Design optimization method for adiabatic compressed air energy storage system

Abstract

The invention belongs to the technical field of novel energy storage, and particularly discloses an adiabatic compressed air energy storage system design optimization method which comprises the following steps: step 1, acquiring inlet temperature and air flow of an expansion unit; 2, the heat storage temperature of a heat accumulator is determined according to the inlet temperature; and 3, performance parameters of the compressor unit are determined according to the heat storage temperature, and the hot water flow of the heat accumulator and the volume of the gas storage are determined according to the air flow. The heat storage temperature of the heat accumulator is determined according to the inlet temperature of the expansion unit, and then the performance parameters of the compressor are determined according to the heat storage temperature of the heat accumulator; furthermore, the hot water flow of the heat accumulator and the volume of the gas storage are determined according to the air flow of the expansion unit, and therefore integrated design optimization is achieved, the standard process is achieved, different design requirements can be met, operation is easy and convenient, and the calculation efficiency is high.

Description

Technical Field

[0001] The invention discloses a design optimization method for an adiabatic compressed air energy storage system, belonging to the technical field of novel energy storage. Background Art

[0002] Compressed air energy storage can be divided into adiabatic compressed air energy storage (A-CAES), liquid air energy storage (LAES), supercritical compressed air energy storage (S-CAES), etc. According to the technical route, adiabatic compressed air energy storage technology abandons the disadvantages of traditional compressed air consuming fossil energy to heat gas, improves system efficiency, and is currently the mainstream technical route for compressed air energy storage.

[0003] The adiabatic compressed air energy storage system consists of an energy storage subsystem and an energy release subsystem. The two subsystems are connected as an integral system through gas storage and cold and heat storage devices. The energy storage subsystem uses the mechanical energy output by the motor to inhale air from the atmosphere and do work on the gas, thereby increasing the internal energy and pressure energy of the gas. After leaving the compressor, the high-temperature and high-pressure air first enters the heat accumulator, transfers the heat of the gas to heat storage materials such as water and molten salt for storage, and then transports the cooled high-pressure air to gas storage devices such as caves and storage tanks for physical storage. The energy release process is the opposite of this. The high-pressure gas transmitted from the gas storage device first enters the heat exchanger for heating, and then enters the expander for expansion and work to drive the generator to generate electricity.

[0004] As compressed air energy storage technology shifts from technical demonstration to commercial application, the need for standardized design of process systems has become increasingly prominent. At present, the design of compressed air energy storage power station process systems is usually modified on the basis of a single scheme, lacking adaptability to different design requirements, which brings difficulties to engineering practice. In addition, in practice, it is necessary to conduct technical and economic comparisons for the selection of different system parameters, and there are difficulties in selecting relevant judgment targets. Summary of the invention

[0005] The purpose of the present invention is to provide a design optimization method for an adiabatic compressed air energy storage system to solve the problem that the compressed air energy storage system design in the prior art lacks a standard process and is subsequently unable to meet the adaptability problem of different design requirements.

[0006] The present invention provides a design optimization method for an adiabatic compressed air energy storage system, comprising: Step 1: Obtain the inlet temperature and air flow rate of the expansion unit.

[0007] Step 2: determining the heat storage temperature of the heat storage device according to the inlet temperature.

[0008] Step 3: Determine the performance parameters of the compressor unit according to the heat storage temperature, and determine the hot water flow of the heat accumulator and the volume of the gas storage reservoir according to the air flow.

[0009] Preferably, obtaining the inlet temperature of the expansion unit specifically includes: Step 1.1, determining the initial inlet temperature of the expansion unit according to the design outlet temperature, expansion ratio and initial adiabatic index of the last-stage expansion machine in the expansion unit.

[0010] Step 1.2, determining a transition adiabatic index according to the initial inlet temperature of the expansion unit, and determining a final adiabatic index according to an error between the transition adiabatic index and the initial adiabatic index.

[0011] Step 1.3, determining the inlet temperature of the expansion unit according to the design outlet temperature, expansion ratio and terminal adiabatic index of the last-stage expansion machine in the expansion unit.

[0012] Preferably, the step 1.2 specifically includes: Step 1.2.1, determining the average inlet and outlet temperatures of the final-stage expander according to the initial inlet temperature of the expander group.

[0013] Step 1.2.2, obtaining the average inlet and outlet pressures of the final-stage expander, and determining a transition adiabatic index according to the average temperature and the average pressure.

[0014] Step 1.2.3: If the error between the transition adiabatic index and the initial adiabatic index is less than a preset threshold, the transition adiabatic index is recorded as the final adiabatic index; otherwise, the transition adiabatic index is recorded as the initial adiabatic index, and steps 1.1 and 1.2 are repeated.

[0015] Preferably, determining the heat storage temperature of the heat accumulator according to the inlet temperature specifically includes: obtaining the upper end difference of the heat exchanger corresponding to the expansion unit; and determining the heat storage temperature of the heat accumulator according to the upper end difference of the heat exchanger and the inlet temperature.

[0016] Preferably, obtaining the air flow rate of the expansion unit specifically includes: obtaining the total enthalpy difference of the expansion machines of each stage in the expansion unit; and determining the air flow rate of the expansion unit according to a preset energy release output power and the total enthalpy difference.

[0017] Preferably, the volume of the gas storage reservoir is determined according to the air flow rate, specifically including: determining the volume of the gas storage reservoir according to the average internal gas density at the upper limit of the gas storage reservoir pressure, the average internal gas density at the lower limit of the gas storage reservoir pressure, the preset energy storage time and the air flow rate.

[0018] Preferably, the hot water flow rate of the heat accumulator is determined according to the air flow rate, specifically including: determining the hot water flow rate of the heat accumulator in the energy storage stage according to the constant-pressure specific heat capacity of air, the constant-pressure specific heat capacity of water in the heat accumulator and the air flow rate; determining the hot water flow rate of the heat accumulator in the energy release stage according to the hot water flow rate of the heat accumulator in the energy storage stage, the preset energy storage time and the energy release time.

[0019] Preferably, the performance parameters of the compressor unit are determined according to the heat storage temperature, specifically including: determining the rated outlet temperature of the compressor unit according to the heat storage temperature and the upper end difference of the heat exchanger; determining the pressure ratio of the compressor according to the rated outlet temperature; determining the number of compressor stages in the compressor unit according to the pressure ratio of the first-stage compressor in the compressor unit.

[0020] Preferably, after determining the number of compressor stages in the compressor group according to the pressure ratio of the first-stage compressor in the compressor group, the method further comprises: obtaining the difference between the inlet enthalpy value and the outlet enthalpy value of each stage of the compressor.

[0021] Preferably, after step 3, the method further comprises: In combination with the volume of the gas storage reservoir, the process of how the pressure and temperature of the gas inside the gas storage reservoir change over time is determined.

[0022] Compared with the prior art, the design optimization method of the adiabatic compressed air energy storage system of the present invention has the following beneficial effects: The present invention determines the heat storage temperature of the heat accumulator according to the inlet temperature of the expansion unit, and then determines the performance parameters of the compressor according to the heat storage temperature of the heat accumulator; further, the present invention also determines the hot water flow of the heat accumulator and the volume of the gas storage reservoir according to the air flow of the expansion unit, thereby realizing integrated design optimization and making it a standard process, which can adapt to different design requirements, is simple and convenient to operate, and has high calculation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the structure of the adiabatic compressed air energy storage system in an embodiment of the present invention.

[0024] In the figure: 1 is a motor; 2 is a generator; 3 is a compressor unit; 4 is an expansion unit; 5 is a heat exchanger; 6 is a heat accumulator; and 7 is a gas storage reservoir. DETAILED DESCRIPTION

[0025] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0026] The embodiment of the present invention provides a design optimization method for an adiabatic compressed air energy storage system, which is applied to a 10-350MW adiabatic compressed air energy storage system. The structure of the adiabatic compressed air energy storage system is as follows: Figure 1 As shown, it includes an energy storage subsystem and an energy release subsystem. The energy storage subsystem includes a motor 1 that converts electrical energy into mechanical energy, a compressor unit 3 that increases the internal energy of the gas, and a heat exchanger 5 that exchanges heat between the gas and the heat exchange medium. The specific working principle of the energy storage subsystem is: after receiving the start command, the motor 1 drives the compressor unit 3 to work and inhales the atmosphere for compression. The compressor unit 3 is composed of a multi-stage compressor. Between the stages of the compressor unit 3, the gas is passed into the heat exchanger 5 for cooling and then passed into the next stage compressor, and the heat is stored in the heat accumulator 6.

[0027] The energy release subsystem includes a generator 2 that converts mechanical energy into electrical energy, an expansion unit 4 that converts gas internal energy into mechanical energy, and a heat exchanger 5 that performs heat exchange between gas and heat exchange medium. The specific working principle of the energy release subsystem is as follows: after receiving the energy release command, the outlet valve of the gas storage reservoir 7 is opened, and the high-pressure gas enters the heat exchanger 5 for heating, and then enters the expansion unit 4 to perform work, and drives the generator 2 to generate electricity. The expansion unit 4 is composed of a multi-stage expansion machine, and the gas between each stage of the multi-stage expansion machine is passed into the heat exchanger 5 for heating before being passed into the next stage expansion machine.

[0028] The energy storage subsystem and the energy release subsystem are decoupled from each other in time and are connected via a heat accumulator 6 and a gas storage reservoir 7 storing high-pressure gas.

[0029] The design optimization method of the adiabatic compressed air energy storage system provided in the embodiment of the present invention is based on the principle of the compressed air energy storage system and the engineering thermodynamic characteristics. First, the relevant parameters of the compressed air energy storage power station are set according to the engineering needs to achieve the design optimization of different design requirements and optimization objects. The relevant parameter settings specifically include three categories: design target parameters, host performance parameters and design optimization parameters. Among them, the design target parameters specifically include the energy release output power , Energy release time , Energy storage duration , Ambient temperature , Environmental Pressure ; The main engine performance parameters include the compressor isentropic efficiency , expander isentropic efficiency , Heat exchanger upper end difference , Heat exchanger lower end difference ; The design optimization parameters specifically include the upper limit of the air storage chamber pressure , Fluctuation range of air storage chamber pressure range , number of expander stages .

[0030] In the actual operation of the adiabatic compressed air energy storage system, the heat storage temperature is determined by the gas temperature at the compressor outlet during the energy storage process. , where is the heat storage temperature, For the The compressor outlet temperature, is the total number of compressor stages, is the upper end difference of the heat exchanger. In engineering design, since the number of compressor stages and the pressure ratio distribution are unknown quantities, they cannot be derived forward. The present invention adopts reverse deduction: first determine the expander inlet temperature, and then determine the heat storage temperature.

[0031] The design optimization method of an adiabatic compressed air energy storage system provided in an embodiment of the present invention specifically comprises the following steps: Step 1: Obtain the inlet temperature and air flow rate of the expansion unit.

[0032] The inlet temperature of the expansion unit is obtained, specifically including: Step 1.1, determining the initial inlet temperature of the expansion unit according to the design outlet temperature, expansion ratio and initial adiabatic index of the last-stage expander in the expansion unit.

[0033] The expansion ratio is determined as follows: In the present invention, the expansion ratio of the multi-stage expander is calculated according to the average distribution principle as follows: (1) In the formula, is the initial value of the expander expansion ratio, is the rated inlet pressure of the expander, For environmental pressure, is the number of expander stages.

[0034] Since the gas between the expander stages needs to be heated by the heat exchanger, the gas will produce pressure loss during the inter-stage heat exchange process. Therefore, the actual expansion ratio also needs to take into account the impact of the inter-stage loss. As the initial value, it is substituted into the nonlinear equation of the following formula (2) to solve the actual expansion ratio of each stage of the expander: .

[0035] (2) In the formula, Design pressure drop for heat exchanger, is the rated inlet pressure of the expander, For environmental pressure.

[0036] After obtaining the actual expansion ratio, the initial inlet temperature of the expansion unit is determined according to the design outlet temperature, expansion ratio and initial adiabatic index of the last-stage expander in the expansion unit, as follows: (3) In the formula, is the inlet temperature of the expansion unit, is the design outlet temperature of the last expander in the expander unit, is the isentropic efficiency of the expander, is the actual expansion ratio of the expander, It is the adiabatic index. It should be noted that in the existing compressed air energy storage system design method, the adiabatic index is generally a fixed value, which is 1.4. However, since the adiabatic index is related to the thermodynamic process, the existing method causes calculation errors to a certain extent. The design optimization method of the present invention adopts the error iteration method to reduce the error caused by the deviation of the adiabatic index. First, the initial adiabatic index is set. is 1.4, and the initial inlet temperature of the expansion unit is calculated using formula (3): .

[0037] Step 1.2, determining a transition adiabatic index according to the initial inlet temperature of the expansion unit, and determining a final adiabatic index according to the error between the transition adiabatic index and the initial adiabatic index, specifically comprising: Step 1.2.1: Determine the average inlet and outlet temperature of the final expander according to the initial inlet temperature of the expander group. .

[0038] In the embodiment of the present invention, since the inlet temperature of each stage of the expander is the same, the initial inlet temperature of the expander group is the same as the inlet temperature of a single expander.

[0039] Step 1.2.2: Obtain the average inlet and outlet pressure of the final expander , and according to the average temperature and average pressure Determine the transition adiabatic index.

[0040] In the embodiment of the present invention, the outlet pressure of the final expansion machine is atmospheric pressure, and the inlet pressure is the product of the outlet pressure and the expansion ratio. and average pressure Determine the transition adiabatic index, specifically: and As the eigenvalue, find the corresponding adiabatic index value and record it as the transition adiabatic index .

[0041] Step 1.2.3: If the error between the transition adiabatic index and the initial adiabatic index is less than a preset threshold, the transition adiabatic index is recorded as the final adiabatic index; otherwise, the transition adiabatic index is recorded as the initial adiabatic index, and steps 1.1 and 1.2 are repeated.

[0042] The error between the transition adiabatic index and the initial adiabatic index is Determined by formula (4): (4) In the formula, is the initial adiabatic index, is the transition adiabatic index.

[0043] Step 1.3, determining the inlet temperature of the expansion unit according to the design outlet temperature, expansion ratio and terminal adiabatic index of the last-stage expansion machine in the expansion unit, specifically, substituting the design outlet temperature, expansion ratio and terminal adiabatic index of the last-stage expansion machine into formula (3) to determine the inlet temperature of the expansion unit.

[0044] Step 2: determining the heat storage temperature of the heat accumulator according to the inlet temperature, specifically comprising: obtaining the upper end difference of the expansion unit corresponding to the heat exchanger; and determining the heat storage temperature of the heat accumulator according to the upper end difference of the heat exchanger and the inlet temperature.

[0045] In the embodiment of the present invention, the upper end difference on the compressor unit side and the upper end difference on the expansion unit side are the same, so no distinction is made.

[0046] The embodiment of the present invention determines the heat storage temperature of the heat storage device according to the following formula (5): : (5) In the formula, is the upper end difference of the heat exchanger, is the inlet temperature of the expansion unit.

[0047] Step 3: Determine the performance parameters of the compressor unit according to the heat storage temperature, and determine the hot water flow of the heat accumulator and the volume of the gas storage reservoir according to the air flow.

[0048] Since the required pressure of compressed air energy storage is relatively large during the energy storage stage (usually >80), a single-stage compressor is difficult to meet the system requirements. Compressed air energy storage is usually equipped with a compressor unit composed of multi-stage compressors 3. In order to facilitate the design and calculation of multi-stage compressors with different numbers of stages, the compressor types are divided into three categories according to the different inlet and outlet condition parameters in the design optimization method of the present invention: (1) first-stage compressor, the air intake condition is the ambient condition; (2) intermediate-stage compressor, the inlet and outlet temperature is constant; (3) final-stage compressor, the outlet condition is set. It should be noted that this classification method is applicable to any multi-stage compressor type with a compressor stage number >2. When the compressor stage number = 2, the intermediate-stage compressor is the final-stage compressor.

[0049] The performance parameters of the compressor unit to be determined in the embodiment of the present invention include the rated outlet temperature of the compressor, the pressure ratio of each stage of the compressor, the enthalpy value, and the number of stages of the compressor unit.

[0050] In the embodiment of the present invention, the rated outlet temperature of the compressor unit is determined according to the heat storage temperature and the upper end difference of the heat exchanger, as shown in formula (6): (6) In the formula, is the rated outlet temperature of the compressor, is the heat storage temperature of the heat storage device, In the embodiment of the present invention, the heat storage temperature is equal to the temperature of the heat storage medium of the heat exchanger in the energy storage stage.

[0051] Furthermore, the pressure ratio of the compressor is determined according to the rated outlet temperature, as shown in formula (7): (7) In the formula, is the pressure ratio, is the isentropic efficiency of the compressor, is the rated outlet temperature of the compressor, is the compressor inlet temperature, is the terminal adiabatic index, which is determined in the same way as above. The determination method is the same and will not be repeated here.

[0052] Furthermore, the number of compressor stages in the compressor group is determined according to the pressure ratio of the first-stage compressor in the compressor group. , as shown in formula (8): (8) In the formula, For environmental pressure, is the pressure ratio of the first-stage compressor, is the outlet pressure of the final compressor, is the floor function.

[0053] The enthalpy difference of the compressor in the embodiment of the present invention is determined according to formula (9): (9) In the formula, For the The enthalpy difference of the compressor stage, For the The outlet enthalpy of the compressor, For the The inlet enthalpy of the compressor.

[0054] The compressor performance calculation module of the embodiment of the present invention determines the rated outlet temperature of the compressor according to the heat storage temperature, and calculates the pressure ratio and the inlet and outlet enthalpy difference of each compressor according to the classification method of the three types of compressors to obtain the overall multi-stage compressor performance. Since the task of the final compressor is usually to adapt to the changes in different back pressure conditions, the pressure ratio is smaller than that of the other two types of compressors, so the number of compressor stages is determined by the number of intermediate compressor stages plus the first and final compressors.

[0055] Step 3 of the embodiment of the present invention also requires determining the hot water flow rate of the heat accumulator and the volume of the gas storage reservoir according to the air flow rate of the expansion unit. The specific method for obtaining the air flow rate of the expansion unit is: obtaining the total enthalpy difference of each stage of the expansion unit in the expansion unit; determining the air flow rate of the expansion unit according to the preset energy release output power and the total enthalpy difference.

[0056] The total enthalpy difference of the above-mentioned expansion machines is determined according to formula (10): (10) In the formula, For the The inlet enthalpy of the first-stage expander, For the The outlet enthalpy of the first-stage expander, is the total enthalpy difference.

[0057] Formula (11) of the embodiment of the present invention determines the air flow rate of the expansion unit in the energy release stage : (11) In the formula, is the preset energy release output power, is the total enthalpy difference.

[0058] The air flow rate of the expander unit during the energy release phase is obtained. After that, the embodiment of the present invention determines the volume of the gas storage according to the air flow rate. The calculation of the gas storage volume is determined by the initial and final states of the gas storage and the total gas consumption. It is necessary to assume the initial and final temperatures of the gas storage at the beginning of the design, and then modify the parameters through the dynamic performance calculation module.

[0059] The method of determining the volume of the gas storage reservoir in the embodiment of the present invention specifically includes: determining the volume of the gas storage reservoir according to the average density of the gas inside the gas storage reservoir when the pressure is at the upper limit, the average density of the gas inside the gas storage reservoir when the pressure is at the lower limit, the preset energy storage time and the air flow rate. , as shown in formula (12): (12) In the formula, is the average density of gas inside the gas storage when the pressure is at the upper limit, is the average density of gas inside the gas storage reservoir at the lower pressure limit, , By checking the value, is the air flow rate of the expander in the energy release stage, The energy storage duration.

[0060] The embodiment of the present invention can also be based on the air flow rate of the expansion unit in the energy release stage Determine the hot water flow rate of the thermal storage tank.

[0061] The type of heat storage and heat exchange device is related to the compressed air energy storage level route. Generally, medium-temperature and medium-high temperature compressed air energy storage technologies use water or heat transfer oil as the heat exchange medium, and high-temperature compressed air energy storage technology uses packed beds as heat exchange devices, which need to be selected according to the heat storage temperature.

[0062] In the embodiment of the present invention, water is used as the heat exchange medium as an example. The method for determining the hot water flow rate of the heat accumulator in the energy release stage and the energy storage stage is as follows: according to the constant pressure specific heat capacity of air in the heat accumulator, the constant pressure specific heat capacity of water and the air flow rate of the expansion unit in the energy release stage Determine the hot water flow rate of the heat storage device during the energy storage phase ; According to the hot water flow rate of the heat accumulator in the energy storage stage, the preset energy storage time and energy release time, determine the hot water flow rate of the heat accumulator in the energy release stage .

[0063] in Determine according to formula (13): (13) In the formula, is the specific heat capacity of air at constant pressure, is the specific heat of water at constant pressure.

[0064] Determine according to formula (14): (14) In the formula, is the hot water flow rate of the heat accumulator during the energy storage stage, For the duration of energy release, The energy storage duration.

[0065] The embodiment of the present invention further includes, after step 3: Step 4: Based on the volume of the gas storage reservoir, determine how the pressure and temperature of the gas inside the gas storage reservoir change over time.

[0066] The current design of adiabatic compressed air energy storage system adopts steady-state calculation method, but the actual storage and release process is a non-steady-state and variable-condition process, and the steady-state calculation method will produce large errors. The present invention embeds the dynamic performance calculation process to realize the non-steady-state calculation of the compressed air energy storage system during the whole time period, thereby improving the calculation accuracy.

[0067] Dynamic performance calculation is based on steady-state performance calculation, supplemented with relevant equations and time iteration steps for the gas state inside the gas storage chamber. The material and energy relationship between the gas storage chamber and the compressor / expander belongs to the problem of an unstable thermodynamic open system. The relevant mass conservation and energy conservation formulas are as follows: (15) In the formula, is the gas quality in the gas storage, are the gas mass flow rates flowing into and out of the gas storage, For time.

[0068] (16) In the formula, is the gas quality in the gas storage, are the gas mass flow rates flowing into and out of the gas storage, For time, is the enthalpy of the inflow and outflow gas, is the gas temperature in the gas storage, is the heat exchange coefficient between the gas storage and the outside world, is the surface area of ​​the air storage chamber. When the shape of the air storage chamber is determined, , is the ambient temperature, is the gas velocity.

[0069] The differential equations for the changes in pressure and temperature of the gas inside the gas storage reservoir over time in the embodiment of the present invention are as follows: (17) In the formula, is the constant pressure specific heat capacity of the gas in the gas storage chamber, is the constant volume specific heat capacity of the gas in the gas storage chamber.

[0070] (18) In the formula is the gas pressure in the gas storage, is the ideal gas constant, take .

[0071] Furthermore, the main performance evaluation indicators of the adiabatic compressed air energy storage system of the embodiment of the present invention are: system efficiency and energy density , respectively as follows: (19) (20) In the formula is the volume of the gas storage, and the system output energy With system input energy They are calculated by the dynamic energy release program and the dynamic energy storage program respectively, and are calculated by the following formula: (twenty one) (twenty two) In the formula are the time iteration steps for energy release and energy storage, is the total enthalpy difference of each stage of expanders, is the total enthalpy difference of each stage of compressor.

[0072] The present invention establishes a complete set of design optimization methods for adiabatic compressed air energy storage systems, which realizes iterative optimization of key parameters of compressed air energy storage systems such as upper and lower limits of air storage chamber pressure and heat storage temperature during the design stage, thereby improving the performance and economy of the overall system.

[0073] The current design of adiabatic compressed air energy storage system adopts steady-state calculation method, but the actual storage and release process is a non-steady-state and variable-condition process, and the steady-state calculation method will produce large errors. The present invention realizes the non-steady-state calculation of the full time period of the compressed air energy storage system operation by embedding dynamic performance calculation, thereby improving the calculation accuracy.

[0074] The above are only several embodiments of the present invention and are not intended to limit the present invention in any form. Although the present invention is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, using the above disclosed technical content to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A design optimization method for an adiabatic compressed air energy storage system, characterized in that: include: Step 1, obtaining the inlet temperature and air flow rate of the expansion unit; Step 2: determining the heat storage temperature of the heat storage device according to the inlet temperature; Step 3: Determine the performance parameters of the compressor unit according to the heat storage temperature, and determine the hot water flow of the heat accumulator and the volume of the gas storage reservoir according to the air flow.

2. The design optimization method of an adiabatic compressed air energy storage system according to claim 1, characterized in that: The obtaining of the inlet temperature of the expansion unit specifically includes: Step 1.1, determining the initial inlet temperature of the expansion unit according to the design outlet temperature, expansion ratio and initial adiabatic index of the last-stage expansion unit in the expansion unit; Step 1.2, determining a transition adiabatic index according to the initial inlet temperature of the expansion unit, and determining a final adiabatic index according to an error between the transition adiabatic index and the initial adiabatic index; Step 1.3, determining the inlet temperature of the expansion unit according to the design outlet temperature, expansion ratio and terminal adiabatic index of the last-stage expansion machine in the expansion unit.

3. The design optimization method of an adiabatic compressed air energy storage system according to claim 2, characterized in that: The step 1.2 specifically includes: Step 1.2.1, determining the average inlet and outlet temperature of the final-stage expander according to the initial inlet temperature of the expander group; Step 1.2.2, obtaining the average inlet and outlet pressures of the final-stage expander, and determining a transition adiabatic index according to the average temperature and the average pressure; Step 1.2.3: If the error between the transition adiabatic index and the initial adiabatic index is less than a preset threshold, the transition adiabatic index is recorded as the final adiabatic index; otherwise, the transition adiabatic index is recorded as the initial adiabatic index, and steps 1.1 and 1.2 are repeated.

4. The design optimization method for an adiabatic compressed air energy storage system according to any one of claims 1 to 3, characterized in that: Determining the heat storage temperature of the heat storage device according to the inlet temperature specifically includes: Obtaining the upper end difference of the heat exchanger corresponding to the expansion unit; The heat storage temperature of the heat accumulator is determined according to the upper end difference of the heat exchanger and the inlet temperature.

5. The design optimization method of an adiabatic compressed air energy storage system according to claim 1, characterized in that: Obtaining the air flow rate of the expansion unit specifically includes: Obtaining the total enthalpy difference of each stage of expanders in the expander group; The air flow rate of the expansion unit is determined according to the preset energy release output power and the total enthalpy difference.

6. The design optimization method for an adiabatic compressed air energy storage system according to claim 1 or 5, characterized in that: Determining the volume of the gas storage according to the air flow rate specifically includes: The volume of the gas storage reservoir is determined according to the average density of the internal gas at the upper limit of the gas storage reservoir pressure, the average density of the internal gas at the lower limit of the gas storage reservoir pressure, the preset energy storage time and the air flow rate.

7. The design optimization method for an adiabatic compressed air energy storage system according to claim 1 or 5, characterized in that: Determining the hot water flow of the heat accumulator according to the air flow specifically includes: Determining the hot water flow rate of the heat accumulator in the energy storage stage according to the constant-pressure specific heat capacity of air, the constant-pressure specific heat capacity of water and the air flow rate in the heat accumulator; The hot water flow rate of the heat accumulator in the energy release stage is determined according to the hot water flow rate of the heat accumulator in the energy storage stage, the preset energy storage time and the energy release time.

8. The design optimization method of an adiabatic compressed air energy storage system according to claim 1, characterized in that: The performance parameters of the compressor unit are determined according to the heat storage temperature, specifically including: Determine the rated outlet temperature of the compressor unit according to the heat storage temperature and the upper end difference of the heat exchanger; determining a pressure ratio of the compressor according to the rated outlet temperature; The number of compressor stages in the compressor group is determined according to the pressure ratio of the first-stage compressor in the compressor group.

9. The design optimization method of an adiabatic compressed air energy storage system according to claim 8, characterized in that: After determining the number of stages of the compressors in the compressor group according to the pressure ratio of the first-stage compressor in the compressor group, the method further includes: Obtain the difference between the inlet enthalpy and the outlet enthalpy of each compressor stage.

10. The design optimization method of an adiabatic compressed air energy storage system according to claim 1, characterized in that: After step 3, the method further includes: In combination with the volume of the gas storage reservoir, the process of how the pressure and temperature of the gas inside the gas storage reservoir change over time is determined.

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