A method and system for calculating the charge amount of a vehicle carbon dioxide heat pump system

Abstract

The present application relates to the technical field of carbon dioxide heat pump system, and provides a charging amount calculation method and system for a carbon dioxide heat pump system for vehicles, comprising: based on the architecture of a carbon dioxide cycle heat pump system, a carbon dioxide cycle heat pump system model is constructed; for each heat pump system operation mode, based on the environmental parameter boundary and the heat pump system operation parameter boundary, different refrigerant charging amounts are given, the carbon dioxide cycle heat pump system model is used to calculate the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature and the compressor discharge pressure, and the charging amount interval is determined; the intersection area of the charging amount intervals under all heat pump system operation modes is taken as the charging amount interval range suitable for the carbon dioxide cycle heat pump system. The best charging amount of the CO2 cycle heat pump system is obtained by means of simulation calculation, which replaces the experimental research mode and saves the project development cycle and cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of carbon dioxide heat pump systems, and particularly relates to a charging amount calculation method and system for a carbon dioxide heat pump system for vehicles. BACKGROUND

[0002] The statements in this section merely provide background information related to the application and do not necessarily constitute prior art.

[0003] At present, all automobile air conditioners are prohibited from using refrigerants with a GWP value greater than 150. With the change of automobiles from fuel power to electric power, it is inevitable for the vehicle air conditioning system to use low-GWP refrigerants, and CO2 will inevitably become a development hotspot. In particular, electric vehicles do not have the waste heat of fuel vehicles for heating in winter, and the use of air source heat pumps will be a more energy-saving and environmentally friendly choice. The transcritical CO2 heat pump air conditioning system can not only absorb environmental heat energy to realize low-temperature heating and effectively improve the endurance of the passenger car, but also can realize high-temperature refrigeration to meet the comprehensive demand for cold and heat of the air conditioning system throughout the year.

[0004] The application of transcritical CO2 cycle system in automobile air conditioning system has developed greatly in recent years. Experimental research shows that the comprehensive performance of the CO2 cycle system is greatly affected by the charging amount: if the refrigerant charging amount is insufficient, the evaporation temperature and pressure of the CO2 cycle system will decrease, the mass flow rate of the refrigerant will decrease, the refrigerant liquid in the evaporator will evaporate into gas without flowing completely, resulting in insufficient refrigerating capacity and excessive outlet superheat, thereby causing the suction and discharge temperatures of the compressor to be too high, causing the compressor to overheat and protect; if the charging amount is too much, the system evaporation pressure and discharge pressure will be too high, which will easily cause the high-pressure protection of the compressor, and may also cause liquid knock of the compressor, affecting the service life of the compressor. Through the research on the charging amount of the CO2 cycle system, there is an optimal charging amount to make the performance of the CO2 cycle system optimal.

[0005] For the research on the charging amount of the CO2 cycle air conditioning system, most of them are through the help of enthalpy difference laboratory to build system bench, and the optimal charging amount of system operation is researched through experimental test method, which can be carried out when the related air conditioning system sample maturity is high in the middle period of vehicle development project development. SUMMARY

[0006] In order to solve the technical problems in the background art, the application provides a charging amount calculation method and system for a carbon dioxide heat pump system for vehicles. Through model establishment, the system performance of different charging amounts under typical working conditions is calculated, and the intersection region is obtained, so as to obtain the optimal charging amount of the CO2 cycle heat pump system by means of simulation calculation, instead of the experimental research method, thereby saving the project development cycle and cost.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A first aspect of the present invention provides a method for calculating the charge amount of a vehicle carbon dioxide heat pump system, comprising:

[0009] Obtain the architecture, environmental parameter boundaries, heat pump system operation mode, and heat pump system operation parameter boundaries of the carbon dioxide cycle heat pump system;

[0010] Based on the architecture, a carbon dioxide circulation heat pump system model is constructed;

[0011] For each heat pump system operating mode, based on the environmental parameter boundaries and the heat pump system operating parameter boundaries, given different refrigerant charge amounts, the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature and the compressor discharge pressure are calculated using the carbon dioxide cycle heat pump system model to determine the charge amount range;

[0012] The intersection of the charging amount ranges under all heat pump system operating modes is used as the charging amount range applicable to the carbon dioxide circulation heat pump system.

[0013] Furthermore, the environmental parameters include the ambient temperature of the evaporation chamber, the relative humidity of the evaporation chamber, the ambient temperature of the condenser, and the relative humidity of the condenser.

[0014] Furthermore, the heat pump system operation mode includes a passenger compartment cooling mode;

[0015] For the passenger compartment cooling condition, the steps for determining the charging amount range include: plotting the changing trend of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature following the refrigerant charging amount, and marking the charging amount value corresponding to the intersection of the values ​​of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature as the charging starting point; plotting the changing trend of the compressor exhaust pressure following the refrigerant charging amount, and marking the charging amount value corresponding to the second section of the compressor exhaust pressure value increase as the charging end point.

[0016] Furthermore, the heat pump system operating mode includes a combined passenger compartment and battery cooling operating mode;

[0017] For the combined operating condition of passenger compartment and battery cooling, the steps for determining the charging amount range include: plotting the changing trend of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature following the refrigerant charging amount, and marking the charging amount value corresponding to the intersection of the values ​​of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature as the charging starting point; plotting the changing trend of the compressor exhaust pressure following the refrigerant charging amount, and marking the charging amount value corresponding to the second segment value increase of the compressor exhaust pressure as the charging end point.

[0018] Further, the heat pump system operation mode includes a passenger cabin heating working condition.

[0019] For the passenger cabin heating working condition, the determination of the charge amount interval includes: drawing a trend of the compressor discharge pressure following the change of the refrigerant charge amount, and marking the charge amount value corresponding to the end point of the first segment of the compressor discharge pressure value increase as the charge start point, and marking the charge amount value corresponding to the start point of the second segment of the compressor discharge pressure value increase as the charge end point.

[0020] Further, the heat pump system operation parameters include the compressor operation speed, the expansion valve opening degree, the on-off state of the cut-off valve, the air outlet mode of the air blower, the air inlet wind speed of the front air cooler, the battery cooler inlet cooling liquid temperature, and the battery cooler inlet cooling liquid flow.

[0021] Further, the architecture of the carbon dioxide cycle heat pump system includes a compressor, a liquid storage regenerator, an air conditioning box assembly, a refrigerant cut-off valve, an electronic expansion valve, an air cooler, a battery cooler, a battery heater, and a connecting pipeline.

[0022] The second aspect of the present application provides a charge amount calculation system of a vehicle carbon dioxide heat pump system, which includes:

[0023] a data acquisition module configured to acquire the architecture of the carbon dioxide cycle heat pump system, the environmental parameter boundary, the heat pump system operation mode, and the heat pump system operation parameter boundary;

[0024] a model construction module configured to construct a carbon dioxide cycle heat pump system model based on the architecture;

[0025] an interval determination module configured to, for each heat pump system operation mode, based on the environmental parameter boundary and the heat pump system operation parameter boundary, given different refrigerant charge amounts, calculate the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature, and the compressor discharge pressure through the carbon dioxide cycle heat pump system model, and determine the charge amount interval;

[0026] an intersection calculation module configured to take the intersection region of the charge amount intervals under all heat pump system operation modes as the charge amount interval range applicable to the carbon dioxide cycle heat pump system.

[0027] The third aspect of the present application provides a computer readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of a vehicle carbon dioxide heat pump system charge amount calculation method as described above.

[0028] A fourth aspect of the present invention provides a computer device comprising a computer-readable storage medium, a processor, and a computer program stored on the computer-readable storage medium and executable on the processor. When the processor executes the program, the steps of the method for calculating the filling amount of a vehicle carbon dioxide heat pump system as described above are implemented.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention can obtain the optimal filling amount of the CO2 circulating heat pump system by means of simulation calculation without the aid of a laboratory. The software model has high calculation efficiency and accuracy, and the model conforms to engineering practice, which can provide an important reference for subsequent engineering development.

[0031] The present invention can obtain the charging amount value of the CO2 circulation air-conditioning system by means of simulation calculation in the early stage of project development, replacing the experimental research method, thus saving the project development cycle and cost.

[0032] The present invention has a simple operation method, does not require the establishment of complex mathematical formulas, is easy to use, and has high work efficiency. A model is established by software to calculate the system performance of different filling volumes under typical working conditions, thereby obtaining optimal filling volume data. The software model has high calculation efficiency and accuracy, and the model conforms to engineering practice, which can provide an important reference for subsequent engineering development. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 This is a flow chart of a method for calculating the charging amount of a vehicle carbon dioxide heat pump system according to a first embodiment of the present invention;

[0035] Figure 2 This is a CO2 cycle heat pump system architecture diagram of the first embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the charging starting point under AC Mode working conditions in Example 1 of the present invention;

[0037] Figure 4 Schematic diagram of the filling endpoint under AC Mode working conditions in Example 1 of the present invention;

[0038] Figure 5 This is a schematic diagram of the filling starting point under the AC & Chiller Mode working condition of the first embodiment of the present invention;

[0039] Figure 6This is a schematic diagram of the filling endpoint under AC&Chiller Mode conditions in Example 1 of the present invention;

[0040] Figure 7 Schematic diagram of the charge amount under Hp Mode working condition in the first embodiment of the present invention;

[0041] Figure 8 1 is a schematic diagram summarizing the filling volume platform intervals under three working conditions of the first embodiment of the present invention;

[0042] Figure 9 It is a structural diagram of a computer device according to the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0044] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0045] Example 1

[0046] This embodiment provides a method for calculating the charge amount of a vehicle carbon dioxide heat pump system.

[0047] This embodiment provides a method for calculating the filling amount of a vehicle carbon dioxide heat pump system. In order to reduce project development costs and improve the project development cycle, a method for calculating the CO2 circulation heat pump system using one-dimensional calculation software is provided. The method does not require the establishment of complex mathematical formulas. A model is established through the software to calculate the optimal filling amount values ​​under different operating conditions. The operation method is simple and does not require the establishment of complex mathematical formulas. The method is simple and easy to use with high work efficiency. The model is established through the software to calculate the system performance of different filling amounts under typical operating conditions, thereby obtaining the optimal filling amount data. The software model has high calculation efficiency and accuracy, and the model conforms to engineering practice, which can provide an important reference for subsequent engineering development.

[0048] This embodiment provides a method for calculating the charge amount of a vehicle carbon dioxide heat pump system, such as Figure 1 As shown, the following steps are included:

[0049] Step 1: Determine the calculation boundary of the CO2 cycle heat pump system charging condition.

[0050] In step 1, the CO2 cycle heat pump system charging condition calculation boundary includes the environmental parameter boundary and the heat pump system operating parameters (including the heat pump system operating mode and the heat pump system operating parameter boundary).

[0051] The parameters of the environmental boundary include: 1) the ambient temperature and relative humidity of the evaporation chamber; 2) the ambient temperature and relative humidity of the condenser.

[0052] The heat pump system operating parameters include: 1) heat pump system operating mode: passenger compartment cooling condition (AC_Mode), battery cooling condition, passenger compartment + battery cooling condition (AC&Chiller_Mode), passenger compartment heating condition (Hp_Mode); 2) compressor operating speed, expansion valve opening, stop valve switch status, blower air outlet mode, front-end air cooler inlet air speed, battery cooler inlet coolant temperature, and battery cooler inlet coolant flow rate.

[0053] In this embodiment, the calculation boundary of the filling amount operating condition is artificially defined, and the boundary condition is a typical operating scenario of the automotive R744 heat pump system. Under the current operating mode, the maximum performance of the heat pump system can be exerted; in other words, it is necessary to verify the optimal filling amount platform area of ​​the system under the scenario where the heat pump system needs to exert its maximum performance.

[0054] For example, the boundary parameters for charge volume calculation are shown in Table 1.

[0055] Table 1. Schematic diagram of boundary parameters for charge volume calculation

[0056]

[0057] Step 2: Establish a CO2 cycle heat pump system model.

[0058] In step 2, a CO2 cycle heat pump system model is established, including obtaining relevant architecture parameters of the CO2 cycle heat pump system and establishing a model.

[0059] like Figure 2 As shown in the figure, the CO2 cycle heat pump system architecture typically consists of a liquid storage tank, gas cooler, shutoff valve, compressor (Edc), liquid storage regenerator (AD-IHX), air conditioning unit (HVAC), refrigerant shutoff valve (SOV), electronic expansion valve (EXV), gas cooler, battery cooler (Chiller), battery heater (LGC), and connecting piping. The HVAC unit includes the evaporator (Evap), intercooler (IGC), blower, and damper components.

[0060] As an implementation method, Figure 2As shown, the CO2 cycle heat pump system architecture is as follows: the outlet of the gas cooler is connected to the liquid storage regenerator (AD-IHX), and a PT-03 (PT is the abbreviation of the pressure and temperature sensor, and 03 is the numbering sequence of the sensor) is provided on the connecting pipe; the outlet of the liquid storage regenerator (AD-IHX) is connected to the compressor (Edc), and a PT-06 is provided on the connecting pipe; the outlet of the compressor (Edc) is connected to the first node, and a PT-01 is provided on the connecting pipe; the first node is also connected to the second refrigerant stop valve (SOV_02), the third refrigerant stop valve (SOV_03) and the fourth electronic expansion valve (EXV_4); the second refrigerant stop valve (SOV_02) is connected to the second node, and the second node is connected to the gas cooler (Gas cooler) inlet and the fifth node; the outlet of the third refrigerant stop valve (SOV_03) is connected to the intercooler (IGC) in the air conditioning box assembly (HVAC); the outlet of the intercooler (IGC) is connected to the third node, and the third node is also connected to the first refrigerant stop valve (SOV_01) and the first electronic expansion valve (EXV_1); the first refrigerant stop valve (SOV_01) is connected to the fifth node; the fifth node is connected to the second node and the sixth node, and a fifth refrigerant stop valve (SOV_05) is provided on the connecting pipeline between the fifth node and the sixth node; the first electronic expansion valve (EXV_1) is connected to the fourth node, and the outlet of the evaporator (Evap) in the air conditioning box assembly (HVAC) is connected to the fourth node; the fourth node is also connected to the fourth refrigerant stop valve (SOV_04), and the fourth refrigerant stop valve (SOV_04) is connected to the sixth node; the sixth node It is also connected to the liquid storage regenerator (AD-IHX), and a PT-02 is provided on the connecting pipeline; the sixth node is also connected to the outlet of the battery cooler (Chiller), and the inlet of the battery cooler (Chiller) is connected to the third electronic expansion valve (EXV_3); the third electronic expansion valve (EXV_3) is connected to the seventh node, and the seventh node is also connected to the fifth electronic expansion valve (EXV_5), the second electronic expansion valve (EXV_2) and the evaporator (Evap) in the air conditioning box assembly (HVAC), and a PT_04 is provided on the connecting pipeline between the seventh node and the evaporator (Evap); the second electronic expansion valve (EXV_2) is also connected to the liquid storage regenerator (AD-IHX); the inlet of the fifth electronic expansion valve (EXV_5) is connected to the battery heater (LGC); the inlet of the battery heater (LGC) is connected to the fourth electronic expansion valve (EXV_4).

[0061] The relevant architectural parameters of the CO2 cycle heat pump system include:

[0062] (1) Evaporator modeling information includes size and structure, heat transfer characteristics, and internal effective volume information;

[0063] (2) Inner-cooler modeling information contains size & structure, heat transfer characteristics, internal effective volume information;

[0064] (3) Blower modeling information is the air flow value under different calculation conditions;

[0065] (4) Liquid storage regenerator modeling information contains internal effective volume;

[0066] (5) Compressor modeling information contains displacement, volumetric efficiency characteristic information;

[0067] (6) Air-cooler modeling information contains size & structure, heat transfer characteristics, internal effective volume information;

[0068] (7) Expansion valve, stop valve modeling information contains the effective cross-sectional area of the valve;

[0069] (8) Battery cooler modeling information contains size & structure, heat transfer characteristics, internal effective volume information;

[0070] (9) Battery heater modeling information contains size & structure, heat transfer characteristics, internal effective volume information;

[0071] (10) Connection pipeline modeling information contains pipeline inner diameter, material, bend angle and curvature radius information.

[0072] Specifically, according to the CO2 cycle heat pump system charging amount calculation boundary, the commonly used commercial one-dimensional thermal management software (such as KULI / AMEsim / GT-suite / Simulink) is used to calculate the relevant parameter data output of the CO2 cycle heat pump system, and combined with the CO2 cycle heat pump system architecture, the CO2 cycle heat pump system calculation model (i.e., CO2 cycle heat pump system model) is established.

[0073] Among them, the software is a thermodynamic calculation engineering calculation software for two-phase flow, for example: Matlab / Simulink or AMEsim, KULI, GT-Suite, etc.

[0074] Step 3: According to the charging amount calculation boundary in step 1 under different working conditions (heat pump system operation mode), the charging amount of different heat pump system operation modes is given, and the suction pressure, discharge pressure, evaporator inlet and outlet refrigerant temperature of different compressors are calculated through the CO2 cycle heat pump system calculation model, and a data chart is generated to determine the charging interval.

[0075] (1) The chart under AC Mode working condition is:

[0076] ① As shown in FIG. 1, the x-axis represents the charging amount of the CO2 cycle heat pump system, and the y-axis represents the suction pressure of the compressor. Figure 3As shown in the figure, the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature follow the change trend of the refrigerant charge amount, and the charge amount value corresponding to the intersection of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature is marked as the AC Mode platform charge starting point;

[0077] ② If Figure 4 As shown, the compressor discharge pressure follows the changing trend of the refrigerant charge, and the charge value corresponding to the starting point of the second segment of the compressor discharge pressure value increase is marked as the AC Mode platform charge end point.

[0078] (2) Graph under AC&ChillerMode operating condition (combined operating condition of passenger compartment and battery cooling):

[0079] like Figure 5 and Figure 6 As shown, it is equivalent to the AC Mode operating condition chart, and the AC&ChillerMode platform charging starting point and AC&ChillerMode platform charging end point are marked simultaneously.

[0080] That is, for the combined operating condition of passenger compartment and battery cooling, the steps for determining the charging amount range include: plotting the changing trends of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature following the refrigerant charging amount, and marking the charging amount value corresponding to the intersection of the values ​​of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature as the charging starting point; plotting the changing trend of the compressor exhaust pressure following the refrigerant charging amount, and marking the charging amount value corresponding to the starting point of the second segment value increase of the compressor exhaust pressure as the charging end point.

[0081] (3) The chart under HP Mode is:

[0082] like Figure 7 As shown, a graph of the compressor exhaust pressure following the change of refrigerant charge is shown, and the charge value corresponding to the point where the compressor exhaust pressure stops increasing following the change of charge is marked as the HP Mode platform charging starting point, and the charge value corresponding to the point where the compressor exhaust pressure starts to increase after following the change of charge is marked as the HP Mode platform charging end point.

[0083] That is, for the passenger compartment heating condition, the steps for determining the filling amount range include: plotting the changing trend of the compressor exhaust pressure following the refrigerant filling amount, and marking the filling amount value corresponding to the end point of the first segment of the compressor exhaust pressure value increase as the filling starting point, and marking the filling amount value corresponding to the starting point of the second segment of the compressor exhaust pressure value increase as the filling end point.

[0084] Step 4: Based on the relevant parameter data in step 3, analyze and obtain the optimal filling volume result.

[0085] In step 4, according to the data output in step 3, the running state of the CO2 circulation heat pump system under different working conditions and different charging amounts is analyzed, and the optimal charging amount value is obtained.

[0086] As shown in Figure 7 According to the relevant parameter data in step 3, the charging amount values corresponding to the charging platform starting points and ending points under different calculation working conditions are summarized, and the intersection section of the platform charging intervals under three working conditions is found, that is, the charging amount interval range suitable for the heat pump system.

[0087] The charging amount calculation method of the vehicle CO2 heat pump system provided in the embodiment can obtain the optimal charging amount of the CO2 circulation heat pump system by simulation calculation without the aid of a laboratory. The software model has high calculation efficiency and accuracy, and the model conforms to the engineering practice, which can provide important reference for subsequent engineering development.

[0088] The charging amount calculation method of the vehicle CO2 heat pump system provided in the embodiment can obtain the charging amount value of the CO2 circulation air conditioning system in the early stage of project development through simulation calculation, replacing the experimental research method, and saving the project development cycle and cost.

[0089] The charging amount calculation method of the vehicle CO2 heat pump system provided in the embodiment has simple operation method, does not need to establish complex mathematical formula, is simple and easy to use, and has high working efficiency. The optimal charging amount data is obtained by establishing a model through software, and calculating the system performance under different charging amounts under typical working conditions. The software model has high calculation efficiency and accuracy, and the model conforms to the engineering practice, which can provide important reference for subsequent engineering development.

[0090] Embodiment Two

[0091] The embodiment provides a charging amount calculation system of a vehicle CO2 heat pump system.

[0092] The charging amount calculation system of the vehicle CO2 heat pump system provided in the embodiment specifically comprises:

[0093] The data acquisition module is configured to acquire the architecture of the CO2 circulation heat pump system, the environmental parameter boundary, the heat pump system running mode and the heat pump system running parameter boundary;

[0094] The model construction module is configured to construct a CO2 circulation heat pump system model based on the architecture;

[0095] an interval determination module configured to: for each heat pump system operating mode, based on the environmental parameter boundary and the heat pump system operating parameter boundary, and given different refrigerant charge amounts, calculate the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature, and the compressor discharge pressure using the carbon dioxide cycle heat pump system model to determine the charge amount interval;

[0096] The intersection calculation module is configured to use the intersection area of ​​the charging amount intervals under all heat pump system operation modes as the charging amount interval range suitable for the carbon dioxide circulation heat pump system.

[0097] It should be noted here that the various modules in this embodiment correspond one-to-one to the various steps in Example 1, and the specific implementation processes are the same, which will not be repeated here.

[0098] Example 3

[0099] This embodiment provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the steps of the method for calculating the charging amount of a vehicle carbon dioxide heat pump system as described in the first embodiment are implemented.

[0100] Example 4

[0101] This embodiment provides a computer device, such as Figure 9 As shown, the system includes a computer-readable storage medium 1003, a processor 1001, a communication interface 1002, and a computer program stored on the computer-readable storage medium 1003 and executable on the processor 1001. The processor 1001, the communication interface 1002, and the computer-readable storage medium 1003 may be connected via a bus or other means. The communication interface 1002 is configured to receive and transmit data, and when the processor 1001 executes the program, the steps of the method for calculating the charge amount of a vehicle carbon dioxide heat pump system as described in the first embodiment are implemented.

[0102] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0103] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0104] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0105] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for calculating the charge amount of a vehicle carbon dioxide heat pump system, characterized in that: include: Obtain the architecture, environmental parameter boundaries, heat pump system operation mode, and heat pump system operation parameter boundaries of the carbon dioxide cycle heat pump system; Based on the architecture, a carbon dioxide cycle heat pump system model is constructed; For each heat pump system operating mode, based on the environmental parameter boundaries and the heat pump system operating parameter boundaries, given different refrigerant charge amounts, the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature and the compressor discharge pressure are calculated using the carbon dioxide cycle heat pump system model to determine the charge amount range; The intersection of the charging amount ranges under all heat pump system operating modes is used as the charging amount range applicable to the carbon dioxide circulation heat pump system.

2. The method for calculating the charge amount of a vehicle carbon dioxide heat pump system according to claim 1, wherein: The environmental parameters include the ambient temperature of the evaporation chamber, the relative humidity of the evaporation chamber, the ambient temperature of the condenser, and the relative humidity of the condenser.

3. The method for calculating the charge amount of a vehicle carbon dioxide heat pump system according to claim 1, wherein: The heat pump system operation mode includes a passenger compartment cooling mode; For the passenger compartment cooling condition, the step of determining the charge amount interval includes: plotting the changing trends of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature along with the refrigerant charge amount, and marking the charge amount value corresponding to the intersection of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature as the charge starting point; The changing trend of the compressor exhaust pressure following the refrigerant charge is plotted, and the charge value corresponding to the second increase in the compressor exhaust pressure value is marked as the charging end point.

4. The method for calculating the charge amount of a vehicle carbon dioxide heat pump system according to claim 1, wherein: The heat pump system operating mode includes a combined passenger compartment and battery cooling mode; For the combined operating condition of passenger compartment and battery cooling, the steps for determining the charging amount range include: plotting the changing trend of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature following the refrigerant charging amount, and marking the charging amount value corresponding to the intersection of the values ​​of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature as the charging starting point; plotting the changing trend of the compressor exhaust pressure following the refrigerant charging amount, and marking the charging amount value corresponding to the second segment value increase of the compressor exhaust pressure as the charging end point.

5. The method for calculating the charge amount of a vehicle carbon dioxide heat pump system according to claim 1, wherein: The heat pump system operation mode includes a passenger compartment heating operation mode; For the passenger compartment heating condition, the step of determining the filling amount range includes: plotting the changing trend of the compressor exhaust pressure following the refrigerant filling amount, and marking the filling amount value corresponding to the end point of the first segment value increase of the compressor exhaust pressure as the filling starting point, and marking the filling amount value corresponding to the starting point of the second segment value increase of the compressor exhaust pressure as the filling end point.

6. The method for calculating the charge amount of a vehicle carbon dioxide heat pump system according to claim 1, wherein: The operating parameters of the heat pump system include the compressor operating speed, expansion valve opening, stop valve switch status, blower air outlet mode, front-end air cooler inlet air speed, battery cooler inlet coolant temperature and battery cooler inlet coolant flow.

7. The method for calculating the charge amount of a vehicle carbon dioxide heat pump system according to claim 1, wherein: The architecture of the carbon dioxide circulation heat pump system includes a compressor, a liquid storage regenerator, an air conditioning box assembly, a refrigerant shut-off valve, an electronic expansion valve, an air cooler, a battery cooler, a battery heater, and connecting pipes.

8. A charging amount calculation system for a vehicle carbon dioxide heat pump system, characterized in that: include: A data acquisition module is configured to: acquire the architecture, environmental parameter boundaries, heat pump system operation mode, and heat pump system operation parameter boundaries of the carbon dioxide cycle heat pump system; A model building module is configured to: build a carbon dioxide cycle heat pump system model based on the architecture; an interval determination module configured to: for each heat pump system operating mode, based on the environmental parameter boundary and the heat pump system operating parameter boundary, and given different refrigerant charge amounts, calculate the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature, and the compressor discharge pressure using the carbon dioxide cycle heat pump system model to determine the charge amount interval; The intersection calculation module is configured to use the intersection area of ​​the charging amount intervals under all heat pump system operation modes as the charging amount interval range suitable for the carbon dioxide circulation heat pump system.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method for calculating the charging amount of a vehicle carbon dioxide heat pump system according to any one of claims 1 to 7 are implemented.

10. A computer device comprising a computer-readable storage medium, a processor, and a computer program stored on the computer-readable storage medium and executable on the processor, wherein: When the processor executes the program, the steps of the method for calculating the charging amount of a vehicle carbon dioxide heat pump system according to any one of claims 1 to 7 are implemented.

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