Compressed air energy storage container pressure buildup stage model building and simulation method and system

Abstract

The invention provides a compressed air energy storage container pressure buildup stage model building and simulation method and system, and the method comprises the steps: dividing an energy storage process into an initial pressure buildup stage, an initial pressure buildup stage and an air compressor pressure supplement stage after multiple cycles; a steam-water mixing container and a high-pressure gas storage container are divided into four parts, namely a gas control body, a liquid control body, a device wall control body in contact with gas and a device wall control body in contact with liquid, and six assumptions are combined; mathematical models (including a gas state equation, a water body control body energy equation, a device wall control body energy equation and the like) of all stages are established on the basis of the law of conservation of energy and the law of conservation of mass respectively, curves of pressure and liquid level changing along with time are obtained through simulation calculation, and the curves are compared with experimental results for verification. According to the method, the multi-physical field coupling effect is comprehensively considered, the dynamic characteristics of the gas storage container can be accurately reflected, and a reliable theoretical basis is provided for system design and engineering application.

Description

Technical Field

[0001] This invention relates to the field of hydraulic compression energy storage technology, specifically to a method and system for establishing and simulating a model of the pressure build-up stage of a compressed air energy storage container. Background Technology

[0002] With the increasing global demand for clean energy, energy storage technology has received widespread attention as a key means to address the intermittency and volatility of renewable energy. Hydraulic compressed air energy storage technology, as a novel large-scale energy storage technology, boasts advantages such as large storage capacity, low cost, and long lifespan, and is considered one of the most promising energy storage methods.

[0003] In hydraulic compressed air energy storage systems, the gas storage container is one of the core components, and its performance directly affects the energy storage efficiency and stability of the entire system. However, current research in this field faces many challenges. On the one hand, existing gas storage container models often only consider the effect of a single physical field, neglecting the strong coupling characteristics between multiple physical fields such as water, gas, mechanical, electrical, and thermal fields. During actual operation, the gas pressure inside the storage container varies over time, affecting the gas's equation of state and physical properties; simultaneously, the air exchanges heat with the external environment through the tank walls, thus affecting the changes in air parameters inside the container. Traditional models fail to fully reflect these complex interrelationships, resulting in low accuracy and reliability.

[0004] On the other hand, during energy storage, parameters such as pressure and liquid level within the gas storage container change rapidly over time, requiring precise understanding of their dynamic characteristics to provide a basis for optimal system design and operational control. However, existing research largely focuses on analysis under steady-state conditions, lacking sufficient ability to simulate and predict dynamic processes. For example, in practical engineering applications, existing technologies struggle to provide accurate analysis and solutions regarding how the gas storage container can respond quickly and maintain stable operation when system loads undergo sudden changes.

[0005] In summary, existing technologies are insufficient in model building and dynamic response characteristic analysis of hydraulic compressed air energy storage devices, making it difficult to meet the requirements of efficient and stable system operation in practical engineering. There is an urgent need for a model building and simulation method that can comprehensively consider multi-physics coupling, deeply analyze dynamic characteristics, and combine system operation modes. Summary of the Invention

[0006] The present invention aims to at least solve one of the technical problems existing in the prior art, and provides a method and system for establishing and simulating the pressure build-up stage model of a compressed air energy storage container.

[0007] This invention provides a method for model building and dynamic characteristic simulation of a hydraulic compressed air energy storage container, comprising the following steps: Step S1: Based on the pressure-time relationship inside the container, establish a mathematical model of the container during the energy storage process of the hydraulic compressed air system; Step S2, the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles, involves using the compressor to fill the two containers with air to the predetermined pressure, and then the compressor stops operating. Step S3: Divide the gas-water mixing container and the high-pressure gas storage container into four parts: gas control body, liquid control body, container wall control body in contact with gas, and container wall control body in contact with liquid. Step S4: The following assumptions are made during the modeling process: Assumption (1): The temperature inside the control body is uniformly distributed and there is no temperature gradient; Assumption (2): The ambient temperature remains constant; Assumption (3): The thermophysical properties of the container wall material are constant; Assumption (4): Heat exchange between the two control bodies is ignored; Assumption (5): All processes are quasi-steady-state processes; Assumption (6): The gas inside the container satisfies the ideal gas law; Assumption (7): The temperature and level of the liquid inside the container remain constant. Step S5: Based on the laws of conservation of energy and mass, establish mathematical models for each control body in the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles, including: the gas state equation in the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles; the energy equation of the water body control body in the gas-water mixing container in the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles; the energy equation of the container wall control body in contact with the gas in the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles; and the energy equation of the container wall control body in contact with the liquid in the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles. Step S6: Combine the mathematical model established in steps S4 and S5 with system parameters to perform simulation calculations and result analysis, obtain the curves of pressure and liquid level changes over time, and compare them with experimental results.

[0008] In some possible embodiments, the gas state equations in the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles in step S5 satisfy the following: the rate of change of gas temperature is the sum of the rate of change of inlet and outlet flow temperature, the rate of change of temperature due to convective heat transfer with water, and the rate of change of temperature due to convective heat transfer with the vessel wall.

[0009]

[0010]

[0011] in, For air temperature, The temperature of the incoming gas. To contact the temperature of the air-contacting vessel wall, To control the body water temperature, For air quality, For air volume, The mass flow rate of the incoming air. Let be the specific heat capacity at constant volume of the gas. The air-water convection heat transfer coefficient is... The convective heat transfer coefficient between the gas and the vessel wall is denoted as . For water body area, The area of ​​the contactor wall with air.

[0012] In some possible embodiments, the energy equation of the control body of the container wall in contact with the gas during the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles in step S5 satisfies: the change in container wall energy is the sum of the heat exchange between the container wall and the gas inside the container and the heat exchange between the container wall and the external atmosphere.

[0013] in, The heat transfer coefficient between the wall and the external environment. The area of ​​the vessel wall exposed to the external environment. The external ambient temperature.

[0014] In some possible embodiments, the energy equation of the control volume of the container wall in contact with the liquid during the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles in step S5 satisfies: the change in container wall energy is the sum of the heat exchange between the container wall and the liquid inside the container and the heat exchange between the container wall and the external atmosphere. .

[0015] In some possible embodiments, the simulation results in step S6 include the pressure inside the gas-water mixing container, the pressure inside the high-pressure gas storage container, and the curve of the liquid level in the gas-water mixing container changing over time during the energy storage process.

[0016] Secondly, embodiments of the present invention provide a system for establishing and simulating a model of the pressure build-up stage of a compressed air energy storage container, comprising: The first module is used to establish a mathematical model of the container during the energy storage process of the hydraulic compressed air system based on the pressure-time relationship inside the container. The charging module is used for the initial pressure building stage and the air compressor pressure replenishment stage after multiple cycles. It uses the compressor to charge air into the two containers to the predetermined air pressure, and then the compressor stops operating. The partitioning module is used to divide the control body of the gas-water mixing container and the high-pressure gas storage container into four parts: gas control body, liquid control body, container wall control body in contact with gas, and container wall control body in contact with liquid. The assumption module is used to make the following assumptions during the modeling process: Assumption (1): The temperature inside the control body is uniformly distributed and there is no temperature gradient; Assumption (2): The ambient temperature remains constant; Assumption (3): The thermophysical properties of the container wall material are constant; Assumption (4): Heat exchange between the two control bodies is ignored; Assumption (5): All processes are quasi-steady-state processes; Assumption (6): The gas inside the container satisfies the ideal gas law; Assumption (7): The temperature and level of the liquid inside the container remain constant. The second module is used to establish mathematical models for each control body in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles, based on the laws of conservation of energy and mass. These models include: the gas state equation in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles; the energy equation of the water body control body in the gas-water mixing container in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles; the energy equation of the container wall control body in contact with the gas in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles; and the energy equation of the container wall control body in contact with the liquid in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles. The simulation module is used to combine the mathematical model established by the hypothesis module and the second establishment module with system parameters to perform simulation calculations and result analysis, obtain the pressure change curve over time, and compare it with the experimental results.

[0017] In some possible embodiments, the gas state equations during the initial pressure build-up phase and the compressor pressurization phase after multiple cycles satisfy the following: the rate of change of gas temperature is the sum of the rates of change of inlet and outlet flow temperatures, the rates of change of temperature due to convective heat transfer with water, and the rates of change of temperature due to convective heat transfer with the vessel wall.

[0018]

[0019]

[0020] in, For air temperature, The temperature of the incoming gas. To contact the temperature of the air-contacting vessel wall, To control the body water temperature, For air quality, For air volume, The mass flow rate of the incoming air. Let be the specific heat capacity at constant volume of the gas. The air-water convection heat transfer coefficient is... The convective heat transfer coefficient between the gas and the vessel wall is denoted as . For water body area, The area of ​​the contactor wall with air.

[0021] In some possible embodiments, the energy equation of the control volume of the container wall in contact with the gas during the initial pressure build-up stage and the compressor pressurization stage after multiple cycles satisfies: the change in container wall energy is the sum of the heat exchange between the container wall and the gas inside the container and the heat exchange between the container wall and the external atmosphere.

[0022] in, The heat transfer coefficient between the wall and the external environment. The area of ​​the vessel wall exposed to the external environment. The external ambient temperature.

[0023] In some possible embodiments, the energy equation of the control volume of the container wall in contact with the liquid during the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles satisfies: the change in container wall energy is the sum of the heat exchange between the container wall and the liquid inside the container and the heat exchange between the container wall and the external atmosphere. .

[0024] In some possible embodiments, the simulation results include the pressure in the gas-water mixing container and the pressure in the high-pressure gas storage container as a function of time during the energy storage process.

[0025] Compared with existing technologies, the method and system for establishing and simulating the pressure build-up stage of a hydraulic compressed air energy storage container provided by this invention can use differential equation models to describe the dynamic characteristics of the gas storage container in the hydraulic compressed air energy storage system during the energy storage process. The differential equation models can clearly reflect the dynamic relationships between various physical quantities, and these relationships can be used to deeply analyze the response mechanism of the gas storage container under different operating conditions, which is of great value for system analysis, calculation, and design. Furthermore, the mathematical models established for four different control bodies comprehensively consider the interactions under the coupling of multiple physical fields, avoiding errors caused by neglecting certain physical field coupling effects in traditional models, thus providing a reliable foundation for system design and analysis. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a hydraulic compressed air energy storage system. Figure 2 A schematic diagram of the four different control bodies. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] Unless otherwise specifically stated, the technical or scientific terms used in the embodiments of this invention should be understood in their ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms "comprising" or "including," as used in the embodiments of this invention, do not limit the shapes, numbers, steps, actions, operations, components, elements, and / or groups thereof mentioned, nor do they exclude the appearance or addition of one or more other different shapes, numbers, steps, actions, operations, components, elements, and / or groups thereof, or the inclusion of these.

[0030] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale, and techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail; however, where appropriate, the illustrated techniques, methods, and apparatus should be considered part of the specification. In all the examples shown and discussed herein, any other specific example may have different values. It should be noted that similar symbols and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0031] In the description of the embodiments of the present invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In the embodiments of the present invention, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in the embodiments of the present invention, as well as the features of different embodiments or examples.

[0032] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0033] refer to Figure 1 The hydraulic compression energy storage system of the present invention includes an electric motor 1, a compressor 2, a high-pressure gas storage container 3, a one-way valve 4, a gas-water mixing container 5, a pressure regulating valve 6, a pressure control valve 7, a water pump 8, a water turbine 9, a generator 10, a water storage tank 11, a pressure regulating valve 12, a second electric motor 13, a second valve 14, and a third valve 15.

[0034] The high-pressure gas storage container 3 is connected to the gas-water mixing container 4 through a pipeline. A one-way valve 4 is installed on the pipeline, which mainly stores the compressed high-pressure air in the gas-water mixing container 4 into the high-pressure gas storage container 3 during the energy storage stage. A pressure control valve 6 and a valve 7 are installed on the pipeline to ensure that the gas pressure in the gas-water mixing container 4 remains constant during the discharge process.

[0035] Reference Figure 2 The high-pressure gas storage container 3 and the gas-water mixing container 4 are divided into control bodies, including: gas control body 01, liquid control body 02, container wall control body 03 in contact with gas, and container wall control body 04 in contact with liquid.

[0036] The system starts operating, first entering the initial pressure build-up phase and then the air compressor pressurization phase after multiple cycles. The motor 1 drives the compressor 2 to work, filling the high-pressure air storage container 3 and the steam-water mixing container 4 with initial pressure. At this time, the pressure in the steam-water mixing container and the high-pressure air storage container increases synchronously with time. When the pressure reaches the set value, the compressor stops operating, and the initial pressure build-up phase and the air compressor pressurization phase after multiple cycles end.

[0037] During the initial pressure build-up phase and the compressor pressurization phase after multiple cycles, the compressor simultaneously pressurizes both the high-pressure gas storage container and the gas-water mixing container. These can be considered as a single controlled entity. Based on the law of conservation of energy, the rate of change of gas temperature should be the sum of the rates of change of inlet and outlet flow temperatures, the rate of change of temperature due to convective heat transfer with the water, and the rate of change of temperature due to convective heat transfer with the container wall. Based on the law of conservation of mass, since gas only flows in and does not flow out, its rate of change of mass should be the mass flow rate of the inflowing gas. The gas pressure can also be expressed based on the ideal gas law. The gas state during the initial pressure build-up phase and the compressor pressurization phase after multiple cycles is as follows: (1) (2) (3) In the formula, Indicates air temperature. Indicates the temperature of the incoming gas. Indicates the temperature of the wall in contact with air. Indicates the water temperature of the water body control zone, in K; Air quality is expressed in kg. Volume is expressed in m³. This indicates the mass flow rate of incoming air, expressed in kg / h. Specific heat capacity at constant volume of a gas, kJ / (kg) K); Indicates the air-water convection heat transfer coefficient. The convective heat transfer coefficient between the gas and the vessel wall, expressed in W / (m²). 2 K); The area of ​​a body of water is expressed in meters (m). 2 .

[0038] Based on the law of conservation of energy, the energy change relationship of the control volume of the compressor wall in contact with the gas during the initial pressure build-up stage and the compressor pressurization stage after multiple cycles should be the sum of the heat exchange between the compressor wall and the gas inside the container and the heat exchange between the compressor wall and the external atmosphere. The equation for the control volume of the compressor wall in contact with the gas is as follows: (4) In the formula, This represents the heat transfer coefficient between the wall and the external environment, expressed in W / (m²). 2 K); This represents the area of ​​the vessel wall exposed to the external environment, in meters (m). 2 ; This indicates the ambient temperature, expressed in Kelvin (K).

[0039] Based on the law of conservation of energy, the energy change relationship of the control volume of the vessel wall in contact with the liquid during the initial pressure build-up stage and the compressor pressurization stage after multiple cycles should be the sum of the heat exchange between the vessel wall and the liquid inside the container and the heat exchange between the vessel wall and the external atmosphere. The equation for the control volume of the vessel wall in contact with the liquid is as follows: (5) After the initial pressure build-up phase and the air compressor pressurization phase following multiple cycles, the water pump energy storage phase begins. The second motor 13 drives the water pump 8, opening the second valve 14 on the pipeline connecting the water pump 8 and the steam-water mixing container 4. The water pump delivers water from the storage tank 11 to the steam-water mixing container 4. The one-way valve 4 connecting the steam-water mixing container and the high-pressure air storage container is opened, allowing the compressed high-pressure air in the steam-water mixing container to be stored in the high-pressure air storage container. As the liquid level in the steam-water mixing container rises, the air pressure in both containers continuously increases. When the pressure in the containers reaches a predetermined value, the liquid level reaches a set value, or a stop energy storage command is received, the water pump stops working, the valve on the pipeline connecting the water pump and the steam-water mixing container is closed, and the energy storage process ends. Electrical energy is converted into air pressure energy and stored in the high-pressure air storage container and the steam-water mixing container.

[0040] The parameters of the two-container mathematical model of the energy storage process established above were set and simulation calculations were performed to obtain the pressure in the high-pressure gas storage container and the pressure in the gas-water mixing container during the energy storage process, and the results were compared and analyzed with the experimental results.

[0041] By comparing the simulation results with the experimental verification results, the trends of each curve are basically consistent and the error is within a reasonable range, indicating that the established dynamic model can reflect the dynamic characteristics of the gas-water mixing container and the high-pressure gas storage container during the pressurization process.

[0042] Based on the same inventive concept, embodiments of the present invention also provide a system for establishing and simulating a model of the pressure build-up stage of a compressed air energy storage container, including: The first module is used to establish a mathematical model of the container during the energy storage process of the hydraulic compressed air system based on the pressure-time relationship inside the container. The charging module is used for the initial pressure building stage and the air compressor pressure replenishment stage after multiple cycles. It uses the compressor to charge air into the two containers to the predetermined air pressure, and then the compressor stops operating. The partitioning module is used to divide the control body of the gas-water mixing container and the high-pressure gas storage container into four parts: gas control body, liquid control body, container wall control body in contact with gas, and container wall control body in contact with liquid. The assumption module is used to make the following assumptions during the modeling process: Assumption (1): The temperature inside the control body is uniformly distributed and there is no temperature gradient; Assumption (2): The ambient temperature remains constant; Assumption (3): The thermophysical properties of the container wall material are constant; Assumption (4): Heat exchange between the two control bodies is ignored; Assumption (5): All processes are quasi-steady-state processes; Assumption (6): The gas inside the container satisfies the ideal gas law; Assumption (7): The temperature and level of the liquid inside the container remain constant. The second module is used to establish mathematical models for each control body in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles, based on the laws of conservation of energy and mass. These models include: the gas state equation in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles; the energy equation of the water body control body in the gas-water mixing container in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles; the energy equation of the container wall control body in contact with the gas in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles; and the energy equation of the container wall control body in contact with the liquid in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles. The simulation module is used to combine the mathematical model established by the hypothesis module and the second establishment module with system parameters to perform simulation calculations and result analysis, obtain the pressure change curve over time, and compare it with the experimental results.

[0043] In some embodiments, the gas state equations during the initial pressure build-up stage and the compressor pressurization stage after multiple cycles satisfy the following: the rate of change of gas temperature is the sum of the rates of change of inlet and outlet flow temperatures, the rates of change of temperature due to convective heat transfer with water, and the rates of change of temperature due to convective heat transfer with the vessel wall.

[0044]

[0045]

[0046] in, For air temperature, The temperature of the incoming gas. To contact the temperature of the air-contacting vessel wall, To control the body water temperature, For air quality, For air volume, The mass flow rate of the incoming air. Let be the specific heat capacity at constant volume of the gas. The air-water convection heat transfer coefficient is... The convective heat transfer coefficient between the gas and the vessel wall is denoted as . For water body area, The area of ​​the contactor wall with air.

[0047] In some embodiments, the energy equation of the control volume of the container wall in contact with the gas during the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles satisfies: the change in container wall energy is the sum of the heat exchange between the container wall and the gas inside the container and the heat exchange between the container wall and the external atmosphere.

[0048] in, The heat transfer coefficient between the wall and the external environment. The area of ​​the vessel wall exposed to the external environment. The external ambient temperature.

[0049] In some embodiments, the energy equation of the control volume of the container wall in contact with the liquid during the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles satisfies: the change in container wall energy is the sum of the heat exchange between the container wall and the liquid inside the container and the heat exchange between the container wall and the external atmosphere. .

[0050] In some embodiments, the simulation results include curves showing the pressure changes over time in the gas-water mixing container and the high-pressure gas storage container during the energy storage process.

[0051] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for establishing and simulating a model of the pressure build-up stage of a compressed air energy storage container, characterized in that, Includes the following steps: Step S1: Based on the pressure-time relationship inside the container, establish a mathematical model of the container during the energy storage process of the hydraulic compressed air system; Step S2, the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles, involves using the compressor to fill the two containers with air to the predetermined pressure, and then the compressor stops operating. Step S3: Divide the gas-water mixing container and the high-pressure gas storage container into four parts: gas control body, liquid control body, container wall control body in contact with gas, and container wall control body in contact with liquid. Step S4: The following assumptions are made during the modeling process: Assumption (1): The temperature inside the control body is uniformly distributed and there is no temperature gradient; Assumption (2): The ambient temperature remains constant; Assumption (3): The thermophysical properties of the container wall material are constant; Assumption (4): Heat exchange between the two control bodies is ignored; Assumption (5): All processes are quasi-steady-state processes; Assumption (6): The gas inside the container satisfies the ideal gas law; Assumption (7): The temperature and level of the liquid inside the container remain constant. Step S5: Based on the laws of conservation of energy and mass, establish mathematical models for each control body in the initial pressure build-up stage, including: the gas state equation in the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles; the energy equation of the water body control body in the gas-water mixing container in the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles; the energy equation of the container wall control body in contact with the gas in the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles; and the energy equation of the container wall control body in contact with the liquid in the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles. Step S6: Combine the mathematical model established in steps S4 and S5 with system parameters to perform simulation calculations and result analysis, obtain the pressure change curve over time, and compare it with the experimental results.

2. The method according to claim 1, characterized in that, In step S5, during the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles, the gas state equation satisfies the following: the rate of change of gas temperature is the sum of the rates of change of inlet and outlet flow temperatures, the rates of change of temperature due to convective heat transfer with water, and the rates of change of temperature due to convective heat transfer with the vessel wall. in, For air temperature, The temperature of the incoming gas. To contact the temperature of the air-contacting vessel wall, To control the body water temperature, For air quality, For air volume, The mass flow rate of the incoming air. Let be the specific heat capacity at constant volume of the gas. The air-water convection heat transfer coefficient is... The convective heat transfer coefficient between the gas and the vessel wall is denoted as . For water body area, The area of ​​the contactor wall with air.

3. The method according to claim 2, characterized in that, In step S5, during the initial pressure build-up stage and the compressor pressurization stage after multiple cycles, the energy equation of the control volume of the container wall in contact with the gas satisfies the following: the change in the energy of the container wall is the sum of the heat exchange between the container wall and the gas inside the container and the heat exchange between the container wall and the external atmosphere. in, The heat transfer coefficient between the wall and the external environment. The area of ​​the vessel wall exposed to the external environment. The external ambient temperature.

4. The method according to claim 3, characterized in that, In step S5, during the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles, the energy equation of the control volume of the container wall in contact with the liquid satisfies the following: the change in the energy of the container wall is the sum of the heat exchange between the container wall and the liquid inside the container and the heat exchange between the container wall and the external atmosphere. 。 5. The method according to any one of claims 1 to 4, characterized in that, The simulation results in step S6 include the pressure changes over time in the gas-water mixing container and the pressure changes over time in the high-pressure gas storage container during the energy storage process.

6. A system for establishing and simulating a model of the pressure build-up stage of a compressed air energy storage container, characterized in that, include: The first module is used to establish a mathematical model of the container during the energy storage process of the hydraulic compressed air system based on the pressure-time relationship inside the container. The charging module is used for the initial pressure building stage and the air compressor pressure replenishment stage after multiple cycles. It uses the compressor to charge air into the two containers to the predetermined air pressure, and then the compressor stops operating. The partitioning module is used to divide the control body of the gas-water mixing container and the high-pressure gas storage container into four parts: gas control body, liquid control body, container wall control body in contact with gas, and container wall control body in contact with liquid. The assumption module is used to make the following assumptions during the modeling process: Assumption (1): The temperature inside the control body is uniformly distributed and there is no temperature gradient; Assumption (2): The ambient temperature remains constant; Assumption (3): The thermophysical properties of the container wall material are constant; Assumption (4): Heat exchange between the two control bodies is ignored; Assumption (5): All processes are quasi-steady-state processes; Assumption (6): The gas inside the container satisfies the ideal gas law; Assumption (7): The temperature and level of the liquid inside the container remain constant. The second module is used to establish mathematical models for each control body in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles, based on the laws of conservation of energy and mass. These models include: the gas state equation in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles; the energy equation of the water body control body in the gas-water mixing container in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles; the energy equation of the container wall control body in contact with the gas in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles; and the energy equation of the container wall control body in contact with the liquid in the initial pressure build-up stage and the compressor pressurization stage after multiple cycles. The simulation module is used to combine the mathematical model established by the hypothesis module and the second establishment module with system parameters to perform simulation calculations and result analysis, obtain the pressure change curve over time, and compare it with the experimental results.

7. The system according to claim 6, characterized in that, The gas state equations during the initial pressure build-up stage and the compressor pressurization stage after multiple cycles satisfy the following: the rate of change of gas temperature is the sum of the rates of change of inlet and outlet flow temperatures, the rates of change of temperature due to convective heat transfer with water, and the rates of change of temperature due to convective heat transfer with the vessel wall. in, For air temperature, The temperature of the incoming gas. To contact the temperature of the air-contacting vessel wall, To control the body water temperature, For air quality, For air volume, The mass flow rate of the incoming air. Let be the specific heat capacity at constant volume of the gas. The air-water convection heat transfer coefficient is... The convective heat transfer coefficient between the gas and the vessel wall is denoted as . For water body area, The area of ​​the contactor wall with air.

8. The system according to claim 7, characterized in that, The energy equation of the control volume of the container wall in contact with the gas during the initial pressure build-up stage and the air compressor pressurization stage after multiple cycles satisfies: the change in the energy of the container wall is the sum of the heat exchange between the container wall and the gas inside the container and the heat exchange between the container wall and the external atmosphere. in, The heat transfer coefficient between the wall and the external environment. The area of ​​the vessel wall exposed to the external environment. The external ambient temperature.

9. The system according to claim 8, characterized in that, The energy equation for the control volume of the container wall in contact with the liquid during the initial pressure build-up stage and the compressor pressurization stage after multiple cycles satisfies the following: the change in container wall energy is the sum of the heat exchange between the container wall and the liquid inside the container and the heat exchange between the container wall and the external atmosphere. 。 10. The system according to any one of claims 6 to 9, characterized in that, The simulation results include the pressure changes over time in the gas-water mixing container and the high-pressure gas storage container during the energy storage process.

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