Dynamic evaluation methods, systems, electronic equipment, and storage media for compressed air energy storage systems.

Abstract

This invention provides a method, system, electronic equipment, and storage medium for dynamically evaluating the charging and storage capacity of a compressed air energy storage system. The method establishes a simulation model of the compressed air energy storage system and conducts variable operating condition tests. It then fits the pressure-flow mapping curves of the inlet and outlet of the gas storage device under various load conditions. By integrating the pressures at the inlet and outlet of the gas storage device, the remaining charging / discharging time is calculated, thereby achieving a dynamic evaluation of the system's remaining energy storage / release capacity. This invention solves the technical problems of imperfect charging and storage capacity evaluation methods and difficulties in real-time grid-storage interaction scheduling during the operation of compressed air energy storage systems, thus promoting the practical benefits of energy storage technology in new energy applications.

Description

Technical Field

[0001] This invention relates to the field of renewable energy storage technology, specifically to a method, system, electronic device, and storage medium for dynamically evaluating the charging and storage capacity of a compressed air energy storage system. Background Technology

[0002] Currently, an increasing number of renewable energy sources, represented by wind and solar power, have been connected to the grid. While large-scale grid connection of renewable energy provides a large amount of low-carbon and clean energy, the inherent uncertainty of its power generation capacity also increases the peak-shaving pressure on the power grid. In addition, renewable energy power generation, mainly wind and solar power, relies on a large number of power electronic devices. As the penetration rate of new energy increases, the total rotational inertia of the power system decreases, which in turn affects the frequency stability of the system.

[0003] With the integration of high-proportion renewable energy sources and the application of high-proportion power electronic equipment, energy storage technology has become a key means to ensure the balance between energy supply and demand and improve energy utilization efficiency. Among these technologies, compressed air energy storage technology, due to its large-scale energy storage potential, is particularly suitable for the utilization of renewable energy and peak-valley regulation of the power grid. It can also provide rotational inertia to participate in frequency regulation, thereby effectively improving grid stability, and has become an important energy storage technology in new energy systems.

[0004] As a type of non-combustion compressed air energy storage technology, the working principle of adiabatic compressed air energy storage system includes two stages: compression energy storage and expansion energy release. In the compression energy storage stage, the system uses electricity to drive a compressor to compress and store air, simultaneously storing the heat energy generated during compression. In the expansion energy release stage, a heat exchanger transfers the stored heat energy back to the high-pressure air, and the expanded air drives a turbine to generate electricity. No greenhouse gas emissions are emitted during operation, making it a green, clean, and efficient energy storage method. However, the operation of compressed air energy storage systems spans a significant time and spatial period, and the air parameters within the storage device constantly change during operation, making real-time performance evaluation of the system difficult. This limits the development of efficient operation and optimization technologies for compressed air energy storage systems. In existing technologies, there is limited operational experience with compressed air energy storage systems, a lack of operational data accumulation, and limited research on the remaining energy storage / release capacity during the charging / discharging process. The integral characteristics of charging capacity have not yet been fully reflected in performance evaluation research, making it difficult for compressed air energy storage power plants to provide real-time feedback on their remaining energy storage / release capacity to the grid. Summary of the Invention

[0005] Purpose of the invention: The first purpose of the invention is to provide a method for dynamic evaluation of the charging and storage capacity of a real-time feedback compressed air energy storage system. The second purpose is to provide a dynamic evaluation system, electronic equipment, and storage medium for the charging and storage capacity of a compressed air energy storage system corresponding to the above-mentioned dynamic evaluation method.

[0006] Technical solution: A method for dynamically evaluating the charging and storage capacity of a compressed air energy storage system, comprising the following steps:

[0007] (1) Based on the design parameters of the compressed air energy storage system and the principles of engineering thermodynamics and heat transfer, a simulation model of each device in the compressed air energy storage system is established.

[0008] (2) Connect the interfaces between the simulation models of each device in the compressed air energy storage system, establish an integrated model of the compressed air energy storage system, and use the variable operating condition characteristic curves of each device in the compressed air energy storage system to establish a thermodynamic model of the compressed air energy storage system.

[0009] (3) Based on the thermodynamic model of the compressed air energy storage system, a variable operating condition test was conducted to obtain a variable operating condition simulation database of the compressed air energy storage system. The system pressure-flow curve was obtained by fitting the variable operating condition simulation data.

[0010] (4) Integrate the pressure using the system pressure-flow curve to obtain the remaining charging or discharging time of the compressed air energy storage system. Multiply the charging or discharging time by the given system load power to obtain the charging or storage capacity of the compressed air energy storage system.

[0011] Specifically, in step (1), the equipment of the compressed air energy storage system includes: compressor, turbine, air storage device, and heat exchanger.

[0012] Specifically, in step (3), the variable operating condition test includes: conducting simulation experiments on the inflation and deflation processes of each device in the compressed air energy storage system under different load conditions, and simulating the changes in air parameters in the storage device over time during the inflation and deflation process by changing the pressure at the inlet and outlet of the storage device.

[0013] Specifically, in step (3), the system pressure-flow curve is obtained by fitting the simulation data of the variable operating conditions using the spline interpolation method.

[0014] Specifically, in step (4), based on the gas state equation and the mass conservation equation, the pressure is integrated using the system pressure-flow curve, with the current inlet and outlet pressures of the gas storage device as the benchmark.

[0015] Specifically, in step (4), the formula for calculating the venting time is:

[0016]

[0017] In the formula: t disch For the deflation time, p cavern p represents the pressure of the gas storage device. cavern,now p is the current outlet pressure of the gas storage unit. cavern,min V is the minimum pressure of the gas storage device. cavernρ is the volume of the gas storage device. max ρ represents the maximum air density inside the gas storage device. min ρ′(p) represents the minimum air density inside the gas storage device. cavern ) is the first derivative of the function relating air density and the pressure of the gas storage device, g disch (p cavern ) is a function relating airflow rate to the pressure of the gas storage device.

[0018] Specifically, in step (4), the formula for calculating the inflation time is:

[0019]

[0020] In the formula: t ch For inflation time, p cavern p represents the pressure of the gas storage device. cavern,now p is the current outlet pressure of the gas storage unit. cavern,max V is the maximum pressure of the gas storage device. cavern ρ is the volume of the gas storage device. max ρ represents the maximum air density inside the gas storage device. min ρ′(p) represents the minimum air density inside the gas storage device. cavern ) is the first derivative of the function relating air density and the pressure of the gas storage device, g ch (p cavern ) is a function relating airflow rate to the pressure of the gas storage device.

[0021] The present invention also provides a dynamic evaluation system for the charging and storage capacity of a compressed air energy storage system, comprising:

[0022] Equipment Model Building Module: Used to build simulation models of each device in a compressed air energy storage system based on the design parameters and engineering thermodynamics and heat transfer principles of the compressed air energy storage system.

[0023] System Model Building Module: Used to connect the interfaces between the simulation models of various devices in the compressed air energy storage system, establish the integrated model of the compressed air energy storage system, and establish the thermodynamic model of the compressed air energy storage system using the variable operating condition characteristic curves of each device in the compressed air energy storage system;

[0024] Variable operating condition simulation module: used to conduct variable operating condition tests based on the thermodynamic model of compressed air energy storage system, obtain a variable operating condition simulation database of compressed air energy storage system, and use the variable operating condition simulation data to fit the system pressure-flow curve;

[0025] The charging or storage capacity estimation module is used to integrate the pressure using the system pressure-flow curve to obtain the remaining charging or discharging time of the compressed air energy storage system. The charging or discharging time is then multiplied by the given system load power to obtain the charging or storage capacity of the compressed air energy storage system.

[0026] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the above-described dynamic evaluation method for the charging and storage capacity of the compressed air energy storage system.

[0027] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-described dynamic evaluation method for the charging and storage capacity of the compressed air energy storage system.

[0028] Beneficial Effects: Compared with existing technologies, the significant advantages of this invention are: By constructing a thermodynamic model of a compressed air energy storage system and introducing a definite relationship between the inlet / outlet pressure and flow rate of the system's gas storage device under a fixed load, this invention effectively achieves accurate real-time evaluation of the charging / discharging performance of the compressed air energy storage system through pressure integration calculation, breaking through the technical bottleneck of efficient operation and optimization of energy storage systems. This application, through dynamic evaluation of the integral characteristics of charging and storage capacity, can provide immediate energy storage / release capacity feedback for compressed air energy storage power stations, solving the difficulties in evaluating the system's charging and storage capacity under varying operating conditions and the challenges in obtaining energy storage absorption capacity from the power source and grid sides during the operation of compressed air energy storage systems. This better responds to the flexible dispatching needs of the grid, provides more robust technical support for the construction of a new energy supply and absorption system, and effectively expands the absorption space of renewable energy. Attached Figure Description

[0029] Figure 1 This is a flowchart of the method of the present invention.

[0030] Figure 2 This is a schematic diagram of the pressure-flow curve of the system of the present invention. Detailed Implementation

[0031] A preferred embodiment of the present invention will be further described below with reference to the accompanying drawings.

[0032] Please see Figure 1 As shown in the figure, this embodiment provides a method for dynamically evaluating the charging and storage capacity of a compressed air energy storage system, including the following steps:

[0033] (1) Based on the design parameters and engineering thermodynamics principles of the compressed air energy storage system, simulation models of the compressor, turbine, air storage device and heat exchanger of the compressed air energy storage system are established using the energy conservation, mass conservation and momentum conservation equations. In some preferred schemes, simulation models of auxiliary equipment such as storage tanks can also be added.

[0034] Taking a typical 300MW high-temperature adiabatic compressed air energy storage system as an example, the system has three compressor stages. The first stage compressor is an axial compressor, while the second and third stage compressors are centrifugal compressors. The compressor power of the system can be calculated using the following formula:

[0035]

[0036] In the formula: W is the compression work (power) per unit time; m is the mass flow rate of air; R is the gas constant; T1 is the air temperature before compression; P1 and P2 are the initial pressure and final pressure, respectively; η C κ represents the isentropic efficiency of the compressor; κ represents the specific heat ratio (κ = c). p / c v ).

[0037] (2) Connect the interfaces between the simulation models of each device in the compressed air energy storage system, establish an integrated model of the compressed air energy storage system, and use the variable operating condition characteristic curves of each device in the compressed air energy storage system (such as the compressor efficiency characteristic curve, turbine efficiency-load curve, etc.) to establish a thermodynamic model of the compressed air energy storage system.

[0038] (3) Based on the thermodynamic model of the compressed air energy storage system, a variable operating condition test was conducted to obtain a variable operating condition simulation database of the compressed air energy storage system. The system pressure-flow curve was obtained by fitting the variable operating condition simulation data.

[0039] In this embodiment, the variable operating condition test includes: conducting simulation experiments on the charging and discharging processes of each device in the compressed air energy storage system under different load conditions; simulating the changes in air parameters within the storage device over time during the charging and discharging process by changing the pressure at the inlet and outlet of the storage device; and obtaining the system pressure-flow rate mapping curve by using spline interpolation fitting method based on the variable operating condition simulation database of the compressed air energy storage system obtained from the variable operating condition simulation experiment, under the condition that the pressure at the inlet and outlet of the storage device changes continuously during the charging / discharging process.

[0040] Taking the venting process as an example, given the matching relationship between the heat exchange medium flow rate and the air flow rate, the turbine inlet temperature can be determined, i.e., the system venting power W. disch Only related to airflow m air,disch With the pressure p inside the gas storage device cavern Relevant, namely:

[0041] W disch =f(m air,disch ,p out )

[0042] Therefore, given a fixed unit load, the air flow rate m air,dischThis can be considered as the outlet pressure p of the gas storage device. out A single-valued function, that is:

[0043] m air,disch =g disch (p out )

[0044] Taking the venting process of the 300MW high-temperature adiabatic compressed air energy storage system mentioned above as an example, the air flow data corresponding to different salt cavern (air storage device) pressures under different load conditions obtained through variable operating condition tests are shown in Table 1 below.

[0045] Table 1

[0046]

[0047] Please refer to Figure 2 As shown, pressure-flow mapping curves under different load conditions can be obtained by spline interpolation.

[0048] (4) Based on the gas state equation and mass conservation equation, with the current inlet and outlet pressures of the gas storage device as the benchmark, the pressure is integrated using the system pressure-flow curve to obtain the remaining charging or discharging time of the compressed air energy storage system. The charging or discharging time is multiplied by the given system load power to obtain the charging or storage capacity of the compressed air energy storage system.

[0049] Specifically, taking the venting process as an example, the pressure change inside the gas storage device is caused by the reduction of air inside the device, which can be obtained from the air mass conservation equation inside the gas storage device:

[0050] V cavern dρ cavern =m air,disch dt

[0051] In the formula: V cavern ρ is the volume of the gas storage device. cavern Let be the air density inside the gas storage device, and t be time. From the gas law, it can be deduced that, assuming the volume of the gas storage device remains constant:

[0052] ρ cavern =ρ(p out ,T cavern )

[0053] That is, the air density ρ inside the gas storage device cavern Only related to the pressure p inside the gas storage device cavern and the temperature T inside the gas storage device cavern related.

[0054] Assuming the gas release process is adiabatic, according to the ideal gas law, we have:

[0055]

[0056] In the formula: T2 and T1 are the gas temperatures inside the gas storage device at the end and beginning of the venting process, respectively; p2 and p1 are the gas pressures inside the gas storage device at the end and beginning of the venting process, respectively; γ is the adiabatic index of the gas; and ρ is the air density inside the gas storage device. cavern It can be simplified to:

[0057] ρ cavern =ρ(p cavern )

[0058] That is, the air density ρ inside the gas storage device cavern The pressure p inside the gas storage device cavern A single-valued function.

[0059] Therefore, we can conclude that:

[0060]

[0061] The total venting time of the system can be calculated using the following formula:

[0062]

[0063] By generalizing from this formula, it is only necessary to measure the outlet pressure of the gas storage device at any moment during the venting process to calculate the remaining venting time:

[0064]

[0065] In the formula: t disch For the deflation time, p cavern p represents the pressure of the gas storage device. cavern,now p is the current outlet pressure of the gas storage unit. cavern,min p is the minimum pressure of the gas storage device. cavern,max V is the maximum pressure of the gas storage device. cavern ρ is the volume of the gas storage device. max ρ represents the maximum air density inside the gas storage device. min ρ′(p) represents the minimum air density inside the gas storage device. cavern ) is the first derivative of the function relating air density and the pressure of the gas storage device, g disch (p cavern ) is a function relating airflow rate and gas storage device pressure during the venting process.

[0066] The remaining energy release capacity Q of the system can be calculated by combining the obtained venting time with the current load command. disch :

[0067] Q disch =W disch t disch

[0068] Here, the current load W disch It changes in real time according to the power grid demand. Under different loads, the efficiency of each device in the system varies significantly. Therefore, the remaining venting time and remaining energy release capacity calculated under different load commands are also different.

[0069] For the inflation process, the calculation is based on the same approach as the deflation process described above. That is, the remaining inflation time is calculated by combining the air density in the gas storage device with the pressure, and the remaining energy storage capacity of the system is calculated by combining the current load. The derivation process will not be repeated here.

[0070] The formula for calculating inflation time is:

[0071]

[0072] In the formula: t ch For inflation time, p cavern p represents the pressure of the gas storage device. cavern,now p is the current outlet pressure of the gas storage unit. cavern,max V is the maximum pressure of the gas storage device. cavern ρ is the volume of the gas storage device. max ρ represents the maximum air density inside the gas storage device. min ρ′(p) represents the minimum air density inside the gas storage device. cavern ) is the first derivative of the function relating air density and the pressure of the gas storage device, g ch (p cavern ) is a function relating airflow rate and pressure in the gas storage device during the inflation process.

[0073] It is worth noting the pressure-flow mapping relationship between the inflation and deflation processes, i.e., m air,disch =g(p out The two are different and cannot be calculated using the same function; they need to be fitted separately.

[0074] Combine the obtained inflation time with the current input W ch The remaining energy storage capacity Q of the system can then be calculated. ch :

[0075] Q ch =W ch t ch

[0076] This invention also provides a dynamic evaluation system for the charging and storage capacity of a compressed air energy storage system, comprising:

[0077] Equipment Model Building Module: Used to build simulation models of each device in a compressed air energy storage system based on the design parameters and engineering thermodynamics and heat transfer principles of the compressed air energy storage system.

[0078] System Model Building Module: Used to connect the interfaces between the simulation models of various devices in the compressed air energy storage system, establish the integrated model of the compressed air energy storage system, and establish the thermodynamic model of the compressed air energy storage system using the variable operating condition characteristic curves of each device in the compressed air energy storage system;

[0079] Variable operating condition simulation module: used to conduct variable operating condition tests based on the thermodynamic model of compressed air energy storage system, obtain a variable operating condition simulation database of compressed air energy storage system, and use the variable operating condition simulation data to fit the system pressure-flow curve;

[0080] The charging or storage capacity estimation module is used to integrate the pressure using the system pressure-flow curve to obtain the remaining charging or discharging time of the compressed air energy storage system. The charging or discharging time is then multiplied by the given system load power to obtain the charging or storage capacity of the compressed air energy storage system.

[0081] This invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the dynamic evaluation method for the charging and storage capacity of the compressed air energy storage system.

[0082] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the above-described dynamic evaluation method for the charging and storage capacity of a compressed air energy storage system.

Claims

1. A method for dynamically evaluating the charging and storage capacity of a compressed air energy storage system, characterized in that, Includes the following steps: (1) Based on the design parameters of the compressed air energy storage system and the principles of engineering thermodynamics and heat transfer, a simulation model of each device in the compressed air energy storage system is established. (2) Connect the interfaces between the simulation models of each device in the compressed air energy storage system, establish an integrated model of the compressed air energy storage system, and use the variable operating condition characteristic curves of each device in the compressed air energy storage system to establish a thermodynamic model of the compressed air energy storage system. (3) Based on the thermodynamic model of the compressed air energy storage system, a variable operating condition test was conducted to obtain a variable operating condition simulation database of the compressed air energy storage system. The system pressure-flow curve was obtained by fitting the variable operating condition simulation data. (4) Integrate the pressure using the system pressure-flow curve to obtain the remaining charging or discharging time of the compressed air energy storage system. Multiply the charging or discharging time by the given system load power to obtain the charging or storage capacity of the compressed air energy storage system.

2. The method for dynamic evaluation of storage capacity according to claim 1, characterized in that: In step (1), the equipment of the compressed air energy storage system includes: compressor, turbine, air storage device, and heat exchanger.

3. The dynamic evaluation method for storage capacity according to claim 2, characterized in that: In step (3), the variable operating condition test includes: conducting simulation experiments on the inflation and deflation processes of each device of the compressed air energy storage system under different load conditions, and simulating the changes in air parameters in the storage device over time during the inflation and deflation process by changing the pressure at the inlet and outlet of the storage device.

4. The method for dynamic evaluation of storage capacity according to claim 1, characterized in that: In step (3), the system pressure-flow curve is obtained by fitting the simulation data of the variable operating conditions using the spline interpolation method.

5. The method for dynamic evaluation of storage capacity according to claim 2, characterized in that: In step (4), based on the gas state equation and the mass conservation equation, the pressure is integrated using the system pressure-flow curve, with the current inlet and outlet pressures of the gas storage device as the reference.

6. The method for dynamic evaluation of storage capacity according to claim 2, characterized in that: In step (4), the formula for calculating the venting time is: In the formula: t disch For the deflation time, p cavern p represents the pressure of the gas storage device. cavern,now p is the current outlet pressure of the gas storage unit. cavern,min V is the minimum pressure of the gas storage device. cavern ρ is the volume of the gas storage device. max ρ represents the maximum air density inside the gas storage device. min ρ′(p) represents the minimum air density inside the gas storage device. cavern ) is the first derivative of the function relating air density and the pressure of the gas storage device, g disch (p cavern ) is a function relating airflow rate to the pressure of the gas storage device.

7. The method for dynamic evaluation of storage capacity according to claim 2, characterized in that: In step (4), the formula for calculating the inflation time is: In the formula: t ch For inflation time, p cavern p represents the pressure of the gas storage device. cavern,now p is the current outlet pressure of the gas storage unit. cavern,max V is the maximum pressure of the gas storage device. cavern ρ is the volume of the gas storage device. max ρ represents the maximum air density inside the gas storage device. min ρ′(p) represents the minimum air density inside the gas storage device. cavern ) is the first derivative of the function relating air density and the pressure of the gas storage device, g ch (p cavern ) is a function relating airflow rate to the pressure of the gas storage device.

8. A dynamic evaluation system for the charging and storage capacity of a compressed air energy storage system, characterized in that, include: Equipment Model Building Module: Used to build simulation models of each device in a compressed air energy storage system based on the design parameters and engineering thermodynamics and heat transfer principles of the compressed air energy storage system. System Model Building Module: Used to connect the interfaces between the simulation models of various devices in the compressed air energy storage system, establish the integrated model of the compressed air energy storage system, and establish the thermodynamic model of the compressed air energy storage system using the variable operating condition characteristic curves of each device in the compressed air energy storage system; Variable operating condition simulation module: used to conduct variable operating condition tests based on the thermodynamic model of compressed air energy storage system, obtain a variable operating condition simulation database of compressed air energy storage system, and use the variable operating condition simulation data to fit the system pressure-flow curve; The charging or storage capacity estimation module is used to integrate the pressure using the system pressure-flow curve to obtain the remaining charging or discharging time of the compressed air energy storage system. The charging or discharging time is then multiplied by the given system load power to obtain the charging or storage capacity of the compressed air energy storage system.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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