Constant-pressure heat compensation compressed air energy storage system relying on pumped storage power station and operation method of constant-pressure heat compensation compressed air energy storage system

Abstract

The invention relates to a constant-pressure heat compensation compressed air energy storage system relying on a pumped storage power station and an operation method of the constant-pressure heat compensation compressed air energy storage system. The invention discloses a constant-pressure heat compensation compressed air energy storage system relying on a pumped storage power station. The constant-pressure heat compensation compressed air energy storage system comprises a constant-pressure compressed air energy storage subsystem and a water source heat pump subsystem. The constant-pressure compressed air energy storage subsystem comprises a constant-pressure compressor, a first heat exchanger, a constant-pressure air storage chamber, a second heat exchanger and a constant-pressure expansion machine which are sequentially connected through pipelines; the constant-pressure gas storage chamber is connected with an upper reservoir of the pumped storage power station through a pressure balance pipeline; the water source heat pump subsystem comprises a heat storage tank, a second heat exchanger, a heat pump expansion machine, a cold storage tank and a heat pump compressor which are sequentially connected through pipelines; the cold storage tank is connected with a lower reservoir of the pumped storage power station through a heat exchange pipeline; the constant-pressure compressed air energy storage subsystem and the water source heat pump subsystem are connected through a second heat exchanger and achieve energy interaction.

Description

Technical Field

[0001] This invention belongs to the field of energy storage technology, specifically relating to a constant pressure supplemental heating compressed air energy storage system based on a pumped storage power station and its operation method. Background Technology

[0002] The construction of new power systems with a high proportion of renewable energy urgently requires addressing the issue of absorbing fluctuating inputs, making energy storage technology crucial for supporting the flexibility and stability of power systems. Pumped storage and compressed air energy storage (CAES) are two major large-scale energy storage technologies. Pumped storage power plants utilize the water level difference between upper and lower reservoirs to store and release energy, offering advantages such as mature technology, high efficiency (approximately 70-80%), and fast response. Compressed air energy storage, as the most commercially mature new physical energy storage technology, can fully utilize various chamber resources to achieve high-energy-density energy storage and high-power energy storage and release. These two technologies have a natural coupling characteristic; relying on the upstream head resources of pumped storage and idle chamber resources, a constant-pressure compressed air energy storage system can be constructed, thereby achieving dual-circulation in one location and dual-control at one station.

[0003] However, the existing constant-pressure compressed air energy storage technology based on pumped hydro storage has three main shortcomings. First, the compressed air energy storage (CAES) system uses the heat of compression to heat the air at the expander inlet, resulting in a relatively low temperature and insufficient turbine work capacity. Second, the limited volume of existing chambers leads to a small capacity of the constant-pressure compressed air system, which is mismatched with the scale of pumped hydro storage power stations and fails to realize its comprehensive value. Third, pumped hydro storage power stations have abundant water resources, and water's high specific heat capacity makes it an excellent constant-temperature source; the hydrothermal / geothermal resources of pumped hydro storage power stations have not yet been fully explored and utilized. These technical shortcomings collectively restrict the large-scale coupled application and promotion of pumped hydro storage and constant-pressure compressed air energy storage technologies. Summary of the Invention

[0004] To address the technical problem that existing constant-pressure compressed air energy storage technology based on pumped storage fails to realize its comprehensive value, this invention proposes a constant-pressure supplementary compressed air energy storage system based on pumped storage power stations, including a constant-pressure compressed air energy storage subsystem and a water source heat pump subsystem.

[0005] The constant pressure compressed air energy storage subsystem includes a constant pressure compressor, a first heat exchanger, a constant pressure air storage chamber, a second heat exchanger, and a constant pressure expander connected in sequence via pipelines; the constant pressure air storage chamber is connected to the upper reservoir of the pumped storage power station via a pressure balancing pipeline.

[0006] The water source heat pump subsystem includes a heat storage tank, a second heat exchanger, a heat pump expander, a cold storage tank, and a heat pump compressor connected in sequence via pipelines; the cold storage tank is connected to the lower reservoir of the pumped storage power station via heat exchange pipelines.

[0007] The constant pressure compressed air energy storage subsystem and the water source heat pump subsystem are connected through a second heat exchanger and achieve energy exchange.

[0008] The constant-pressure air storage chamber is connected to the upper reservoir of the pumped-storage power station via a pressure balancing pipeline, using the water head pressure of the upper reservoir to directly maintain a constant air pressure inside the chamber. This design eliminates the reliance on the volume of traditional chambers, eliminating the need to increase the chamber volume to ensure energy storage capacity, thus allowing the capacity of the constant-pressure compressed air system to match the scale of the pumped-storage power station.

[0009] The cold storage tank of the water source heat pump subsystem is connected to the lower reservoir of the pumped storage power station through heat exchange pipelines, and uses the near constant temperature water in the lower reservoir as the low temperature heat source of the heat pump heat collection system; the heat pump compressor absorbs heat energy from the lower reservoir, heats it and stores it in the heat storage tank, realizing the exploitation and utilization of the hydrothermal / geothermal resources of the pumped storage power station.

[0010] Furthermore, in the constant pressure compressed air energy storage subsystem,

[0011] The constant pressure compressor has an atmospheric pressure inlet connected to the atmosphere, and its outlet is connected in sequence to the inlet of the first heat exchanger and the constant pressure gas storage chamber via pipelines.

[0012] The outlet of the constant pressure gas storage chamber is connected to the first heat exchanger, the second heat exchanger, and the inlet of the constant pressure expander via pipelines.

[0013] The outlet of the constant pressure expander is connected to the atmosphere.

[0014] Furthermore, in the aforementioned water source heat pump system,

[0015] The outlet of the heat storage tank is connected in sequence to the inlet of the second heat exchanger and the heat pump expander via pipelines.

[0016] The outlet of the heat pump expander is connected to the inlet of the cold storage tank via a pipeline.

[0017] The outlet of the cold storage tank is connected to the inlet of the heat pump compressor via a pipeline.

[0018] The outlet of the heat pump compressor is connected to the inlet of the heat storage tank via a pipeline.

[0019] Furthermore, before entering the constant pressure expander, the air is heated by passing through the first heat exchanger and the second heat exchanger in sequence, and the heating temperature provided by the first heat exchanger is lower than that provided by the second heat exchanger, forming a stepped heating structure.

[0020] In the constant pressure compressed air energy storage subsystem, the air is heated sequentially by the first heat exchanger and the second heat exchanger before entering the constant pressure expander. The heating temperature provided by the first heat exchanger is lower than that of the second heat exchanger, forming a stepped heating structure to improve the air temperature quality. The water source heat pump subsystem provides high-quality heat to the constant pressure compressed air energy storage subsystem through the second heat exchanger, further increasing the air temperature at the expander inlet and enhancing the turbine's work capacity.

[0021] Furthermore, the first heat exchanger employs non-contact heat exchange.

[0022] Furthermore, it also includes a control system, which is electrically connected to the equipment in the compressed air energy storage subsystem and the water source heat pump subsystem, respectively, and is used to control the start and stop of each device, adjust the operating parameters, and switch the working mode.

[0023] The present invention also provides an operation method based on the system, including an energy storage process and a power generation process:

[0024] The energy storage process includes: starting the constant pressure compressor of the compressed air energy storage subsystem, compressing the air, exchanging heat through the first heat exchanger, and sending it into the constant pressure air storage chamber. During this stage, the heat energy is temporarily stored in the first heat exchanger; starting the heat pump compressor of the water source heat pump subsystem, absorbing heat energy from the lower reservoir, heating it, and storing it in the heat storage tank.

[0025] The power generation process includes: air is released from the constant pressure gas storage chamber, heated sequentially by the first heat exchanger and the second heat exchanger, and then used to drive the constant pressure expander to do work; the heat storage tank releases heat through the second heat exchanger, absorbs heat from the lower reservoir through the heat pump expander and the cold storage tank, and then returns to the heat storage tank through the heat pump compressor to complete the cycle.

[0026] Furthermore, the heating temperature provided by the first heat exchanger is lower than the heating temperature provided by the second heat exchanger.

[0027] Furthermore, during the period when the high-temperature and high-pressure air drives the constant-pressure expander to generate electricity, the air pressure at the inlet of the constant-pressure expander is constant, and the air temperature can be regulated by the heat pump circulation, thereby changing the power output of the constant-pressure expander.

[0028] Furthermore, the control system adjusts the operating status of each device in real time based on the collected pressure and temperature parameters to ensure that the air forms a stepped temperature distribution during the heating process.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] This invention proposes a constant-pressure compressed air energy storage system based on a pumped-storage power station, comprising a constant-pressure compressed air energy storage subsystem and a water source heat pump subsystem. The constant-pressure compressed air energy storage subsystem includes a constant-pressure compressor, a first heat exchanger, a constant-pressure air storage chamber, a second heat exchanger, and a constant-pressure expander connected sequentially via pipelines. The constant-pressure air storage chamber is connected to the upper reservoir of the pumped-storage power station via a pressure balancing pipeline. The water source heat pump subsystem includes a heat storage tank, a second heat exchanger, a heat pump expander, a cold storage tank, and a heat pump compressor connected sequentially via pipelines. The cold storage tank is connected to the lower reservoir of the pumped-storage power station via a heat exchange pipeline. The constant-pressure compressed air energy storage subsystem and the water source heat pump subsystem are connected through the second heat exchanger and achieve energy exchange. The constant-pressure compressed air energy storage subsystem utilizes the water head of the upper reservoir to maintain a constant-pressure air storage environment, ensuring stable pressure conditions during air compression and expansion. The water source heat pump subsystem uses the constant-temperature water resources of the lower reservoir as a low-temperature heat source, converting low-grade heat energy into high-grade heat energy through heat pump technology, and then heating the inlet air of the expander in the compressed air energy storage subsystem via a second heat exchanger. This design deeply integrates the water head resources and hydrothermal resources of pumped hydro storage with compressed air energy storage technology, allowing energy of different grades to flow in a cascade manner within the system and be utilized efficiently, avoiding energy waste.

[0031] This invention proposes an operation method for a constant-pressure supplemental heat compressed air energy storage system based on a pumped-storage power station. During energy storage, a constant-pressure compressor compresses air and temporarily stores the heat energy in a first heat exchanger; a heat pump compressor absorbs heat from the lower reservoir and stores it in a heat storage tank; during power generation, air released from the constant-pressure air storage chamber is heated in stages by the first and second heat exchangers to drive a constant-pressure expander; and heat released from the heat storage tank is circulated back to the heat storage tank. Combined with the technical means of connecting the constant-pressure air storage chamber to the upper reservoir to maintain constant pressure and connecting the cold storage tank to the lower reservoir to utilize water resources, this achieves efficient cascaded utilization of energy. It ensures that the constant-pressure expander operates under stable pressure and that the power output is changed by regulating the air temperature through heat pump circulation, thereby improving system efficiency, energy storage density, and economy, and fully leveraging the comprehensive value of pumped-storage power station resources. Attached Figure Description

[0032] Figure 1 A topology diagram of a constant-pressure reheating compressed air energy storage system relying on a pumped storage power station;

[0033] Among them, 110 is a constant pressure compressor; 120 is a first heat exchanger; 130 is a constant pressure gas storage chamber; 140 is a second heat exchanger; 150 is a constant pressure expander; 210 is a heat storage tank; 220 is a heat pump expander; 230 is a cold storage tank; and 240 is a heat pump compressor. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] Based on the existing reservoir resources of pumped storage power stations, this embodiment proposes a "constant pressure heat-compensating compressed air energy storage system relying on pumped storage power stations". It couples advanced adiabatic compressed air technology with water source heat pump technology. By using the near constant temperature water source in the lower reservoir as a low temperature source, the heat pump cycle is used to achieve high temperature heat compensation of the air at the inlet of the expander, achieving a highly efficient, clean and flexible coupled energy storage arrangement.

[0037] like Figure 1 As shown, the energy storage system includes a constant-pressure compressed air energy storage subsystem and a water source heat pump subsystem:

[0038] The constant-pressure compressed air energy storage subsystem includes a constant-pressure compressor 110, a first heat exchanger 120, a constant-pressure air storage chamber 130, a second heat exchanger 140, and a constant-pressure expander 150 connected in sequence via pipelines, responsible for realizing constant-pressure compressed air energy storage operation; the constant-pressure air storage chamber 130 is connected to the upper reservoir of the pumped storage power station via a pressure balancing pipeline; the atmospheric pressure inlet of the constant-pressure compressor 110 is connected to the atmosphere, and the outlet is connected in sequence via pipelines to the inlet of the first heat exchanger 120 and the constant-pressure air storage chamber 130; the outlet of the constant-pressure air storage chamber 130 is connected via pipelines to the inlet of the first heat exchanger 120, the second heat exchanger 140, and the constant-pressure expander 150; the outlet of the constant-pressure expander 150 is connected to the atmosphere.

[0039] The water source heat pump subsystem includes a heat storage tank 210, a second heat exchanger 140, a heat pump expander 220, a cold storage tank 230, and a heat pump compressor 240 connected in sequence via pipelines, responsible for achieving high-temperature heat replenishment. The cold storage tank 230 is connected to the lower reservoir of the pumped storage power station via a heat exchange pipeline. The outlet of the heat storage tank 210 is connected in sequence via pipelines to the inlet of the second heat exchanger 140 and the heat pump expander 220. The outlet of the heat pump expander 220 is connected via a pipeline to the inlet of the cold storage tank 230, the outlet of the cold storage tank 230 is connected via a pipeline to the inlet of the heat pump compressor 240, and the outlet of the heat pump compressor 240 is connected via a pipeline to the inlet of the heat storage tank 210.

[0040] The constant pressure compressed air energy storage subsystem and the water source heat pump subsystem are connected through the second heat exchanger 140 and achieve energy exchange.

[0041] Before entering the constant pressure expander, the air is heated by passing through the first heat exchanger 120 and the second heat exchanger 140 in sequence. The heating temperature provided by the first heat exchanger 120 is lower than that provided by the second heat exchanger 140, forming a stepped heating structure.

[0042] The first heat exchanger 120 adopts non-contact heat exchange.

[0043] As a preferred implementation of this embodiment, a control system is also included. The control system is electrically connected to the equipment in the compressed air energy storage subsystem and the water source heat pump subsystem, respectively, and is used to control the start and stop of each device, adjust the operating parameters, and switch the working mode.

[0044] The two subsystems exchange energy through a second heat exchanger 140. The heat pump cycle provides high-grade heat energy to the constant-pressure compressed air energy storage cycle, thereby improving the inlet parameters of the air expander and achieving a significant increase in rated power and specific power density. The constant-pressure air storage chamber fully utilizes the head of the upper reservoir of the pumped storage power station to achieve a constant-pressure environment; while the heat pump system fully utilizes the near-constant-temperature water source of the lower reservoir as a low-temperature source to achieve efficient collection and high-grade conversion of large-scale low-temperature heat energy.

[0045] The working principle of the constant pressure compressed air subsystem is as follows:

[0046] 1) Energy storage process

[0047] Gas compression stage: The constant pressure compressor 110 is connected to the atmosphere at its atmospheric pressure inlet, which compresses the air to produce high temperature and high pressure compressed air.

[0048] Heat recovery and storage stage: Compressed air is connected sequentially to the first heat exchanger 120 and the constant pressure air storage chamber 130 through pipelines. The heat energy in the air is temporarily stored in the first heat exchanger 120 through non-contact heat exchange before being transferred to the constant pressure air storage chamber 130. The constant pressure air storage chamber 130 is connected to the upper reservoir through pipelines. The air in the constant pressure air storage chamber 130 pushes the water back to the upper reservoir along the water intake pipe of the pumped storage upper reservoir. During this period, the pressure in the constant pressure air storage chamber 130 remains constant.

[0049] 2) Power generation process

[0050] Gas preheating stage: Low-temperature and high-pressure air in constant-pressure storage chamber 130 flows through pipelines to the first heat exchanger 120 and the second heat exchanger 140 before being transported to constant-pressure expander 150. After absorbing the temporarily stored heat in the first heat exchanger 120 (3-4), the air further absorbs the high-temperature heat from the heat pump cycle (4-5) through the second heat exchanger 140, thereby further increasing the air temperature and enhancing its working capacity.

[0051] Expansion power generation stage: High temperature and high pressure air drives the constant pressure expander 150 to generate electricity. During this period, the air pressure at the inlet of the constant pressure expander 150 is constant, while the air temperature can be regulated by heat pump circulation, thereby changing the power output of the constant pressure expander 150.

[0052] The working principle of the water source heat pump subsystem is as follows:

[0053] 1) High-temperature heat release: The high-temperature working fluid in the heat storage tank 210 releases heat (6-7) through the second heat exchanger 140, and the temperature of the air is reduced to that of the medium-temperature working fluid after heating.

[0054] 2) Expansion for cooling: The medium-temperature working fluid flows into the heat pump expander 220 (7-8) for further cooling to a low-temperature working fluid, and then is stored in the cold storage tank 230.

[0055] 3) Low-temperature heat source utilization: The low-temperature working fluid in the 230 cold storage tank uses the near-constant temperature water in the lower reservoir of the pumped storage power station as a low-temperature heat source, and absorbs a large amount of low-temperature heat to near room temperature (9-10) through heat exchange.

[0056] 4) Compression and heating cycle: The near-room temperature working fluid is heated efficiently by the heat pump compressor 240 (10-11). The working fluid with high-grade heat is temporarily stored in the heat storage tank 210 to complete the heat pump cycle and is reserved as a high-temperature heat source for use in the energy release stage of the constant pressure compressed air energy storage system.

[0057] The energy storage system proposed in this embodiment employs multi-stage heat replenishment technology and water source heat pump integration technology. Building upon the compressed air energy storage system's utilization of heat generated during compression to heat the released air, an additional high-efficiency heat pump heating cycle is designed to heat the air at the expander inlet and provide temperature regulation. This fully utilizes the ambient temperature water resources of the pumped storage power station's lower reservoir, providing a stable low-temperature heat source for the heat pump system, thus making full use of the various resources of the pumped storage power station.

[0058] The system innovatively integrates pumped-storage geothermal / hydrothermal resources with constant-pressure compressed air energy storage technology. While maintaining the upper reservoir head pressure of the pumped-storage power station to sustain the air storage environment of the constant-pressure compressed air energy storage system, it utilizes near-constant-temperature water from the lower reservoir as a low-temperature heat source for the heat pump collector system. This heat is converted into high-grade heat via heat pump technology and then used to heat the inlet air of the expander in the constant-pressure compressed air energy storage system, thus achieving efficient cascaded energy utilization. While ensuring the constant-pressure expander operates stably under optimal conditions, it also features output control via a temperature regulation system. This constant-pressure supplemental-heat compressed air energy storage system has dual adjustable parameters for upper reservoir head height (constant pressure) and heat pump cycle high-temperature source temperature (expander inlet air temperature). Its system efficiency, energy density, and economy are comprehensively superior to pure constant-pressure compressed air energy storage systems, providing an innovative solution for the in-depth exploitation of pumped-storage resources and the large-scale construction of constant-pressure supplemental-heat compressed air energy storage systems.

[0059] Example 2

[0060] This embodiment provides an operation method for a constant pressure reheating compressed air energy storage system relying on a pumped storage power station, including the energy storage process and the power generation process.

[0061] The energy storage process includes:

[0062] The constant pressure compressor 110 of the compressed air energy storage subsystem is started, the air is compressed and then heat-exchanged through the first heat exchanger 120 and sent into the constant pressure air storage chamber 130. During this stage, the heat energy is temporarily stored in the first heat exchanger 120. The heat pump compressor 240 of the water source heat pump subsystem is started, the heat energy is absorbed from the lower reservoir and heated and then stored in the heat storage tank 210.

[0063] The power generation process includes:

[0064] Air is released from the constant pressure air storage chamber 130 and heated by the first heat exchanger 130 and the second heat exchanger 140 in sequence, which then drives the constant pressure expander 150 to do work. The heat storage tank 210 releases heat through the second heat exchanger 140, absorbs heat from the lower reservoir through the heat pump expander 220 and the cold storage tank 230, and then returns to the heat storage tank 210 through the heat pump compressor 240 to complete the cycle.

[0065] The heating temperature provided by the first heat exchanger 120 is lower than that provided by the second heat exchanger 140. During the power generation process of the constant pressure expander 150 driven by high-temperature and high-pressure air, the inlet air pressure of the constant pressure expander 150 remains constant, and the air temperature can be regulated by the heat pump circulation, thereby changing the power output of the constant pressure expander 150. The control system adjusts the operating status of each device in real time according to the collected pressure and temperature parameters to ensure that the air forms a stepped temperature distribution during the heating process.

[0066] The present invention has the following beneficial effects:

[0067] 1) It pioneered a new energy storage system topology that deeply integrates pumped hydro storage resources with compressed air energy storage. It breaks through by using the head pressure of pumped hydro power stations to provide a constant pressure gas storage environment and using the ambient temperature water in the lower reservoir as a constant temperature heat source for the heat pump system, realizing a "gas-water-heat" ternary coupled energy storage system architecture and forming a brand-new composite energy storage technology route.

[0068] 2) Innovative synergistic operation strategy of constant pressure gas storage and variable temperature heat compensation. Constant pressure gas storage is achieved by utilizing the water head pressure of the upper reservoir, ensuring stable operation of the expander at the rated pressure ratio; at the same time, the near-constant temperature water of the lower reservoir is used to provide a low-temperature heat source for the heat pump system, giving full play to the multiple functions of pumped storage energy resources, providing more controllable dimensions and higher work capacity for the compressed air energy storage system, and further improving system efficiency and energy storage density.

[0069] 3) An innovative energy cascade utilization technology suitable for constant pressure compressed air energy storage systems is proposed. Through precise temperature matching, the compression heat and high-temperature heat of the heat pump cycle in the constant pressure compressed air energy storage system are designed separately, with their temperature ranges set in a cascade manner. This not only improves the thermal quality of the air but also achieves efficient cascade utilization of the system's energy.

[0070] 4) Pioneering a highly efficient coupled energy storage system for pumped storage power stations. The system encompasses three major technology systems: pumped storage, compressed air, and heat pumps, achieving effective integration. These three technologies not only support and cooperate with each other but can also operate independently without affecting each other. Therefore, the entire system has multiple modes of operation, including single-cycle operation and coupled operation, and can be customized to respond to external needs, thereby improving scenario support capabilities and system economic benefits.

[0071] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A constant pressure heat-supplemented compressed air energy storage system relying on pumped hydroelectric power station, characterized in that, The constant pressure compressed air energy storage subsystem and the water source heat pump subsystem are connected through the second heat exchanger and realize energy interaction. The constant pressure compressed air energy storage subsystem, The atmospheric pressure inlet of the constant pressure compressor is connected with the atmosphere, and the outlet is connected with the inlet of the first heat exchanger and the constant pressure air storage chamber through a pipeline in sequence. The outlet of the constant pressure air storage chamber is connected with the inlets of the first heat exchanger, the second heat exchanger and the constant pressure expander through a pipeline.

2. The system of claim 1, wherein, The outlet of the constant pressure expander is connected with the atmosphere. The water source heat pump system, The outlet of the heat storage tank is connected with the inlets of the second heat exchanger and the heat pump expander through a pipeline in sequence. The outlet of the heat pump expander is connected with the inlet of the cold storage tank through a pipeline.

3. The system of claim 1, wherein, The outlet of the cold storage tank is connected with the inlet of the heat pump compressor through a pipeline. The outlet of the heat pump compressor is connected with the inlet of the heat storage tank through a pipeline. The air is heated in sequence by the first heat exchanger and the second heat exchanger before entering the constant pressure expander, and the heating temperature provided by the first heat exchanger is lower than that provided by the second heat exchanger, forming a step heating structure. The first heat exchanger adopts non-contact heat exchange. The control system is electrically connected with the devices in the compressed air energy storage subsystem and the water source heat pump subsystem respectively, and is used for controlling the start-stop, operation parameter adjustment and working mode switching of the devices.

4. The system of claim 2, wherein, The energy storage process and the power generation process are included.

5. The system of claim 2, wherein, The energy storage process includes: starting the constant pressure compressor of the compressed air energy storage subsystem, compressing the air, and then heating the air by the first heat exchanger and sending the air into the constant pressure air storage chamber, and the heat energy is temporarily stored in the first heat exchanger; starting the heat pump compressor of the water source heat pump subsystem, absorbing heat energy from the lower reservoir and storing the heat energy in the heat storage tank after being heated; 6. The system of claim 1, wherein, The power generation process includes: the constant pressure air storage chamber releases air, which is heated in sequence by the first heat exchanger and the second heat exchanger and then drives the constant pressure expander to work; the heat storage tank releases heat through the second heat exchanger, absorbs heat from the lower reservoir through the heat pump expander and the cold storage tank, and then returns to the heat storage tank through the heat pump compressor to complete the cycle.

7. A method of operating a system according to any one of claims 1 to 6, characterised in that, The heating temperature provided by the first heat exchanger is lower than that provided by the second heat exchanger. During the driving of the constant pressure expander by the high-temperature and high-pressure air to generate power, the air pressure at the inlet of the constant pressure expander is constant, and the air temperature can be adjusted through the heat pump circulation, so as to change the power output of the constant pressure expander. The control system adjusts the running state of each device in real time according to the collected pressure and temperature parameters, and ensures that the air forms a step temperature distribution in the heating process.

8. The method of claim 7, wherein, ​ 9. The method of claim 7, wherein, ​ 10. The method of claim 9, wherein, ​

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