Thermal management system for avoiding frosting of passenger compartment, operation method and vehicle applying thermal management system

Abstract

The invention discloses a thermal management system for avoiding frosting of a passenger compartment, an operation method and a vehicle applying the thermal management system, and relates to the technical field of thermal management systems of new energy vehicles. Comprising the steps that when the refrigerating capacity demand of a passenger compartment reaches a preset low refrigerating capacity demand threshold value, a control object of a passenger compartment throttling device is defined as the refrigerant outlet pressure P of a passenger compartment evaporator, and the target value of the refrigerant outlet pressure P of the passenger compartment evaporator is defined as a preset anti-frosting refrigerant outlet pressure threshold value P1; and when the refrigerant evaporation temperature of the first refrigerant circulation branch is reduced to the environment frosting temperature, the second refrigerant circulation branch and the liquid cooling medium circulation module are started to share the refrigerating capacity of the refrigerant circulation module. The invention mainly solves the problem of how to provide a reasonable and efficient thermal management system for a new energy heavy vehicle. The evaporator of the passenger compartment is not prone to frosting, the compressor of the refrigerant circulation module does not need to be started and stopped frequently, the temperature uniformity of the passenger compartment is ensured, and therefore the comfort of the passenger compartment is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal management systems for new energy vehicles, and in particular to a thermal management system for avoiding frost in a passenger compartment, an operating method, and a vehicle using the thermal management system. Background Art

[0002] Heavy-duty vehicles (such as heavy-duty trucks, heavy-duty engineering vehicles, and heavy-duty mining vehicles) are the main vehicles for logistics transportation and engineering operations. Their fuel consumption and exhaust emissions are huge. With the continuous development of battery technology, motor technology, and electronic control technology, as well as the continuous advancement of environmental protection concepts, new energy drive platforms are gradually expanding from household cars to heavy-duty vehicles.

[0003] The battery system, motor system and passenger compartment (air conditioning or heating) of the above-mentioned new energy heavy-duty vehicles are all thermal management objects. Therefore, for new energy heavy-duty vehicles, their thermal management system not only undertakes the functions of air conditioning, heating and defrosting, but also undertakes the cooling / insulation functions of the battery system and motor system to ensure that the battery system and motor system are at the best working efficiency.

[0004] In order to save the material cost, development cost and installation cost of the thermal management system, the above-mentioned new energy heavy-duty vehicles usually adopt an integrated thermal management system, that is, the battery system, motor system and passenger compartment share the same thermal management system.

[0005] However, the battery system capacity of new energy heavy-duty vehicles is relatively large, which makes the cooling capacity required by the battery system of new energy heavy-duty vehicles significantly higher than that of the battery system of household cars. The displacement of its compressor is usually as high as 45cc or more, which makes the cooling capacity of the whole vehicle of new energy heavy-duty vehicles relatively large. When the passenger compartment is cooled separately and the cooling capacity demand is low (for example, under conditions such as low light intensity, low passenger compartment temperature, and low blower gear), even if the compressor runs at the lowest speed, its actual cooling capacity is much higher than the cooling capacity demand of the passenger compartment. In this case, the compressor is prone to frequent start and stop or frosting of the passenger compartment.

[0006] In summary, how to provide a reasonable and efficient thermal management system and its operation method for new energy heavy-duty vehicles has become one of the urgent problems to be solved. Summary of the invention

[0007] The object of the present invention is to provide a thermal management system, an operating method and a vehicle using the same for avoiding frost in the passenger compartment, which can provide a reasonable and efficient thermal management system and an operating method thereof for new energy heavy-duty vehicles.

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a thermal management system for avoiding frost in the passenger compartment, applied to a vehicle, the vehicle comprising a battery pack and a passenger compartment; the vehicle comprising at least a refrigerant circulation module and a liquid cooling medium circulation module; the refrigerant circulation module comprising a compressor, a condenser, a passenger compartment throttling device, a passenger compartment evaporator, a battery pack throttling device and a heat exchanger; the compressor, condenser, passenger compartment throttling device and passenger compartment evaporator of the refrigerant circulation module can be selectively circulated and connected in sequence to form a first refrigerant circulation branch; the compressor, condenser, battery pack throttling device and heat exchanger of the refrigerant circulation module can be selectively circulated and connected in sequence to form a second refrigerant circulation branch; the battery pack can exchange heat with the heat exchanger of the refrigerant circulation module through the liquid cooling medium circulation module; the passenger compartment can exchange heat with the passenger compartment evaporator of the refrigerant circulation module;

[0009] When the refrigerant circulation module operates in the passenger cabin single cooling mode, there are:

[0010] (1) When the cooling capacity requirement of the passenger compartment reaches a preset low cooling capacity requirement threshold:

[0011] The control object of the passenger compartment throttling device is defined as the outlet pressure P of the passenger compartment evaporator, and the target value of the outlet pressure P of the passenger compartment evaporator is defined as a preset anti-frosting outlet pressure threshold value P1;

[0012] Wherein, the refrigerant used by the refrigerant circulation module has a saturation temperature corresponding to a value greater than the ambient frosting temperature at the anti-frosting outlet pressure threshold value P1;

[0013] (2) When the speed of the compressor reaches the minimum allowable value, the opening of the passenger compartment throttling device reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature:

[0014] Starting the second refrigerant circulation branch and the liquid cooling medium circulation module to share the cooling capacity of the refrigerant circulation module;

[0015] When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature+preset margin value), the second refrigerant circulation branch and the liquid cooling medium circulation module are stopped.

[0016] In the above technical solution, the cooling capacity demand of the passenger compartment reaches a preset low cooling capacity demand threshold, specifically: ambient temperature ≤ 26°C.

[0017] In the above technical solution, the refrigerant used by the refrigerant circulation module is R134a, and the anti-frost outlet pressure threshold P1 is 360 kPa.

[0018] In the above technical solution, the refrigerant circulation module also includes a gas-liquid separator; the gas-liquid separator is connected before the inlet end of the compressor.

[0019] In the above technical solution, the vehicle also includes an electric energy conversion component; the liquid-cooling medium circulation module includes a first water pump, a four-way valve, a radiator water tank, a second water pump and a battery pack electric heater; when the four-way valve is in a first connected state: the first water pump, the liquid-cooling medium channel of the heat exchanger, the four-way valve, the battery pack electric heater and the liquid-cooling medium channel of the battery pack are circulated and connected in sequence, and the second water pump, the four-way valve, the liquid-cooling medium channel of the electric energy conversion component and the radiator water tank are circulated and connected in sequence; when the four-way valve is in a second connected state: the first water pump, the liquid-cooling medium channel of the heat exchanger, the four-way valve, the liquid-cooling medium channel of the electric energy conversion component, the radiator water tank, the second water pump, the four-way valve, the battery pack electric heater and the liquid-cooling medium channel of the battery pack are circulated and connected in sequence.

[0020] In the above technical solution, when the speed of the compressor reaches the minimum allowable value and the opening of the passenger compartment throttling device reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frost temperature, specifically: starting the battery pack throttling device in the second refrigerant circulation branch with an opening of 20%; switching the four-way valve of the liquid-cooling medium circulation module to the first connected state, and starting the first water pump in the liquid-cooling medium circulation module at the minimum speed; until the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature + preset margin value), closing the battery pack throttling device to stop the second refrigerant circulation branch, and stopping the first water pump to stop the liquid-cooling medium circulation module.

[0021] A method for operating a thermal management system for avoiding frost in a passenger compartment, which applies the above-mentioned thermal management system for avoiding frost in a passenger compartment; the method comprises:

[0022] The thermal management system for avoiding frost in the passenger compartment is capable of operating in at least a passenger compartment single cooling mode;

[0023] When the refrigerant circulation module operates in the passenger cabin single cooling mode, there are:

[0024] (1) When the cooling capacity requirement of the passenger compartment reaches a preset low cooling capacity requirement threshold:

[0025] The control object of the passenger compartment throttling device is defined as the outlet pressure P of the passenger compartment evaporator, and the target value of the outlet pressure P of the passenger compartment evaporator is defined as a preset anti-frosting outlet pressure threshold value P1;

[0026] Wherein, the refrigerant used by the refrigerant circulation module has a saturation temperature corresponding to a value greater than the ambient frosting temperature at the anti-frosting outlet pressure threshold value P1;

[0027] (2) When the speed of the compressor reaches the minimum allowable value, the opening of the passenger compartment throttling device reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature:

[0028] Starting the second refrigerant circulation branch and the liquid cooling medium circulation module to share the cooling capacity of the refrigerant circulation module;

[0029] When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature+preset margin value), the second refrigerant circulation branch and the liquid cooling medium circulation module are stopped.

[0030] In the above technical solution, the cooling demand of the passenger compartment reaches a preset low cooling demand threshold, specifically: the ambient temperature ≤ 26°C; the refrigerant used by the refrigerant circulation module is R134a, and the anti-frost outlet pressure threshold P1 is 360kPa.

[0031] In the above technical solution, the vehicle also includes an electric energy conversion component; the liquid-cooling medium circulation module includes a first water pump, a four-way valve, a heat sink, a second water pump and a battery pack electric heater; when the four-way valve is in a first connected state: the first water pump, the liquid-cooling medium channel of the heat exchanger, the four-way valve, the battery pack electric heater and the liquid-cooling medium channel of the battery pack are circulated and connected in sequence, and the second water pump, the four-way valve, the liquid-cooling medium channel of the electric energy conversion component and the heat sink are circulated and connected in sequence; when the four-way valve is in a second connected state: the first water pump, the liquid-cooling medium channel of the heat exchanger, the four-way valve, the liquid-cooling medium channel of the electric energy conversion component, the heat sink, the second water pump, the four-way valve, the battery pack electric heater and the liquid-cooling medium channel of the battery pack are circulated and connected in sequence;

[0032] When the speed of the compressor reaches the minimum allowable value, and the opening of the passenger compartment throttling device reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature, specifically:

[0033] Starting the battery pack throttling device in the second refrigerant circulation branch at an opening of 20%;

[0034] The four-way valve of the liquid cooling medium circulation module is switched to a first connection state, and the first water pump in the liquid cooling medium circulation module is started at the lowest speed;

[0035] When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature + preset margin value), the battery pack throttling device is closed to stop the second refrigerant circulation branch, and the first water pump is stopped to stop the liquid cooling medium circulation module.

[0036] A vehicle comprises the above-mentioned thermal management system for avoiding frost in the passenger compartment.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows: the thermal management system, operation method and vehicle using the same for avoiding passenger compartment frost of the present invention, when the refrigeration demand of the passenger compartment reaches a preset low refrigeration demand threshold: the control object of the passenger compartment throttling device is defined as the outlet pressure P of the passenger compartment evaporator, and the target value of the outlet pressure P of the passenger compartment evaporator is defined as the preset anti-frost outlet pressure threshold P1; when the speed of the compressor reaches the minimum allowable value, and the opening of the passenger compartment throttling device reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature: the second refrigerant circulation branch and the liquid cooling medium circulation module are started to share the refrigeration capacity of the refrigerant circulation module; the thermal management system is operated in the above manner, so that the refrigerant evaporation temperature of the first refrigerant circulation branch is always maintained above the ambient frosting temperature, so that the passenger compartment evaporator is not easy to frost, and there is no need to frequently start and stop the compressor of the refrigerant circulation module, thereby avoiding damage to the compressor caused by frequent start and stop, and ensuring the temperature uniformity of the passenger compartment, thereby improving the comfort of the passenger compartment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural view of the thermal management system of the present invention.

[0039] The figures are marked as follows: 100, passenger compartment; 200, battery pack; 300, electric energy conversion component; 1, compressor; 2, condenser; 3, passenger compartment throttling device; 4, passenger compartment evaporator; 5, battery pack throttling device; 6, heat exchanger; 7, gas-liquid separator; 8, first water pump; 9, four-way valve; 10, cooling water tank; 11, second water pump; 12, battery pack electric heater. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0041] This embodiment provides a thermal management system for avoiding frost in the passenger compartment, which can be applied to vehicles, especially new energy heavy-duty vehicles or new energy transportation vehicles that use battery packs to store energy and use electric motors as (one of) the driving forces.

[0042] The vehicle includes a battery pack 200 and a passenger compartment 100 . The battery pack 200 is usually a lithium-ion battery pack 200 . The passenger compartment 100 is used to provide space for the driver and passengers of the vehicle.

[0043] The vehicle also includes an electric energy conversion component 300, which can be a motor or a controller (i.e., a motor driver). In this embodiment, the electric energy conversion component 300 is a motor, a vehicle controller (MCU), and a three-in-one (3in1) controller integrated in the same module.

[0044] See also Figure 1 The thermal management system for avoiding frost in the passenger compartment of this embodiment includes at least a refrigerant circulation module and a liquid cooling medium circulation module.

[0045] The refrigerant circulation module includes a compressor 1, a condenser 2, a passenger compartment throttling device 3, a passenger compartment evaporator 4, a battery pack throttling device 5 and a heat exchanger 6; wherein the compressor 1 is a compressor 1 for compressing refrigerant in a refrigeration system, preferably a variable frequency compressor; the condenser 2 is a condenser 2 in a refrigeration system, and air convection devices such as fans are optional configurations of the condenser 2; the passenger compartment throttling device 3 and the battery pack throttling device 5 are both throttling devices in the refrigeration system, and in the present embodiment, both are electronic expansion valves; the passenger compartment evaporator 4 and the heat exchanger 6 are both used as evaporators in the refrigeration system, wherein the heat exchanger 6 has a liquid-cooling medium channel, which can exchange heat with the liquid-cooling medium flowing through its liquid-cooling medium channel, and the passenger compartment evaporator 4 can exchange heat with the air.

[0046] The compressor 1, condenser 2, passenger compartment throttling device 3 and passenger compartment evaporator 4 of the refrigerant circulation module can be selectively circulated and connected in sequence to form a first refrigerant circulation branch; the compressor 1, condenser 2, battery pack throttling device 5 and heat exchanger 6 of the refrigerant circulation module can be selectively circulated and connected in sequence to form a second refrigerant circulation branch.

[0047] The battery pack 200 can exchange heat with the heat exchanger 6 of the refrigerant circulation module through the liquid cooling medium circulation module; specifically, in this embodiment, the liquid cooling medium circulation module includes a first water pump 8, a four-way valve 9, a heat dissipation water tank 10, a second water pump 11 and a battery pack electric heater 12; wherein the first water pump 8 and the second water pump 11 are both liquid cooling medium dedicated circulation pumps, such as electronic water pumps; the four-way valve 9 is an electrically controlled four-way valve 9, such as an electric four-way valve 9 or a magnetically controlled four-way valve 9, which includes a port a, a port b, a port c and a port d that are opened / closed by a host computer (such as a vehicle controller, a programmable controller and an embedded system); the heat dissipation water tank 10 is a metal cooler having multiple liquid flow channels, and heat dissipation fins are arranged between each liquid flow channel, which can dissipate heat for the liquid cooling medium flowing through it by forced convection or natural convection, and the battery pack electric heater 12 is a vehicle water heater (WPTC), which can heat the liquid cooling medium; please refer to Figure 1 , when the four-way valve 9 is in the first connected state: the first water pump 8, the liquid-cooling medium channel of the heat exchanger 6, the four-way valve 9, the battery pack electric heater 12 and the liquid-cooling medium channel of the battery pack 200 are circulated and connected in sequence, and the second water pump 11, the four-way valve 9, the liquid-cooling medium channel of the electric energy conversion component 300 and the heat dissipation water tank 10 are circulated and connected in sequence (in this state, the liquid medium circulation flow channels driven by the first water pump 8 and the second water pump 11 are not connected to each other); when the four-way valve 9 is in the second connected state: the first water pump 8, the liquid-cooling medium channel of the heat exchanger 6, the four-way valve 9, the liquid-cooling medium channel of the electric energy conversion component 300, the heat dissipation water tank 10, the second water pump 11, the four-way valve 9, the battery pack electric heater 12 and the liquid-cooling medium channel of the battery pack 200 are circulated and connected in sequence (in this state, the liquid medium circulation flow channels driven by the first water pump 8 and the second water pump 11 are connected to each other).

[0048] The passenger compartment 100 can exchange heat with the passenger compartment evaporator 4 of the refrigerant circulation module. Specifically, by configuring an air-conditioning fan in the air-conditioning module of the passenger compartment 100, forced convection is performed on the passenger compartment evaporator 4 of the refrigerant circulation module, so that the passenger compartment 100 can exchange heat with the passenger compartment evaporator 4 of the refrigerant circulation module.

[0049] Furthermore, the refrigerant circulation module also includes a gas-liquid separator 7, wherein the gas-liquid separator 7 is a refrigerant gas-liquid separator 7 in the refrigeration system, which is used to separate the gas and liquid in the refrigerant to prevent the liquid refrigerant from entering the compressor 1, thereby reducing the "liquid hammer" phenomenon of the compressor 1. The gas-liquid separator 7 is connected before the inlet end of the compressor 1.

[0050] The refrigerant circulation module of this embodiment is provided with a pressure sensor and a temperature sensor (not shown in the figure) at least on the outlet side of the passenger compartment evaporator 4 to detect the refrigerant outlet pressure and the refrigerant evaporation temperature of the passenger compartment evaporator 4.

[0051] The thermal management system for avoiding frost in the passenger compartment of this embodiment is also equipped with an ambient temperature sensor connected to the host computer signal. The ambient temperature sensor is arranged in the passenger compartment 100, and can detect the ambient temperature and feed back to the host computer.

[0052] In the thermal management system of this embodiment for avoiding frost in the passenger compartment, the condenser 2 of the refrigerant circulation module and the heat sink 10 of the liquid cooling medium circulation module share a set / one fan (preferably a precision electronic fan) for forced convection heat dissipation.

[0053] It can be understood that the thermal management system for avoiding frost in the passenger compartment of this embodiment is configured with a host computer (such as a vehicle control unit (VCU) or a dedicated controller for the thermal management system); the compressor 1 of the refrigerant circulation module, the passenger compartment throttling device 3, the battery pack throttling device 5, the pressure sensor and temperature sensor arranged on the outlet side of the passenger compartment evaporator 4, the first water pump 8 of the liquid cooling medium circulation module, the actuator of the four-way valve 9, the second water pump 11 and the battery pack electric heater 12 are all connected to the host computer signal to be controlled by the host computer.

[0054] It is understandable that the host computer can also be connected to the battery management system (BMS) signal of the battery pack 200, for example, through a CAN bus, to obtain information such as the cell temperature, remaining power, and charge / discharge mode of the battery pack 200.

[0055] It can be understood that the thermal management system for avoiding frost in the passenger compartment constitutes an automatic control system with a host computer as the control core, and its control objects can be ambient temperature, refrigerant outlet pressure of the passenger compartment evaporator 4 and refrigerant evaporation temperature, etc.

[0056] In the prior art, if the displacement of the compressor 1 is too large (the displacement of the compressor 1 of the new energy heavy-duty vehicle is as high as 45cc or more), when the refrigerant circulation module is operating in the passenger compartment 100 single cooling mode (that is, only the passenger compartment 100 has a cooling demand, and the temperature / operating conditions of the battery pack 200 and the electric energy conversion component 300 are not yet required for cooling), if the cooling capacity demand of the passenger compartment 100 is relatively low (for example, the ambient temperature is ≤26°C, the light intensity is low, the air-conditioning fan gear in the air-conditioning module of the passenger compartment 100 is low, etc.), even if the speed of the compressor 1 reaches the minimum allowable value (usually 1000r / min), the cooling capacity of the passenger compartment 100 is relatively low (for example, the ambient temperature is ≤26°C, the light intensity is low, the air-conditioning fan gear in the air-conditioning module of the passenger compartment 100 is low, etc. ... compressor 1 has a low cooling capacity, the cooling capacity of the passenger compartment 100 is pm), and its cooling capacity is also much greater than the cooling capacity demand of the passenger compartment 100. At this time, the passenger compartment evaporator 4 may be frosted; the reason for the frosting is that the evaporation temperature of the refrigerant in the passenger compartment evaporator 4 is lower than the ambient frosting temperature (usually 4°C). At this time, the upper computer will control the compressor 1 to stop, so that the entire refrigerant circulation module stops refrigeration. When the evaporation temperature of the refrigerant in the passenger compartment evaporator 4 is higher than 6°C, the upper computer will control the compressor 1 to restart. Obviously, such repeated start and stop will have a serious impact on the service life of the compressor 1 and the comfort of the passenger compartment 100.

[0057] In order to avoid the above technical problems, this embodiment proposes the following technical solutions:

[0058] When the refrigerant circulation module operates in the passenger compartment 100 single cooling mode (i.e., only the passenger compartment 100 has a cooling demand, and the temperature / operating conditions of the battery pack 200 and the electric energy conversion component 300 do not require cooling), there are:

[0059] (1) When the cooling capacity requirement of the passenger compartment 100 reaches a preset low cooling capacity requirement threshold:

[0060] The control object of the passenger compartment throttling device 3 is defined as the refrigerant outlet pressure P of the passenger compartment evaporator 4 (the pressure sensor disposed at the outlet side of the passenger compartment evaporator 4 feeds back to the upper computer in real time), and the target value of the refrigerant outlet pressure P of the passenger compartment evaporator 4 is defined as a preset anti-frosting refrigerant outlet pressure threshold value P1;

[0061] The saturation temperature of the refrigerant used by the refrigerant circulation module at the anti-frost refrigerant outlet pressure threshold value P1 is greater than the ambient frosting temperature;

[0062] (2) When the speed of the compressor 1 reaches the minimum allowable value, and the opening of the passenger compartment throttling device 3 reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch (feedback to the upper computer in real time by the temperature sensor configured on the outlet side of the passenger compartment evaporator 4) drops to the ambient frosting temperature:

[0063] Start the second refrigerant circulation branch and the liquid cooling medium circulation module to share the cooling capacity of the refrigerant circulation module;

[0064] When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature + preset margin value), the second refrigerant circulation branch and the liquid cooling medium circulation module are stopped.

[0065] Specifically, the cooling capacity demand of the passenger compartment 100 reaches a preset low cooling capacity demand threshold, specifically: ambient temperature ≤ 26°C.

[0066] Specifically, the refrigerant used by the refrigerant circulation module is R134a, and the anti-frost refrigerant outlet pressure threshold value P1 is 360 kPa.

[0067] Specifically, when the speed of the compressor 1 reaches the minimum allowable value, and the opening of the passenger compartment throttling device 3 reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature, specifically:

[0068] The battery pack throttling device 5 in the second refrigerant circulation branch is started at an opening of 20%;

[0069] The four-way valve 9 of the liquid cooling medium circulation module is switched to the first connection state, and the first water pump 8 in the liquid cooling medium circulation module is started at the lowest speed;

[0070] When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature + preset margin value), the battery pack throttling device 5 is closed to stop the second refrigerant circulation branch, and the first water pump 8 is stopped to stop the liquid cooling medium circulation module.

[0071] The present embodiment also provides a method for operating a thermal management system for avoiding frost in the passenger compartment, which applies the above-mentioned thermal management system for avoiding frost in the passenger compartment.

[0072] The method includes:

[0073] The thermal management system to avoid frost in the passenger compartment can be operated in at least a 100% cooling mode for the passenger compartment;

[0074] When the refrigerant circulation module operates in the passenger compartment 100 single cooling mode, there are:

[0075] (1) When the cooling capacity requirement of the passenger compartment 100 reaches a preset low cooling capacity requirement threshold:

[0076] The control object of the passenger compartment throttling device 3 is defined as the outlet pressure P of the passenger compartment evaporator 4, and the target value of the outlet pressure P of the passenger compartment evaporator 4 is defined as a preset anti-frosting outlet pressure threshold value P1;

[0077] Among them, the refrigerant used by the refrigerant circulation module has a saturation temperature corresponding to a frost-resistant outlet pressure threshold value P1 that is greater than the ambient frost temperature;

[0078] (2) When the speed of the compressor 1 reaches the minimum allowable value, and the opening of the passenger compartment throttling device 3 reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature:

[0079] Start the second refrigerant circulation branch and the liquid cooling medium circulation module to share the cooling capacity of the refrigerant circulation module;

[0080] When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature + preset margin value), the second refrigerant circulation branch and the liquid cooling medium circulation module are stopped.

[0081] Specifically, the cooling capacity demand of the passenger compartment 100 reaches a preset low cooling capacity demand threshold, specifically: ambient temperature ≤ 26°C.

[0082] Specifically, the refrigerant used by the refrigerant circulation module is R134a, and the anti-frost refrigerant outlet pressure threshold value P1 is 360 kPa.

[0083] Specifically, when the speed of the compressor 1 reaches the minimum allowable value, and the opening of the passenger compartment throttling device 3 reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature, specifically:

[0084] The battery pack throttling device 5 in the second refrigerant circulation branch is started at an opening of 20%;

[0085] The four-way valve 9 of the liquid cooling medium circulation module is switched to the first connection state, and the first water pump 8 in the liquid cooling medium circulation module is started at the lowest speed;

[0086] When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature + preset margin value), the battery pack throttling device 5 is closed to stop the second refrigerant circulation branch, and the first water pump 8 is stopped to stop the liquid cooling medium circulation module.

[0087] The following will use a specific case to explain the above technical solution in detail:

[0088] A certain new energy heavy-duty vehicle is equipped with the above-mentioned thermal management system for avoiding frost in the passenger compartment. The refrigerant used in its refrigerant circulation module is R134a. When the refrigerant circulation module operates in the passenger compartment 100 single cooling mode, the ambient temperature sensor configured in the passenger compartment 100 detects the ambient temperature in real time. When the ambient temperature is ≤26°C, it is determined that the refrigeration demand of the passenger compartment 100 reaches the preset low refrigeration demand threshold. At this time, the above-mentioned control logic (1) is entered: the control object of the passenger compartment throttling device 3 is defined as the refrigerant outlet pressure P of the passenger compartment evaporator 4 (the pressure sensor configured on the outlet side of the passenger compartment evaporator 4 feeds back to the upper computer in real time), and the passenger compartment evaporator The target value of the refrigerant outlet pressure P of the evaporator 4 is defined as 360 kPa (i.e., the anti-frost refrigerant outlet pressure threshold value P1). In fact, by controlling the opening of the passenger compartment throttling device 3, the refrigerant outlet pressure P of the passenger compartment evaporator 4 can be controlled. For R134a refrigerant, the corresponding saturation temperature at the refrigerant outlet pressure of 360 kPa is 5.84°C, which is higher than the ambient frosting temperature (4°C in this embodiment). By operating in this way, the passenger compartment evaporator 4 is not easy to frost, and there is no need to frequently start and stop the compressor 1. However, the above control logic (1) may not necessarily completely ensure that the passenger compartment evaporator 4 is not frosted, because the compressor 1 has a minimum speed to maintain operation. speed, the passenger compartment throttling device 3 (electronic expansion valve) also has a maximum opening. When the speed of the compressor 1 reaches the minimum allowable value and the opening of the passenger compartment throttling device 3 reaches the maximum allowable value, at this time, the refrigerant outlet pressure P of the passenger compartment evaporator 4 will no longer be controlled, and the refrigerant evaporation temperature of the first refrigerant circulation branch of the passenger compartment evaporator 4 (the temperature sensor configured on the outlet side of the passenger compartment evaporator 4 provides real-time feedback to the upper computer) may still continue to drop until it reaches the ambient frosting temperature; at this time, it is necessary to enter the above-mentioned control logic (2): start the battery pack throttling device 5 in the second refrigerant circulation branch with an opening of 20%, and switch the four-way valve 9 of the liquid cooling medium circulation module to the first connection In the open state, the first water pump 8 in the liquid-cooling medium circulation module is started at the lowest speed. At this time, the second refrigerant circulation branch and the liquid-cooling medium circulation module are started to share the cooling capacity of the refrigerant circulation module. By operating in this way, the passenger compartment evaporator 4 is not easy to frost, and there is no need to frequently start and stop the compressor 1; until the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature + preset margin value), the battery pack throttling device 5 is closed to stop the second refrigerant circulation branch, and the first water pump 8 is stopped to stop the liquid-cooling medium circulation module; in this embodiment, the ambient frost temperature is regarded as 4°C, and the preset margin value is defined as 4°C, that is, (ambient frost temperature + preset margin value) is 8°C.

[0089] This embodiment also provides a vehicle, which includes the above-mentioned thermal management system for avoiding frost in the passenger compartment.

[0090] In the thermal management system, operation method and vehicle using the same for avoiding passenger compartment frost of the present embodiment, when the cooling capacity demand of the passenger compartment 100 reaches a preset low cooling capacity demand threshold value: the control object of the passenger compartment throttling device 3 is defined as the outlet pressure P of the passenger compartment evaporator 4, and the target value of the outlet pressure P of the passenger compartment evaporator 4 is defined as the preset anti-frost outlet pressure threshold value P1; when the speed of the compressor 1 reaches the minimum allowable value, and the opening of the passenger compartment throttling device 3 reaches the maximum allowable value, and the refrigerant evaporator of the first refrigerant circulation branch reaches the maximum allowable value, ... When the temperature drops to the ambient frosting temperature: start the second refrigerant circulation branch and the liquid cooling medium circulation module to share the cooling capacity of the refrigerant circulation module; operate the thermal management system in the above manner to keep the refrigerant evaporation temperature of the first refrigerant circulation branch above the ambient frosting temperature at all times, so that the passenger compartment evaporator 4 is not easy to frost, and there is no need to frequently start and stop the compressor 1 of the refrigerant circulation module, thus avoiding damage to the compressor 1 due to frequent start and stop, and ensuring the temperature uniformity of the passenger compartment 100, thereby improving the comfort of the passenger compartment 100.

[0091] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A thermal management system for avoiding frost in a passenger compartment, applied to a vehicle, wherein the vehicle comprises a battery pack and a passenger compartment; characterized in that: It at least includes a refrigerant circulation module and a liquid cooling medium circulation module; The refrigerant circulation module includes a compressor, a condenser, a passenger compartment throttling device, a passenger compartment evaporator, a battery pack throttling device and a heat exchanger; the compressor, condenser, passenger compartment throttling device and passenger compartment evaporator of the refrigerant circulation module can be selectively circulated and connected in sequence to form a first refrigerant circulation branch; The compressor, condenser, battery pack throttling device and heat exchanger of the refrigerant circulation module can be selectively circulated and connected in sequence to form a second refrigerant circulation branch; The battery pack can exchange heat with the heat exchanger of the cooling medium circulation module through the liquid cooling medium circulation module; The passenger compartment is capable of exchanging heat with the passenger compartment evaporator of the refrigerant circulation module; When the refrigerant circulation module operates in the passenger cabin single cooling mode, there are: (1) When the cooling capacity requirement of the passenger compartment reaches a preset low cooling capacity requirement threshold: The control object of the passenger compartment throttling device is defined as the refrigerant outlet pressure P of the passenger compartment evaporator, and the target value of the refrigerant outlet pressure P of the passenger compartment evaporator is defined as a preset anti-frosting refrigerant outlet pressure threshold value P1; Wherein, the refrigerant used by the refrigerant circulation module has a saturation temperature corresponding to a value greater than the ambient frosting temperature at the anti-frosting refrigerant outlet pressure threshold value P1; (2) When the speed of the compressor reaches the minimum allowable value, the opening of the passenger compartment throttling device reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature: Starting the second refrigerant circulation branch and the liquid cooling medium circulation module to share the cooling capacity of the refrigerant circulation module; When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature+preset margin value), the second refrigerant circulation branch and the liquid cooling medium circulation module are stopped.

2. The thermal management system for avoiding frost in the passenger compartment according to claim 1, characterized in that: The cooling capacity requirement of the passenger compartment reaches a preset low cooling capacity requirement threshold, specifically: Ambient temperature ≤26℃.

3. The thermal management system for avoiding frost in the passenger compartment according to claim 1 or 2, characterized in that: The refrigerant used by the refrigerant circulation module is R134a, and the anti-frost refrigerant outlet pressure threshold value P1 is 360 kPa.

4. The thermal management system for avoiding frost in the passenger compartment according to claim 1, characterized in that: The refrigerant circulation module also includes a gas-liquid separator; The gas-liquid separator is connected before the inlet end of the compressor.

5. The thermal management system for avoiding frost in the passenger compartment according to claim 1, characterized in that: The vehicle also includes an electric energy conversion component; The liquid cooling medium circulation module includes a first water pump, a four-way valve, a heat dissipation water tank, a second water pump and a battery pack electric heater; When the four-way valve is in the first connected state: the first water pump, the liquid cooling medium channel of the heat exchanger, the four-way valve, the battery pack electric heater and the liquid cooling medium channel of the battery pack are cyclically connected in sequence, and the second water pump, the four-way valve, the liquid cooling medium channel of the electric energy conversion component and the heat dissipation water tank are cyclically connected in sequence; When the four-way valve is in the second connected state: the first water pump, the liquid-cooling medium channel of the heat exchanger, the four-way valve, the liquid-cooling medium channel of the electric energy conversion component, the heat dissipation water tank, the second water pump, the four-way valve, the battery pack electric heater and the liquid-cooling medium channel of the battery pack are connected in a circular manner.

6. The thermal management system for avoiding frost in the passenger compartment according to claim 5, characterized in that: When the speed of the compressor reaches the minimum allowable value, and the opening of the passenger compartment throttling device reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature, specifically: Starting the battery pack throttling device in the second refrigerant circulation branch at an opening of 20%; The four-way valve of the liquid cooling medium circulation module is switched to a first connection state, and the first water pump in the liquid cooling medium circulation module is started at the lowest speed; When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature + preset margin value), the battery pack throttling device is closed to stop the second refrigerant circulation branch, and the first water pump is stopped to stop the liquid cooling medium circulation module.

7. A method for operating a thermal management system to avoid frost in a passenger compartment, characterized in that: It applies the thermal management system for avoiding frost in the passenger compartment as described in any one of claims 1 to 6; The method includes: The thermal management system for avoiding frost in the passenger compartment is capable of operating in at least a passenger compartment single cooling mode; When the refrigerant circulation module operates in the passenger cabin single cooling mode, there are: (1) When the cooling capacity requirement of the passenger compartment reaches a preset low cooling capacity requirement threshold: The control object of the passenger compartment throttling device is defined as the refrigerant outlet pressure P of the passenger compartment evaporator, and the target value of the refrigerant outlet pressure P of the passenger compartment evaporator is defined as a preset anti-frosting refrigerant outlet pressure threshold value P1; Wherein, the refrigerant used by the refrigerant circulation module has a saturation temperature corresponding to a value greater than the ambient frosting temperature at the anti-frosting refrigerant outlet pressure threshold value P1; (2) When the speed of the compressor reaches the minimum allowable value, the opening of the passenger compartment throttling device reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature: Starting the second refrigerant circulation branch and the liquid cooling medium circulation module to share the cooling capacity of the refrigerant circulation module; When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature+preset margin value), the second refrigerant circulation branch and the liquid cooling medium circulation module are stopped.

8. The method for operating a thermal management system for avoiding frost in a passenger compartment according to claim 7, characterized in that: The cooling capacity requirement of the passenger compartment reaches a preset low cooling capacity requirement threshold, specifically: the ambient temperature ≤ 26°C; The refrigerant used by the refrigerant circulation module is R134a, and the anti-frost refrigerant outlet pressure threshold value P1 is 360 kPa.

9. The method for operating a thermal management system to avoid frost in a passenger compartment according to claim 7 or 8, characterized in that: The vehicle also includes an electric energy conversion component; The liquid cooling medium circulation module includes a first water pump, a four-way valve, a heat dissipation water tank, a second water pump and a battery pack electric heater; When the four-way valve is in the first connected state: the first water pump, the liquid cooling medium channel of the heat exchanger, the four-way valve, the battery pack electric heater and the liquid cooling medium channel of the battery pack are cyclically connected in sequence, and the second water pump, the four-way valve, the liquid cooling medium channel of the electric energy conversion component and the heat dissipation water tank are cyclically connected in sequence; When the four-way valve is in the second connected state: the first water pump, the liquid cooling medium channel of the heat exchanger, the four-way valve, the liquid cooling medium channel of the electric energy conversion component, the heat dissipation water tank, the second water pump, the four-way valve, the battery pack electric heater and the liquid cooling medium channel of the battery pack are cyclically connected in sequence; When the speed of the compressor reaches the minimum allowable value, and the opening of the passenger compartment throttling device reaches the maximum allowable value, and the refrigerant evaporation temperature of the first refrigerant circulation branch drops to the ambient frosting temperature, specifically: Starting the battery pack throttling device in the second refrigerant circulation branch at an opening of 20%; The four-way valve of the liquid cooling medium circulation module is switched to a first connection state, and the first water pump in the liquid cooling medium circulation module is started at the lowest speed; When the refrigerant evaporation temperature of the first refrigerant circulation branch reaches (ambient frost temperature + preset margin value), the battery pack throttling device is closed to stop the second refrigerant circulation branch, and the first water pump is stopped to stop the liquid cooling medium circulation module.

10. A vehicle, characterized in that: A thermal management system for avoiding frost in the passenger compartment comprising any one of claims 1-6.

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