Charging quantity calculation method and system for vehicle carbon dioxide heat pump system

Abstract

The invention relates to the technical field of carbon dioxide heat pump systems, and provides a method and system for calculating the charge quantity of a vehicle carbon dioxide heat pump system, and the method comprises the steps: building a carbon dioxide circulation heat pump system model based on the architecture of the carbon dioxide circulation heat pump system; for each heat pump system operation mode, different refrigerant charge amounts are given based on the environment parameter boundary and the heat pump system operation parameter boundary, the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature and the compressor exhaust pressure are calculated through the carbon dioxide cycle heat pump system model, and the charge amount interval is determined; and the intersection area of the charge amount intervals in all the heat pump system operation modes serves as the charge amount interval range suitable for the carbon dioxide circulation heat pump system. The optimal charge quantity of the CO2 circulating heat pump system is obtained by means of simulation calculation, an experimental research mode is replaced, and the project development period and cost are saved.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon dioxide heat pump systems, and in particular relates to a method and system for calculating the filling amount of a vehicle carbon dioxide heat pump system. Background Art

[0002] The statements in this section merely provide background information related to the present invention 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. As cars are transformed from fuel-powered to electric-powered, it is an inevitable trend for on-board air conditioning systems to use low-GWP refrigerants, and CO2 is bound to become a hot spot for development. 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. Transcritical CO2 heat pump air conditioning systems can absorb environmental heat energy to achieve low-temperature heating, effectively improving the endurance of buses, and can also achieve high-temperature cooling, meeting the comprehensive cooling and heating needs of air conditioning systems throughout the year.

[0004] The application of transcritical CO2 circulation system in automobile air conditioning system has made great progress in recent years. Experimental research shows that the comprehensive performance of CO2 circulation system is greatly affected by the filling amount: if the refrigerant filling amount is insufficient, the evaporation temperature and evaporation pressure of CO2 circulation system will decrease, the mass flow rate of refrigerant will decrease, and the refrigerant liquid in the evaporator will evaporate into gas before it flows through the whole process, resulting in insufficient cooling capacity and excessive outlet superheat, which will lead to excessive suction and exhaust temperature of compressor and cause overheat protection of compressor; if the filling amount is too much, the evaporation pressure and exhaust pressure of the system will be too high, which will easily cause high pressure protection of compressor, and may also cause liquid hammer of compressor and affect the life of compressor. Through the research on the filling amount of CO2 circulation system, there is an optimal filling amount to make the performance of CO2 circulation system optimal.

[0005] For the research on the filling amount of CO2 cycle air-conditioning system, most of them are done by building a system bench with the help of enthalpy difference laboratory, and then studying the optimal filling amount for system operation through experimental testing. Generally, the research can only be carried out in the middle stage of vehicle model project development when the relevant air-conditioning system samples are more mature. Summary of the invention

[0006] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a method and system for calculating the filling amount of a vehicle carbon dioxide heat pump system. After establishing a model and calculating the system performance of different filling amounts under typical working conditions, the intersection area is obtained to obtain the optimal filling amount of the CO2 cycle heat pump system by means of simulation calculation, thereby replacing the experimental research method and saving project development cycle and cost.

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

[0008] A first aspect of the present invention provides a method for calculating the charging 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 cycle heat pump system model is constructed;

[0011] For each heat pump system operation mode, based on the environmental parameter boundary and the heat pump system operation parameter boundary, given different refrigerant charging amounts, the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature and the compressor exhaust pressure are calculated through the carbon dioxide cycle heat pump system model to determine the charging amount range;

[0012] The intersection area of ​​the charging amount ranges under all the heat pump system operation 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] Further, the heat pump system operation mode includes a passenger compartment cooling condition;

[0015] For the passenger compartment cooling condition, the step of determining the charging amount interval includes: 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 value increase of the compressor exhaust pressure as the charging end point.

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

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

[0018] Further, the heat pump system operation mode includes a passenger compartment heating condition;

[0019] 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.

[0020] Furthermore, the operating parameters of the heat pump system include the operating speed of the compressor, the opening of the expansion valve, the switch state of the stop valve, the blower air outlet mode, the inlet wind speed of the front-end air cooler, the inlet coolant temperature of the battery cooler and the inlet coolant flow rate of the battery cooler.

[0021] Furthermore, 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.

[0022] A second aspect of the present invention provides a charging amount calculation system for a vehicle carbon dioxide heat pump system, comprising:

[0023] 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;

[0024] A model building module is configured to: build a carbon dioxide cycle heat pump system model based on the architecture;

[0025] The interval determination module is 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 charging amounts, calculate the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature and the compressor exhaust pressure through the carbon dioxide cycle heat pump system model, and determine the charging amount interval;

[0026] 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.

[0027] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the above-mentioned method for calculating the charging amount of a vehicle carbon dioxide heat pump system.

[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, wherein when the processor executes the program, the steps in 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 circulation 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 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 invention has a simple operation method, does not require the establishment of complex mathematical formulas, is easy to use, and has high working 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, and can provide an important reference for subsequent engineering development. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings in the specification, 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 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 Schematic diagram of the charging starting point under AC Mode working condition of the first embodiment of the present invention;

[0037] Figure 4 1 is a schematic diagram of the filling end point under AC Mode working condition of the first embodiment 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 61 is a schematic diagram of the filling end point under the AC&Chiller Mode working condition of the first embodiment of the present invention;

[0040] Figure 7 is a schematic diagram of the filling amount under the Hp Mode working condition of 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] Fig. 9 It is a structural diagram of a computer device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0043] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

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

[0045] Embodiment 1

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

[0047] The present 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 development cycle of a project, a method for calculating a CO2 cycle heat pump system is provided by one-dimensional calculation software. There is no need to establish complex mathematical formulas. A model is established by the software to calculate the optimal filling amount values ​​under different working 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 by the software to calculate the system performance of different filling amounts under typical working conditions, thereby obtaining the optimal filling amount data. The software model has high calculation efficiency and accuracy, and the model conforms to the actual project, which can provide an important reference for subsequent project development.

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

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

[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 operating parameters of the heat pump system 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 wind speed, battery cooler inlet coolant temperature, battery cooler inlet coolant flow.

[0053] In this embodiment, the calculation boundary of the filling amount condition is artificially defined, and the boundary condition is a typical working scenario of the automotive R744 heat pump system. Under the current working 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 filling volume calculation boundary parameters 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 included in 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 is usually composed of a liquid storage tank, a gas cooler, a stop valve, a compressor (Edc), a liquid storage regenerator (AD-IHX), an air conditioning box assembly (HVAC), a refrigerant stop valve (SOV), an electronic expansion valve (EXV), a gas cooler (Gas cooler), a battery cooler (Chiller), a battery heater (LGC), and connecting pipes. Among them, the air conditioning box assembly (HVAC) includes: an evaporator (Evap), an internal cooler (IGC), a blower (Blower), and damper structural 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 (Pressure) and temperature (temperature) sensor, and 03 is the numbering sequence of the sensor) is arranged on the connecting pipeline; the outlet of the liquid storage regenerator (AD-IHX) is connected to the compressor (Edc), and a PT-06 is arranged on the connecting pipeline; the outlet of the compressor (Edc) is connected to the first node, and a PT-01 is arranged on the connecting pipeline; 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 PT-02 is arranged 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 PT_04 is arranged 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 architecture parameters of the CO2 cycle heat pump system include:

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

[0063] (2) The modeling information of the internal cooler includes size & structure, heat transfer characteristics, and internal effective volume information;

[0064] (3) The blower modeling information is the air volume value under different calculation conditions;

[0065] (4) The modeling information of the liquid storage regenerator includes the internal effective volume;

[0066] (5) Compressor modeling information includes displacement and volumetric efficiency characteristics;

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

[0068] (7) The modeling information of expansion valves and stop valves includes the effective cross-sectional area of ​​the valves;

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

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

[0071] (10) The connection pipeline modeling information includes the pipeline inner diameter, material, bend angle and curvature radius information.

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

[0073] 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 filling amount calculation boundary under different working conditions (heat pump system operation mode) in step 1, given the filling amount of different heat pump system operation modes, the suction and exhaust pressures of different compressors, the evaporator inlet and outlet refrigerant temperatures are calculated and output through the CO2 cycle heat pump system calculation model, and a data chart is generated to determine the filling range.

[0075] (1) The graph under AC Mode is as follows:

[0076] ① Such as Figure 3As shown, 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 exhaust pressure correlation follows the changing trend of the refrigerant charge amount, and the charge amount value corresponding to the starting point of the second segment value increase of the compressor exhaust pressure is marked as the AC Mode platform charge end point.

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

[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&Chiller Mode platform charging end point are simultaneously marked.

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

[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 amount value corresponding to the point where the compressor exhaust pressure stops increasing following the change of charge amount is marked as the HP Mode platform charging starting point, and the charge amount value corresponding to the point where the compressor exhaust pressure starts to increase after following the change of charge amount is marked as the HP Mode platform charging end point.

[0083] That is, for the heating condition of the passenger compartment, 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 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.

[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 calculated and output in step 3, the operating state of the CO2 cycle heat pump system under different working conditions and different filling amounts is analyzed, and the optimal filling amount value is analyzed.

[0086] like Figure 7 As shown, according to the relevant parameter data in step 3, the filling volume values ​​corresponding to the starting point and end point of the filling platform under different calculation conditions are summarized, and the intersection area of ​​the platform filling interval segments applicable to the three conditions is found, which is the filling volume interval range applicable to this heat pump system.

[0087] The present embodiment provides a method for calculating the filling amount of a vehicle carbon dioxide heat pump system. The method can obtain the optimal filling amount of the CO2 cycle 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, and can provide an important reference for subsequent engineering development.

[0088] The present embodiment provides a method for calculating the filling amount of a vehicle carbon dioxide heat pump system, which can obtain the filling amount value of the CO2 cycle air-conditioning system by simulation calculation in the early stage of project development, replacing the experimental research method, saving project development cycle and cost.

[0089] The present embodiment provides a method for calculating the filling amount of a vehicle carbon dioxide heat pump system. The method of operation is simple, 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 amounts under typical working conditions, thereby obtaining the optimal filling amount data. The software model has high calculation efficiency and accuracy, and the model conforms to engineering practice, and can provide an important reference for subsequent engineering development.

[0090] Embodiment 2

[0091] This embodiment provides a charging amount calculation system for a vehicle carbon dioxide heat pump system.

[0092] The present embodiment provides a charging amount calculation system for a vehicle carbon dioxide heat pump system, which specifically includes:

[0093] 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;

[0094] A model building module is configured to: build a carbon dioxide cycle heat pump system model based on the architecture;

[0095] The interval determination module is 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 charging amounts, calculate the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature and the compressor exhaust pressure through the carbon dioxide cycle heat pump system model, and determine the charging 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 each module in this embodiment corresponds to each step in Example 1 one by one, and the specific implementation process is the same, which will not be repeated here.

[0098] Embodiment 3

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

[0100] Embodiment 4

[0101] This embodiment provides a computer device, such as Fig. 9 As shown, it 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, wherein the processor 1001, the communication interface 1002, and the computer-readable storage medium 1003 can be connected via a bus or other means. The communication interface 1002 is used to receive and send data, and when the processor 1001 executes the program, the steps in the method for calculating the charging 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 flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, 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 flowchart and / or block diagram. 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 capable of directing a computer or other programmable data processing device to operate 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 A 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 operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0105] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for calculating the charging 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 operation mode, based on the environmental parameter boundary and the heat pump system operation parameter boundary, given different refrigerant charging amounts, the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature and the compressor exhaust pressure are calculated through the carbon dioxide cycle heat pump system model to determine the charging amount range; The intersection area of ​​the charging amount ranges under all the heat pump system operation modes is used as the charging amount range applicable to the carbon dioxide circulation heat pump system.

2. The method for calculating the charging amount of a vehicle carbon dioxide heat pump system according to claim 1, characterized in that: 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 charging amount of a vehicle carbon dioxide heat pump system according to claim 1, characterized in that: The heat pump system operation mode includes a passenger compartment cooling condition; For the passenger compartment cooling condition, the step of determining the charging amount interval includes: 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 point of the values ​​of the evaporator inlet refrigerant temperature and the evaporator outlet refrigerant temperature as the charging starting point; Plot the changing trend of the compressor exhaust pressure following the refrigerant charge amount, and mark the charge amount value corresponding to the second section of the compressor exhaust pressure increase as the charging end point.

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

5. The method for calculating the charging amount of a vehicle carbon dioxide heat pump system according to claim 1, characterized in that: The heat pump system operation mode includes a passenger compartment heating condition; 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 charging amount of a vehicle carbon dioxide heat pump system according to claim 1, characterized in that: The operating parameters of the heat pump system include the operating speed of the compressor, the opening of the expansion valve, the switch state of the stop valve, the blower air outlet mode, the inlet wind speed of the front-end air cooler, the inlet coolant temperature of the battery cooler and the inlet coolant flow rate of the battery cooler.

7. A method for calculating the charging amount of a vehicle carbon dioxide heat pump system according to claim 1, characterized in that: 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; The interval determination module is 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 charging amounts, calculate the evaporator inlet refrigerant temperature, the evaporator outlet refrigerant temperature and the compressor exhaust pressure through the carbon dioxide cycle heat pump system model, and determine the charging 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 in the method for calculating the charging amount of a vehicle carbon dioxide heat pump system as described in 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 in the computer-readable storage medium and executable on the processor, characterized in that: When the processor executes the program, the steps in 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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