Control method and equipment for refrigerant valve in whole vehicle thermal management system and storage medium

Abstract

The embodiment of the invention discloses a control method and device for a refrigerant valve in a whole vehicle thermal management system and a storage medium. The method comprises the steps that the working mode of the whole vehicle thermal management system is determined; according to the working mode, a control strategy corresponding to each refrigerant valve in the working mode is determined; and the opening degree of each refrigerant valve is controlled based on the corresponding control strategy of each refrigerant valve in the working mode. By the adoption of the method, the whole vehicle thermal management system can be switched to different control schemes according to different working modes so as to be matched with various complex working conditions, the working efficiency and the energy efficiency ratio of the whole vehicle thermal management system are effectively improved, and unnecessary energy waste is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle thermal management systems, and in particular to a control method, device and storage medium for a refrigerant valve in a whole vehicle thermal management system. Background Art

[0002] The vehicle thermal management system of electric vehicles is responsible for controlling and regulating the temperature inside the entire vehicle, including the temperature control and regulation of components or areas such as the battery pack, motor and electronic control system, and passenger compartment of the electric vehicle. By coordinating and controlling the vehicle thermal management system, it can ensure that electric vehicles can operate within a suitable temperature range under various working conditions, thereby improving the performance, safety, and comfort of electric vehicles.

[0003] The refrigerant valve is an important part of the thermal management system, and its control accuracy greatly affects the thermal energy utilization rate of the thermal management system. Existing thermal management systems are usually individually controlled based on the real-time temperature of the component outlet corresponding to the location of each refrigerant valve and the preset linear relationship. This control method is relatively simple and does not take into account various complex working conditions. The opening control accuracy of the refrigerant valve is low, which makes the thermal energy utilization rate of the vehicle thermal management system low. Summary of the invention

[0004] The embodiments of the present invention aim to provide a control method, device and storage medium for a refrigerant valve in a vehicle thermal management system, so as to solve the problem that the control method of the refrigerant valve in the prior art is single and cannot match various complex working conditions, resulting in low thermal energy utilization rate of the vehicle thermal management system.

[0005] To solve the above technical problems, the embodiments of the present invention provide the following technical solutions:

[0006] According to one aspect of the present invention, a control method for a refrigerant valve in a vehicle thermal management system is provided, wherein each refrigerant valve in the vehicle thermal management system corresponds to at least one control strategy, and each control strategy corresponds to one or more working modes of the vehicle thermal management system. The method comprises:

[0007] Determining an operating mode of the vehicle thermal management system;

[0008] According to the working mode, determining the control strategies corresponding to each refrigerant valve in the working mode;

[0009] The opening of each refrigerant valve is controlled based on the control strategy corresponding to each refrigerant valve in the working mode.

[0010] Optionally, the first control strategy of each refrigerant valve is: determining a target opening position of each refrigerant valve according to the working mode.

[0011] Optionally, other control strategies for each refrigerant valve include:

[0012] The state parameter obtained in the vehicle thermal management system is compared with the threshold range of the state parameter. If the state parameter is within the threshold range of the state parameter, the corresponding refrigerant valve is controlled to maintain the opening; if the state parameter exceeds the threshold range of the state parameter, the corresponding refrigerant valve is controlled to increase or decrease the opening so that the state parameter is within the threshold range of the state parameter.

[0013] Optionally, each refrigerant valve corresponds to a preset limited opening range, and controlling the corresponding refrigerant valve to increase or decrease the opening so that the state parameter is within the threshold range of the state parameter includes:

[0014] The corresponding refrigerant valve is controlled to increase or decrease its opening within the limited opening range so that the state parameter is within the threshold range of the state parameter.

[0015] Optionally, the vehicle thermal management system includes a first refrigerant valve leading to the evaporator inlet, and the second control strategy of the first refrigerant valve is:

[0016] Determine whether the actual superheat at the evaporator outlet is greater than the preset maximum limit of the superheat at the evaporator outlet;

[0017] If yes, controlling the first refrigerant valve to increase its opening so that the actual superheat at the evaporator outlet is less than or equal to the maximum limit of the superheat at the evaporator outlet;

[0018] If not, the first subcooling range corresponding to the first refrigerant valve is determined according to the internal and external circulation status of the vehicle thermal management system and the current air volume gear, and according to the actual subcooling at the condenser outlet and the first subcooling range, the first refrigerant valve is controlled to increase, decrease or maintain the opening so that the actual subcooling at the condenser outlet is within the first subcooling range.

[0019] Optionally, the third control strategy of the first refrigerant valve is:

[0020] Determine whether the actual superheat at the evaporator outlet is greater than the preset maximum limit of the superheat at the evaporator outlet;

[0021] If yes, controlling the first refrigerant valve to increase its opening so that the actual superheat at the evaporator outlet is less than or equal to the maximum limit of the superheat at the evaporator outlet;

[0022] If not, obtain the current ambient temperature, the target set temperature and the target air volume level, and determine the target opening position of the first refrigerant valve according to the current ambient temperature, the target set temperature, the target air volume level and a preset first opening lookup table.

[0023] Optionally, the vehicle thermal management system includes a second refrigerant valve leading to a CHILLER inlet, and a second control strategy of the second refrigerant valve is:

[0024] determining a second subcooling interval corresponding to the second refrigerant valve according to the operating state of the compressor;

[0025] According to the actual subcooling degree at the condenser outlet and the second subcooling degree range, the second refrigerant valve is controlled to increase, decrease or maintain its opening so that the actual subcooling degree at the condenser outlet is within the second subcooling degree range.

[0026] Optionally, the third control strategy of the second refrigerant valve is:

[0027] Determine whether the actual superheat at the CHILLER outlet is greater than the preset maximum limit of the CHILLER outlet superheat;

[0028] If yes, control the second refrigerant valve to increase its opening so that the actual superheat at the CHILLER outlet is less than or equal to the maximum limit of the superheat at the CHILLER outlet;

[0029] If not, redetermine the restricted opening range of the second refrigerant valve according to the battery water inlet temperature and the evaporator outlet temperature, and determine whether the current opening of the second refrigerant valve is within the restricted opening range; if so, calculate the battery temperature difference between the battery water inlet temperature and the preset battery target temperature; based on the battery temperature difference and the preset battery temperature difference target range, control the second refrigerant valve to increase, decrease or maintain the opening within the restricted opening range so that the battery temperature difference is within the battery temperature difference target range; if not, when the current opening of the second refrigerant valve is greater than the upper limit value of the restricted opening range, determine the target opening position of the second refrigerant valve to be the upper limit value of the restricted opening range; when the current opening of the second refrigerant valve is less than the lower limit value of the restricted opening range, determine the target opening position of the second refrigerant valve to be the lower limit value of the restricted opening range.

[0030] Optionally, according to the battery temperature difference value and a preset battery temperature difference target range, controlling the second refrigerant valve to increase, decrease or maintain the opening in the restricted opening range so that the battery temperature difference value is within the battery temperature difference target range includes:

[0031] Determining whether the battery temperature difference value is greater than an upper limit value of the battery temperature difference target range;

[0032] If yes, controlling the second refrigerant valve to increase its opening within the limited opening range so that the battery temperature difference value is less than or equal to the upper limit value of the battery temperature difference target range;

[0033] If not, determine whether the battery temperature difference value is less than the lower limit value of the battery temperature difference target range. If so, control the second refrigerant valve to reduce the opening in the limited opening range so that the battery temperature difference value is greater than or equal to the lower limit value of the battery temperature difference target range. If not, control the second refrigerant valve to maintain the current opening.

[0034] Optionally, the vehicle thermal management system includes a third refrigerant valve leading to the condenser inlet, and the second control strategy of the third refrigerant valve is:

[0035] Get the current ambient temperature, target set temperature and target air volume level;

[0036] The target opening position of the third refrigerant valve is determined according to the current ambient temperature, the target set temperature, the target air volume gear and a preset second opening lookup table.

[0037] Optionally, before comparing the state parameter obtained in the vehicle thermal management system with the threshold range of the state parameter, the method further includes:

[0038] The initial opening position of each refrigerant valve is determined according to the rotation speed of the compressor.

[0039] According to another aspect of the present invention, a computer device is provided, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of any one of the above methods when executing the computer program.

[0040] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the processor executes the steps of implementing any one of the methods described above.

[0041] The beneficial effects of the embodiments of the present invention are as follows: Different from the prior art, in the embodiments of the present invention, a control method for the refrigerant valve in the thermal management system of a whole vehicle is provided. First, each refrigerant valve in the thermal management system of the whole vehicle corresponds to at least one control strategy, and each control strategy corresponds to one or more working modes of the thermal management system of the whole vehicle; secondly, the working mode of the thermal management system of the whole vehicle is determined, and according to the working mode, the control strategy of each refrigerant valve in the thermal management system of the whole vehicle under the working mode is determined, and the opening of each refrigerant valve is controlled based on the control strategy of each refrigerant valve under the working mode. By adopting the method of the present invention, the thermal management system of the whole vehicle can switch to different control schemes according to different working modes to match various complex working conditions, effectively improving the working efficiency and energy efficiency ratio of the thermal management system of the whole vehicle, and reducing unnecessary energy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0043] Figure 1 It is a structural schematic diagram of a vehicle thermal management system provided by the present invention;

[0044] Figure 2 It is a flow chart of a control method of a refrigerant valve in a vehicle thermal management system provided by the present invention;

[0045] Figure 3 It is a specific flow chart of the second control strategy of the first refrigerant valve provided by the present invention;

[0046] Figure 4 is a specific flow chart of the second control strategy for the second refrigerant valve provided by the present invention;

[0047] Figure 5 is a specific flow chart of the third control strategy of the second refrigerant valve provided by the present invention;

[0048] Figure 6 It is a schematic diagram of the system cycle of the vehicle thermal management system provided by the present invention in the passenger compartment heating mode;

[0049] Figure 7 It is a schematic diagram of the system cycle of the vehicle thermal management system provided by the present invention in the passenger compartment cooling + motor cooling mode;

[0050] Figure 8 It is a structural schematic diagram of a computer device provided by the present invention. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0054] See also Figure 1 , is a schematic diagram of the structure of a vehicle thermal management system provided by the present invention. The vehicle thermal management system includes a refrigerant circuit, a battery coolant circuit and a motor coolant circuit.

[0055] Among them, the refrigerant circuit is composed of gas-liquid separator ACCU, third temperature and pressure sensor PT3, compressor COMP, first temperature and pressure sensor PT1, water-cooled condenser LCC, second temperature and pressure sensor PT2, third refrigerant valve CONDEXV, high-pressure safety valve HP SV, condenser CONDENSER, first refrigerant temperature sensor R-T1, first refrigerant valve EVAPEXV, evaporator EVAP, third refrigerant temperature sensor R-T3, one-way valve CV, low-pressure safety valve LPSV, second refrigerant valve CHILLEREXV, CHILLER and second refrigerant temperature sensor R-T2 and other components.

[0056] The battery coolant circuit is composed of components such as a battery BATTERY, a second water temperature sensor T2, a first water pump PUMP1, a first five-way valve 5WV1, a CHILLER, a second five-way valve 5WV2 and a third water temperature sensor T3.

[0057] The motor coolant circuit is composed of the motor MOTOR, the radiator water tank RAD, the first five-way valve 5WV1, the second water pump PUMP2, the water-cooled condenser LCC, the heater PTC, the heat exchanger HEATER, the first water temperature sensor T1, the second five-way valve 5WV2 and the fourth water temperature sensor T4 and other components.

[0058] In the embodiment of the present invention, each refrigerant valve may specifically be an electronic expansion valve.

[0059] In order to achieve thermal management of the whole vehicle, the working state of each component in each circuit can be controlled according to the current working mode of the thermal management system of the whole vehicle. The embodiment of the present invention mainly describes the control strategy of the refrigerant valve in the thermal management system of the whole vehicle, that is, the unified control of each refrigerant valve based on the working mode of the thermal management system of the whole vehicle, so that the thermal management system of the whole vehicle can quickly reach the target state, effectively improve the working efficiency and energy efficiency ratio of the thermal management system of the whole vehicle, and reduce unnecessary energy waste.

[0060] See also Figure 2, is a flow chart of a control method of a refrigerant valve in a vehicle thermal management system provided by the present invention. The method can be applied to the vehicle thermal management system, and specifically includes the following steps:

[0061] Step S201, determining the operating mode of the vehicle thermal management system.

[0062] In one embodiment, the working mode of the vehicle thermal management system can be determined according to the various functions enabled by the vehicle thermal management system. Among them, the vehicle thermal management system may include functions such as passenger compartment heating, passenger compartment cooling, battery cooling, and motor cooling. The activation of each function corresponds to a preset trigger condition. For example, the trigger condition for turning on the passenger compartment heating function is that the control panel issues a request, and the heating and cooling air doors are in the full warm position; the trigger condition for turning on the battery cooling function is that the BMS (BATTERYMANAGEMENT SYSTEM) issues a request; the trigger condition for turning on the motor cooling function is that the MCU (MICROCONTROLLER UNIT) inlet water temperature exceeds the preset first temperature threshold, or the OBC (ONBOARD CHARGER) temperature exceeds the preset second temperature threshold, as well as other similar temperature limits.

[0063] When the functions enabled by the vehicle thermal management system change, the working mode of the vehicle thermal management system also changes accordingly. In order to determine the working mode of the vehicle thermal management system, it is necessary to monitor whether the triggering conditions of each function of the vehicle thermal management system are met. For example, at a certain moment, the vehicle thermal management system receives a command from the control panel to turn on the passenger compartment heating function, and the working mode of the vehicle thermal management system is the passenger compartment heating mode. Subsequently, the vehicle thermal management system receives a battery cooling request from the BMS, and the working mode of the vehicle thermal management system is switched from the passenger compartment heating mode to the battery cooling + passenger compartment heating mode.

[0064] In one embodiment, the working modes of the vehicle thermal management system may include passenger compartment heating mode, passenger compartment cooling mode, battery cooling mode, motor cooling mode, battery / motor cooling mode, passenger compartment heating + battery / motor cooling mode, passenger compartment cooling + battery / motor cooling mode, etc. In each working mode, the vehicle thermal management system achieves the target state of the working mode by controlling the opening, closing or opening degree of each component in the refrigerant circuit, the motor coolant circuit and the battery coolant circuit.

[0065] Step S202: According to the working mode, determine the control strategies corresponding to each refrigerant valve in the working mode.

[0066] In an embodiment of the present invention, the vehicle thermal management system may include one or more refrigerant valves. Figure 1The vehicle thermal management system shown includes three refrigerant valves, specifically a first refrigerant valve leading to the evaporator inlet, a second refrigerant valve leading to the CHILLER inlet, and a third refrigerant valve leading to the condenser CONDENSER inlet. In some embodiments, the vehicle thermal management system may also only include the first refrigerant valve leading to the evaporator inlet and the second refrigerant valve leading to the CHILLER inlet.

[0067] In each working mode, in order to achieve the target state of the working mode, each refrigerant valve should adopt a corresponding control strategy. Specifically, each refrigerant valve can correspond to one or more control strategies. In order to meet the needs of different working modes, it is necessary to establish a mapping relationship between the working mode and the control strategy of each refrigerant valve, so that the vehicle thermal management system can determine the control strategy corresponding to each refrigerant valve in the working mode according to the working mode. Among them, each control strategy of the refrigerant valve can correspond to one or more working modes of the vehicle thermal management system.

[0068] In one embodiment, the first control strategy of each refrigerant valve is: determine the target opening position of each refrigerant valve according to the working mode. The target opening position includes closed, fully open and limited value. For example, when the working mode of the vehicle thermal management system is mode 1, the first refrigerant valve corresponds to the first control strategy, and the target opening position is fully open.

[0069] Other control strategies for each refrigerant valve include: comparing the state parameter obtained in the vehicle thermal management system with the threshold range of the state parameter, if the state parameter is within the threshold range of the state parameter, controlling the corresponding refrigerant valve to maintain the opening, if the state parameter exceeds the threshold range of the state parameter, controlling the corresponding refrigerant valve to increase or decrease the opening so that the state parameter is within the threshold range of the state parameter. The state parameter includes one or more of the actual superheat at the evaporator outlet, the actual supercooling at the condenser outlet, the actual superheat at the chiller outlet, the supercooling range of each refrigerant valve, the battery water inlet temperature, and the battery temperature difference of the preset battery target temperature.

[0070] In one embodiment, each refrigerant valve corresponds to a preset limited opening interval, and the limited opening interval may correspond to different ranges based on different working modes. The step of controlling the corresponding refrigerant valve to increase or decrease the opening so that the state parameter is within the threshold range of the state parameter includes: controlling the corresponding refrigerant valve to increase or decrease the opening within the limited opening interval so that the state parameter is within the threshold range of the state parameter. In one embodiment, the refrigerant valve is controlled to increase or decrease the opening according to a preset adjustment step in units of control cycles to determine the target opening position of the refrigerant valve. Specifically, in each control cycle, it is determined whether the current control cycle is the first control cycle. If so, the opening adjustment step is entered; if not, it is determined whether the state parameter is within the threshold range of the state parameter. If so, the target opening position of the refrigerant valve is set to the current opening position of the refrigerant valve, and the control is jumped out, and the next control cycle is no longer entered. If not, the opening adjustment step is entered.

[0071] Among them, the opening adjustment step specifically includes: increasing or decreasing the preset adjustment step based on the current opening position of the refrigerant valve to obtain the next opening position of the refrigerant valve. When increasing the opening, determine whether the next opening position is greater than the upper limit of the opening interval. If so, set the target opening position of the refrigerant valve to the upper limit of the opening interval, and jump out of control without entering the next control cycle; if not, set the current opening position of the refrigerant valve to the next opening position, and enter the next control cycle to continue adjustment. When reducing the opening, determine whether the next opening position is less than the lower limit of the opening interval. If so, set the target opening position of the refrigerant valve to the lower limit of the opening interval, and jump out of control without entering the next control cycle; if not, set the current opening position of the refrigerant valve to the next opening position, and enter the next control cycle to continue adjustment.

[0072] Below Figure 1 The vehicle thermal management system architecture shown is taken as an example to describe the specific control strategies of the first refrigerant valve, the second refrigerant valve and the third refrigerant valve.

[0073] In one embodiment, the first refrigerant valve may correspond to three control strategies, each of which corresponds to a different working mode. For example, the vehicle thermal management system has a total of 7 working modes. When the working mode of the vehicle thermal management system is mode 1, 2, or 5, the first refrigerant valve corresponds to the first control strategy; when the vehicle thermal management mode is mode 4 or 7, the first refrigerant valve corresponds to the second control strategy; when the vehicle thermal management mode is mode 3 or 6, the first refrigerant valve corresponds to the third control strategy.

[0074] Specifically, the first control strategy of the first refrigerant valve is: determine the target opening position of the first refrigerant valve according to the working mode. The target opening position includes closed, fully open and limited value. For example, when the working mode of the vehicle thermal management system is mode 1, the first refrigerant valve corresponds to the first control strategy, and the target opening position is fully open.

[0075] The second control strategy of the first refrigerant valve is: determine whether the actual superheat at the evaporator outlet is greater than the preset maximum limit of the evaporator outlet superheat; if so, control the first refrigerant valve to increase the opening so that the actual superheat at the evaporator outlet is less than or equal to the maximum limit of the evaporator outlet superheat; if not, determine the first subcooling range corresponding to the first refrigerant valve according to the internal and external circulation status of the vehicle thermal management system and the current air volume gear, and according to the actual subcooling at the condenser outlet and the first subcooling range, control the first refrigerant valve to increase the opening, decrease the opening or maintain the opening so that the actual subcooling at the condenser outlet is within the first subcooling range.

[0076] The third control strategy of the first refrigerant valve is: determine whether the actual superheat at the evaporator outlet is greater than the preset maximum limit of the superheat at the evaporator outlet; if so, control the first refrigerant valve to increase the opening so that the actual superheat at the evaporator outlet is less than or equal to the maximum limit of the superheat at the evaporator outlet; if not, obtain the current ambient temperature, the target setting temperature and the target air volume gear, and determine the target opening position of the first refrigerant valve according to the current ambient temperature, the target setting temperature, the target air volume gear and the preset first opening lookup table. Among them, the structure of the first opening lookup table is shown in Table 1 below:

[0077] Table 1

[0078]

[0079] In one embodiment, the second refrigerant valve may also correspond to three control strategies, each of which corresponds to a different working mode.

[0080] Specifically, the first control strategy of the second refrigerant valve is the same as the first control strategy of the first refrigerant valve, that is, the target opening position of the second refrigerant valve is determined according to the working mode. The target opening position includes closed, fully open and limit value.

[0081] The second control strategy of the second refrigerant valve is: determine the second subcooling range corresponding to the second refrigerant valve according to the operating state of the compressor; according to the actual subcooling at the condenser outlet and the second subcooling range, control the second refrigerant valve to increase, decrease or maintain the opening so that the actual subcooling at the condenser outlet is within the second subcooling range.

[0082] The third control strategy of the second refrigerant valve is: judging whether the actual superheat degree at the CHILLER outlet is greater than the preset maximum limit value of the CHILLER outlet superheat degree;

[0083] If yes, control the second refrigerant valve to increase its opening so that the actual superheat at the CHILLER outlet is less than or equal to the maximum limit of the superheat at the CHILLER outlet;

[0084] If not, redetermine the restricted opening interval of the second refrigerant valve according to the battery water inlet temperature and the evaporator outlet temperature, and determine whether the current opening of the second refrigerant valve is within the restricted opening interval; if so, calculate the battery temperature difference between the battery water inlet temperature and the preset battery target temperature; based on the battery temperature difference and the preset battery temperature difference target range, control the second refrigerant valve to increase, decrease or maintain the opening within the restricted opening interval so that the battery temperature difference is within the battery temperature difference target range; if not, when the current opening of the second refrigerant valve is greater than the upper limit value of the restricted opening interval, determine the target opening position of the second refrigerant valve as the upper limit value of the restricted opening interval; when the current opening of the second refrigerant valve is less than the lower limit value of the restricted opening interval, determine the target opening position of the second refrigerant valve as the lower limit value of the restricted opening interval.

[0085] In one embodiment, the third refrigerant valve may correspond to two control strategies, and each control strategy corresponds to a different working mode.

[0086] Specifically, the first control strategy of the third refrigerant valve is the same as the first control strategy of the first refrigerant valve, that is, the target opening position of the third refrigerant valve is determined according to the working mode. The target opening position includes closed, fully open and limit value.

[0087] The second control strategy of the third refrigerant valve is: obtaining the current ambient temperature, the target set temperature and the target air volume level; determining the target opening position of the third refrigerant valve according to the current ambient temperature, the target set temperature, the target air volume level and a preset second opening lookup table. The structure of the second opening lookup table is the same as that of the first opening lookup table, which will not be described in detail here.

[0088] Step S203: controlling the opening of each refrigerant valve based on the control strategy corresponding to each refrigerant valve in the working mode.

[0089] In one embodiment, in the case where the target opening position of the refrigerant valve needs to be determined by calculating the superheat or subcooling, before comparing the state parameter obtained in the vehicle thermal management system with the threshold range of the state parameter, it also includes: determining the initial opening position of each refrigerant valve according to the speed of the compressor. This is because when the system is just started, the operation is not stable yet and the superheat or subcooling cannot be calculated.

[0090] See also Figure 3 , is a schematic diagram of a specific flow chart of the second control strategy for the first refrigerant valve, comprising the following steps:

[0091] Step S301, calculating the actual superheat at the evaporator outlet.

[0092] by Figure 1 Taking the vehicle thermal management system in as an example, the actual superheat at the evaporator outlet is the difference between the saturation temperature measured by PT3 and the actual temperature measured by R-T3.

[0093] Step S302, determining whether the actual superheat at the evaporator outlet is greater than a preset maximum limit of the superheat at the evaporator outlet, if so, proceeding to step S303, if not, proceeding to step S304.

[0094] Step S303, control the first refrigerant valve to increase the opening so that the actual superheat at the evaporator outlet is less than or equal to the maximum limit of the superheat at the evaporator outlet. Step S304 determines the first supercooling interval corresponding to the first refrigerant valve according to the internal and external circulation state of the vehicle thermal management system and the current air volume gear.

[0095] In one embodiment, a mapping relationship table of internal and external circulation states, current air volume gear and first supercooling range may be preset in the vehicle thermal management system, as shown in Table 2 below:

[0096] Table 2

[0097]

[0098] Step S305, determining whether the actual degree of subcooling at the condenser outlet is greater than the upper limit of the first subcooling interval, if so, proceeding to step S306, if not, proceeding to step S307.

[0099] For example, assuming that the current system is in the internal circulation state and the current air volume level is 2, the first subcooling interval is [C0, C1]. If the actual subcooling degree at the condenser outlet is greater than C1, proceed to step S306; if not, proceed to step S307.

[0100] Step S306, controlling the first refrigerant valve to increase its opening so that the actual subcooling degree at the condenser outlet is less than or equal to the upper limit value of the first subcooling degree range.

[0101] Step S307, determining whether the actual subcooling degree at the condenser outlet is less than the lower limit value of the first subcooling degree interval, if so, proceeding to step S308, if not, proceeding to step S309.

[0102] Step S308, controlling the first refrigerant valve to reduce its opening so that the actual subcooling degree at the condenser outlet is greater than or equal to the lower limit of the first subcooling degree range. Step S309, controlling the first refrigerant valve to maintain its current opening degree.

[0103] See also Figure 4 , is a specific flow chart of the second control strategy for the second refrigerant valve, comprising the following steps:

[0104] Step S401, determining a second subcooling range corresponding to a second refrigerant valve according to the operating state of the compressor.

[0105] Specifically, a mapping relationship between the operating state of the compressor and the second subcooling range is preset.

[0106] Step S402, determining whether the actual degree of subcooling at the condenser outlet is greater than the upper limit of the second subcooling range, if so, proceeding to step S403, if not, proceeding to step S404.

[0107] Step S403, controlling the second refrigerant valve to increase its opening so that the actual subcooling degree at the condenser outlet is less than or equal to the upper limit value of the second subcooling degree range.

[0108] Step S404, determining whether the actual degree of subcooling at the condenser outlet is less than the lower limit of the second subcooling range, if so, proceeding to step S405, if not, proceeding to step S406.

[0109] Step S405, controlling the second refrigerant valve to reduce its opening so that the actual degree of subcooling at the condenser outlet is greater than or equal to the lower limit of the second subcooling range.

[0110] Step S406, controlling the second refrigerant valve to maintain the current opening.

[0111] See also Figure 5 , is a specific flow chart of the third control strategy of the second refrigerant valve, comprising the following steps:

[0112] Step S501, calculating the actual superheat degree at the CHILLER outlet.

[0113] by Figure 1 Taking the vehicle thermal management system in as an example, the actual superheat at the CHILLER outlet is the difference between the saturation temperature measured by PT3 and the actual temperature measured by R-T2.

[0114] Step S502, determining whether the actual superheat degree at the CHILLER outlet is greater than the preset maximum limit of the CHILLER outlet superheat degree, if so, proceeding to step S503, if not, proceeding to step S504.

[0115] Step S503, controlling the second refrigerant valve to increase its opening so that the actual superheat at the CHILLER outlet is less than or equal to the maximum limit of the superheat at the CHILLER outlet.

[0116] Step S504, re-determine the limited opening range of the second refrigerant valve according to the battery water inlet temperature and the evaporator outlet temperature.

[0117] by Figure 1 Taking the vehicle thermal management system in as an example, the battery water inlet temperature is the temperature measured by T3, and the evaporator outlet temperature is the temperature measured by R-T3.

[0118] In one embodiment, a mapping relationship between the battery water inlet temperature, the evaporator outlet temperature and the restricted opening range of the second refrigerant valve is preset in the vehicle thermal management system.

[0119] Step S505, determining whether the current opening of the second refrigerant valve is within the restricted opening range, if so, proceeding to step S506, if not, proceeding to step S512.

[0120] Step S505, calculating the battery temperature difference between the battery water inlet temperature and the preset battery target temperature.

[0121] Step S507, determining whether the battery temperature difference value is greater than an upper limit value of a preset battery temperature difference target range, if so, proceeding to step S508, if not, proceeding to step S509.

[0122] Step S508 , controlling the second refrigerant valve to increase its opening in the limited opening range so that the battery temperature difference value is less than or equal to the upper limit value of the battery temperature difference target range.

[0123] Step S509, determining whether the battery temperature difference value is less than the lower limit value of the battery temperature difference target range, if so, proceeding to step S510, if not, proceeding to step S511.

[0124] Step S510: Control the second refrigerant valve to reduce its opening degree in the limited opening range so that the battery temperature difference value is greater than or equal to the lower limit value of the battery temperature difference target range.

[0125] Step S511, controlling the second refrigerant valve to maintain the current opening.

[0126] Step S512, when the current opening of the second refrigerant valve is greater than the upper limit value of the restricted opening interval, the target opening position of the second refrigerant valve is determined to be the upper limit value of the restricted opening interval; when the current opening of the second refrigerant valve is less than the lower limit value of the restricted opening interval, the target opening position of the second refrigerant valve is determined to be the lower limit value of the restricted opening interval.

[0127] The following takes the vehicle thermal management system in the passenger compartment heating mode and the passenger compartment cooling + motor cooling mode as an example to illustrate the control method of the refrigerant valve in the vehicle thermal management system.

[0128] See also Figure 6 , which is a schematic diagram of the system cycle of the vehicle thermal management system provided by the present invention in the passenger compartment heating mode. In the passenger compartment heating mode, the working process of the refrigerant circuit is as follows: the low-temperature and low-pressure gaseous refrigerant enters COMP from ACCU through PT3, and is transformed into a high-temperature and high-pressure gaseous refrigerant through the work of COMP; the high-temperature and high-pressure gaseous refrigerant flows into LCC through PT1, and exchanges heat with the low-temperature coolant flowing into LCC under the action of PUMP2 to become a medium-temperature and medium-pressure gas-liquid mixed refrigerant; the medium-temperature and medium-pressure gas-liquid mixed refrigerant is transformed into a low-temperature and low-pressure gas-liquid mixed refrigerant under the throttling action of CONDEXV (i.e., the third refrigerant valve) and flows into CONDENSER, and heat exchanges with the air under the action of the fan, absorbing heat and the temperature rises slightly, and then enters CHILLER through the fully opened CHILLEREXV (i.e., the second refrigerant valve), exchanges heat with the coolant flowing out of the motor side, and becomes a low-pressure gas and flows into ACCU.

[0129] The working process of the coolant circuit is as follows: the low-temperature coolant flows into the LCC under the action of PUMP2 and exchanges heat with the high-temperature and high-pressure gaseous refrigerant. The coolant that has absorbed heat for the first time passes through the heater PTC for a second heating, and enters the HEATER after becoming a high-temperature coolant. The high-temperature coolant that enters the HEATER exchanges heat with the air under the action of the fan, releases heat and turns into a low-temperature coolant. The low-temperature coolant enters PUMP2 from the 2 inlets and 1 outlet of 5WV2 to realize circulation. The outside air rises in temperature after the heat exchange with the high-temperature coolant, and is blown into the passenger compartment to achieve heating of the passenger compartment.

[0130] In the right Figure 6 When controlling the refrigerant valve in the vehicle, first determine that the working mode of the vehicle thermal management system is the passenger compartment heating mode, and the control strategies of the first refrigerant valve and the second refrigerant valve are the first control strategies of the corresponding refrigerant valves, and the control strategy of the third refrigerant valve is the second control strategy of the third refrigerant valve; then control the opening of each refrigerant valve based on the control strategy of each refrigerant valve.

[0131] Specifically, for the first refrigerant valve, the opening of the first refrigerant valve in the passenger compartment heating mode is controlled to be closed. For the second refrigerant valve, the opening of the second refrigerant valve in the passenger compartment heating mode is controlled to be fully open. For the third refrigerant valve, the target opening position of the third refrigerant valve is determined according to the current ambient temperature, the target set temperature, the target air volume gear and the preset second opening lookup table, and the opening of the third refrigerant valve is controlled according to the target opening position.

[0132] See also Figure 7 , which is a system cycle diagram of the vehicle thermal management system provided by the present invention in the passenger compartment cooling + motor cooling mode. In the passenger compartment cooling + motor cooling mode, the working process of the refrigerant circuit is as follows: the low-temperature and low-pressure gaseous refrigerant enters COMP from ACCU through PT3, and is transformed into a high-temperature and high-pressure gaseous refrigerant through the work of COMP; the high-temperature and high-pressure gaseous refrigerant flows into LCC through PT1, and exchanges heat with the low-temperature coolant flowing into LCC under the action of PUMP2 to become a medium-temperature and medium-pressure liquid refrigerant; the medium-temperature and medium-pressure liquid refrigerant flows into CONDENSER through the fully opened CONDEXV (i.e., the third refrigerant valve), and under the action of the fan, it exchanges heat with the air, releases heat and becomes a medium-temperature and medium-pressure liquid refrigerant with a supercooled state; the medium-temperature and medium-pressure liquid refrigerant with a supercooled state passes through the throttling effect of EVAPEXV (i.e., the first refrigerant valve) and becomes a low-temperature and low-pressure gaseous refrigerant and enters EVAP; under the action of the blower, it exchanges heat with the air and absorbs the heat of the air, becomes a low-temperature and low-pressure gaseous refrigerant with a superheated state, and then flows into ACCU through the CV check valve. After the outside air exchanges heat with the low-temperature coolant, the temperature drops and is blown into the passenger compartment to achieve passenger compartment cooling. It should be noted that in this state, the air door between the passenger compartment air conditioner HEATER and EVAP is closed, and the air blown by the blower does not pass through the HEATER.

[0133] The working process of the coolant circuit is as follows: the high-temperature coolant flows out from the MOTOR under the action of PUMP2, passes through RAD, and under the action of the fan, exchanges heat with the air blown out from the CONDENSER side, releases heat and turns into low-temperature coolant; the low-temperature coolant enters from port 2 and exits from port 3 of 5WV1, first flows into PUMP2, then flows into LCC, exchanges heat with the high-temperature refrigerant in the LCC, absorbs heat and turns into medium-temperature coolant; the medium-temperature coolant passes through PTC and HEATER, then enters from port 2 and exits from port 5 of 5WV2, and flows into the MOTOR, thereby cooling the motor.

[0134] In the right Figure 7 When controlling the refrigerant valve in the vehicle, first determine that the control strategy of the first refrigerant valve is the third control strategy of the first refrigerant valve, and the control strategies of the second refrigerant valve and the third refrigerant valve are the first control strategies of the corresponding refrigerant valves according to the working mode of the vehicle thermal management system, which is the passenger compartment cooling + motor cooling mode; and then control the opening of each refrigerant valve based on the control strategy of each refrigerant valve.

[0135] Specifically, for the first refrigerant valve, first determine the initial opening position of the first refrigerant valve according to the speed of the compressor, then determine whether the actual superheat at the evaporator outlet is greater than the preset maximum limit of the superheat at the evaporator outlet. If so, control the first refrigerant valve to increase the opening so that the actual superheat at the evaporator outlet is less than or equal to the maximum limit of the superheat at the evaporator outlet; if not, obtain the current ambient temperature, target setting temperature and target air volume gear, determine the target opening position of the first refrigerant valve according to the current ambient temperature, the target setting temperature, the target air volume gear and the preset first opening lookup table, and control the opening of the first refrigerant valve according to the target opening position. For the second refrigerant valve, control the opening of the second refrigerant valve to be closed in the passenger compartment cooling + motor cooling mode. For the third refrigerant valve, control the opening of the third refrigerant valve to be fully open in the passenger compartment cooling + motor cooling mode.

[0136] The control method of the refrigerant valve in the vehicle thermal management system provided by the embodiment of the present invention first sets the corresponding control strategy of each refrigerant valve based on each working mode. When the vehicle thermal management system is running, the working mode of the vehicle thermal management system is first determined, and then the control strategy of each refrigerant valve under the working mode is determined according to the working mode, and then the opening of each refrigerant valve is controlled based on the control strategy of each refrigerant valve under the working mode. By adopting the method of the present invention, the vehicle thermal management system can switch to different control schemes according to different working modes to match various complex working conditions, effectively improving the working efficiency and energy efficiency ratio of the vehicle thermal management system and reducing unnecessary energy waste.

[0137] According to an embodiment of the present invention, a computer device is provided, such as Figure 8 As shown, it is a schematic diagram of the structure of an optional computer device provided by the present invention, and the computer device may include a processor 801, a communication interface 802, a memory 803 and a communication bus 804, wherein the processor 801, the communication interface 802 and the memory 803 complete mutual communication through the communication bus 804. The processor 801 can call the logic instructions in the memory 803 to execute the control method of the refrigerant valve in the whole vehicle thermal management system, and the method includes: determining the working mode of the whole vehicle thermal management system; according to the working mode, determining the control strategy corresponding to each refrigerant valve in the working mode; and controlling the opening of each refrigerant valve based on the control strategy corresponding to each refrigerant valve in the working mode.

[0138] In addition, the logic instructions in the above-mentioned memory 803 can be implemented in the form of software functional units and can be stored in several computer-readable storage media when sold or used as independent products. Based on such an understanding, the technical solution of the present invention can be essentially or partly reflected in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the above-mentioned method of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM, READ-ONLY MEMORY), a random access memory (RAM, RANDOMACCESS MEMORY), a magnetic disk or an optical disk.

[0139] According to an embodiment of the present invention, a computer-readable storage medium is provided, the type of which is as described above, and the computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the processor executes the steps of the method for controlling the refrigerant valve in the vehicle thermal management system.

[0140] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a general hardware platform, and of course, by hardware. Based on this understanding, the above technical solution, in essence, or the part that contributes to the relevant technology, can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment.

[0141] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application. Therefore, any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A control method for a refrigerant valve in a vehicle thermal management system, characterized in that: Each refrigerant valve in the vehicle thermal management system corresponds to at least one control strategy, and each control strategy corresponds to one or more working modes of the vehicle thermal management system. The method includes: Determining an operating mode of the vehicle thermal management system; According to the working mode, determining the control strategies corresponding to each refrigerant valve in the working mode; The opening of each refrigerant valve is controlled based on the control strategy corresponding to each refrigerant valve in the working mode.

2. The method according to claim 1, characterized in that The first control strategy of each refrigerant valve is to determine the target opening position of each refrigerant valve according to the working mode.

3. The method according to claim 1, characterized in that Other control strategies for each refrigerant valve include: The state parameter obtained in the vehicle thermal management system is compared with the threshold range of the state parameter. If the state parameter is within the threshold range of the state parameter, the corresponding refrigerant valve is controlled to maintain the opening; if the state parameter exceeds the threshold range of the state parameter, the corresponding refrigerant valve is controlled to increase or decrease the opening so that the state parameter is within the threshold range of the state parameter.

4. The method according to claim 3, characterized in that Each refrigerant valve corresponds to a preset limited opening range, and the control of the corresponding refrigerant valve to increase or decrease the opening so that the state parameter is within the threshold range of the state parameter includes: The corresponding refrigerant valve is controlled to increase or decrease its opening within the limited opening range so that the state parameter is within the threshold range of the state parameter.

5. The method according to any one of claims 1 to 4, characterized in that: The vehicle thermal management system includes a first refrigerant valve leading to the evaporator inlet, and the second control strategy of the first refrigerant valve is: Determine whether the actual superheat at the evaporator outlet is greater than the preset maximum limit of the superheat at the evaporator outlet; If yes, controlling the first refrigerant valve to increase its opening so that the actual superheat at the evaporator outlet is less than or equal to the maximum limit of the superheat at the evaporator outlet; If not, the first subcooling range corresponding to the first refrigerant valve is determined according to the internal and external circulation status of the vehicle thermal management system and the current air volume gear, and according to the actual subcooling at the condenser outlet and the first subcooling range, the first refrigerant valve is controlled to increase, decrease or maintain the opening so that the actual subcooling at the condenser outlet is within the first subcooling range.

6. The method according to claim 5, characterized in that The third control strategy of the first refrigerant valve is: Determine whether the actual superheat at the evaporator outlet is greater than the preset maximum limit of the superheat at the evaporator outlet; If yes, controlling the first refrigerant valve to increase its opening so that the actual superheat at the evaporator outlet is less than or equal to the maximum limit of the superheat at the evaporator outlet; If not, obtain the current ambient temperature, the target set temperature and the target air volume level, and determine the target opening position of the first refrigerant valve according to the current ambient temperature, the target set temperature, the target air volume level and a preset first opening lookup table.

7. The method according to any one of claims 1 to 4, characterized in that: The vehicle thermal management system includes a second refrigerant valve leading to a CHILLER inlet, and a second control strategy of the second refrigerant valve is: determining a second subcooling interval corresponding to the second refrigerant valve according to the operating state of the compressor; According to the actual subcooling degree at the condenser outlet and the second subcooling degree range, the second refrigerant valve is controlled to increase, decrease or maintain its opening so that the actual subcooling degree at the condenser outlet is within the second subcooling degree range.

8. The method according to claim 7, characterized in that The third control strategy of the second refrigerant valve is: Determine whether the actual superheat at the CHILLER outlet is greater than the preset maximum limit of the CHILLER outlet superheat; If yes, control the second refrigerant valve to increase its opening so that the actual superheat at the CHILLER outlet is less than or equal to the maximum limit of the superheat at the CHILLER outlet; If not, redetermine the restricted opening range of the second refrigerant valve according to the battery water inlet temperature and the evaporator outlet temperature, and determine whether the current opening of the second refrigerant valve is within the restricted opening range; if so, calculate the battery temperature difference between the battery water inlet temperature and the preset battery target temperature; based on the battery temperature difference and the preset battery temperature difference target range, control the second refrigerant valve to increase, decrease or maintain the opening within the restricted opening range so that the battery temperature difference is within the battery temperature difference target range; if not, when the current opening of the second refrigerant valve is greater than the upper limit value of the restricted opening range, determine the target opening position of the second refrigerant valve to be the upper limit value of the restricted opening range; when the current opening of the second refrigerant valve is less than the lower limit value of the restricted opening range, determine the target opening position of the second refrigerant valve to be the lower limit value of the restricted opening range.

9. The method according to claim 8, characterized in that According to the battery temperature difference value and a preset battery temperature difference target range, controlling the second refrigerant valve to increase, decrease or maintain the opening in the restricted opening range so that the battery temperature difference value is within the battery temperature difference target range includes: Determining whether the battery temperature difference value is greater than an upper limit value of the battery temperature difference target range; If yes, controlling the second refrigerant valve to increase its opening within the limited opening range so that the battery temperature difference value is less than or equal to the upper limit value of the battery temperature difference target range; If not, determine whether the battery temperature difference value is less than the lower limit value of the battery temperature difference target range. If so, control the second refrigerant valve to reduce the opening in the limited opening range so that the battery temperature difference value is greater than or equal to the lower limit value of the battery temperature difference target range. If not, control the second refrigerant valve to maintain the current opening.

10. The method according to any one of claims 1 to 4, characterized in that: The vehicle thermal management system includes a third refrigerant valve leading to the condenser inlet, and the second control strategy of the third refrigerant valve is: Get the current ambient temperature, target set temperature and target air volume level; The target opening position of the third refrigerant valve is determined according to the current ambient temperature, the target set temperature, the target air volume gear and a preset second opening lookup table.

11. The method according to claim 3, characterized in that Before comparing the state parameter obtained in the vehicle thermal management system with the threshold range of the state parameter, the method further includes: The initial opening position of the corresponding refrigerant valve is determined according to the speed of the compressor.

12. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 11 are implemented.

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the processor performs steps to implement the method according to any one of claims 1 to 11.

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