Compressed air energy storage container dual power generation stage model establishment and simulation method and system

Abstract

The invention provides a compressed air energy storage container double-power-generation-stage model building method and system and a compressed air energy storage container double-power-generation-stage model simulation method and system. 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. The method comprehensively considers the multi-physical field coupling effect, can accurately reflect the dynamic characteristics of the gas storage container in the discharge process, and provides a reliable theoretical basis for system optimization design and stable operation.

Description

Technical Field

[0001] This invention relates to the field of hydraulic compressed energy storage technology, specifically to a method and system for establishing and simulating a dual-generation stage model 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. In actual operation, gas compression / expansion is accompanied by drastic temperature changes, resulting in coupling between the thermal field and the fluid field; gas pressure has time-varying characteristics, causing pressure fluctuations within the container, resulting in coupling between the pressure field and the mechanical field; with changes in liquid level, parameters such as the gas-liquid contact area and the wall area in contact with water dynamically change, affecting the heat transfer process. Traditional models fail to fully reflect these complex interrelationships, leading to low accuracy and reliability.

[0004] 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 actual 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 mode. Summary of the Invention

[0005] 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 a dual-generation stage model of a compressed air energy storage container.

[0006] In a first aspect, embodiments of the present invention provide a method for establishing and simulating a dual-generation stage model of a 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 discharge process of the hydraulic compressed air energy storage system; Step S2, the two containers work together to generate electricity. The air in the high-pressure gas storage container is delivered to the gas-water mixing container through the gas pressure control valve to maintain its constant gas pressure until the pressure of both containers drops to the predetermined value. 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; Step S5: Establish mathematical models for each control body in the two-container co-operation power generation stage, including: the state equation of the gas control body in the two containers, the energy equation of the water control body, the energy equation of the control body of the gas-water mixing container in contact with the gas in the power generation stage, and the energy equation of the control body of the control body of the gas-water mixing container in contact with the liquid in the power generation stage. Step S6: Combine the mathematical model established in step 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.

[0007] Furthermore, in step S5, the gas control body state equation during the power generation stage of the two containers working together satisfies the following: the rate of change of gas temperature in the steam-water mixing container is the sum of the net rate of change of inflow gas temperature, the rate of change of steam-water heat exchange temperature, the rate of change of heat exchange with the container wall, and the rate of change of temperature during the ideal gas expansion process; the rate of change of gas temperature in the high-pressure gas storage container is the sum of the net rate of change of outflow gas temperature and the rate of change of heat exchange with the container wall; the mass flow rate of gas flowing into the steam-water mixing container is equal to the mass flow rate of gas flowing out of the high-pressure gas storage container.

[0008] in, This refers to the air temperature in the high-pressure gas storage container. The air temperature in the container for mixing soda and water. The contact wall temperature with the high-pressure gas storage container. The temperature of the air in contact with the wall inside the container where the soda and water are mixed. The specific heat capacity of air at constant volume in a high-pressure gas storage container. The specific heat capacity of air at constant volume in a container for mixing carbonated beverages. For the air quality of the high-pressure gas storage container. Air quality in the soda / water mixing container The volume of air in the container for mixing soda and water. The mass flow rate of air flowing from the high-pressure gas storage container into the steam-water mixing container.

[0009] Furthermore, in step S5, the energy equation for the water volume control of the gas-water mixing container satisfies the following: the change in water energy is the sum of the net energy change due to the work done by the expansion of compressed air and the outflow of water, the heat exchange between the water and the gas, and the heat exchange between the water and the container wall.

[0010] in, The density of water, The specific heat capacity of water, The height of the liquid level. The temperature of the wall in contact with the water. The heat transfer coefficient between the liquid and the wall is... This refers to the area of ​​the vessel wall in contact with the liquid.

[0011] Furthermore, in step S5, the energy equation of the control volume of the container wall in contact with the gas during the gas-water mixing container power generation stage 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.

[0012] 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.

[0013] Furthermore, in step S5, the energy equation of the control volume of the container wall in contact with the liquid during the power generation stage of the steam-water mixing container satisfies: 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. .

[0014] Furthermore, the simulation results in step S6 include the pressure inside the steam-water mixing container, the pressure inside the high-pressure gas storage container, and the curve of the liquid level inside the steam-water mixing container changing with time during the discharge process.

[0015] Secondly, embodiments of the present invention provide a system for establishing and simulating a dual-generation stage model of a compressed air energy storage container, comprising: The first module is used to establish a mathematical model of the container during the discharge process of the hydraulic compressed air energy storage system based on the pressure-time relationship inside the container. The delivery module is used to deliver air from the high-pressure gas storage container to the gas-water mixing container through a pressure control valve during the power generation phase when the two containers work together, maintaining a constant gas pressure until the pressure of both containers drops to a predetermined value. 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. The second module is used to establish mathematical models for each control body in the power generation stage of the two containers working together, including: the state equation of the gas control body of the two containers in this stage, the energy equation of the water control body, the energy equation of the control body of the container wall in contact with the gas in the power generation stage of the gas-water mixing container, and the energy equation of the control body of the container wall in contact with the liquid in the power generation stage of the gas-water mixing container. The simulation module is used to combine the mathematical model established by the second module 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.

[0016] Furthermore, the state equations of the gas control volume during the power generation stage of the two containers working together satisfy the following: the rate of change of gas temperature in the steam-water mixing container is the sum of the net rate of change of inflow gas temperature, the rate of change of steam-water heat exchange temperature, the rate of change of heat exchange with the container wall, and the rate of change of temperature during the ideal gas expansion process; the rate of change of gas temperature in the high-pressure gas storage container is the sum of the net rate of change of outflow gas temperature and the rate of change of heat exchange with the container wall; the mass flow rate of gas flowing into the steam-water mixing container is equal to the mass flow rate of gas flowing out of the high-pressure gas storage container.

[0017] in, This refers to the air temperature in the high-pressure gas storage container. The air temperature in the container for mixing soda and water. The contact wall temperature with the high-pressure gas storage container. The temperature of the air in contact with the wall inside the container where the soda and water are mixed. The specific heat capacity of air at constant volume in a high-pressure gas storage container. The specific heat capacity of air at constant volume in a container for mixing carbonated beverages. For the air quality of the high-pressure gas storage container. Air quality in the soda / water mixing container The volume of air in the container for mixing soda and water. The mass flow rate of air flowing from the high-pressure gas storage container into the steam-water mixing container.

[0018] Furthermore, the energy equation for the water volume control of the gas-water mixing container satisfies the following: the change in water energy is the sum of the net energy change due to the work done by the expansion of compressed air and the outflow of water, the heat exchange between the water and the gas, and the heat exchange between the water and the container wall.

[0019] in, The density of water, The specific heat capacity of water, The height of the liquid level. The temperature of the wall in contact with the water. The heat transfer coefficient between the liquid and the wall is... This refers to the area of ​​the vessel wall in contact with the liquid.

[0020] Furthermore, the energy equation of the control volume of the container wall in contact with the gas during the gas-water mixing container power generation stage 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.

[0021] in, The heat transfer coefficient between the wall and the external environment. The area of ​​the vessel wall exposed to the external environment. External ambient temperature; The energy equation for the control volume of the container wall in contact with the liquid during the power generation stage of the steam-water mixing container 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. .

[0022] Compared with existing technologies, the dual-stage power generation model establishment and simulation method and system for compressed air energy storage containers provided by this invention can use differential equation models to describe the dynamic characteristics of the air storage container in a hydraulic compressed air energy storage system during the power generation process. The differential equation models can clearly reflect the dynamic relationships between various physical quantities, allowing for in-depth analysis of the response mechanism of the air storage container under different operating conditions. This is of significant 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

[0023] 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.

[0024] 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; Figure 3 A comparison chart of simulated pressure and actual measured pressure inside the steam-water mixing container during power generation; Figure 4 A comparison chart of simulated pressure and actual measured pressure inside the high-pressure gas storage container during power generation; Figure 5 This is a comparison chart of the simulated liquid level and the actual measured liquid level in the steam-water mixing container during the power generation process. Detailed Implementation

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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 control valve 6, a valve 7, a water pump 8, a water turbine 9, a generator 10, a water storage tank 11, a gas pressure regulating valve 12, a second electric motor 13, a second valve 14, and a third valve 15.

[0031] 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.

[0032] Reference Figure 2The 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.

[0033] The standalone power generation phase of the steam-water mixing container ends, and the air pressure inside the container drops to the preset pressure value, entering the combined power generation phase of both containers. The pressure control valves 6 and 7 on the connecting pipeline between the high-pressure air storage container 3 and the steam-water mixing container 5 are opened, allowing air from the high-pressure air storage container to be continuously pumped into the steam-water mixing container, driving water into the turbine to perform work. During this process, the flow rate into the steam-water mixing container is flexibly adjusted by regulating the opening of the pressure control valves to maintain a constant pressure within the container. During the combined power generation phase, the air pressure in the high-pressure air storage container gradually decreases, while the pressure inside the steam-water mixing container remains constant at the preset value. When the pressure in the high-pressure air storage container also drops to the preset value, the power generation phase ends, and the water flowing out of the turbine enters the reservoir 11 for the next system cycle.

[0034] During the dual-container power generation phase, due to the pressure difference between the two containers, the gas in the steam-water mixing container and the gas in the high-pressure gas storage container are treated as two distinct control volumes. Based on the law of conservation of energy, the rate of temperature change of the gas in the steam-water mixing container should be the sum of the net rate of temperature change of the inflowing gas, the rate of temperature change of the steam-water heat exchange within the container, the rate of temperature change of the heat exchange with the container wall, and the rate of temperature change during the ideal gas expansion process; the rate of temperature change of the gas in the high-pressure gas storage container should be the sum of the net rate of temperature change of the outflowing gas and the rate of temperature change of the heat exchange with the container wall. Based on the law of conservation of mass, the rate of volume change of the gas in the steam-water mixing container should be equal to the volumetric flow rate of the outflowing water; the mass flow rate of the gas flowing into the steam-water mixing container is equal to the mass flow rate of the gas flowing out of the high-pressure gas storage container. Based on the ideal gas law, the gas pressure in the steam-water mixing container can also be expressed as a constant value. The gas state equations for the dual-container power generation phase are as follows: (1) In the formula, This indicates the air temperature in the high-pressure gas storage container. This indicates the air temperature in the container where the soda and water are mixed. This indicates the temperature of the wall in contact with the high-pressure gas storage container. This indicates the temperature of the air in contact with the wall inside the container where the mixture is mixed with the soda, and the unit is K. This indicates the specific heat capacity of air at constant volume in a high-pressure gas storage container. This indicates the specific heat capacity of air at constant volume in a container for mixing carbonated beverages, expressed in kJ / (kg). K); This indicates the air quality in the high-pressure gas storage container. The mass of air in the container for mixing soft drinks is expressed in kg. The volume of air in a container for mixing soda and water is expressed in meters (m). 3 ; This indicates the mass flow rate of air flowing from the high-pressure gas storage container into the steam-water mixing container.

[0035] Based on the law of conservation of energy, the energy change of the water control volume during the power generation stage of a steam-water mixing container should be the sum of the net energy change due to the work done by the expansion of compressed air and the water flowing out of the container, the heat exchange between the water and the gas, and the heat exchange between the water and the container wall. The equation for the water control volume is as follows: (2) In the formula, The density of water is expressed in kg / m³. The specific heat capacity of water is expressed in kJ / (kg). K); Indicates the liquid level height, in meters (m). Indicates the temperature of the wall in contact with the water, in K; The heat transfer coefficient between the liquid and the wall is expressed in W / (m²). 2 K); The area of ​​the container wall in contact with the liquid, expressed in m². 2 .

[0036] Based on the law of conservation of energy, the energy change relationship of the control volume of the vessel wall in contact with the gas during the gas-water mixing container power generation stage should be the sum of the heat exchange between the vessel wall and the gas 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 gas is as follows: (3) 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).

[0037] 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 power generation stage of the steam-water mixing container 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: (4) The energy equations for the water control volume and the vessel wall control volume during the two-container co-generation stage are respectively referred to equations (2), (3) and (4) for the steam-water mixing container working alone during the power generation stage.

[0038] The parameters of the two-container mathematical model of the power generation process established above were set and simulation calculations were performed to obtain the pressure in the high-pressure gas storage container, the pressure in the gas-water mixing container, and the liquid level in the gas-water mixing container during the power generation process, and the results were compared and analyzed with the experimental results.

[0039] Reference Figures 3-5 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 steam-water mixing container and the high-pressure gas storage container during the power generation process.

[0040] Based on the same inventive concept, embodiments of the present invention also provide a system for establishing and simulating a dual-generation stage model of a compressed air energy storage container, including: The first module is used to establish a mathematical model of the container during the discharge process of the hydraulic compressed air energy storage system based on the pressure-time relationship inside the container. The delivery module is used to deliver air from the high-pressure gas storage container to the gas-water mixing container through a pressure control valve during the power generation phase when the two containers work together, maintaining a constant gas pressure until the pressure of both containers drops to a predetermined value. 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. The second module is used to establish mathematical models for each control body in the power generation stage of the two containers working together, including: the state equation of the gas control body of the two containers in this stage, the energy equation of the water control body, the energy equation of the control body of the container wall in contact with the gas in the power generation stage of the gas-water mixing container, and the energy equation of the control body of the container wall in contact with the liquid in the power generation stage of the gas-water mixing container. The simulation module is used to combine the mathematical model established by the second module 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.

[0041] Furthermore, the state equations of the gas control volume during the power generation stage of the two containers working together satisfy the following: the rate of change of gas temperature in the steam-water mixing container is the sum of the net rate of change of inflow gas temperature, the rate of change of steam-water heat exchange temperature, the rate of change of heat exchange with the container wall, and the rate of change of temperature during the ideal gas expansion process; the rate of change of gas temperature in the high-pressure gas storage container is the sum of the net rate of change of outflow gas temperature and the rate of change of heat exchange with the container wall; the mass flow rate of gas flowing into the steam-water mixing container is equal to the mass flow rate of gas flowing out of the high-pressure gas storage container.

[0042] in, This refers to the air temperature in the high-pressure gas storage container. The air temperature in the container for mixing soda and water. The contact wall temperature with the high-pressure gas storage container. The temperature of the air in contact with the wall inside the container where the soda and water are mixed. The specific heat capacity of air at constant volume in a high-pressure gas storage container. The specific heat capacity of air at constant volume in a container for mixing carbonated beverages. For the air quality of the high-pressure gas storage container. Air quality in the soda / water mixing container The volume of air in the container for mixing soda and water. The mass flow rate of air flowing from the high-pressure gas storage container into the steam-water mixing container.

[0043] Furthermore, the energy equation for the water volume control of the gas-water mixing container satisfies the following: the change in water energy is the sum of the net energy change due to the work done by the expansion of compressed air and the outflow of water, the heat exchange between the water and the gas, and the heat exchange between the water and the container wall.

[0044] in, The density of water, The specific heat capacity of water, The height of the liquid level. The temperature of the wall in contact with the water. The heat transfer coefficient between the liquid and the wall is... This refers to the area of ​​the vessel wall in contact with the liquid.

[0045] Furthermore, the energy equation of the control volume of the container wall in contact with the gas during the gas-water mixing container power generation stage 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.

[0046] in, The heat transfer coefficient between the wall and the external environment. The area of ​​the vessel wall exposed to the external environment. External ambient temperature; The energy equation for the control volume of the container wall in contact with the liquid during the power generation stage of the steam-water mixing container 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. .

[0047] The dual-stage power generation model establishment and simulation method and system for compressed air energy storage containers provided in this invention can use differential equation models to describe the dynamic characteristics of the air storage container in a hydraulic compressed air energy storage system during the power generation process. The differential equation models clearly reflect the dynamic relationships between various physical quantities, allowing for in-depth analysis of the response mechanism of the air storage container under different operating conditions. This is of significant 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.

[0048] 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 dual-generation stage model 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 discharge process of the hydraulic compressed air energy storage system; Step S2, the two containers work together to generate electricity. The air in the high-pressure gas storage container is delivered to the gas-water mixing container through the gas pressure control valve to maintain its constant gas pressure until the pressure of both containers drops to the predetermined value. 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; Step S5: Establish mathematical models for each control body in the two-container co-operation power generation stage, including: the state equation of the gas control body in the two containers, the energy equation of the water control body, the energy equation of the control body of the gas-water mixing container in contact with the gas in the power generation stage, and the energy equation of the control body of the control body of the gas-water mixing container in contact with the liquid in the power generation stage. Step S6: Combine the mathematical model established in step 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.

2. The method according to claim 1, characterized in that, In step S5, during the power generation stage where the two containers work together, the gas control volume state equation satisfies the following: the rate of change of gas temperature in the steam-water mixing container is the sum of the net rate of change of inflow gas temperature, the rate of change of steam-water heat exchange temperature, the rate of change of heat exchange temperature with the container wall, and the rate of change of temperature during the ideal gas expansion process; the rate of change of gas temperature in the high-pressure gas storage container is the sum of the net rate of change of outflow gas temperature and the rate of change of heat exchange temperature with the container wall; the mass flow rate of gas flowing into the steam-water mixing container is equal to the mass flow rate of gas flowing out of the high-pressure gas storage container. in, This refers to the air temperature in the high-pressure gas storage container. The air temperature in the container for mixing soda and water. The contact wall temperature with the high-pressure gas storage container. The temperature of the air in contact with the wall inside the container where the soda and water are mixed. The specific heat capacity of air at constant volume in a high-pressure gas storage container. The specific heat capacity of air at constant volume in a container for mixing carbonated beverages. For the air quality of the high-pressure gas storage container. Air quality in the soda / water mixing container The volume of air in the container for mixing soda and water. The mass flow rate of air flowing from the high-pressure gas storage container into the steam-water mixing container.

3. The method according to claim 2, characterized in that, In step S5, the energy equation for the water volume control of the gas-water mixing container satisfies the following: the change in water energy is the sum of the net energy change due to the work done by the expansion of compressed air and the outflow of water, the heat exchange between the water and the gas, and the heat exchange between the water and the container wall. in, The density of water, The specific heat capacity of water, The height of the liquid level. The temperature of the wall in contact with the water. The heat transfer coefficient between the liquid and the wall is... This refers to the area of ​​the vessel wall in contact with the liquid.

4. The method according to claim 3, characterized in that, In step S5, the energy equation of the control volume of the container wall in contact with the gas during the gas-water mixing container power generation stage 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.

5. The method according to claim 4, characterized in that, In step S5, the energy equation of the control volume of the container wall in contact with the liquid during the power generation stage of the steam-water mixing container 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. 。 6. The method according to any one of claims 1 to 5, characterized in that, The simulation results in step S6 include the pressure inside the steam-water mixing container, the pressure inside the high-pressure gas storage container, and the curve of the liquid level in the steam-water mixing container changing with time during the discharge process.

7. A system for establishing and simulating a dual-generation stage model 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 discharge process of the hydraulic compressed air energy storage system based on the pressure-time relationship inside the container. The delivery module is used to deliver air from the high-pressure gas storage container to the gas-water mixing container through a pressure control valve during the power generation phase when the two containers work together, maintaining a constant gas pressure until the pressure of both containers drops to a predetermined value. 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. The second module is used to establish mathematical models for each control body in the power generation stage of the two containers working together, including: the state equation of the gas control body of the two containers in this stage, the energy equation of the water control body, the energy equation of the control body of the container wall in contact with the gas in the power generation stage of the gas-water mixing container, and the energy equation of the control body of the container wall in contact with the liquid in the power generation stage of the gas-water mixing container. The simulation module is used to combine the mathematical model established by the second module 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.

8. The system according to claim 7, characterized in that, The state equations of the gas control volume during the power generation stage of the two containers working together satisfy the following: the rate of change of gas temperature in the steam-water mixing container is the sum of the net rate of change of inflow gas temperature, the rate of change of steam-water heat exchange temperature, the rate of change of heat exchange with the container wall, and the rate of change of temperature during the ideal gas expansion process; the rate of change of gas temperature in the high-pressure gas storage container is the sum of the net rate of change of outflow gas temperature and the rate of change of heat exchange with the container wall; the mass flow rate of gas flowing into the steam-water mixing container is equal to the mass flow rate of gas flowing out of the high-pressure gas storage container. in, This refers to the air temperature in the high-pressure gas storage container. The air temperature in the container for mixing soda and water. The contact wall temperature with the high-pressure gas storage container. The temperature of the air in contact with the wall inside the container where the soda and water are mixed. The specific heat capacity of air at constant volume in a high-pressure gas storage container. The specific heat capacity of air at constant volume in a container for mixing carbonated beverages. For the air quality of the high-pressure gas storage container. Air quality in the soda / water mixing container The volume of air in the container for mixing soda and water. The mass flow rate of air flowing from the high-pressure gas storage container into the steam-water mixing container.

9. The system according to claim 8, characterized in that, The energy equation for the water volume control of a gas-water mixing container satisfies the following: the change in water energy is the sum of the net energy change due to the work done by the expansion of compressed air and the outflow of water, the heat exchange between the water and the gas, and the heat exchange between the water and the container wall. in, The density of water, The specific heat capacity of water, The height of the liquid level. The temperature of the wall in contact with the water. The heat transfer coefficient between the liquid and the wall is... This refers to the area of ​​the vessel wall in contact with the liquid.

10. The system according to claim 9, characterized in that, The energy equation for the control volume of the container wall in contact with the gas during the gas-water mixing container power generation stage 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. External ambient temperature; The energy equation for the control volume of the container wall in contact with the liquid during the power generation stage of the steam-water mixing container 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. 。

Images