Battery refrigerant direct cooling plate state calculation method and device and storage medium

Abstract

The embodiment of the application provides a battery refrigerant direct cooling plate state calculation method, device and storage medium, and relates to the technical field of new energy vehicles. The method comprises the following steps: obtaining the heating power of a battery under a current vehicle working condition; using the heating power and a preset evaporation temperature of a refrigerant direct cooling plate to calculate a state parameter of the refrigerant direct cooling plate; calculating a throttle valve parameter according to the temperature and pressure state parameters of the refrigerant direct cooling plate; and calculating the refrigerant direct cooling plate state parameter according to the throttle valve parameter. The method can determine the thermodynamic state of the refrigerant direct cooling plate before the design of the power battery refrigerant direct cooling plate and the vehicle air conditioning system, provide better operation data support for the design of the refrigerant direct cooling system, shorten the development cycle, and solve the problem that the existing method cannot provide better operation data support for the design of the refrigerant direct cooling system.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle technology, and more specifically, to a method, apparatus and storage medium for calculating the state of a battery refrigerant direct cooling plate. Background Technology

[0002] Direct cooling technology for power batteries is a new and efficient thermal management technology for power batteries. It makes full use of the refrigerant in the air conditioning system of electric vehicles to directly cool the power battery to achieve good cooling performance. Compared with the mature liquid cooling technology for power batteries, the new direct cooling technology for power batteries not only has higher cooling performance, but also has a low cost advantage, and has become an important development direction for thermal management technology of power batteries in new energy vehicles.

[0003] However, before the detailed design of the refrigerant direct cooling plate and air conditioning system components, there is no method to identify the thermal operating status of each component of the refrigerant direct cooling system connected in parallel with the battery and air conditioner through calculation and analysis. This makes it impossible to identify risks and provide better operating data support for the design of the refrigerant direct cooling system. Summary of the Invention

[0004] The purpose of this application is to provide a method, device, and storage medium for calculating the state of a battery refrigerant direct cooling plate. This method can determine the thermodynamic state of the refrigerant direct cooling plate in the early stages of the design of the power battery refrigerant direct cooling plate and the vehicle air conditioning system, providing better operational data support for the design of the refrigerant direct cooling system, shortening the development cycle, and solving the problem that existing methods cannot provide better operational data support for the design of the refrigerant direct cooling system.

[0005] This application provides a method for calculating the state of a direct-cooling plate for battery refrigerant, the method comprising:

[0006] Obtain the battery's heat dissipation power under the current vehicle operating conditions;

[0007] Using the heating power and the preset evaporation temperature of the refrigerant direct cooling plate, calculate the state parameters of the refrigerant direct cooling plate;

[0008] Calculate the throttle valve parameters based on the temperature and pressure parameters of the refrigerant direct cooling plate;

[0009] Calculate the refrigerant direct cooling plate status parameters based on the throttle valve parameters.

[0010] In the above implementation process, the thermodynamic state prediction of the key refrigerant direct cooling plate, as well as the thermal performance state of each air conditioning circuit component, battery heat dissipation power, and air conditioning system, can be determined in the early stage of the design of the power battery refrigerant direct cooling plate and the vehicle air conditioning system. This provides better operating data support for the design of the refrigerant direct cooling system, shortens the development cycle, and solves the problem that existing methods cannot provide better operating data support for the design of the refrigerant direct cooling system.

[0011] Furthermore, obtaining the battery's heat dissipation power under the current vehicle operating conditions includes:

[0012] Obtain the current spectrum of the battery under the current vehicle operating conditions;

[0013] The heating power of the battery is calculated based on the current spectrum, and the calculation formula is as follows:

[0014] Q = I(EU) + IT*dE / dT;

[0015] Where I is the current value, U is the battery terminal voltage, E is the battery open-circuit voltage; dE / dT is the entropy coefficient; and T is the average Kelvin temperature inside the battery.

[0016] In the above implementation process, the heating power of the battery under the current operating conditions can be obtained by using the current spectrum. Moreover, the heating power changes with time, which is closer to the actual working conditions of the battery and improves the accuracy of the calculation results.

[0017] Furthermore, the calculation of the temperature and pressure parameters of the refrigerant direct cooling plate using the heating power and the preset evaporation temperature of the refrigerant direct cooling plate includes:

[0018] The corresponding evaporation pressure is obtained by finding the preset evaporation temperature.

[0019] The inlet pressure and outlet pressure of the cold plate are calculated based on the pressure drop of the refrigerant direct cooling plate and the evaporation pressure.

[0020] The corresponding outlet temperature and outlet enthalpy can be obtained by referring to the table based on the outlet pressure of the cold plate.

[0021] In the above process, the temperature and pressure parameters of the refrigerant direct cooling plate, such as the inlet pressure, outlet pressure and outlet temperature of the cooling plate, can be calculated based on the heating power and the preset evaporation temperature.

[0022] Further, the calculation of the throttle valve parameters based on the temperature and pressure parameters of the refrigerant direct cooling plate includes:

[0023] Calculate the compressor operating parameters based on the temperature and pressure parameters of the refrigerant direct cooling plate;

[0024] Calculate the condenser status parameters based on the compressor operating status parameters;

[0025] The throttle valve parameters are calculated based on the condenser status parameters.

[0026] In the above implementation process, the compressor operating parameters are calculated by the temperature and pressure parameters of the refrigerant direct cooling plate, and then the condenser parameters and throttle valve parameters are calculated in sequence. The throttle valve parameters are necessary for calculating the refrigerant direct cooling plate parameters, and the thermal performance status of each air conditioning circuit component can also be obtained.

[0027] Further, the calculation of compressor operating status parameters based on the temperature and pressure state parameters of the refrigerant direct cooling plate includes:

[0028] The compressor inlet suction temperature is calculated based on the outlet temperature of the refrigerant direct cooling plate and the preset superheat.

[0029] The corresponding inhalation pressure, inhalation density, and inhalation enthalpy can be obtained by referring to a table based on the inhalation temperature.

[0030] Based on the isentropic compression of the compressor, the exhaust pressure, exhaust density, and exhaust enthalpy are calculated.

[0031] In the above process, the compressor operating parameters can be calculated from the temperature and pressure parameters of the refrigerant direct cooling plate.

[0032] Further, the step of calculating the condenser state parameters based on the compressor operating state parameters includes:

[0033] The inlet temperature of the condenser is calculated based on the compressor's discharge temperature and the preset subcooling.

[0034] The inlet pressure and inlet enthalpy are obtained by looking up a table based on the preset condensation temperature and the inlet temperature.

[0035] The outlet pressure of the condenser is calculated based on the pressure drop of the condenser and the inlet pressure.

[0036] The corresponding outlet temperature and outlet enthalpy can be obtained based on the outlet pressure.

[0037] In the above implementation process, the condenser state parameters can be obtained through the compressor operating state parameters.

[0038] Further, the calculation of the throttle valve parameters based on the condenser state parameters includes:

[0039] Based on isenthalpic expansion, the inlet pressure and inlet temperature of the throttling valve are determined by the inlet pressure and inlet temperature of the condenser;

[0040] The inlet density and inlet enthalpy are obtained by referring to a table based on the inlet pressure and inlet temperature of the throttle valve.

[0041] In the above implementation process, the throttle valve parameters can be obtained based on the condensate state parameters.

[0042] Further, the calculation of the refrigerant direct-cooling plate state parameters based on the throttle valve parameters includes:

[0043] The inlet temperature of the cold plate is calculated based on the outlet temperature of the throttle valve and the preset superheat.

[0044] The inlet pressure, inlet enthalpy, and intake density are obtained by referring to a table based on the inlet temperature of the cold plate.

[0045] The outlet enthalpy value is obtained by looking up the table based on the preset evaporation temperature and outlet temperature;

[0046] The cold plate mass flow rate is calculated using the inlet enthalpy and the outlet enthalpy, and the cold plate mass flow rate is expressed as:

[0047] m = Q / △h*3600 / 1000;

[0048] Where Q represents the battery's heating power, and Δh represents the difference between the outlet enthalpy and the inlet enthalpy.

[0049] In the above implementation process, the refrigerant direct cooling plate status parameters, such as the cold plate mass flow rate, can be obtained based on the throttle valve parameters, providing better operating data support for the design of the refrigerant direct cooling system.

[0050] This application embodiment also provides a battery refrigerant direct cooling plate state calculation device, the device comprising:

[0051] The heat generation power calculation module is used to obtain the heat generation power of the battery under the current vehicle operating conditions.

[0052] The temperature and pressure state parameter calculation module is used to calculate the state parameters of the refrigerant direct cooling plate using the heating power and the preset evaporation temperature of the refrigerant direct cooling plate.

[0053] The throttle valve parameter calculation module is used to calculate the throttle valve parameters based on the temperature and pressure state parameters of the refrigerant direct cooling plate.

[0054] The refrigerant direct cooling plate state parameter calculation module is used to calculate the refrigerant direct cooling plate state parameters based on the throttle valve parameters.

[0055] In the above implementation process, the thermodynamic state prediction of the key refrigerant direct cooling plate, as well as the thermal performance state of each air conditioning circuit component, battery heat dissipation power, and air conditioning system, can be determined in the early stage of the design of the power battery refrigerant direct cooling plate and the vehicle air conditioning system. This provides better operating data support for the design of the refrigerant direct cooling system, shortens the development cycle, and solves the problem that existing methods cannot provide better operating data support for the design of the refrigerant direct cooling system.

[0056] This application also provides a readable storage medium storing computer program instructions. When the computer program instructions are read and executed by a processor, the battery refrigerant direct cooling plate state calculation method described in any of the above-described embodiments is performed. Attached Figure Description

[0057] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 A flowchart illustrating a method for calculating the state of a direct cooling plate for battery refrigerant, provided in an embodiment of this application;

[0059] Figure 2 A schematic diagram of a refrigerant direct cooling system in parallel for a new energy vehicle battery and air conditioner, provided in an embodiment of this application;

[0060] Figure 3 A flowchart for calculating the heat generation power of a battery provided in an embodiment of this application;

[0061] Figure 4 This is a schematic diagram of battery heat generation power under current operating conditions provided in the embodiments of this application;

[0062] Figure 5 A flowchart for calculating the temperature and pressure state parameters of the refrigerant direct cooling plate provided in the embodiments of this application;

[0063] Figure 6 A flowchart for calculating throttle valve parameters provided in an embodiment of this application;

[0064] Figure 7 A flowchart for calculating compressor operating status parameters provided in this application embodiment;

[0065] Figure 8 A flowchart for calculating condenser state parameters provided in this application embodiment;

[0066] Figure 9 A flowchart illustrating the specific calculation process for the throttle valve parameters provided in this application embodiment;

[0067] Figure 10 A flowchart illustrating the calculation of refrigerant direct-cooling plate state parameters provided in an embodiment of this application;

[0068] Figure 11 A structural block diagram of the battery refrigerant direct cooling plate state calculation device provided in the embodiments of this application;

[0069] Figure 12 A structural block diagram of another battery refrigerant direct cooling plate state calculation device provided in an embodiment of this application.

[0070] icon:

[0071] 1-Compressor; 2-Condenser; 3-Cooling Fan; 4-First Expansion Valve; 5-Second Expansion Valve; 6-Battery Cooling Heat Exchanger; 7-Evaporator; 8-Temperature and Pressure Sensor; 100-Heating Power Calculation Module; 200-Temperature and Pressure Status Parameter Calculation Module; 300-Throttle Valve Parameter Calculation Module; 301-Compressor Parameter Calculation Module; 302-Condenser Parameter Calculation Module; 303-Throttle Valve Parameter Acquisition Module; 400-Refrigerant Direct Cooling Plate Status Parameter Calculation Module. Detailed Implementation

[0072] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0073] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0074] Example 1

[0075] Please refer to Figure 1 , Figure 1 A flowchart illustrating a method for calculating the state of a direct-cooling plate for battery refrigerant, provided in this application embodiment. The method specifically includes the following steps:

[0076] Step S100: Obtain the heat generation power of the battery under the current vehicle operating conditions;

[0077] Step S200: Calculate the temperature and pressure parameters of the refrigerant direct cooling plate using the heating power and the preset evaporation temperature of the refrigerant direct cooling plate;

[0078] Step S300: Calculate the throttle valve parameters based on the temperature and pressure parameters of the refrigerant direct cooling plate;

[0079] Step S400: Calculate the refrigerant direct cooling plate status parameters based on the throttle valve parameters.

[0080] like Figure 2The diagram shows a refrigerant direct cooling system in which the battery and air conditioner of a new energy vehicle are connected in parallel. The outlet of compressor 1 is connected to condenser 2, and a cooling fan 3 is installed on condenser 2. The outlet of condenser 2 is connected in parallel to evaporator 7 and battery pack. A battery cooling heat exchanger 6 is installed on the battery pack. A first expansion valve 4 is installed on the branch where evaporator 7 is located, and a second expansion valve 5 and a temperature and pressure sensor 8 are installed on the branch where battery pack is located.

[0081] The method described in this application can identify the thermal operating status of each component of the refrigerant direct cooling system connected in parallel with the battery and air conditioner through calculation and analysis before the detailed design of the refrigerant direct cooling plate and air conditioning system components. This allows for early identification of risks and early determination of key component size data, providing better operating data support for the refrigerant direct cooling system. It also eliminates the need to wait for detailed digital model design before conceptualizing the solution and building the system architecture, thus shortening the development cycle.

[0082] like Figure 3 The diagram shown is a flowchart for calculating the heat dissipation power of a battery. Specifically:

[0083] Step S100 specifically includes the following steps:

[0084] Step S101: Obtain the current spectrum of the battery under the current vehicle operating conditions;

[0085] Step S102: Calculate the battery's heat generation power based on the current spectrum. The calculation formula is as follows:

[0086] Q = I(EU) + IT*dE / dT;

[0087] Where I is the current value, U is the battery terminal voltage, E is the battery open-circuit voltage; dE / dT is the entropy coefficient; and T is the average Kelvin temperature inside the battery.

[0088] like Figure 4 The diagram shown illustrates the battery heat generation power under the current operating conditions. After determining the vehicle's operating conditions, the battery spectrum under these conditions is obtained, and then the battery heat generation power is calculated using the Bernardi formula.

[0089] like Figure 5 The diagram shown is a flowchart for calculating the temperature and pressure parameters of a refrigerant direct-cooling plate. Step S200 specifically includes the following steps:

[0090] Step S201: Obtain the corresponding evaporation pressure based on the preset evaporation temperature;

[0091] Step S202: Calculate the inlet pressure and outlet pressure of the cold plate based on the pressure drop of the refrigerant direct cooling plate and the evaporation pressure;

[0092] Excessive pressure drop in the refrigerant direct cooling plate will cause an excessive temperature difference between the inlet and outlet. The preset temperature difference is within 5℃. The pressure drop of the refrigerant direct cooling plate can be calculated based on a 5℃ temperature difference, and the target pressure drop is 50Kpa.

[0093] Step S203: The corresponding outlet temperature and outlet enthalpy can be obtained by looking up the table based on the outlet pressure of the cold plate.

[0094] The evaporation temperature of the refrigerant direct-cooling plate is an empirical value, for example, it can be set to 10℃. Then, based on the pressure drop of the cold plate, the inlet pressure of the cold plate is obtained by subtracting half of the pressure drop from the evaporation pressure, and the outlet pressure of the cold plate is obtained by adding half of the pressure drop to the evaporation pressure.

[0095] The calculation of the outlet enthalpy value here generally needs to be performed in a vaporized state, otherwise it will cause liquid slugging at the inlet of compressor 1.

[0096] like Figure 6 The diagram shown is a flowchart for calculating the parameters of a throttle valve. Step S300 specifically includes the following steps:

[0097] Step S310: Calculate the operating status parameters of compressor 1 based on the temperature and pressure status parameters of the refrigerant direct cooling plate;

[0098] Step S320: Calculate the state parameters of the condenser 2 based on the operating state parameters of the compressor 1;

[0099] Step S330: Calculate the throttle valve parameters based on the state parameters of the condenser 2.

[0100] The first expansion valve 4 and the second expansion valve 5 in the figure are both throttle valves.

[0101] like Figure 7 The diagram shown is a flowchart for calculating the operating status parameters of compressor 1. Step S310 specifically includes the following steps:

[0102] Step S311: Calculate the suction temperature at the inlet of compressor 1 based on the outlet temperature of the refrigerant direct cooling plate and the preset superheat.

[0103] Step S312: Obtain the corresponding inhalation pressure, inhalation density, and inhalation enthalpy by looking up the table based on the inhalation temperature;

[0104] Step S313: Based on the isentropic compression of compressor 1, calculate the exhaust pressure, exhaust density, and exhaust enthalpy.

[0105] The superheat value is calculated to be 2℃ based on a certain empirical value of superheat or the actual length of the return pipe. The outlet temperature of the refrigerant direct cooling plate plus 2℃ is the suction temperature of the compressor 1 inlet. The corresponding suction pressure, suction density and suction enthalpy are found by referring to the table. Based on the isentropic compression of compressor 1, the discharge pressure, discharge density and discharge enthalpy are calculated.

[0106] like Figure 8 The diagram shown is a flowchart for calculating the state parameters of condenser 2. Step S320 specifically includes the following steps:

[0107] Step S321: Calculate the inlet temperature of the condenser 2 based on the discharge temperature of the compressor 1 and the preset subcooling.

[0108] The exhaust temperature can be obtained by referring to a table based on the exhaust pressure and exhaust enthalpy of compressor 1.

[0109] Step S322: Obtain the inlet pressure and inlet enthalpy value by looking up the table based on the preset condensation temperature and the inlet temperature;

[0110] Step S323: Calculate the outlet pressure of condenser 2 based on the pressure drop of condenser 2 and the inlet pressure;

[0111] Step S324: Obtain the corresponding outlet temperature and outlet enthalpy value based on the outlet pressure.

[0112] Based on a certain empirical value of superheat or calculated from the actual length of the exhaust pipe, the subcooling value is 2℃. The exhaust temperature of compressor 1 minus 2℃ is the inlet temperature of condenser 2. The condensing temperature is set to 45℃. The inlet pressure and inlet enthalpy are obtained by referring to a table based on the condensing temperature and the inlet temperature. Then, based on the pressure drop of condenser 2, the inlet pressure of condenser 2 plus 1 / 2 of the pressure drop of condenser 2 is the outlet pressure of condenser 2. The outlet temperature and outlet enthalpy of condenser 2 are then obtained by referring to a table.

[0113] like Figure 9 The diagram shown is a flowchart illustrating the specific calculation process for the throttle valve parameters. Step S330 specifically includes the following steps:

[0114] Step S331: Based on isenthalpic expansion, determine the inlet pressure and inlet temperature of the throttling valve using the inlet pressure and inlet temperature of the condenser 2;

[0115] Step S332: Based on the inlet pressure and inlet temperature of the throttle valve, look up the table to obtain the inlet density and inlet enthalpy.

[0116] Based on isenthalpic expansion, the inlet temperature and inlet pressure of the throttle valve are the same as those of condenser 2. The difference between empirical estimation and actual measurement is not significant, and the calculation can assume that the values ​​are the same. The density before the valve and the inlet enthalpy can be obtained by referring to the table.

[0117] like Figure 10 The diagram shown is a flowchart for calculating the refrigerant direct-cooling plate state parameters. Step S400 specifically includes the following steps:

[0118] Step S401: Calculate the inlet temperature of the cold plate based on the outlet temperature of the throttle valve and the preset superheat.

[0119] A throttle valve is an isenthalpic expansion device. The outlet temperature of the throttle valve can be calculated by referring to a table based on the inlet temperature, inlet pressure, and inlet enthalpy of the throttle valve.

[0120] Step S402: Obtain the inlet pressure, inlet enthalpy, and intake density by referring to the table based on the inlet temperature of the cold plate;

[0121] Step S403: Obtain the outlet enthalpy value by looking up the table based on the preset evaporation temperature and the outlet temperature;

[0122] Step S404: Calculate the cold plate mass flow rate using the inlet enthalpy and the outlet enthalpy, wherein the cold plate mass flow rate is expressed as:

[0123] m = Q / △h*3600 / 1000;

[0124] Where Q represents the battery's heating power, and Δh represents the difference between the outlet enthalpy and the inlet enthalpy.

[0125] Based on the outlet temperature and pressure of the throttle valve, and using a certain empirical value for superheat or a value calculated based on the actual length of the suction pipe (2℃), the outlet temperature of the throttle valve plus 2℃ gives the inlet temperature of the cold plate. From the inlet temperature, the inlet pressure, inlet enthalpy, and corresponding suction density are obtained from a table; the outlet enthalpy is obtained from the evaporation temperature and outlet temperature. The enthalpy difference Δh is the difference between the outlet enthalpy and the inlet enthalpy. The mass flow rate m of the cold plate can then be calculated using the above formula.

[0126] The exhaust density of the cold plate can be calculated by referring to a table based on the outlet enthalpy and outlet temperature of the cold plate.

[0127] The mass flow rate of the cold plate needs to be determined to see if it exceeds the range provided by compressor 1, that is, whether it exceeds the capacity range of compressor 1.

[0128] The above method can be used to recalculate the next working condition.

[0129] Using this method, the performance of the parallel battery and air conditioning system can be calculated in advance before it is installed in the actual vehicle. It provides a simple, standardized and easy-to-implement method for thermodynamic calculation and state prediction of the refrigerant direct cooling system of parallel battery and air conditioning in new energy vehicles.

[0130] Using the calculation and analysis methods described in this application, the thermodynamic state of the key refrigerant direct cooling plate, the thermal performance state of each air conditioning circuit component, the battery heat dissipation power, and the heat load of the air conditioning system can be determined in the early stages of the design of the power battery refrigerant direct cooling plate and the vehicle air conditioning system.

[0131] Example 2

[0132] This application provides a battery refrigerant direct cooling plate state calculation device, such as... Figure 11 The diagram shown is a structural block diagram of a battery refrigerant direct cooling plate state calculation device, which includes, but is not limited to:

[0133] The heat generation power calculation module 100 is used to obtain the heat generation power of the battery under the current vehicle operating conditions.

[0134] The specific calculation process is as follows:

[0135] Obtain the current spectrum of the battery under the current vehicle operating conditions;

[0136] The heating power of the battery is calculated based on the current spectrum, and the calculation formula is as follows:

[0137] Q = I(EU) + IT*dE / dT;

[0138] Where I is the current value, U is the battery terminal voltage, E is the battery open-circuit voltage; dE / dT is the entropy coefficient; and T is the average Kelvin temperature inside the battery.

[0139] Temperature and pressure state parameter calculation module 200 is used to calculate the temperature and pressure state parameters of the refrigerant direct cooling plate using the heating power and the preset evaporation temperature of the refrigerant direct cooling plate.

[0140] The throttle valve parameter calculation module 300 is used to calculate the throttle valve parameters based on the temperature and pressure parameters of the refrigerant direct cooling plate.

[0141] The refrigerant direct cooling plate state parameter calculation module 400 is used to calculate the refrigerant direct cooling plate state parameters based on the throttle valve parameters.

[0142] Based on the outlet temperature and pressure of the throttle valve, and using a certain empirical value for superheat or a value calculated based on the actual length of the suction pipe (2℃), the outlet temperature of the throttle valve plus 2℃ gives the inlet temperature of the cold plate. From the inlet temperature, the inlet pressure, inlet enthalpy, and corresponding suction density are obtained from a table; the outlet enthalpy is obtained from the evaporation temperature and outlet temperature. The enthalpy difference Δh is the difference between the outlet enthalpy and the inlet enthalpy. The mass flow rate m of the cold plate can then be calculated using the above formula.

[0143] like Figure 12 The diagram shown is a structural block diagram of another battery refrigerant direct cooling plate state calculation device. The throttle valve parameter calculation module 300 may specifically include:

[0144] The compressor parameter calculation module 301 is used to calculate the operating status parameters of the compressor 1 based on the temperature and pressure status parameters of the refrigerant direct cooling plate.

[0145] The condenser parameter calculation module 302 is used to calculate the condenser 2 status parameters based on the compressor 1 operating status parameters;

[0146] The throttle valve parameter acquisition module 303 is used to calculate the throttle valve parameters based on the state parameters of the condenser 2.

[0147] The specific calculation process has been explained in detail in Example 1, and will not be repeated here.

[0148] This device can determine the thermodynamic state prediction of key refrigerant direct cooling plates, as well as the thermal performance state of each air conditioning circuit component, battery heat dissipation power, and air conditioning system heat load in the early stages of designing power battery refrigerant direct cooling plates and vehicle air conditioning systems. It provides better operational data support for the design of refrigerant direct cooling systems, shortens the development cycle, and solves the problem that existing methods cannot provide better operational data support for the design of refrigerant direct cooling systems.

[0149] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor runs the computer program to enable the electronic device to perform the battery refrigerant direct cooling plate state calculation method described in Embodiment 1.

[0150] This application also provides a readable storage medium storing computer program instructions. When the computer program instructions are read and executed by a processor, the battery refrigerant direct cooling plate state calculation method described in Embodiment 1 is performed.

[0151] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0152] In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0153] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0154] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0155] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0156] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for calculating the state of a direct cooling plate for battery refrigerant, characterized in that, The method includes: Obtain the battery's heat dissipation power under the current vehicle operating conditions; Using the heating power and the preset evaporation temperature of the refrigerant direct cooling plate, the temperature and pressure parameters of the refrigerant direct cooling plate are calculated, including: finding the corresponding evaporation pressure based on the preset evaporation temperature; calculating the inlet pressure and outlet pressure of the cold plate based on the pressure drop of the refrigerant direct cooling plate and the evaporation pressure; and obtaining the corresponding outlet temperature and outlet enthalpy value by looking up the table based on the outlet pressure of the cold plate. Based on the temperature and pressure parameters of the refrigerant direct cooling plate, the throttle valve parameters are calculated. Specifically: based on the temperature and pressure parameters of the refrigerant direct cooling plate, the compressor operating parameters are calculated, including: calculating the compressor inlet suction temperature based on the outlet temperature of the refrigerant direct cooling plate and the preset superheat; obtaining the corresponding suction pressure, suction density, and suction enthalpy from a table based on the suction temperature; calculating the discharge pressure, discharge density, and discharge enthalpy based on the compressor's isentropic compression; and calculating the condenser operating parameters based on the compressor operating parameters, specifically including: calculating the condenser operating parameters based on the compressor's discharge temperature and the preset superheat. The subcooling is used to calculate the inlet temperature of the condenser; the inlet pressure and inlet enthalpy are obtained by looking up a table based on the preset condensing temperature and the inlet temperature; the outlet pressure of the condenser is calculated based on the pressure drop of the condenser and the inlet pressure; the corresponding outlet temperature and outlet enthalpy are obtained by looking up the outlet pressure; the throttle valve parameters are calculated based on the condenser state parameters, specifically including: determining the inlet pressure and inlet temperature of the throttle valve based on isenthalpic expansion using the inlet pressure and inlet temperature of the condenser; and obtaining the inlet density and inlet enthalpy of the throttle valve by looking up a table based on the inlet pressure and inlet temperature of the throttle valve. Calculate the refrigerant direct cooling plate status parameters based on the throttle valve parameters.

2. The method for calculating the state of the direct cooling plate for battery refrigerant according to claim 1, characterized in that, The process of obtaining the battery's heat dissipation power under the current vehicle operating conditions includes: Obtain the current spectrum of the battery under the current vehicle operating conditions; The heating power of the battery is calculated based on the current spectrum, and the calculation formula is as follows: Q = I(EU) + IT*dE / dT; Where I is the current value, U is the battery terminal voltage, E is the battery open-circuit voltage; dE / dT is the entropy coefficient; and T is the average Kelvin temperature inside the battery.

3. The method for calculating the state of the direct cooling plate for battery refrigerant according to claim 1, characterized in that, The calculation of the refrigerant direct-cooling plate state parameters based on the throttle valve parameters includes: The inlet temperature of the cold plate is calculated based on the outlet temperature of the throttle valve and the preset superheat. The inlet pressure, inlet enthalpy, and intake density are obtained by referring to a table based on the inlet temperature of the cold plate. The outlet enthalpy value is obtained by referring to a table based on the preset evaporation temperature and outlet temperature; The cold plate mass flow rate is calculated using the inlet enthalpy and the outlet enthalpy, and the cold plate mass flow rate is expressed as: m = Q / △h * 3600 / 1000; Where Q represents the battery's heating power, and Δh represents the difference between the outlet enthalpy and the inlet enthalpy.

4. A battery refrigerant direct cooling plate state calculation device, characterized in that, The device includes: The heat generation power calculation module is used to obtain the heat generation power of the battery under the current vehicle operating conditions. The temperature and pressure state parameter calculation module is used to calculate the temperature and pressure state parameters of the refrigerant direct cooling plate using the heating power and the preset evaporation temperature of the refrigerant direct cooling plate. This includes: finding the corresponding evaporation pressure based on the preset evaporation temperature; calculating the inlet pressure and outlet pressure of the cold plate based on the pressure drop of the refrigerant direct cooling plate and the evaporation pressure; and obtaining the corresponding outlet temperature and outlet enthalpy value by looking up the outlet pressure in a table. The throttle valve parameter calculation module is used to calculate throttle valve parameters based on the temperature and pressure state parameters of the refrigerant direct cooling plate. Specifically, it calculates compressor operating state parameters based on the temperature and pressure state parameters of the refrigerant direct cooling plate, including: calculating the compressor inlet suction temperature based on the outlet temperature of the refrigerant direct cooling plate and the preset superheat; obtaining the corresponding suction pressure, suction density, and suction enthalpy from a table based on the suction temperature; calculating the discharge pressure, discharge density, and discharge enthalpy based on the compressor's isentropic compression; and calculating condenser state parameters based on the compressor operating state parameters, specifically including: calculating the compressor discharge... The inlet temperature of the condenser is calculated based on the temperature and a preset subcooling. The inlet pressure and enthalpy are obtained by looking up a table based on the preset condensing temperature and the inlet temperature. The outlet pressure of the condenser is calculated based on the pressure drop and the inlet pressure. The corresponding outlet temperature and enthalpy are obtained by looking up the outlet pressure. The parameters of the throttle valve are calculated based on the condenser's state parameters, specifically including: determining the inlet pressure and inlet temperature of the throttle valve based on isenthalpic expansion using the inlet pressure and inlet temperature of the condenser; and obtaining the pre-valve density and inlet enthalpy based on the inlet pressure and inlet temperature of the throttle valve. The refrigerant direct cooling plate state parameter calculation module is used to calculate the refrigerant direct cooling plate state parameters based on the throttle valve parameters.

5. A readable storage medium, characterized in that, The readable storage medium stores computer program instructions, which are read and executed by a processor to perform the battery refrigerant direct cooling plate state calculation method according to any one of claims 1 to 3.

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