Calculation method and device for pre-cooling capacity of liquid air energy storage system

Abstract

The invention relates to the technical field of liquid air energy storage, and provides a method and device for calculating the precooling capacity of a liquid air energy storage system, and the method comprises the steps: determining the heat leakage capacity of a storage tank based on the current environment temperature and the internal temperature of the storage tank of the liquid air energy storage system; determining the precooling heat release amount of the equipment in the storage tank for transferring heat to the precooling medium; determining the gas heat release amount of the gas in the storage tank for transferring heat to the pre-cooling medium; the storage tank heat leakage amount, the precooling heat release amount and the gas heat release amount are determined as the total heat release amount of the liquid air energy storage system; based on the total heat release amount, the liquid nitrogen consumption amount in the pre-cooling process of the liquid air energy storage system is determined, accurate calculation of the total heat release amount of the liquid air energy storage system is achieved based on the storage tank heat leakage amount, the pre-cooling heat release amount and the gas heat release amount, and then accurate calculation of the liquid nitrogen consumption amount in the pre-cooling process is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid air energy storage, and in particular to a method and device for calculating the precooling amount of a liquid air energy storage system. Background Art

[0002] Liquid air energy storage technology, as a large-scale energy storage solution with high energy storage density and not constrained by geographical conditions, has a pivotal strategic significance for enhancing the peak-shaving capacity of the power grid and effectively reducing carbon emissions. This technology is regarded as one of the effective strategies to alleviate the challenges of volatility and intermittency of renewable energy. In the construction of liquid air energy storage systems, the storage tank is the core device for storing liquefied air, and its performance and stability are directly related to the efficiency of the entire system.

[0003] During the pre-cooling and long-term operation phases, the tank is supplied with pre-cooling medium to maintain a low-temperature environment and ensure that the liquid air maintains its liquid form in the tank. Obviously, the pre-cooling liquid consumption of the tank is crucial to the efficiency of the entire system, and the accurate calculation of the pre-cooling liquid consumption of the tank is an important issue that needs to be solved in the industry. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method and device for calculating the precooling amount of a liquid air energy storage system, which takes into account changes in ambient temperature to determine the precise heat leakage of the storage tank, thereby achieving accurate calculation of the liquid nitrogen consumption during the precooling process, thereby improving the precooling efficiency.

[0005] The present invention provides a method for calculating the precooling capacity of a liquid air energy storage system, comprising the following steps: Determine the amount of heat leakage from the tank based on the current ambient temperature and the internal temperature of the tank of the liquid air energy storage system; Determine the amount of precooling heat transferred from the equipment in the tank to the precooling medium; Determine the amount of heat released by the gas in the tank to transfer heat to the precooling medium; The heat leakage of the storage tank, the heat release of precooling and the heat release of gas are determined as the total heat release of the liquid air energy storage system; Based on the total heat release, the liquid nitrogen consumption during the precooling process of the liquid air energy storage system is determined.

[0006] According to a method for calculating the precooling amount of a liquid air energy storage system provided by the present invention, the liquid air energy storage system includes a propane tank, and the method for determining the heat leakage of the tank based on the current ambient temperature and the internal temperature of the tank of the liquid air energy storage system includes: Determining a first heat leakage amount of the bottom of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the bottom of the propane tank; Determining a second heat leakage amount at the side of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the cold insulation layer at the side of the propane tank; determining a third amount of heat leakage at the top of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the top of the propane tank; The sum of the first heat leakage, the second heat leakage and the third heat leakage is determined as the propane tank heat leakage.

[0007] According to a method for calculating the precooling amount of a liquid air energy storage system provided by the present invention, the liquid air energy storage system further includes a low-temperature methanol tank, and the method for determining the heat leakage of the tank based on the current ambient temperature and the internal temperature of the tank of the liquid air energy storage system includes: Determine a first heat conduction amount of the side of the low-temperature methanol tank based on the current ambient temperature, the internal temperature of the low-temperature methanol tank and a first heat conduction resistance, wherein the first heat conduction resistance is the heat conduction resistance of the cold insulation layer on the side of the low-temperature methanol tank; Determining a second heat conduction value of the end of the low-temperature methanol tank based on the current ambient temperature, the internal temperature of the low-temperature methanol tank, and the second heat conduction resistance, wherein the second heat conduction resistance is the heat conduction resistance of the end of the low-temperature methanol tank; The sum of the first heat conductivity and the second heat conductivity is determined as the heat leakage of the low-temperature methanol tank.

[0008] According to a method for calculating the precooling amount of a liquid air energy storage system provided by the present invention, the liquid air energy storage system further includes a liquid air storage tank, and determining the heat leakage of the storage tank based on the current ambient temperature and the internal temperature of the storage tank of the liquid air energy storage system includes: Determining a fourth amount of heat leakage at the bottom of the liquid air storage tank based on the current ambient temperature, the internal temperature of the liquid air storage tank, and the thermal conductivity resistance of the bottom of the liquid air storage tank; Determine a fifth amount of heat leakage at the side of the liquid air storage tank based on the current ambient temperature, the internal temperature of the liquid air storage tank, and the thermal conductivity resistance of the cold insulation layer at the side of the liquid air storage tank; Determine the sixth heat leakage amount at the top of the liquid air storage tank based on the current ambient temperature, the internal temperature of the liquid air storage tank, the thermal conductivity resistance at the top of the liquid air storage tank, and the average logarithmic heat exchange area; The sum of the fourth heat leakage, the fifth heat leakage and the sixth heat leakage is determined as the liquid air storage tank heat.

[0009] According to a method for calculating the precooling amount of a liquid air energy storage system provided by the present invention, the liquid nitrogen consumption during the precooling process of the liquid air energy storage system is determined based on the total heat release, including: Based on the sensible heat precooling method of the precooling medium, determine the minimum precooling liquid consumption corresponding to the total heat release; Based on the latent heat precooling method of the precooling medium, determine the maximum precooling liquid consumption corresponding to the total heat release; Based on the minimum pre-cooling liquid consumption and the maximum pre-cooling liquid consumption, the pre-cooling amount of the liquid air energy storage system is determined.

[0010] According to a method for calculating the precooling amount of a liquid air energy storage system provided by the present invention, the first heat leakage amount at the bottom of the propane tank is determined based on the current ambient temperature, the internal temperature of the propane tank and the thermal conductivity resistance of the bottom of the propane tank, including: Determine the first heat leakage at the bottom of the propane tank based on formula (1); (1) in, Indicates the first heat leak at the bottom of the propane tank. Indicates the internal temperature of the propane tank. Indicates the current ambient temperature. represents the bottom area of ​​the propane tank, Represents the thermal resistance of the bottom of the propane tank.

[0011] According to a method for calculating the precooling amount of a liquid air energy storage system provided by the present invention, the second heat leakage amount on the side of the propane tank is determined based on the current ambient temperature, the internal temperature of the propane tank and the thermal conductivity and thermal resistance of the cold insulation layer on the side of the propane tank, including: Determine the second heat leakage at the side of the propane tank based on formula (2); (2) in, Indicates the second heat leak on the side of the propane tank. It represents the thermal conductivity resistance of the cold insulation layer on the side of the propane tank. , represents the average thermal conductivity of the outer surface of the propane tank, Indicates the outer diameter of the propane tank. Indicates the inner diameter of each layer of the propane tank insulation layer. Indicates the corresponding thermal conductivity of each layer of the propane tank insulation layer, Indicates the propane tank height.

[0012] According to a method for calculating the precooling amount of a liquid air energy storage system provided by the present invention, the third heat leakage amount at the top of the propane tank is determined based on the current ambient temperature, the internal temperature of the propane tank and the thermal conductivity resistance of the top of the propane tank, including: Determine the heat radiation leakage at the top of the propane tank based on formula (3); (3) in, Indicates the amount of heat radiation leakage, that is, the amount of heat radiation leakage of the ceiling; Indicates the surface temperature of the ceiling above the propane tank. represents the radiant heat resistance of the vault on top of the propane tank to the suspended ceiling, , represents the reflectivity of the inner surface of the vault, represents the emissivity of the upper surface of the ceiling insulation layer, represents the surface area of ​​the inner surface of the vault, Indicates the surface area of ​​the upper surface of the ceiling insulation layer. It represents the angle coefficient of the upper surface of the ceiling insulation layer to the inner surface of the vault; Based on formula (4), determine the heat transferred from the propane tank ceiling insulation layer to the tank; (4) in, represents the transfer of heat, Indicates the thermal conductivity resistance of the ceiling insulation layer; The sum of the thermal radiation leakage heat and the transferred heat is determined as the third leakage heat of the top of the propane tank.

[0013] The present invention also provides a device for calculating the precooling capacity of a liquid air energy storage system, comprising: A first determination module is used to determine the amount of heat leakage of the storage tank based on the current ambient temperature and the internal temperature of the storage tank of the liquid air energy storage system; The second determination module is used to determine the amount of precooling heat transferred from the equipment in the storage tank to the precooling medium; The third determination module is used to determine the amount of heat released by the gas in the storage tank to transfer heat to the pre-cooling medium; A fourth determination module is used to determine the heat leakage of the storage tank, the pre-cooling heat release and the gas heat release as the total heat release of the liquid air energy storage system; The fifth determination module is used to determine the liquid nitrogen consumption during the precooling process of the liquid air energy storage system based on the total heat release.

[0014] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, a method for calculating the precooling amount of a liquid air energy storage system as described in any one of the above-mentioned methods is implemented.

[0015] The method for calculating the precooling amount of the liquid air energy storage system provided by the present invention determines the heat leakage of the tank based on the current ambient temperature and the internal temperature of the storage tank of the liquid air energy storage system, determines the precooling heat release of the equipment in the tank to the precooling medium, determines the gas heat release of the gas in the tank to the precooling medium, and accurately calculates the total heat release of the liquid air energy storage system based on the heat leakage of the tank, the precooling heat release and the gas heat release, thereby realizing the accurate calculation of the liquid nitrogen consumption during the precooling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is one of the flow charts of the method for calculating the precooling capacity of the liquid air energy storage system provided by the present invention.

[0018] Figure 2 This is the second flow chart of the method for calculating the precooling capacity of the liquid air energy storage system provided by the present invention.

[0019] Figure 3 This is the third flow chart of the method for calculating the precooling capacity of the liquid air energy storage system provided by the present invention.

[0020] Figure 4 This is the fourth flow chart of the method for calculating the precooling capacity of the liquid air energy storage system provided by the present invention.

[0021] Figure 5 This is the fifth flow chart of the method for calculating the precooling capacity of the liquid air energy storage system provided by the present invention.

[0022] Figure 6 It is a structural schematic diagram of a device for calculating the precooling amount of a liquid air energy storage system provided by the present invention.

[0023] Figure 7 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Combine the following Figure 1-Figure 5 The present invention describes a method for calculating the precooling capacity of the liquid air energy storage system.

[0026] The embodiment of the first aspect of the present invention provides a method for calculating the precooling capacity of a liquid air energy storage system, such as Figure 1 As shown, the method comprises the following steps: Step 100: Determine the amount of heat leakage from the storage tank based on the current ambient temperature and the internal temperature of the storage tank of the liquid air energy storage system.

[0027] Step 200: Determine the amount of precooling heat released by the equipment in the storage tank to transfer heat to the precooling medium.

[0028] Step 300: Determine the amount of heat released by the gas in the storage tank when transferring heat to the precooling medium.

[0029] Step 400: The heat release of the storage tank, the heat release of precooling and the heat release of gas are determined as the total heat release of the liquid air energy storage system.

[0030] Step 500: Determine the liquid nitrogen consumption during the precooling process of the liquid air energy storage system based on the total heat release.

[0031] It is understandable that there is a direct relationship between the liquid nitrogen consumption during the pre-cooling process of the liquid air energy storage system and the heat leakage of the liquid air energy storage system. For example, the more heat the storage tank of the liquid air energy storage system transfers to the outside through the cold insulation layer, that is, the greater the heat leakage, in order to keep the liquid in the tank at a low temperature, more refrigerant is needed to absorb this part of the additional heat entering. Therefore, the liquid nitrogen consumption during the pre-cooling process will increase with the increase in heat leakage. It can be seen that the accuracy of the heat leakage calculation results of the liquid air energy storage system directly affects the accuracy of the liquid nitrogen consumption results during the pre-cooling process.

[0032] Specifically, the heat leakage of the tank is calculated based on the current ambient temperature and the internal temperature of the tank of the liquid air energy storage system to realize the heat exchange calculation of heat transfer from the environment to the tank through the tank wall during the precooling process of the tank; the precooling heat release of the equipment in the tank to the precooling medium is calculated to realize the heat exchange calculation of heat transfer from the equipment in the tank to the precooling medium during the precooling process of the tank; the gas heat release of the gas in the tank to the precooling medium is calculated to realize the heat exchange calculation of heat transfer from the gas in the tank to the precooling medium during the precooling process of the tank; and the sum of the heat leakage of the tank, the precooling heat release and the gas heat release is used as the total heat release of the liquid air energy storage system. In this way, this embodiment determines the total heat release of the system by calculating the heat leakage of the tank, the precooling heat release and the gas heat release, and realizes the heat calculation of the three heat exchange processes of heat transfer from the environment to the tank through the tank wall, heat transfer from the equipment in the tank to the precooling medium, and heat transfer from the gas in the tank to the precooling medium during the precooling process of the tank, thereby realizing the accurate calculation of the heat leakage of the liquid air energy storage system, and then realizing the accurate calculation of the liquid nitrogen consumption during the precooling process.

[0033] It should be noted that the calculation of the heat leakage of the storage tank takes into account the change of the ambient temperature. The calculation of the heat leakage of the storage tank is adjusted according to the real-time current ambient temperature to improve the accuracy of the calculation of the heat leakage of the storage tank and further improve the accuracy of the liquid nitrogen consumption during the pre-cooling process.

[0034] The method for calculating the precooling amount of the liquid air energy storage system provided in the embodiment of the present invention determines the heat leakage of the tank based on the current ambient temperature and the internal temperature of the storage tank of the liquid air energy storage system, determines the precooling heat release of the equipment in the tank to the precooling medium, determines the gas heat release of the gas in the tank to the precooling medium, and accurately calculates the total heat release of the liquid air energy storage system based on the heat leakage of the tank, the precooling heat release and the gas heat release, thereby realizing the accurate calculation of the liquid nitrogen consumption during the precooling process.

[0035] Optionally, when the liquid air energy storage system includes a propane tank, step 100 can determine the heat leakage of the propane tank. Specifically, the heat leakage of the propane tank can be determined by calculating the heat leakage of the bottom of the propane tank, the heat leakage of the tank wall, and the heat leakage of the tank top. The heat leakage calculation of each part takes into account the corresponding material thermal conductivity, tank size, internal and external temperature difference and other factors to improve the accuracy of the heat leakage of the propane tank; Figure 2 As shown, step 100 specifically includes the following steps: Step 110: Determine a first heat leakage amount at the bottom of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the bottom of the propane tank.

[0036] For example, the first heat leakage at the bottom of the propane tank is determined based on formula (1); (1) in, Indicates the first heat leakage at the bottom of the propane tank, in watts (W), that is, the heat leakage at the bottom of the propane tank; Indicates the internal temperature of the propane tank in Kelvin (K); Indicates the current ambient temperature in Kelvin (K); Represents the bottom area of ​​the propane tank in square meters ( ); represents the thermal resistance of the bottom of the propane tank, In order to improve the thermal insulation effect, the bottom of the propane tank is made of multiple layers of materials with different properties. Indicates the thickness of the material of each part of the propane tank bottom, in meters (m). Indicates the thermal conductivity of each material in the bottom of the propane tank in Watts per meter Kelvin (W / (m·K)).

[0037] Step 120: Determine a second heat leakage amount at the side of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the cold insulation layer at the side of the propane tank.

[0038] For example, the second heat leakage amount of the propane tank side is determined based on formula (2); (2) in, Indicates the second heat leakage on the side of the propane tank, in watts (W), that is, the heat leakage of the propane tank wall; It represents the thermal conductivity resistance of the cold insulation layer on the side of the propane tank. ; Represents the average thermal conductivity of the outer surface of the propane tank in Watts per meter Kelvin (W / (m·K)); Indicates the outer diameter of the propane tank in meters (m); Indicates the inner diameter of each layer of the propane tank insulation layer, in meters (m); Indicates the corresponding thermal conductivity of each layer of the propane tank insulation layer, Indicates the propane tank height in meters (m).

[0039] Step 130: Determine a third heat leakage amount at the top of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the top of the propane tank.

[0040] For example, the heat radiation leakage at the top of the propane tank is determined based on formula (3); (3) in, Indicates the amount of heat leakage from thermal radiation, in watts (W); Indicates the surface temperature of the ceiling above the propane tank. It represents the radiation heat resistance of the arch on the top of the propane tank to the ceiling. The surface temperature under the ceiling is consistent with the temperature of the inner tank. , represents the reflectivity of the inner surface of the vault, represents the emissivity of the upper surface of the ceiling insulation layer, represents the surface area of ​​the inner surface of the vault, Indicates the surface area of ​​the upper surface of the ceiling insulation layer. It represents the angle coefficient of the upper surface of the ceiling insulation layer to the inner surface of the vault; Based on formula (4), determine the heat transferred from the propane tank ceiling insulation layer to the tank; (4) in, It indicates the transferred heat, that is, the heat transferred to the inner tank through the ceiling insulation layer; Indicates the thermal resistance of the ceiling insulation layer. In order to improve the thermal insulation effect, the propane tank ceiling insulation layer uses multiple layers of materials with different properties. Indicates the thickness of each part of the propane tank ceiling insulation layer, in meters (m). It indicates the thermal conductivity of each material of the propane tank ceiling insulation layer, with the unit of watt per meter Kelvin (W / (m·K)).

[0041] The sum of the heat radiation leakage and the heat transfer is determined as the third heat leakage at the top of the propane tank, that is, and The third heat leakage at the top of the propane tank is added together to obtain the third heat leakage at the top of the propane tank, and the third heat leakage at the top of the propane tank is used as the tank top leakage heat of the propane tank.

[0042] Step 140: Determine the sum of the first heat leakage, the second heat leakage and the third heat leakage as the propane tank heat leakage.

[0043] It can be understood that the heat leakage of the propane tank is obtained by adding together the heat leakage of the bottom of the propane tank, the heat leakage of the tank wall and the heat leakage of the tank top.

[0044] Optionally, when the liquid air energy storage system includes a liquid air storage tank, step 100 can determine the heat leakage of the liquid air storage tank. Specifically, the heat leakage of the liquid air storage tank can be determined by calculating the heat leakage of the tank bottom, the tank wall and the tank top. The heat leakage calculation of each part takes into account the corresponding material thermal conductivity, tank size, internal and external temperature difference and other factors to improve the accuracy of the heat leakage of the liquid air storage tank; Figure 3 As shown, step 100 specifically includes the following steps: Step 150: Determine a fourth heat leakage amount of the bottom of the liquid air storage tank based on the current ambient temperature, the internal temperature of the liquid air storage tank, and the thermal conductivity resistance of the bottom of the liquid air storage tank.

[0045] It should be noted that the calculation of heat leakage of liquid air storage tanks also includes the tank bottom, tank wall and tank top. The fourth heat leakage at the bottom of the liquid air storage tank is the tank bottom heat leakage of the liquid air storage tank. The same calculation method as the tank bottom heat leakage of the propane tank can be used. The specific parameters are adaptively adjusted according to the structure and materials of the liquid air storage tank.

[0046] Step 160: Determine a fifth heat leakage amount at the side of the liquid air storage tank based on the current ambient temperature, the internal temperature of the liquid air storage tank, and the thermal conductivity resistance of the cold insulation layer at the side of the liquid air storage tank.

[0047] It should be noted that the fifth heat leakage on the side of the liquid air storage tank is the heat leakage of the tank wall of the liquid air storage tank, and the same calculation method as the heat leakage of the tank wall of the propane tank can be used. The specific parameters are adaptively adjusted according to the structure and materials of the liquid air storage tank.

[0048] Step 170: Determine the sixth heat leakage amount at the top of the liquid air storage tank based on the current ambient temperature, the internal temperature of the liquid air storage tank, the thermal conductivity resistance at the top of the liquid air storage tank, and the average logarithmic heat exchange area.

[0049] It can be understood that the liquid air storage tank is a full-capacity double-domed tank, and the heat leakage form of the tank top is that the heat is transferred to the inside of the tank through the top cold insulation layer. Specifically, the sixth heat leakage amount of the top of the liquid air storage tank can be determined based on formula (5); (5) in, It indicates the sixth heat leakage at the top of the liquid air storage tank, in watts (W), i.e. the heat leakage at the top of the liquid air storage tank; Indicates the internal temperature of the liquid air storage tank in Kelvin (K); Indicates the thickness of each part of the cold insulation layer on the top of the liquid air storage tank, in meters (m). Indicates the thermal conductivity of each material of the cold insulation layer on the top of the liquid air storage tank, in watts per meter Kelvin (W / (m·K)); Represents the average logarithmic heat transfer area in square meters ( ), , represents the heat flowing out of the system in kJ, Represents the amount of heat entering the system in kJ.

[0050] Step 180: Determine the sum of the fourth heat leakage, the fifth heat leakage and the sixth heat leakage as the liquid air storage tank heat.

[0051] It can be understood that the heat leakage of the liquid air storage tank is obtained by adding the heat leakage of the tank bottom, the tank wall and the tank top.

[0052] Optionally, when the liquid air energy storage system includes a cryogenic methanol tank, step 100 may determine the cryogenic methanol tank, such as Figure 4 As shown, the specific steps include: Step 190, determining a first thermal conductivity of the side of the cryogenic methanol tank based on the current ambient temperature, the internal temperature of the cryogenic methanol tank and the first thermal conductivity resistance, where the first thermal conductivity resistance is the thermal conductivity resistance of the cold insulation layer on the side of the cryogenic methanol tank.

[0053] It can be understood that the heat leakage of the low-temperature methanol tank adopts a horizontal storage tank, and its heat leakage is mainly the heat transferred to the interior through the cold insulation material in the form of heat conduction, specifically including the first heat conduction at the side of the low-temperature methanol tank and the second heat conduction at the end of the low-temperature methanol tank.

[0054] For example, the first heat conduction value of the side of the low-temperature methanol tank is determined based on formula (6); (6) in, It indicates the first heat conduction of the side of the low-temperature methanol tank, that is, the heat is transferred into the interior in the form of heat conduction through the cold insulation material of the low-temperature methanol tank wall. Indicates the internal temperature of the cryogenic methanol tank in Kelvin (K); It indicates the thermal conductivity resistance of the cold insulation layer of the low-temperature methanol tank wall. , Represents the average thermal conductivity of the outer surface of the cryogenic methanol tank, in watts per meter Kelvin (W / (m·K)); Indicates the outer diameter of the cryogenic methanol tank in meters (m); It indicates the inner diameter of each layer of the cold insulation layer of the low-temperature methanol tank, in meters (m); Indicates the corresponding thermal conductivity of each layer of the low-temperature methanol tank insulation layer, Indicates the length of the side wall of the low-temperature methanol tank in meters (m).

[0055] Step 110, determining the second thermal conductivity of the end of the low-temperature methanol tank based on the current ambient temperature, the internal temperature of the low-temperature methanol tank and the second thermal conductivity resistance, where the second thermal conductivity resistance is the thermal conductivity resistance of the end of the low-temperature methanol tank.

[0056] For example, the second heat conduction value at the end of the low-temperature methanol tank is determined based on formula (7); (7) in, It indicates the second heat conduction value at the end of the low-temperature methanol tank, that is, the heat is transferred into the interior in the form of heat conduction through the cold insulation materials at both ends of the low-temperature methanol tank; Indicates the thermal resistance of the two ends of the low-temperature methanol storage tank. , Indicates the surface area of ​​the cold insulation layer of the low-temperature methanol tank, in square meters ( ), in order to improve the thermal insulation effect, the low-temperature methanol tank cold insulation material is low-density closed-cell foam glass, Indicates the thickness of the cold insulation material of the low-temperature methanol tank, in meters (m). It indicates the thermal conductivity of the cold insulation material of the low-temperature methanol tank, with the unit of watt per meter Kelvin (W / (m·K)).

[0057] Step 111: determine the sum of the first heat conductivity and the second heat conductivity as the heat leakage of the low-temperature methanol tank.

[0058] It can be understood that the first heat conductivity and the second heat conductivity are added to obtain the heat leakage of the low-temperature methanol tank.

[0059] It should be noted that when the liquid air energy storage system includes a propane tank, a liquid air storage tank and a low-temperature methanol tank, the propane tank is divided into a medium-temperature propane tank and a low-temperature propane tank, and the above steps 110 to 140 can be used to calculate the heat leakage, and the sum of the heat leakage of the low-temperature propane tank, the heat leakage of the medium-temperature propane tank, the heat leakage of the liquid air storage tank and the heat leakage of the low-temperature methanol tank is determined as the tank heat leakage.

[0060] In one embodiment of the present invention, step 200 may specifically include the following contents: The heat released by the equipment components in the tank of the liquid air energy storage system is calculated by the following formula (8); (8) in, Indicates the heat release, that is, the pre-cooling heat released by the equipment in the tank to the pre-cooling medium. represents the specific heat capacity of each component in the tank, Indicates the mass of each component. is the average specific heat capacity of each component in the tank, is the precooling temperature drop, .

[0061] Example, 304 stainless steel heat capacity for: ,in, represents mass heat capacity; Temperature, in °C; the average mass heat capacity of the tank during precooling for: .

[0062] It should be noted that the heat released by the equipment in the storage tank during the precooling process includes the following: the low-temperature methanol tank includes the heat released by the storage tank and the low bulk density closed-cell foam glass of the cold insulation layer; the propane tank includes the heat released by the inner tank of the storage tank, the bottom glass bricks, the tank wall elastic felt, the tank wall pearl sand and the tank top cold insulation layer; the liquid air storage tank includes the heat released by the inner tank of the storage tank, the bottom glass bricks, the tank wall elastic felt, the tank wall pearl sand and the tank top pearl sand. It should be noted that since the thermal resistance of the inner tank of the storage tank is smaller than that of the insulation layer, this part of the thermal resistance is omitted; the heat released by the insulation layer is calculated based on its average temperature.

[0063] In one embodiment of the present invention, step 300 may specifically include the following contents: The first heat brought into the system by the cooling medium is calculated by formula (9); (9) in, Indicates the first heat, m 1 represents the liquid inflow rate of the precooling medium, h 1 represents the enthalpy value when the precooling medium flows into the liquid air energy storage system, It indicates the average liquid supply rate of the precooling medium within the time Δt.

[0064] The second heat carried away by the cooling medium flowing out of the system is calculated by formula (10); (10) in, represents the second heat, represents the mass flow rate out of the liquid air energy storage system, represents the specific enthalpy of the cooling medium flowing out of the tank, represents the average specific enthalpy, Indicates Δ t The average mass flow rate out of the system over time.

[0065] The heat released by the gas in the storage tank to the pre-cooling medium is obtained by making a difference between the first heat and the second heat, that is, subtracting the second heat from the first heat.

[0066] In one embodiment of the present invention, step 400 specifically includes the following contents: The heat of the storage tank transmitted from the outside through the heat leakage of the liquid air energy storage system is calculated by the following formula (11); (11) in, represents the amount of heat leakage from the outside into the storage tank through the cold-insulating structure. The amount of heat leakage from the storage tank in step 100 is is the precooling time, Indicated in Average heat leakage of internal heat transfer storage tank.

[0067] According to the first law of thermodynamics, the total heat release of the liquid air energy storage system is calculated by formula (12); (12) in, represents the total heat release, , are the mass of the gas in the tank at the beginning and end of precooling, , Respectively represent the specific internal energy of the gas in the tank at the beginning and end of precooling.

[0068] For example, the initial gas in the storage tank is air with a temperature of 5.3°C, which is a mixture of 78.1% nitrogen, 20.9% oxygen, 0.939% argon, 0.031% carbon dioxide, and 0.03% water vapor. At the end of precooling, the gas in the tank is nitrogen at the precooling temperature.

[0069] In one embodiment of the present invention, Figure 5 As shown, step 500 may specifically include the following steps: Step 510: Determine the minimum precooling liquid consumption corresponding to the total heat release based on the sensible heat precooling method of the precooling medium.

[0070] Step 520: Determine the maximum precooling liquid consumption corresponding to the total heat release based on the latent heat precooling method of the precooling medium.

[0071] Step 530: Determine the precooling capacity of the liquid air energy storage system based on the minimum precooling liquid consumption and the maximum precooling liquid consumption.

[0072] It can be understood that by accurately calculating the minimum and maximum liquid consumption during the pre-cooling process, it can be ensured that the system design is neither too conservative nor too aggressive, which helps to avoid cost increases caused by over-design, while ensuring that the system has sufficient capacity to cope with the most extreme working conditions; and the liquid consumption range between the minimum and maximum liquid consumption can help engineers optimize operating parameters, such as the flow rate and temperature of the cooling medium, thereby improving the overall thermodynamic efficiency of the system; and the minimum and maximum liquid consumption facilitate the understanding of the liquid consumption during the pre-cooling process, and also help to formulate a reasonable maintenance plan to ensure that the cooling system and other related equipment are properly maintained to extend their service life.

[0073] It is understandable that during the precooling process of the storage tank, the precooling medium absorbs the heat in the heat source mainly through two ways to achieve the purpose of cooling. One is to use the precooling medium gasification process to absorb latent heat for precooling, and the other is to use the precooling medium to absorb sensible heat for precooling. At this time, there are two extreme cases: minimum precooling liquid consumption and maximum precooling liquid consumption. When both the latent heat of the precooling medium and the sensible heat of the precooling medium are utilized in the precooling process, the minimum precooling liquid consumption can be obtained, but the precooling speed of this process is very slow; when only the latent heat of the precooling medium is utilized in the precooling process but the sensible heat of the precooling medium is not utilized, the maximum precooling liquid consumption can be obtained.

[0074] Specifically, suppose the latent heat absorbed by the precooling medium when it vaporizes is Q1, and the heat absorbed by the vaporized medium vapor when cooling the tank to the working temperature is Q2, then the total heat absorption is Calculated by formula (13); (13) in, It indicates the amount of liquid consumed by the cooling medium to cool to the working temperature per unit time. represents the latent heat of vaporization of the cooling medium, T represents the gas temperature in the tank, Δ t Indicates the cooling time. Indicates the saturation temperature of the cooling medium, represents the average specific heat of steam; let , then .

[0075] System temperature drops and releases heat Qt It includes two parts: one is the heat from the outside environment leaking into the tank through the tank insulation material, and the other is the heat released by the equipment in the tank when it is cooled to the working temperature. Qt It can be expressed by formula (14); (14) in, The average heat transfer rate can be approximated to be equal to half of the steady-state decreasing heat transfer rate, so , represents the steady-state heat transfer rate of the system.

[0076] The simultaneous equations give , that is, refer to formula (15); (15) This results in minimum fluid consumption for: The maximum liquid consumption is : For example, the normal container liquid consumption can be calculated based on the latent heat of liquid vaporization and 20%~30% of the sensible heat, where the sensible heat is from Tb to 278.45 K. Set the sensible heat utilization to 25% and the tank precooling rate to 3℃ / h.

[0077] It is calculated that the total amount of liquid nitrogen consumed in the storage tank during the pre-cooling process is 1075.76 tons. In addition, some liquid nitrogen is stored at the bottom of the liquid tank and cannot be extracted, weighing 285.58 tons. Therefore, 1361.34 tons of liquid nitrogen are consumed during the pre-cooling process of the storage tank. The unit price of liquid nitrogen is calculated at 1200 yuan / ton, and the cost of pre-cooling the storage tank is 1633608 yuan.

[0078] The following is a description of a device for calculating the precooling amount of a liquid air energy storage system provided by the present invention. The device for calculating the precooling amount of a liquid air energy storage system described below and the method for calculating the precooling amount of a liquid air energy storage system described above can be referred to each other.

[0079] The embodiment of the present invention provides a device for calculating the precooling capacity of a liquid air energy storage system, such as Figure 6 As shown, the device includes a first determination module 610, a second determination module 620, a third determination module 630, a fourth determination module 640 and a fifth determination module 650; wherein: The first determination module 610 is used to determine the amount of heat leakage of the storage tank based on the current ambient temperature and the internal temperature of the storage tank of the liquid air energy storage system.

[0080] The second determination module 620 is used to determine the amount of pre-cooling heat transferred from the equipment in the storage tank to the pre-cooling medium.

[0081] The third determination module 630 is used to determine the amount of heat released by the gas in the storage tank when transferring heat to the pre-cooling medium.

[0082] The fourth determination module 640 is used to determine the total heat release of the liquid air energy storage system by combining the heat leakage of the storage tank, the heat release of precooling and the heat release of gas.

[0083] The fifth determination module 650 is used to determine the liquid nitrogen consumption during the precooling process of the liquid air energy storage system based on the total heat release.

[0084] Figure 7 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 7As shown, the electronic device may include: a processor 710, a communication interface 720, a memory 730 and a communication bus 740, wherein the processor 710, the communication interface 720 and the memory 730 communicate with each other through the communication bus 740. The processor 710 may call the logic instructions in the memory 730 to execute a method for calculating the precooling amount of the liquid air energy storage system, the method comprising: determining the amount of heat leakage of the storage tank based on the current ambient temperature and the internal temperature of the storage tank of the liquid air energy storage system; determining the amount of heat released by the equipment in the storage tank to transfer heat to the precooling medium; determining the amount of heat released by the gas in the storage tank to transfer heat to the precooling medium; determining the amount of heat released by the gas in the storage tank to transfer heat to the precooling medium; determining the amount of heat released by the storage tank, the amount of heat released by the precooling and the amount of heat released by the gas as the total heat released by the liquid air energy storage system; and determining the amount of liquid nitrogen consumed during the precooling process of the liquid air energy storage system based on the total heat released.

[0085] In addition, the logic instructions in the above-mentioned memory 730 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0086] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the calculation method of the precooling amount of the liquid air energy storage system provided by the above methods, the method including: determining the heat leakage of the tank based on the current ambient temperature and the internal temperature of the tank of the liquid air energy storage system; determining the precooling heat release of the equipment in the tank to the precooling medium; determining the gas heat release of the gas in the tank to the precooling medium; determining the tank heat leakage, precooling heat release and gas heat release as the total heat release of the liquid air energy storage system; and determining the liquid nitrogen consumption during the precooling process of the liquid air energy storage system based on the total heat release.

[0087] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the method for calculating the precooling amount of the liquid air energy storage system provided by the above-mentioned methods, the method comprising: determining the heat leakage of the tank based on the current ambient temperature and the internal temperature of the storage tank of the liquid air energy storage system; determining the precooling heat release from the equipment in the tank to the precooling medium; determining the gas heat release from the gas in the tank to the precooling medium; determining the heat leakage of the tank, the precooling heat release and the gas heat release as the total heat release of the liquid air energy storage system; and determining the liquid nitrogen consumption during the precooling process of the liquid air energy storage system based on the total heat release.

[0088] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0089] Through the description of the above implementation modes, those skilled in the art can clearly understand that each implementation mode can be implemented by means of software plus a necessary general hardware platform, or of course by hardware. Based on such an understanding, the above technical solution can essentially or in other words be embodied in the form of a software product that contributes to the prior art. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiment.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the precooling capacity of a liquid air energy storage system, characterized in that: include: Determine the amount of heat leakage from the tank based on the current ambient temperature and the internal temperature of the tank of the liquid air energy storage system; Determine the amount of precooling heat transferred from the equipment in the tank to the precooling medium; Determine the amount of heat released by the gas in the tank to transfer heat to the precooling medium; The heat leakage of the storage tank, the heat release of precooling and the heat release of gas are determined as the total heat release of the liquid air energy storage system; Based on the total heat release, the liquid nitrogen consumption during the precooling process of the liquid air energy storage system is determined.

2. The method for calculating the precooling capacity of the liquid air energy storage system according to claim 1, characterized in that: The liquid air energy storage system includes a propane tank, and determining the amount of heat leakage of the tank based on the current ambient temperature and the internal temperature of the tank of the liquid air energy storage system includes: Determining a first heat leakage amount of the bottom of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the bottom of the propane tank; Determining a second heat leakage amount at the side of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the cold insulation layer at the side of the propane tank; determining a third amount of heat leakage at the top of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the top of the propane tank; The sum of the first heat leakage, the second heat leakage and the third heat leakage is determined as the propane tank heat leakage.

3. The method for calculating the precooling capacity of the liquid air energy storage system according to claim 2, characterized in that: The liquid air energy storage system further includes a low-temperature methanol tank, and the method of determining the heat leakage of the tank based on the current ambient temperature and the internal temperature of the tank of the liquid air energy storage system includes: Determine a first heat conduction amount of the side of the low-temperature methanol tank based on the current ambient temperature, the internal temperature of the low-temperature methanol tank and a first heat conduction resistance, wherein the first heat conduction resistance is the heat conduction resistance of the cold insulation layer on the side of the low-temperature methanol tank; Determining a second heat conduction value of the end of the low-temperature methanol tank based on the current ambient temperature, the internal temperature of the low-temperature methanol tank, and the second heat conduction resistance, wherein the second heat conduction resistance is the heat conduction resistance of the end of the low-temperature methanol tank; The sum of the first heat conductivity and the second heat conductivity is determined as the heat leakage of the low-temperature methanol tank.

4. The method for calculating the precooling capacity of the liquid air energy storage system according to claim 3 is characterized in that: The liquid air energy storage system further includes a liquid air storage tank, and determining the amount of heat leakage of the storage tank based on the current ambient temperature and the internal temperature of the storage tank of the liquid air energy storage system includes: Determining a fourth amount of heat leakage at the bottom of the liquid air storage tank based on the current ambient temperature, the internal temperature of the liquid air storage tank, and the thermal conductivity resistance of the bottom of the liquid air storage tank; Determine a fifth amount of heat leakage at the side of the liquid air storage tank based on the current ambient temperature, the internal temperature of the liquid air storage tank, and the thermal conductivity resistance of the cold insulation layer at the side of the liquid air storage tank; Determine the sixth heat leakage amount at the top of the liquid air storage tank based on the current ambient temperature, the internal temperature of the liquid air storage tank, the thermal conductivity resistance at the top of the liquid air storage tank, and the average logarithmic heat exchange area; The sum of the fourth heat leakage, the fifth heat leakage and the sixth heat leakage is determined as the liquid air storage tank heat.

5. The method for calculating the precooling capacity of the liquid air energy storage system according to claim 2, characterized in that: The determining, based on the total heat release, the amount of liquid nitrogen consumed during the precooling process of the liquid air energy storage system comprises: Based on the sensible heat precooling method of the precooling medium, determine the minimum precooling liquid consumption corresponding to the total heat release; Based on the latent heat precooling method of the precooling medium, determine the maximum precooling liquid consumption corresponding to the total heat release; Based on the minimum pre-cooling liquid consumption and the maximum pre-cooling liquid consumption, the pre-cooling amount of the liquid air energy storage system is determined.

6. The method for calculating the precooling capacity of the liquid air energy storage system according to any one of claims 2 to 5, characterized in that: The determining of a first heat leakage amount of the bottom of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the bottom of the propane tank comprises: Determine the first heat leakage at the bottom of the propane tank based on formula (1); （1） in, Indicates the first heat leak at the bottom of the propane tank. Indicates the internal temperature of the propane tank. Indicates the current ambient temperature. represents the bottom area of ​​the propane tank, Represents the thermal resistance of the bottom of the propane tank.

7. The method for calculating the precooling capacity of the liquid air energy storage system according to any one of claims 2 to 5, characterized in that: The determining of a second heat leakage amount on the side of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity and thermal resistance of the cold insulation layer on the side of the propane tank comprises: Determine the second heat leakage at the side of the propane tank based on formula (2); （2） in, Indicates the second heat leak on the side of the propane tank. It represents the thermal conductivity resistance of the cold insulation layer on the side of the propane tank. , represents the average thermal conductivity of the outer surface of the propane tank, Indicates the outer diameter of the propane tank. Indicates the inner diameter of each layer of the propane tank insulation layer. Indicates the corresponding thermal conductivity of each layer of the propane tank insulation layer, Indicates the propane tank height.

8. The method for calculating the precooling capacity of the liquid air energy storage system according to any one of claims 2 to 5, characterized in that: The determining of a third amount of heat leakage at the top of the propane tank based on the current ambient temperature, the internal temperature of the propane tank, and the thermal conductivity resistance of the top of the propane tank comprises: Determine the heat radiation leakage at the top of the propane tank based on formula (3); （3） in, Indicates the amount of heat radiation leakage, that is, the amount of heat radiation leakage of the ceiling; Indicates the surface temperature of the ceiling above the propane tank. represents the radiant heat resistance of the vault on top of the propane tank to the suspended ceiling, , represents the reflectivity of the inner surface of the vault, represents the emissivity of the upper surface of the ceiling insulation layer, represents the surface area of ​​the inner surface of the vault, Indicates the surface area of ​​the upper surface of the ceiling insulation layer. It represents the angle coefficient of the upper surface of the ceiling insulation layer to the inner surface of the vault; Based on formula (4), determine the heat transferred from the propane tank ceiling insulation layer to the tank; （4） in, represents the transfer of heat, Indicates the thermal conductivity resistance of the ceiling insulation layer; The sum of the thermal radiation leakage heat and the transferred heat is determined as the third leakage heat of the top of the propane tank.

9. A device for calculating the precooling capacity of a liquid air energy storage system, characterized in that: include: A first determination module is used to determine the amount of heat leakage of the storage tank based on the current ambient temperature and the internal temperature of the storage tank of the liquid air energy storage system; The second determination module is used to determine the amount of precooling heat transferred from the equipment in the storage tank to the precooling medium; The third determination module is used to determine the amount of heat released by the gas in the storage tank to transfer heat to the pre-cooling medium; A fourth determination module is used to determine the heat leakage of the storage tank, the pre-cooling heat release and the gas heat release as the total heat release of the liquid air energy storage system; The fifth determination module is used to determine the liquid nitrogen consumption during the precooling process of the liquid air energy storage system based on the total heat release.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for calculating the precooling amount of the liquid air energy storage system as described in any one of claims 1 to 8 is implemented.

Images