the inclined temperature layer of the heat storage tank. At the end of the heat storage and release stages, the heat of the inclined temperature layer of the heat storage tank is supplied to the outside to ensure that there is only cold water in the heat storage tank before the next charging and discharging cycle. There is no need to wait for the next storage or release period to store cold and hot water at the same time, thereby improving the heat storage efficiency.

[0029] The present invention provides a compressed air energy storage heat recovery method. When storing heat, the heat storage valve is opened, and the heat release valve, the first heat supply valve and the second heat supply valve are closed. When releasing heat, the heat release valve is opened, and the heat storage valve, the first heat supply valve and the second heat supply valve are closed. When storing heat, a part of cold water flows out of the cold side of the heat storage tank, and the cold water flows into the hot side of the heat storage tank after being heated by the heat storage component. At the same time, another part of cold water flows out of the cold side of the heat storage tank, and the cold water flows into the expansion component, and heat storage is completed. When releasing heat, a part of hot water flows out of the hot side of the heat storage tank, and the hot water flows into the cold side of the heat storage tank after heat dissipation by the heat release component. At the same time, the expansion component replenishes cold water to the cold side of the heat storage tank. When releasing heat, the first heat supply valve is opened and the heat release valve is closed. When the outlet water temperature of the heat storage tank reaches the lower limit of the heating temperature, the heat exchange component performs heat exchange on the heat storage tank, and heat release is completed. Realize the energy storage and heating of the compressed air energy storage heat recovery system, solve the problem that the heat of the pressurized water thermocline layer cannot be utilized, improve the comprehensive energy utilization rate and heat storage efficiency, enhance the feasibility of heat storage in the thermocline layer of the heat storage tank, and ensure that only cold water exists in the heat storage tank before the next charging and discharging cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of a compressed air energy storage heat recovery system provided by an embodiment of the present invention Figure 1 ;

[0031] Figure 2 Schematic diagram of a compressed air energy storage heat recovery system provided by an embodiment of the present invention Figure 2 ;

[0032] Figure 3 Schematic diagram of a compressed air energy storage heat recovery system provided by an embodiment of the present invention Figure 3 ;

[0033] Figure 4 A flow chart of a compressed air energy storage heat recovery method provided in an embodiment of the present invention.

[0034] Reference numerals:

[0035] 1. Heat storage tank; 2. First heating valve; 3. Second heating valve; 4. Heat release valve; 5. Heat storage valve; 6. Heat release device; 7. Heat release pump; 8. Heat storage device; 9. Heat storage pump; 10. Expansion tank; 11. Expansion constant pressure pump; 12. Expansion valve; 13. Heat exchanger; 14. Radiator; 15. Compressor; 16. Cooler; 17. Gas storage tank; 18. Heater; 19. Turbine. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0037] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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 a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between 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.

[0038] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0040] like Figure 1-Figure 3As shown, in this embodiment, a compressed air energy storage heat recovery system includes a heat storage tank 1, an expansion component, a first heating valve 2, a second heating valve 3, a heat exchange component, a heat release mechanism and a heat storage mechanism. The heat storage tank 1 has a cold side and a hot side, the expansion component is connected to the cold side of the heat storage tank 1, the expansion component is used to maintain the liquid level of the heat storage tank 1 during the charging and discharging process, one end of the first heating valve 2 is connected to the hot side of the heat storage tank 1, one end of the second heating valve 3 is connected to the cold side of the heat storage tank 1, and the heat exchange component is connected to the other end of the first heating valve 2 and the second heating valve 3. The heat release mechanism includes a heat release valve 4 and a heat release component, the input end of the heat release component is connected to the hot side of the heat storage tank 1, the output end of the heat release component is connected to one end of the heat release valve 4, and the other end of the heat release valve 4 is connected to the cold side of the heat storage tank 1. The heat storage mechanism includes a heat storage valve 5 and a heat storage component, the input end of the heat storage component is connected to one end of the heat storage valve 5, the output end of the heat storage component is connected to the hot side of the heat storage tank 1, and the other end of the heat storage valve 5 is connected to the cold side of the heat storage tank 1. Specifically, the heat storage tank 1 is used to store hot water, cold water, or hot water in the upper space and cold water in the lower space, and adopts closed circulating water. The upper and lower parts of the heat storage tank 1 are respectively provided with a hot side and a cold side. Preferably, the number of the heat storage tanks 1 is one or more, and the multiple heat storage tanks 1 are connected in series or in parallel. The first heating valve 2 and the second heating valve 3 are connected between the heat storage tank 1 and the heat exchange component. The heat exchange component is used for external heat supply and heat dissipation. The heat storage closed circulating water is used. The heat supplied is the heat of the temperature slope layer of the heat storage tank 1, or the heat storage tank 1 is provided with heat dissipation to ensure that the temperature of the circulating water returned to the heat storage tank 1 reaches the rated temperature of the cold side of the heat storage tank 1. The opening and closing switching of the heat release valve 4 and the heat storage valve 5 realizes the energy storage and heating of the compressed air energy storage heat recovery system. According to the current working conditions and the location of the temperature slope layer of the heat storage tank 1, the cold side or hot side of the heat storage tank 1 is selected to realize the external heat supply, and the pressurized water heat storage temperature slope layer is returned to the initial state to prepare for the next energy storage and energy release cycle, thereby enhancing the flexibility of the pressurized heat storage temperature slope layer water. When the heat release valve 4 is opened and the heat storage valve 5 is closed, the heat release component is used to provide power for the hot water to return to the cold side of the heat storage tank 1 after flowing through the heat-using system, and to release heat from the circulating water in the heat storage system to a cold state; when the heat release valve 4 is closed and the heat storage valve 5 is opened, the heat storage component is used to provide power for the cold water to return to the hot side of the heat storage tank 1 after flowing through the heating system, and to heat the circulating water in the heat storage system from a cold state to a hot state.

[0041] The working principle of the compressed air energy storage heat recovery system is as follows: when storing heat, the hot water in the heat storage tank 1 after being heated returns to the heat storage tank 1, that is, the heat storage valve 5 is opened, the heat release valve 4, the first heat supply valve 2 and the second heat supply valve 3 are closed, and a part of the cold water flows out of the cold side of the heat storage tank 1, and the cold water flows into the hot side of the heat storage tank 1 after being heated by the heat storage component. At the same time, another part of the cold water flows out of the cold side of the heat storage tank 1, and the cold water is discharged into the expansion component to maintain the liquid level height and the pressure in the heat storage tank 1, and complete the heat storage of the compressed air energy storage heat recovery system with a pressurized oblique temperature layer. When releasing heat, the cold water in the heat storage tank 1 after the hot water dissipates heat returns to the heat storage tank 1, and supplies the heat of the oblique temperature layer to the outside, the heat release valve 4 is opened, the heat storage valve 5, the first heat supply valve 2 and the second heat supply valve 3 are closed, and a part of the hot water flows out of the hot side of the heat storage tank 1, and the hot water flows into the cold side of the heat storage tank 1 after being dissipated by the heat release component. At the same time, the expansion component adds cold water to the cold side of the heat storage tank 1, maintains the liquid level height and the pressure in the heat storage tank 1, opens the first heating valve 2, and closes the heat release valve 4. When the outlet water temperature of the heat storage tank 1 reaches the lower limit of the heating temperature, the heat exchange component performs heat exchange on the heat storage tank 1 to complete the heat release of the pressurized thermoclimatic layer compressed air energy storage heat recovery system. Solve the problem that the heat of the pressurized water thermoclimatic layer cannot be utilized, improve the comprehensive utilization rate of energy, and enhance the feasibility of heat storage in the thermoclimatic layer of the heat storage tank 1. At the end of the heat storage and heat release stage, the heat of the thermoclimatic layer of the heat storage tank 1 is supplied to the outside to ensure that there is only cold water in the heat storage tank 1 before the next charge and discharge cycle. There is no need to wait for the next energy storage or release period for the simultaneous storage of cold and hot water, thereby improving the heat storage efficiency.

[0042] Further, continue to refer to Figure 1-Figure 3 , the heat release component includes a heat release device 6 and a heat release pump 7. The input end of the heat release device 6 is connected to the hot side of the heat storage tank 1, the output end of the heat release device 6 is connected to the input end of the heat release pump 7, and the output end of the heat release pump 7 is connected to the heat release valve 4. The heat storage component includes a heat storage device 8 and a heat storage pump 9. The input end of the heat storage pump 9 is connected to the heat storage valve 5, the output end of the heat storage pump 9 is connected to the input end of the heat storage device 8, and the output end of the heat storage device 8 is connected to the hot side of the heat storage tank 1. Specifically, the heat release device 6 and the heat release pump 7 are used to realize the heat release function. The heat release device 6 releases the circulating water in the heat storage system from the hot state to the cold state of 40°C. The heat release pump 7 is a circulation pump. The hot water of the heat release pump 7 flows through the heat use system and returns to the cold side of the heat storage tank 1 to provide power. The temperature range of the hot water supplied is 176-200°C. The heat supplied is the hot side, not the heat in the inclined temperature layer of the heat storage tank 1. The heat storage device 8 and the heat storage pump 9 are used to realize the heat storage function. The heat storage device 8 heats the circulating water in the heat storage system from a cold state of 40°C to a hot state of 200°C. The heat source is determined according to the application scenario of the pressurized thermocline heat storage. The heat storage pump 9 is a circulation pump. The heat storage pump 9 provides power for the 40°C cold water to flow through the heating system and then return to the hot side of the heat storage tank 1.

[0043] Further, continue to refer to Figure 1-Figure 3The expansion assembly includes an expansion tank 10, an expansion constant pressure pump 11 and an expansion valve 12. The expansion constant pressure pump 11 and the expansion valve 12 are arranged in parallel. The input end of the expansion constant pressure pump 11 is connected to the expansion tank 10, and the output end of the expansion constant pressure pump 11 is connected to the cold side of the heat storage tank 1. The input end of the expansion valve 12 is connected to the cold side of the heat storage tank 1, and the output end of the expansion valve 12 is connected to the expansion tank 10. Specifically, the expansion tank 10 is used to maintain the liquid level of the heat storage tank 1 when charging and discharging energy, and maintain the volume difference caused by the density difference between cold and hot water. The expansion tank 10 is connected to the heat storage tank 1 through a water pump or a pipeline to store part of the low-temperature closed-loop circulating water. The expansion constant pressure pump 118 is used to realize the expansion tank 107 to replenish water to the heat storage tank 1. When releasing heat, the cold water in the expansion tank 10 is discharged into the cold side of the heat storage tank 1. The expansion valve 12 is used to realize the heat storage tank 1 to drain water to the expansion tank 107. When storing heat, the cold water in the heat storage tank 1 is discharged into the expansion tank 10.

[0044] Further, continue to refer to Figure 1-Figure 3 The heat exchange component includes a heat exchanger 13 and a radiator 14. The heat exchanger 13 and the radiator 14 are arranged in parallel. The heat exchanger 13 is used to supply heat to the outside, and the radiator 14 is used to dissipate heat from the heat storage tank 1. Specifically, the heat exchanger 13 is used to supply heat to the outside, and the heat supplied is the heat in the temperature gradient layer. One side of the heat exchanger 13 is heat storage closed circulating water, and the other side is the user on the heat side. The radiator 14 is used to dissipate heat. One side of the radiator 14 is heat storage closed circulating water, and the other side is air cooling or water cooling. After the heat storage closed circulating water completes the heating, it is ensured that the temperature when it returns to the heat storage tank 1 can reach the rated temperature of the cold side of the heat storage tank 1.

[0045] Further, continue to refer to Figure 1-Figure 3The compressed air energy storage heat recovery system also includes a gas storage component and a heating component. The gas storage component is connected to the heating component. The gas storage component and the heating component are both connected between the heat release mechanism and the heat storage mechanism. The gas storage component is used to pressurize and cool the air, and the heating component is used to heat and pressurize the air. Specifically, the gas storage component includes a compressor 15, a cooler 16 and a gas tank 17, and the heating component includes a heater 18 and a turbine 19. The compressor 15 is connected to the cooler 16, the cooler 16 is connected to the gas tank 17, the gas tank 17 is connected to the heater 18, and the heater 18 is connected to the turbine 19. The turbine 19 is a dynamic compressor with a high-speed rotating impeller. It relies on the interaction force between the rotating impeller and the airflow to increase the gas pressure, and at the same time, the airflow generates acceleration to obtain kinetic energy, and then converts the kinetic energy into pressure energy to further increase the pressure. The compressor 15 is used to pressurize the air, the cooler 16 is used to cool the pressurized air and recover the heat generated by the compressor 15, and the gas tank 17 is used to store the cooled pressurized air. The heater 18 is used to heat the air delivered from the air tank 17, and the turbine 19 is used to perform work on the heated air. In the heat storage and energy charging stage, the compressed air energy storage heat recovery system is charged by the start and stop control of the compressor 15 and the cooler 16. In the heat release and energy release stage, the compressed air energy storage heat recovery system is released by the start and stop control of the turbine 19. Assuming that the total mass of the circulating water is 10,000 tons, the ratio of the thermocline layer to the total water mass is 10%, the average water temperature on the cold side of the heat storage tank 1 is estimated to be 45°C, and the average water temperature on the hot side of the heat storage tank 1 is estimated to be 195°C. According to the exhaust temperature of the turbine 19, the temperature of the circulating water before it releases heat and enters the radiator 14 is estimated to be 50°C, the available temperature range for heat supply outside the thermocline layer is 100-176°C, and the corresponding water volume is estimated to be 900 tons. The compressed air energy storage heat recovery system can store 6233.7GJ of heat when storing and charging, and 5571.7GJ of heat can be released when releasing heat and energy. The thermocline layer can recover 292.9GJ of heat. Compared with the situation where the thermocline layer heat is not recovered, the thermal energy utilization rate can be increased by 4.42%.

[0046] This embodiment also provides a compressed air energy storage heat recovery method, such as Figure 4 As shown, through the implementation of the above compressed air energy storage heat recovery system, the compressed air energy storage heat recovery system has a heat storage state and a heat release state. The compressed air energy storage heat recovery method includes:

[0047] When storing heat, the cold water in the heat storage tank 1 is heated and then converted into hot water and returned to the heat storage tank 1. The process is as follows:

[0048] S100: When storing heat, the heat storage valve 5 and the expansion valve 12 are opened, and the heat release valve 4, the first heating valve 2 and the second heating valve 3 are closed.

[0049] S200: Turn on the heat storage pump 9 and start the compressor 15. A portion of cold water flows out of the cold side of the heat storage tank 1. The cold water flows into the hot side of the heat storage tank 1 after being heated by the heat storage device 8. At the same time, another portion of cold water flows out of the cold side of the heat storage tank 1. The cold water is discharged into the expansion tank 10 through the expansion valve 12 to maintain the liquid level and the pressure in the heat storage tank 1. The gas storage tank 17 is inflated to the rated high pressure, the compressor 15 is stopped, and the heat storage pump 9 is turned off to complete the heat storage of the pressurized inclined temperature layer compressed air energy storage heat recovery system.

[0050] When releasing heat, the hot water in the heat storage tank 1 dissipates heat and becomes cold water, which returns to the heat storage tank 1 and supplies heat to the temperature gradient layer. The process is as follows:

[0051] S100: When releasing heat, the heat release valve 4 is opened, and the heat storage valve 5, the expansion valve 12, the first heating valve 2 and the second heating valve 3 are closed.

[0052] S200: Turn on the heat release pump 7 and the expansion constant pressure pump 11, start the turbine 19, and a portion of hot water flows out of the hot side of the heat storage tank 1. The hot water flows into the cold side of the heat storage tank 1 after dissipating heat through the radiator 6. At the same time, the cold water in the expansion tank 10 is replenished to the cold side of the heat storage tank 1 by the expansion constant pressure pump 11 to maintain the liquid level height and the pressure in the heat storage tank 1. The gas storage tank 17 is inflated to the rated low pressure, the turbine 19 is stopped, and the heat release pump 7 is turned off.

[0053] S300: Open the first heating valve 2 and close the heat release valve 4. When the outlet water temperature of the heat storage tank 1 reaches the lower limit of the heating temperature, the heat exchanger 13 supplies heat to the outside, and the radiator 14 reduces the temperature of the cold side circulating water of the heat storage tank 1 to the rated temperature and flows into the cold side of the heat storage tank 1, completing the heat release of the pressurized inclined temperature layer compressed air energy storage heat recovery system.

[0054] The compressed air energy storage heat recovery method provided in this embodiment is implemented by the compressed air energy storage heat recovery system. When storing heat, the heat storage valve 5 is opened, and the heat release valve 4, the first heat supply valve 2 and the second heat supply valve 3 are closed. When releasing heat, the heat release valve 4 is opened, and the heat storage valve 5, the first heat supply valve 2 and the second heat supply valve 3 are closed. When storing heat, a part of cold water flows out of the cold side of the heat storage tank 1, and the cold water flows into the hot side of the heat storage tank 1 after being heated by the heat storage component. At the same time, another part of cold water flows out of the cold side of the heat storage tank 1, and the cold water flows into the expansion component, and the heat storage is completed. When releasing heat, a part of hot water flows out of the hot side of the heat storage tank 1, and the hot water flows into the cold side of the heat storage tank 1 after being dissipated by the heat release component. At the same time, the expansion component replenishes cold water to the cold side of the heat storage tank 1. When releasing heat, the first heat supply valve 2 is opened, and the heat release valve 4 is closed. When the outlet water temperature of the heat storage tank 1 reaches the lower limit of the heating temperature, the heat exchange component performs heat exchange on the heat storage tank 1, and the heat release is completed. The opening and closing switching of the heat release valve 4 and the heat storage valve 5 realizes the energy storage and heat supply of the compressed air energy storage heat recovery system, solves the problem that the heat of the pressurized water thermocline layer cannot be utilized, improves the comprehensive utilization rate of energy, and enhances the feasibility of heat storage in the thermocline layer of the heat storage tank 1. At the end of the heat storage and heat release stage, the heat of the thermocline layer of the heat storage tank 1 is supplied to the outside to ensure that there is only cold water in the heat storage tank 1 before the next charge and discharge cycle, and there is no need to wait for the next energy storage or discharge period for the simultaneous storage of cold and hot water, thereby improving the heat storage efficiency.

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A compressed air energy storage heat recovery system, characterized in that: include: A heat storage tank (1), wherein the heat storage tank (1) has a cold side and a hot side; An expansion component connected to the cold side of the heat storage tank (1), the expansion component being used to maintain the liquid level of the heat storage tank (1) during the charging and discharging process; A first heating valve (2), one end of the first heating valve (2) being connected to the hot side of the heat storage tank (1); A second heating valve (3), one end of the second heating valve (3) being connected to the cold side of the heat storage tank (1); A heat exchange component connected to the other end of the first heating valve (2) and the second heating valve (3); A heat release mechanism, comprising a heat release valve (4) and a heat release component, wherein the input end of the heat release component is connected to the hot side of the heat storage tank (1), the output end of the heat release component is connected to one end of the heat release valve (4), and the other end of the heat release valve (4) is connected to the cold side of the heat storage tank (1); A heat storage mechanism comprises a heat storage valve (5) and a heat storage component, wherein an input end of the heat storage component is connected to one end of the heat storage valve (5), an output end of the heat storage component is connected to the hot side of the heat storage tank (1), and the other end of the heat storage valve (5) is connected to the cold side of the heat storage tank (1).

2. The compressed air energy storage heat recovery system according to claim 1 is characterized in that: The heat release component comprises a heat release device (6) and a heat release pump (7), wherein the input end of the heat release device (6) is connected to the hot side of the heat storage tank (1), the output end of the heat release device (6) is connected to the input end of the heat release pump (7), and the output end of the heat release pump (7) is connected to the heat release valve (4).

3. The compressed air energy storage heat recovery system according to claim 1 is characterized in that: The heat storage component comprises a heat storage device (8) and a heat storage pump (9), wherein the input end of the heat storage pump (9) is connected to the heat storage valve (5), the output end of the heat storage pump (9) is connected to the input end of the heat storage device (8), and the output end of the heat storage device (8) is connected to the hot side of the heat storage tank (1).

4. The compressed air energy storage heat recovery system according to claim 1 is characterized in that: The expansion assembly comprises an expansion tank (10), an expansion constant pressure pump (11) and an expansion valve (12); the expansion constant pressure pump (11) and the expansion valve (12) are arranged in parallel; an input end of the expansion constant pressure pump (11) is connected to the expansion tank (10); an output end of the expansion constant pressure pump (11) is connected to the cold side of the heat storage tank (1); an input end of the expansion valve (12) is connected to the cold side of the heat storage tank (1); and an output end of the expansion valve (12) is connected to the expansion tank (10).

5. The compressed air energy storage heat recovery system according to claim 1 is characterized in that: The heat exchange component comprises a heat exchanger (13) and a radiator (14); the heat exchanger (13) and the radiator (14) are arranged in parallel; the heat exchanger (13) is used to supply heat to the outside, and the radiator (14) is used to dissipate heat from the heat storage tank (1).

6. The compressed air energy storage heat recovery system according to claim 1, characterized in that: The compressed air energy storage heat recovery system also includes an air storage component and a heating component. The air storage component is connected to the heating component. Both the air storage component and the heating component are connected between the heat release mechanism and the heat storage mechanism. The air storage component is used to pressurize and cool the air, and the heating component is used to heat and pressurize the air.

7. The compressed air energy storage heat recovery system according to claim 6 is characterized in that: The gas storage component includes a compressor (15), a cooler (16) and a gas storage tank (17); the heating component includes a heater (18) and a turbine (19); the compressor (15) is connected to the cooler (16); the cooler (16) is connected to the gas storage tank (17); the gas storage tank (17) is connected to the heater (18); and the heater (18) is connected to the turbine (19).

8. A compressed air energy storage heat recovery method, characterized in that: By implementing the compressed air energy storage heat recovery system according to any one of claims 1 to 7, the compressed air energy storage heat recovery system has a heat storage state and a heat release state, and the compressed air energy storage heat recovery method includes: S100: when storing heat, the heat storage valve (5) is opened, and the heat release valve (4), the first heating valve (2) and the second heating valve (3) are closed; when releasing heat, the heat release valve (4) is opened, and the heat storage valve (5), the first heating valve (2) and the second heating valve (3) are closed; S200: When storing heat, a portion of cold water flows out of the cold side of the heat storage tank (1), and the cold water flows into the hot side of the heat storage tank (1) after being heated by the heat storage component. At the same time, another portion of cold water flows out of the cold side of the heat storage tank (1), and the cold water flows into the expansion component. Heat storage is completed. When releasing heat, a portion of hot water flows out of the hot side of the heat storage tank (1), and the hot water flows into the cold side of the heat storage tank (1) after being cooled by the heat release component. At the same time, the expansion component replenishes cold water to the cold side of the heat storage tank (1); S300: When releasing heat, the first heating valve (2) is opened and the heat release valve (4) is closed. When the outlet water temperature of the heat storage tank (1) reaches the lower limit of the heating temperature, the heat exchange component performs heat exchange on the heat storage tank (1), and heat release is completed.

9. The compressed air energy storage heat recovery method according to claim 8, characterized in that: The expansion assembly comprises an expansion tank (10), an expansion constant pressure pump (11) and an expansion valve (12); the expansion constant pressure pump (11) and the expansion valve (12) are arranged in parallel; an input end of the expansion constant pressure pump (11) is connected to the expansion tank (10); an output end of the expansion constant pressure pump (11) is connected to the cold side of the heat storage tank (1); an input end of the expansion valve (12) is connected to the cold side of the heat storage tank (1); and an output end of the expansion valve (12) is connected to the expansion tank (10); In the compressed air energy storage heat recovery method, when storing heat, the expansion valve (12) is opened, the expansion constant pressure pump (11) is closed, and the cold water in the heat storage tank (1) flows into the expansion tank (10) through the expansion valve (12); when releasing heat, the expansion valve (12) is closed, the expansion constant pressure pump (11) is opened, and the cold water in the expansion tank (10) flows into the heat storage tank (1) through the expansion constant pressure pump (11).

10. The compressed air energy storage heat recovery method according to claim 8, characterized in that: The compressed air energy storage heat recovery system further includes a gas storage component and a heating component, wherein the gas storage component is connected to the heating component, and both the gas storage component and the heating component are connected between the heat release mechanism and the heat storage mechanism; In the compressed air energy storage heat recovery method S200, when storing heat, the gas storage component is started, and the compressed air energy storage heat recovery system completes charging. When releasing heat, the heating component is started, and the compressed air energy storage heat recovery system completes releasing.

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