Battery thermal management branch, battery thermal management method, and thermal management system

Abstract

A battery thermal management branch (3), a battery thermal management method, a thermal management system, a control method for a thermal management system, and a vehicle. The battery thermal management branch (3) comprises a first throttling apparatus (31), a battery pack heat exchange apparatus (32), and a second throttling apparatus (33), which are sequentially connected in a heat exchange medium transmission direction. The first throttling apparatus (31) and the second throttling apparatus (33) are used for adjusting the pressure of the battery pack heat exchange apparatus (32). The battery pack heat exchange apparatus (32) is used for performing heat exchange for a battery pack.

Description

Battery thermal management branch, battery thermal management method and thermal management system

[0001] Cross-reference to related disclosures

[0002] The present disclosure claims priority to the Chinese patent publication No. 202410878377.0, filed on July 01, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of automobile thermal management, and in particular to a battery thermal management branch, a battery thermal management method, a thermal management system, a thermal management system control method and a vehicle. BACKGROUND

[0004] In the prior art, a throttling device is usually arranged at the inlet of the corresponding battery pack heat exchange device for battery thermal management, so as to adjust the energy provided for battery thermal management to meet the corresponding working conditions. TECHNICAL PROBLEM

[0005] However, the method in the prior art easily causes the heat exchange efficiency of the battery pack heat exchange device to be limited, thereby affecting the performance of battery thermal management. TECHNICAL SOLUTION

[0006] The present disclosure provides a battery thermal management branch, a battery thermal management method, a thermal management system, a thermal management system control method and a vehicle, which can improve the heat exchange efficiency of the battery pack heat exchange device to at least partially solve the above technical problems.

[0007] In order to achieve the above-mentioned purpose, according to a first aspect of the present disclosure, a battery thermal management branch is provided, which comprises:

[0008] a first throttling device, a battery pack heat exchange device and a second throttling device connected in sequence along the transmission direction of the heat exchange medium;

[0009] The first throttling device and the second throttling device are used to adjust the pressure of the battery pack heat exchange device;

[0010] The battery pack heat exchange device is used to exchange heat for the battery pack.

[0011] Optionally, the first throttling device comprises a first electronic expansion valve, and / or the second throttling device comprises a second electronic expansion valve.

[0012] Optionally, the battery thermal management branch further comprises:

[0013] a first temperature and pressure sensor and a second temperature and pressure sensor;

[0014] The first temperature and pressure sensor is arranged between the outlet of the first throttling device and the inlet of the battery pack heat exchange device; and the second temperature and pressure sensor is arranged between the outlet of the battery pack heat exchange device and the inlet of the second throttling device.

[0015] According to a second aspect of the present disclosure, a battery thermal management method is provided, which is applied to the battery thermal management branch in any of the above embodiments; the battery thermal management method comprises:

[0016] According to the heat exchange demand of the battery pack heat exchange device and the supplied heat exchange amount of the battery thermal management branch, the throttling openings of the first throttling device and the second throttling device are controlled.

[0017] Optionally, according to the heat exchange demand of the battery pack heat exchange device and the supplied heat exchange amount of the battery thermal management branch, the throttling openings of the first throttling device and the second throttling device are controlled, comprising:

[0018] When the supplied heat exchange amount of the battery thermal management branch is less than a first preset heat exchange amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device are detected, and according to the inlet pressure and the outlet pressure, the throttling openings of the first throttling device and the second throttling device are controlled.

[0019] Optionally, the first preset heat exchange amount comprises a preset refrigeration amount, and when the supplied heat exchange amount of the battery thermal management branch is less than the first preset heat exchange amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device are detected, and according to the inlet pressure and the outlet pressure, the throttling openings of the first throttling device and the second throttling device are controlled, comprising:

[0020] When the heat exchange demand of the battery pack heat exchange device is a refrigeration demand, and the supplied refrigeration amount of the battery thermal management branch is less than a preset refrigeration amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device are detected.

[0021] If the inlet pressure is greater than a first preset inlet pressure, the throttling opening of the first throttling device is reduced.

[0022] After adjusting the throttling opening of the first throttling device, if the outlet pressure is less than a first preset outlet pressure, the throttling opening of the second throttling device is reduced.

[0023] Optionally, the first preset heat exchange amount comprises a preset heating amount, and when the supplied heat exchange amount of the battery thermal management branch is less than the first preset heat exchange amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device are detected, and according to the inlet pressure and the outlet pressure, the throttling openings of the first throttling device and the second throttling device are controlled, comprising:

[0024] When the heat exchange demand of the battery pack heat exchange device is a heating demand, and the supplied heating amount of the battery thermal management branch is less than a preset heating amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device are detected.

[0025] If the inlet pressure is greater than the second preset inlet pressure, the throttling opening of the first throttling device is decreased;

[0026] After adjusting the throttling opening of the first throttling device, if the outlet pressure is greater than the second preset outlet pressure, the throttling opening of the second throttling device is increased.

[0027] Optionally, the throttling openings of the first throttling device and the second throttling device are controlled according to the heat exchange demand of the battery pack heat exchange device and the supply heat exchange amount of the battery thermal management branch, including:

[0028] When the supply heat exchange amount of the battery thermal management branch is greater than the second preset heat exchange amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device are detected;

[0029] If the inlet pressure is less than the third preset inlet pressure, the throttling opening of the first throttling device is increased;

[0030] After adjusting the throttling opening of the first throttling device, if the outlet pressure is greater than the third preset outlet pressure, the throttling opening of the second throttling device is increased.

[0031] Or, after adjusting the throttling opening of the first throttling device, if the outlet pressure is less than the third preset outlet pressure, the throttling opening of the second throttling device is decreased.

[0032] Optionally, the throttling openings of the first throttling device and the second throttling device are controlled according to the heat exchange demand of the battery pack heat exchange device and the supply heat exchange amount of the battery thermal management branch, including:

[0033] When the supply heat exchange amount of the battery thermal management branch is greater than the third preset heat exchange amount, the inlet pressure and the outlet temperature of the battery pack heat exchange device are detected;

[0034] If the inlet pressure is less than the fourth preset inlet pressure, the throttling opening of the first throttling device is increased;

[0035] After adjusting the throttling opening of the first throttling device, if the heat exchange demand of the battery pack heat exchange device is refrigeration demand and the outlet superheat degree corresponding to the outlet temperature is greater than the preset superheat degree, the throttling opening of the first throttling device is increased, and if the heat exchange demand of the battery pack heat exchange device is refrigeration demand and the outlet superheat degree corresponding to the outlet temperature is less than the preset superheat degree, the throttling opening of the first throttling device is decreased.

[0036] Or, after adjusting the throttling opening of the first throttling device, if the heat exchange demand of the battery pack heat exchange device is heating demand and the outlet subcooling degree corresponding to the outlet temperature is greater than the preset subcooling degree, the throttling opening of the first throttling device is increased, and if the heat exchange demand of the battery pack heat exchange device is heating demand and the outlet subcooling degree corresponding to the outlet temperature is less than the preset subcooling degree, the throttling opening of the first throttling device is decreased.

[0037] Optionally, the battery thermal management method further comprises:

[0038] detecting the inlet pressure and the inlet temperature of the battery pack heat exchange device;

[0039] detecting the throttling effect of the first throttling device and the second throttling device according to the inlet pressure, the inlet temperature, the system target pressure and the system target temperature of the battery pack heat exchange device.

[0040] Optionally, the inlet pressure and the inlet temperature of the battery pack heat exchange device are obtained by a first temperature and pressure sensor, and the outlet pressure and the outlet temperature of the battery pack heat exchange device are obtained by a second temperature and pressure sensor.

[0041] According to a third aspect of the present disclosure, a thermal management system is provided, which comprises the battery thermal management branch and the main circuit, the air conditioner thermal management branch in any of the above embodiments:

[0042] The outlet of the main circuit is connected to the inlet of the first throttling device and the inlet of the air conditioner thermal management branch respectively, and the inlet of the main circuit is connected to the outlet of the second throttling device and the outlet of the air conditioner thermal management branch respectively.

[0043] The main circuit is used to provide energy required for thermal management to the battery thermal management branch and the air conditioner thermal management branch respectively.

[0044] Optionally, the main circuit comprises: a third temperature and pressure sensor, an electric compressor, a first electromagnetic valve, a condenser and a pressure sensor connected in sequence.

[0045] The third temperature and pressure sensor is arranged between the outlet of the second throttling device and the inlet of the electric compressor, and the pressure sensor is arranged between the outlet of the condenser and the inlet of the first throttling device.

[0046] Optionally, the main circuit further comprises a second electromagnetic valve, which is arranged between the inlet of the first electromagnetic valve and the outlet of the condenser.

[0047] Optionally, the air conditioner thermal management branch comprises an evaporator, a thermal expansion valve and a third electromagnetic valve connected in sequence.

[0048] The outlet of the evaporator is connected to the inlet of the main circuit, and the inlet of the third electromagnetic valve is connected to the outlet of the main circuit.

[0049] Optionally, the thermal management system further comprises a heating circuit, which comprises a PTC heater and a plate heat exchanger.

[0050] The plate heat exchanger is arranged between the outlet of the second throttling device and the inlet of the main circuit.

[0051] The PTC heater is connected to the plate heat exchanger and is used to exchange heat with the plate heat exchanger.

[0052] According to a fourth aspect of the present disclosure, a heat management system control method is provided, which is applied to the heat management system in any of the above embodiments. The heat management system control method comprises:

[0053] According to the output heat exchange capacity of the main circuit and the heat management working condition, the supply heat exchange capacities provided to the battery heat management branch and the air conditioner heat management branch are controlled.

[0054] Optionally, according to the output heat exchange capacity of the main circuit and the heat management working condition, the supply heat exchange capacities provided to the battery heat management branch and the air conditioner heat management branch are controlled, comprising:

[0055] When the output heat exchange capacity of the main circuit is greater than the fourth preset heat exchange capacity and the heat management working condition is the battery and air conditioner dual opening working condition, the supply heat exchange capacities of the battery heat management branch and the air conditioner heat management branch are increased respectively.

[0056] Optionally, according to the output heat exchange capacity of the main circuit and the heat management working condition, the supply heat exchange capacities provided to the battery heat management branch and the air conditioner heat management branch are controlled, comprising:

[0057] When the output heat exchange capacity of the main circuit is less than the fourth preset heat exchange capacity and the heat management working condition is the battery and air conditioner dual opening but battery priority working condition, the supply heat exchange capacity of the air conditioner heat management branch is reduced and the supply heat exchange capacity of the battery heat management branch is increased.

[0058] When the output heat exchange capacity of the main circuit is less than the third preset heat exchange capacity and the heat management working condition is the battery and air conditioner dual opening but air conditioner priority working condition, the supply heat exchange capacity of the air conditioner heat management branch is increased and the supply heat exchange capacity of the battery heat management branch is reduced.

[0059] Optionally, the heat management system further comprises a heating circuit connected between the outlet of the second throttling device and the inlet of the main circuit; the heat management system control method further comprises:

[0060] When the heat exchange demand of the battery heat management branch and / or the air conditioner heat management branch is heating demand, the heating circuit is controlled to start to heat the heat exchange medium flowing therethrough.

[0061] Optionally, the heat management system control method further comprises:

[0062] The inlet pressure and the inlet temperature of the electric compressor in the main circuit are detected;

[0063] According to the inlet pressure and the inlet temperature of the electric compressor, the return gas superheat degree of the electric compressor is determined;

[0064] According to the return gas superheat degree of the electric compressor, the liquid knock risk size of the electric compressor is determined.

[0065] According to a fifth aspect of the present disclosure, there is provided a vehicle comprising the thermal management system of any of the above embodiments. Advantages

[0066] In the battery thermal management branch of the embodiments of the present disclosure, the first throttling device is arranged at the inlet of the battery pack heat exchange device, and the second throttling device is further arranged at the outlet of the battery pack heat exchange device. First, the second throttling device can adjust the outlet pressure of the battery pack heat exchange device, so that the battery pack heat exchange device works in a relatively stable pressure environment, thereby improving the heat exchange efficiency of the battery pack heat exchange device. Second, the second throttling device can also adjust the evaporation pressure and condensation pressure of the battery pack heat exchange device. When the energy provided to the battery thermal management is insufficient, the evaporation temperature and condensation temperature of the battery pack heat exchange device can be adjusted, so that the limited energy can be more evenly provided to each battery cell, thereby improving the heat exchange efficiency of the battery pack heat exchange device.

[0067] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0068] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed in the following embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art.

[0069] In order to more completely understand the present disclosure and its beneficial effects, the following will be described in conjunction with the drawings, wherein the same reference numerals in the following description represent the same parts.

[0070] FIG. 1 is a module schematic diagram of the thermal management system provided in the exemplary embodiments disclosed by the present disclosure;

[0071] FIG. 2 is a specific structure schematic diagram of the thermal management system provided in the exemplary embodiments disclosed by the present disclosure;

[0072] FIG. 3 is a module schematic diagram of the thermal management system containing a heating circuit provided in the exemplary embodiments disclosed by the present disclosure;

[0073] FIG. 4 is a specific structure schematic diagram of the thermal management system containing a heating circuit provided in the exemplary embodiments disclosed by the present disclosure;

[0074] FIG. 5 is a module schematic diagram of the thermal management system containing a controller provided in the exemplary embodiments disclosed by the present disclosure;

[0075] FIG. 6 is a refrigeration mode refrigerant circulation schematic diagram provided in the exemplary embodiments disclosed by the present disclosure;

[0076] Fig. 7 is a schematic view of a refrigerant cycle in a heating mode according to an exemplary embodiment of the present disclosure.

[0077] BRIEF DESCRIPTION OF DRAWINGS 100, thermal management system execution part; 200, thermal management system control part; 1, main circuit; 111, electric compressor; 121, first electromagnetic valve; 131, condenser; 141, second electromagnetic valve; 151, pressure sensor; 161, third temperature and pressure sensor; 2, air conditioning thermal management branch; 211, evaporator; 221, thermal expansion valve; 231, third electromagnetic valve; 3, battery thermal management branch; 31, first throttling device; 32, battery pack heat exchange device; 33, second throttling device; 311, first electronic expansion valve; 321, battery pack heat exchange plate; 331, second electronic expansion valve; 341, first temperature and pressure sensor; 351, second temperature and pressure sensor; 4, heating circuit; 411, PTC heater; 421, plate heat exchanger; 5, controller.

[0078] Embodiments of the present disclosure

[0079] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present disclosure.

[0080] The related terms involved in the present disclosure are explained as follows:

[0081] Single opening: refers to only battery cooling / heating working.

[0082] Double opening: refers to air conditioning refrigeration / heating and battery cooling / heating working at the same time.

[0083] Refrigerant: in an air conditioning system, a substance that transfers heat through evaporation and condensation.

[0084] Throttling valve: refers to a valve that controls fluid flow by changing the throttling section or throttling length.

[0085] Saturation temperature: saturation temperature refers to the temperature that a liquid and a vapor have when they are in a dynamic equilibrium state, i.e. a saturation state. In the saturation state, the temperature of the liquid and the vapor is equal. When the saturation temperature is constant, the saturation pressure is also constant; conversely, when the saturation pressure is constant, the saturation temperature is also constant. When the pressure increases, a new dynamic equilibrium state will be formed at a new temperature. A certain saturation temperature of a substance corresponds to a certain saturation pressure.

[0086] Superheat degree: refers to the difference between the superheat temperature and the saturation temperature of a working medium under the same evaporation pressure in a cycle.

[0087] Subcooling: refers to the difference between the saturation temperature corresponding to the same condensing pressure in the cycle and the actual temperature of the working medium.

[0088] According to a first aspect of the present disclosure, referring to FIG. 1, a battery thermal management branch 3 is provided, which comprises:

[0089] The first throttling device 31, the battery pack heat exchange device 32 and the second throttling device 33 are connected in sequence along the heat transfer medium transmission direction.

[0090] The first throttling device 31 and the second throttling device 33 are used to adjust the pressure of the battery pack heat exchange device.

[0091] The battery pack heat exchange device is used to exchange heat with the battery pack.

[0092] Among them, the battery pack heat exchange device 32 is the core component in the battery thermal management branch 3, which is used to realize heat exchange with the battery pack, so as to realize cooling or heating of the battery pack. Similarly, the air conditioning thermal management branch 2 also contains a corresponding heat exchange device, which is used to realize heat exchange with the vehicle environment, so as to realize cooling or heating of the vehicle environment.

[0093] Among them, the throttling device is a device for limiting the flow speed of fluid, which causes the flow speed of fluid to increase and the pressure to drop by reducing the cross-sectional area of the channel, so as to realize the throttling effect of fluid. The first throttling device 31 and the second throttling device 33 can select corresponding types or types of throttling devices according to actual needs, such as throttling valves, flow regulating valves, etc.

[0094] Among them, the first throttling device 31 and the second throttling device 33 are specifically used to adjust the outlet pressure, evaporation pressure and / or condensing pressure of the battery pack heat exchange device.

[0095] Among them, the battery pack heat exchange device 32 usually works in a relatively stable pressure environment, so its outlet pressure under normal circumstances is also relatively stable. When the outlet pressure is detected to be stable, it means that the battery pack heat exchange device 32 works in a relatively stable pressure environment.

[0096] Among them, the heat transfer medium usually refers to refrigerant.

[0097] The evaporation pressure refers to the pressure of the refrigerant when it changes from a liquid state to a gaseous state at a certain temperature. Specifically, evaporation is the process of liquid molecules changing from a liquid phase to a gas phase. When the molecules on the surface of the liquid obtain enough energy to overcome the surface tension, they can separate from the liquid and change into a gas. The evaporation pressure is the lowest pressure at which the liquid molecules can separate from the liquid surface. The evaporation pressure can affect the evaporation temperature of the refrigerant. The greater the evaporation pressure, the higher the evaporation temperature of the refrigerant, and the smaller the proportion of gaseous refrigerant. In this embodiment, when the heat management system cannot provide sufficient refrigeration energy to the battery heat management branch, such as when the heat management system needs to prioritize the refrigeration energy of the air conditioning heat management branch, the throttling opening of the second throttling device 33 can be reduced to reduce the outflow speed of the refrigerant in the battery pack heat exchange device 32, thereby increasing the evaporation pressure of the refrigerant in the battery pack heat exchange device 32, further increasing the evaporation temperature of the refrigerant, and ultimately reducing the proportion of gaseous refrigerant. Liquid refrigerant can flow through each cell area of the battery pack, enhancing the uniformity of the battery during cooling. If the evaporation pressure is not controlled at this time, the liquid refrigerant will lose too quickly in the battery pack heat exchange device 32, causing some cells in the battery pack to be cooled while others are not, resulting in a large temperature difference in the battery pack.

[0098] Similarly, the condensation pressure refers to the pressure of the refrigerant when it changes from a gaseous state to a liquid state at a certain temperature. Specifically, condensation is the process of gas molecules changing from a gas phase to a liquid phase. When the gas molecules lose enough energy and cannot overcome the attractive force, they will gather together to form a liquid. The condensation pressure is the lowest pressure at which the gas changes to a liquid. The condensation pressure can affect the condensation temperature of the refrigerant. The smaller the condensation pressure, the smaller the condensation temperature of the refrigerant, and the smaller the proportion of liquid refrigerant. In this embodiment, when the heat management system cannot provide sufficient heating energy to the battery heat management branch, such as when the heat management system needs to prioritize the heating energy of the air conditioning heat management branch, the throttling opening of the second throttling device 33 can be increased to increase the outflow speed of the refrigerant in the battery pack heat exchange device 32, thereby reducing the condensation pressure of the refrigerant in the battery pack heat exchange device 32, further reducing the condensation temperature of the refrigerant, and ultimately reducing the proportion of liquid refrigerant. Gaseous refrigerant can flow through each cell area of the battery pack, enhancing the uniformity of the battery during heating. If the condensation pressure is not controlled at this time, the gaseous refrigerant will lose too quickly in the battery pack heat exchange device 32, causing some cells in the battery pack to be heated while others are not, resulting in a large temperature difference in the battery pack.

[0099] The refrigerant involved in the present disclosure includes but is not limited to R134a, R1234yf, etc. R134a is a hydrofluorocarbon compound, the chemical name of which is 1,1,1,2-tetrafluoroethane; it is a colorless, odorless, non-toxic refrigerant, which has good thermodynamic properties and chemical stability. R1234yf is a hydrofluoroalkene, the chemical name of which is 2,3,3,3-tetrafluoropropene; compared with R134a, R1234yf is a low global warming potential refrigerant, that is, it has less contribution to the greenhouse effect.

[0100] In the battery thermal management branch of the embodiment of the present disclosure, on the basis of the first throttling device arranged at the inlet of the battery pack heat exchange device, a second throttling device is further arranged at the outlet of the battery pack heat exchange device. First, the second throttling device can adjust the outlet pressure of the battery pack heat exchange device, so that the battery pack heat exchange device works in a relatively stable pressure environment, so as to improve the heat exchange efficiency thereof; second, the second throttling device can also adjust the evaporation pressure and the condensation pressure of the battery pack heat exchange device, so that when the energy provided to the battery thermal management is insufficient, the evaporation temperature and the condensation temperature of the battery pack heat exchange device can be adjusted, and then the limited energy can be more uniformly provided to each battery cell, so as to improve the heat exchange efficiency of the battery pack heat exchange device.

[0101] In some embodiments, as shown in FIGS. 1 and 2, the first throttling device 31 includes a first electronic expansion valve 311, and the second throttling device 33 includes a second electronic expansion valve 331.

[0102] In some embodiments, as shown in FIGS. 1 and 2, the first throttling device 31 includes a first electronic expansion valve 311, and the second throttling device 33 includes a second electronic expansion valve 331.

[0103] In some embodiments, as shown in FIG. 2, the battery thermal management branch 3 further includes a first temperature and pressure sensor 341 and a second temperature and pressure sensor 351.

[0104] The first temperature and pressure sensor 341 is arranged between the outlet of the first electronic expansion valve 311 and the inlet of the battery pack heat exchange plate 321, so as to detect the inlet pressure and the inlet temperature of the battery pack heat exchange plate 321; the second temperature and pressure sensor 351 is arranged between the outlet of the battery pack heat exchange plate 321 and the inlet of the second electronic expansion valve 331, so as to detect the outlet pressure and the outlet temperature of the battery pack heat exchange plate 321.

[0105] In the above embodiments, it has been mentioned that the second electronic expansion valve 331 can adjust the outlet pressure of the battery pack heat exchange plate 321 when the outlet pressure of the battery pack heat exchange plate 321 does not meet the requirements, provided that the outlet pressure of the battery pack heat exchange plate 321 needs to be obtained, which can be realized by the second temperature and pressure sensor 351 in the present embodiment. After the second temperature and pressure sensor 351 detects the pressure, the corresponding pressure data is fed back.

[0106] In addition, the second temperature and pressure sensor 351 can realize temperature detection in addition to pressure detection, so as to obtain the outlet temperature of the battery pack heat exchange plate 321 (including the outlet superheat degree in the refrigeration mode and the outlet subcooling degree in the refrigeration mode), and feedback the corresponding temperature data.

[0107] The first temperature and pressure sensor 341 can realize detection of the inlet pressure and the inlet temperature of the battery pack heat exchange plate 321, so as to check the throttling effect of the first electronic expansion valve 311 and the second electronic expansion valve 331. Specifically, the pressure drop in the battery pack heat exchange plate 321 can be approximately constant, and the refrigerant pressure in the battery pack heat exchange plate 321 is controlled by the first electronic expansion valve 311 and the second electronic expansion valve 331. When the pressure data and the temperature data detected by the first temperature sensor 341 are normal, it indicates that the first electronic expansion valve 311 throttles normally, and the system pressure is adjusted by the second electronic expansion valve 331. When the system pressure cannot be maintained, it indicates that the second electronic expansion valve 331 throttles abnormally.

[0108] As shown in FIG. 2, the first temperature and pressure sensor 341 and the second temperature and pressure sensor 351 both adopt a contact measurement method and are arranged at corresponding positions. Alternatively, in other embodiments, a non-contact measurement method such as a sound wave or a light wave can be adopted.

[0109] According to a second aspect of the present disclosure, a battery thermal management method is provided, which is applied to the battery thermal management branch 3 in any of the above embodiments. The battery thermal management method comprises:

[0110] According to the heat exchange demand of the battery pack heat exchange device 32 and the supply heat exchange amount of the battery thermal management branch 3, the throttling opening of the first throttling device 31 and the second throttling device 33 is controlled.

[0111] The heat exchange demand includes a refrigeration demand and a heating demand, and the supply heat exchange amount also includes a supply refrigeration amount and a supply heating amount.

[0112] Alternatively, according to the heat exchange demand of the battery pack heat exchange device 32 and the supply heat exchange amount of the battery thermal management branch 3, the throttling opening of the first throttling device 31 and the second throttling device 33 is controlled, which comprises:

[0113] When the supply heat exchange amount of the battery thermal management branch 3 is less than the first preset heat exchange amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device 32 are detected, and the throttling opening of the first throttling device 31 and the second throttling device 33 is controlled according to the inlet pressure and the outlet pressure.

[0114] The supply heat exchange amount of the battery thermal management branch 3 being less than the first preset heat exchange amount is only used to represent the premise that the energy supply of the battery thermal management branch 3 is insufficient, and is not limited to the size relationship between specific values.

[0115] Wherein, the above embodiments have mentioned that when the energy supply is insufficient, the outlet pressure, the evaporation pressure and / or the condensation pressure of the battery pack heat exchange device 32 can be adjusted by the first throttling device 31 and the second throttling device 33, so as to improve the heat exchange performance thereof.

[0116] Optionally, the first preset heat exchange amount includes a preset refrigeration amount, when the supply heat exchange amount of the battery thermal management branch 3 is less than the first preset heat exchange amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device 32 are detected, and the throttling opening of the first throttling device 31 and the second throttling device 33 is controlled according to the inlet pressure and the outlet pressure, including:

[0117] When the heat exchange demand of the battery pack heat exchange device 32 is a refrigeration demand, and the supply refrigeration amount of the battery thermal management branch 3 is less than the preset refrigeration amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device 32 are detected;

[0118] If the inlet pressure is greater than the first preset inlet pressure, the throttling opening of the first throttling device 31 is reduced;

[0119] After adjusting the throttling opening of the first throttling device 31, if the outlet pressure is less than the first preset outlet pressure, the throttling opening of the second throttling device 33 is reduced.

[0120] Wherein, the inlet pressure greater than the first preset inlet pressure is used to represent that the current throttling opening of the first throttling device 31 is large, so that more refrigerant flows into the battery thermal management branch 3, which conflicts with the premise of energy deficiency, so the throttling opening of the first throttling device 31 needs to be reduced.

[0121] Wherein, the outlet pressure less than the first preset outlet pressure is used to represent that the current throttling opening of the second throttling device 33 is large.

[0122] Wherein, in the case of insufficient refrigeration, the core is to improve the evaporation pressure of the battery pack heat exchange device 32, so the second throttling device 33 also needs to be in a small opening when the first throttling device 31 is in a small opening.

[0123] Optionally, the first preset heat exchange amount includes a preset heating amount, when the supply heat exchange amount of the battery thermal management branch 3 is less than the first preset heat exchange amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device 32 are detected, and the throttling opening of the first throttling device 31 and the second throttling device 33 is controlled according to the inlet pressure and the outlet pressure, including:

[0124] When the heat exchange demand of the battery pack heat exchange device 32 is a heating demand, and the supply heating amount of the battery thermal management branch 3 is less than the preset heating amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device 32 are detected;

[0125] If the inlet pressure is greater than the second preset inlet pressure, the throttling opening of the first throttling device 31 is reduced;

[0126] After adjusting the throttling opening of the first throttling device 31, if the outlet pressure is greater than the second preset outlet pressure, the throttling opening of the second throttling device 33 is increased.

[0127] Wherein, the inlet pressure greater than the second preset inlet pressure is also used to represent that the current throttling opening of the first throttling device 31 is large, and more refrigerant flows into the battery thermal management branch 3, which conflicts with the premise of insufficient energy, so the throttling opening of the first throttling device 31 needs to be reduced.

[0128] Wherein, the outlet pressure greater than the first preset outlet pressure is used to represent that the current throttling opening of the second throttling device 33 is small.

[0129] Wherein, in the case of insufficient heating, the core is to reduce the condensing pressure of the battery pack heat exchange device 32, so the second throttling device 33 needs to be in a large opening when the first throttling device 31 is in a small opening.

[0130] Optionally, according to the heat exchange demand of the battery pack heat exchange device 32 and the supply heat exchange amount of the battery thermal management branch 3, the throttling openings of the first throttling device 31 and the second throttling device 33 are controlled, comprising:

[0131] When the supply heat exchange amount of the battery thermal management branch 3 is greater than the second preset heat exchange amount, the inlet pressure and the outlet pressure of the battery pack heat exchange device 32 are detected;

[0132] If the inlet pressure is less than the third preset inlet pressure, the throttling opening of the first throttling device 31 is increased;

[0133] After adjusting the throttling opening of the first throttling device 31, if the outlet pressure is greater than the third preset outlet pressure, the throttling opening of the second throttling device 33 is increased;

[0134] Or, after adjusting the throttling opening of the first throttling device 31, if the outlet pressure is less than the third preset outlet pressure, the throttling opening of the second throttling device 33 is reduced.

[0135] Wherein, the supply heat exchange amount of the battery thermal management branch 3 greater than the second preset heat exchange amount is only used to represent the premise condition that the energy supply of the battery thermal management branch 3 is sufficient, and is not limited to the size relationship between specific values.

[0136] Wherein, the inlet pressure less than the third preset inlet pressure is used to represent that the current throttling opening of the first throttling device 31 is small, and less refrigerant flows into the battery thermal management branch 3, which conflicts with the premise of sufficient energy, so the throttling opening of the first throttling device 31 needs to be increased.

[0137] The outlet pressure greater than the third preset outlet pressure is used to represent that the throttling opening of the second throttling device 33 is currently small, and the outlet pressure less than the third preset outlet pressure is used to represent that the throttling opening of the second throttling device 33 is currently large.

[0138] The outlet pressure greater than the third preset outlet pressure is used to represent that the throttling opening of the second throttling device 33 is currently small, and the outlet pressure less than the third preset outlet pressure is used to represent that the throttling opening of the second throttling device 33 is currently large.

[0139] Optionally, according to the heat exchange demand of the battery pack heat exchange device 32 and the supply heat exchange amount of the battery thermal management branch 3, the throttling openings of the first throttling device 31 and the second throttling device 33 are controlled, including:

[0140] When the supply heat exchange amount of the battery thermal management branch 3 is greater than the third preset heat exchange amount, the inlet pressure and the outlet temperature of the battery pack heat exchange device 32 are detected.

[0141] If the inlet pressure is less than the fourth preset inlet pressure, the throttling opening of the first throttling device 31 is increased.

[0142] After adjusting the throttling opening of the first throttling device 31, if the heat exchange demand of the battery pack heat exchange device 32 is refrigeration demand and the outlet superheat degree corresponding to the outlet temperature is greater than the preset superheat degree, the throttling opening of the first throttling device 31 is increased, and if the heat exchange demand of the battery pack heat exchange device 32 is refrigeration demand and the outlet superheat degree corresponding to the outlet temperature is less than the preset superheat degree, the throttling opening of the first throttling device 31 is decreased.

[0143] Or, after adjusting the throttling opening of the first throttling device 31, if the heat exchange demand of the battery pack heat exchange device 32 is heating demand and the outlet subcooling degree corresponding to the outlet temperature is greater than the preset subcooling degree, the throttling opening of the first throttling device 31 is increased, and if the heat exchange demand of the battery pack heat exchange device 32 is heating demand and the outlet subcooling degree corresponding to the outlet temperature is less than the preset subcooling degree, the throttling opening of the first throttling device 31 is decreased.

[0144] The supply heat exchange amount of the battery thermal management branch 3 greater than the third preset heat exchange amount is only used to represent the prerequisite that the energy supply of the battery thermal management branch 3 is sufficient, and is not limited to the size relationship between specific values.

[0145] The inlet pressure less than the fourth preset inlet pressure is used to represent that the throttling opening of the first throttling device 31 is currently small, so that less refrigerant flows into the battery thermal management branch 3, which conflicts with the prerequisite of sufficient energy, and therefore the throttling opening of the first throttling device 31 needs to be increased.

[0146] Wherein, the outlet temperature corresponding to the outlet superheat greater than the preset superheat or the outlet temperature corresponding to the outlet subcooling greater than the preset subcooling is used to represent insufficient refrigeration or insufficient heating, so the first throttling device 31 needs to be further increased in throttling opening; the outlet temperature corresponding to the outlet superheat less than the preset superheat or the outlet temperature corresponding to the outlet subcooling less than the preset subcooling is used to represent excessive refrigeration or excessive heating, so the first throttling device 31 needs to be reduced in throttling opening. According to the second aspect of the present disclosure, referring to FIG. 1, a thermal management system is provided, which comprises a main circuit 1, an air conditioner thermal management branch 2, and a battery thermal management branch 3, the battery thermal management branch 3 comprising a first throttling device 31, a battery pack heat exchange device 32 and a second throttling device 33 connected in sequence.

[0147] The outlet of the main circuit 1 is connected with the inlet of the air conditioner thermal management branch 2 and the inlet of the first throttling device 31 respectively, and the outlet of the air conditioner thermal management branch 2 and the outlet of the second throttling device 33 are connected with the inlet of the main circuit 1 respectively.

[0148] The main circuit 1 is used to provide energy required for thermal management to the air conditioner thermal management branch 2 and the battery thermal management branch 3 respectively.

[0149] Wherein, the main circuit 1 is used to output energy, which contains a compressor, a condenser, etc., and energy transfer is realized by compression of refrigerant.

[0150] Wherein, continuing to refer to FIG. 1 and FIG. 2, the battery pack heat exchange device 32 comprises a battery pack heat exchange plate 321, the main circuit 1 comprises an electric compressor 111, a first electromagnetic valve 121, a condenser 131, a second electromagnetic valve 141 and a pressure sensor 151, and the air conditioner thermal management branch 2 comprises an evaporator 211, a thermal expansion valve 221 and a third electromagnetic valve 231.

[0151] Wherein, the outlet of the electric compressor 111 is connected with the inlet of the first electromagnetic valve 121 and the inlet of the second electromagnetic valve 141 respectively, the outlet of the first electromagnetic valve 121 is connected with the inlet of the condenser 131, the outlet of the condenser 131 and the outlet of the second electromagnetic valve 141 are connected with the inlet of the third electromagnetic valve 231 and the inlet of the first electronic expansion valve 311 respectively, and the pressure sensor 151 is arranged between the outlet of the condenser 131 and the inlet of the third electromagnetic valve 231. The outlet of the third electromagnetic valve 231 is connected with the inlet of the thermal expansion valve 221, the outlet of the thermal expansion valve 221 is connected with the inlet of the evaporator 211, and the outlet of the evaporator 211 and the outlet of the second electronic expansion valve 331 are connected with the inlet of the electric compressor 111 respectively.

[0152] Optionally, in other embodiments, the air-conditioning thermal management branch 2 is not limited to the direct cooling circuit formed by the evaporator 211, the thermal expansion valve 221 and the third electromagnetic valve 231 in cooperation in FIG. 2, but can also be other cooling cycles or cold-heat dual-cycle circuits.

[0153] When the energy that the thermal management system can provide is sufficient, it is necessary to ensure that the passenger cabin and the battery pack can both achieve sufficient heat exchange. If it is detected that the outlet of the battery pack heat exchange plate 321 is overheated or overcooled at this time, it means that the heat exchange of the battery pack is insufficient, and effective cooling or heating is not achieved. That is, the second temperature and pressure sensor 351 arranged at the outlet of the battery pack heat exchange plate 321 can achieve temperature detection, thereby effectively judging whether the battery pack is sufficiently heat exchanged.

[0154] In some embodiments, as shown in FIG. 2, the main circuit 1 further includes a third temperature and pressure sensor 161 arranged between the outlet of the evaporator 211 and the inlet of the electric compressor 111.

[0155] The third temperature and pressure sensor 161 is used to detect the inlet pressure and inlet temperature of the electric compressor 111.

[0156] Among them, based on the pressure data and temperature data detected by the third temperature and pressure sensor 161, it can be judged whether the return gas overheating degree and the return gas overcooling degree of the electric compressor 111 are abnormal, so that subsequent abnormality can be processed in time, thereby preventing faults such as liquid hammer from occurring, and achieving the purpose of protecting the system hardware.

[0157] Among them, the same as the first temperature and pressure sensor 341 and the second temperature and pressure sensor 351, the third temperature and pressure sensor 161 adopts a contact type measurement method and is arranged at a corresponding position. Optionally, in other embodiments, a non-contact measurement method such as sound wave, light wave, etc. can also be used.

[0158] In some embodiments, as shown in FIG. 3, the thermal management system further includes a heating circuit 4.

[0159] The heating circuit 4 is connected between the outlet of the air-conditioning thermal management branch 2 and the inlet of the main circuit 1, and is used to output heating energy when the heating startup state.

[0160] Among them, usually, in the heating mode, the heating energy output that can be achieved by only the compressor and the condenser and other components in the main circuit 1 is limited, and it is not easy to meet the heating energy demand required by the system. Therefore, in this embodiment, the corresponding heating circuit 4 is added, so that it is converted to the heating startup state when the system is in the heating mode, thereby completing the output of the heating energy and meeting the heating energy demand of the system.

[0161] In some embodiments, as shown in FIG. 4, the heating loop 4 comprises a PTC heater 411 and a plate exchanger 421.

[0162] In some embodiments, as shown in FIG. 4, the heating loop 4 comprises a PTC heater 411 and a plate exchanger 421.

[0163] In some embodiments, as shown in FIG. 5, the thermal management system further comprises a controller 5.

[0164] In some embodiments, as shown in FIG. 5, the thermal management system further comprises a controller 5.

[0165] According to the output heat exchange amount of the main loop 1 and the thermal management working condition, the supply heat exchange amount provided to the battery thermal management branch 3 and the air conditioning thermal management branch 2 is controlled.

[0166] In some embodiments, as shown in FIG. 4, the heating loop 4 comprises a PTC heater 411 and a plate exchanger 421.

[0167] According to the output heat exchange amount of the main loop 1 and the thermal management working condition, the supply heat exchange amount provided to the battery thermal management branch 3 and the air conditioning thermal management branch 2 is controlled.

[0168] When the output heat exchange amount of the main circuit 1 is greater than the fourth preset heat exchange amount and the thermal management working condition is the battery and air conditioner dual opening working condition, the supply heat exchange amounts of the battery thermal management branch 3 and the air conditioner thermal management branch 2 are respectively increased.

[0169] The output heat exchange amount of the main circuit 1 being greater than the fourth preset heat exchange amount is only used to represent the premise that the energy supply of the battery thermal management branch 3 and the air conditioner thermal management branch 2 is sufficient, and is not limited to the size relationship between specific values.

[0170] Optionally, according to the output heat exchange amount of the main circuit 1 and the thermal management working condition, the supply heat exchange amounts provided to the battery thermal management branch 3 and the air conditioner thermal management branch 2 are controlled, and the control includes:

[0171] When the output heat exchange amount of the main circuit 1 is less than the fourth preset heat exchange amount and the thermal management working condition is the battery and air conditioner dual opening but battery priority working condition, the supply heat exchange amount of the air conditioner thermal management branch 2 is reduced and the supply heat exchange amount of the battery thermal management branch 3 is increased.

[0172] When the output heat exchange amount of the main circuit 1 is less than the fourth preset heat exchange amount and the thermal management working condition is the battery and air conditioner dual opening but air conditioner priority working condition, the supply heat exchange amount of the air conditioner thermal management branch 2 is increased and the supply heat exchange amount of the battery thermal management branch 3 is reduced.

[0173] The output heat exchange amount of the main circuit 1 being less than the fourth preset heat exchange amount is only used to represent the premise that the energy supply of the battery thermal management branch 3 and the air conditioner thermal management branch 2 can only be sufficient, and is not limited to the size relationship between specific values.

[0174] Optionally, the thermal management system further comprises a heating circuit 4 connected between the outlet of the second throttling device 33 and the inlet of the main circuit 1; and the thermal management system control method further comprises:

[0175] When the heat exchange demand of the battery thermal management branch 3 and / or the air conditioner thermal management branch 2 is a heating demand, the heating circuit is controlled to start to heat the heat exchange medium flowing therethrough.

[0176] Optionally, the thermal management system control method further comprises:

[0177] The inlet pressure and the inlet temperature of the electric compressor 111 in the main circuit 1 are detected.

[0178] According to the inlet pressure and the inlet temperature of the electric compressor 111, the back gas superheat degree of the electric compressor 111 is determined.

[0179] According to the back gas superheat degree of the electric compressor 111, the liquid knock risk size of the electric compressor 111 is determined.

[0180] The first preset heat exchange amount, the second preset heat exchange amount, the third preset heat exchange amount and the fourth preset heat exchange amount mentioned in the above embodiments are all used to represent whether the corresponding energy is sufficient, and do not represent specific values.

[0181] The first preset inlet pressure, the second preset inlet pressure, the third preset inlet pressure and the fourth preset inlet pressure mentioned in the above embodiments are all used to represent the target throttling opening of the first throttling device 31 when the battery thermal management branch 3 is sufficient in energy, and can be set according to the inlet pressure corresponding to the target throttling opening, can be set to the same value, or can be set to different values with slight differences.

[0182] The first preset outlet pressure mentioned in the above embodiments corresponds to the outlet pressure reached when the target evaporation pressure is reached in the refrigeration mode, the second preset outlet pressure corresponds to the outlet pressure reached when the target condensation pressure is reached in the heating mode, and the third preset outlet pressure corresponds to the outlet pressure reached when the stable pressure environment of the battery pack heat exchange device 32 is reached in the refrigeration mode or the heating mode. In general, different values need to be set.

[0183] In some embodiments, as shown in FIG. 6, during the cooling process, the refrigerant becomes a high-temperature and high-pressure gas after being compressed by the electric compressor 111, at this time the first electromagnetic valve 121 is connected, the second electromagnetic valve 141 is closed, and then the refrigerant is condensed into a supercooled liquid phase in the condenser 131, and after being depressurized by the third electromagnetic valve 231, the thermal expansion valve 221 and the first electronic expansion valve 311, it becomes a saturated gas-liquid mixed two-phase state, evaporates into a superheated saturated gas phase in the evaporator 211 and the battery pack heat exchange plate 321, and then returns to the inlet of the electric compressor 111. The circulation loop includes the electric compressor 111, the first electromagnetic valve 121, the condenser 131 and the pressure sensor 151 connected in sequence and communicated at the ends along the flow direction of the refrigerant. After passing through the pressure sensor 151, the air conditioner thermal management branch 2 and the battery thermal management branch 3 are formed in parallel. The air conditioner thermal management branch 2 includes the third electromagnetic valve 231, the thermal expansion valve 221 and the evaporator 211 connected in sequence along the flow direction of the refrigerant. The battery thermal management branch 3 includes the first electronic expansion valve 311, the first temperature and pressure sensor 341, the battery pack heat exchange plate 321, the second temperature and pressure sensor 351 and the second electronic expansion valve 331 connected in sequence along the flow direction of the refrigerant. Then the air conditioner thermal management branch and the battery thermal management branch converge, pass through the plate heat exchanger 421 and the third temperature and pressure sensor 161, and then enter the electric compressor 111.

[0184] In the cooling process, the PTC heater 411 does not work, and the plate heat exchanger 421 is equivalent to an ordinary pipeline.

[0185] In single and double open priority battery cooling (such as high temperature direct current charging, continuous severe driving conditions, battery temperature is too high and other thermal load serious working conditions, which will preferentially meet the battery cooling demand, otherwise it will prolong the charging time, affect the vehicle power output, and even cause thermal runaway problem), that is, in the case of sufficient cold quantity, the second temperature and pressure sensor 351 collects the outlet temperature and pressure signal of the battery pack heat exchange plate 321. According to the signal, the outlet overheating degree of the battery pack heat exchange plate 321 can be obtained. If the outlet overheating degree is higher than the preset target overheating degree, the opening of the first electronic expansion valve 311 is increased. If the outlet overheating degree is lower than the preset target overheating degree, the opening of the first electronic expansion valve 311 is reduced, until the outlet overheating degree and the preset target overheating degree are consistent. According to the signal, the outlet pressure of the battery pack heat exchange plate 321 can also be obtained. If the outlet pressure is higher than the preset target pressure, the opening of the second electronic expansion valve 331 is increased. If the outlet pressure is lower than the preset target pressure, the opening of the second electronic expansion valve 331 is reduced, until the outlet pressure of the battery pack heat exchange plate 321 and the preset target pressure are consistent, so as to realize the working temperature and temperature difference requirements of the battery pack.

[0186] In the double open priority passenger cabin (evaporator) cooling, that is, in the case of insufficient cold quantity, the outlet temperature and pressure signal of the battery pack heat exchange plate 321 are also collected by the second temperature and pressure sensor 351. According to the signal, the outlet overheating degree of the battery pack heat exchange plate 321 is obtained. At this time, since the system needs to preferentially provide cold quantity to the air conditioning thermal management branch 2, the first electronic expansion valve 311 will be limited to a small opening to limit the supply of cold quantity to the battery thermal management branch 3. At this time, if the evaporation pressure of the battery pack heat exchange plate 321 is not controlled, the liquid refrigerant will be lost too quickly in the battery pack heat exchange plate 321, so that part of the battery cells in the battery pack are cooled, and the other part of the battery cells are not cooled, resulting in large temperature difference of the battery pack. Therefore, the opening of the second electronic expansion valve 331 is controlled to regulate the evaporation pressure of the battery pack heat exchange plate 321, so as to raise the evaporation temperature in the battery pack heat exchange plate 321, increase the range of liquid refrigerant flow, reduce the proportion of gaseous refrigerant, and enhance the battery temperature uniformity.

[0187] In some embodiments, as shown in FIG. 7, during the heating process, the refrigerant is compressed into a high-temperature and high-pressure gas by the electric compressor 111, at which time the first solenoid valve 121 is closed and the second solenoid valve 141 is connected, and after being throttled and depressurized by the third solenoid valve 231, the thermal expansion valve 221 and the first electronic expansion valve 311, the refrigerant becomes a saturated gas-liquid mixed two-phase state, is condensed into a supercooled liquid phase in the battery pack heat exchange plate 321, and after being further throttled, flows into the plate heat exchanger 421. The plate heat exchanger 421 exchanges heat with the PTC heater 411 to ensure that the refrigerant is a superheated saturated gas and then returns to the inlet of the electric compressor 111. The circulation loop includes the electric compressor 111, the second solenoid valve 141, and the pressure sensor 151 connected in series in the direction of refrigerant flow. After passing through the pressure sensor 151, the air conditioning thermal management branch 2 and the battery thermal management branch 3 are formed in parallel. The air conditioning thermal management branch 2 includes the third solenoid valve 231, the thermal expansion valve 221, and the evaporator 211 connected in series in the direction of refrigerant flow. The battery thermal management branch 3 includes the first electronic expansion valve 311, the first temperature and pressure sensor 341, the battery pack heat exchange plate 321, the second temperature and pressure sensor 351, and the second electronic expansion valve 331 connected in series in the direction of refrigerant flow. Then, the air conditioning thermal management branch and the battery thermal management branch converge, pass through the plate heat exchanger 421 and the third temperature and pressure sensor 161, and then enter the electric compressor 111.

[0188] In the heating process, the double-opening condition must first ensure the comfort of the passenger compartment in a low-temperature environment, otherwise it will affect the safety of the driver and passengers. Therefore, the double-opening condition defaults to prioritize passenger compartment heating.

[0189] In the single-opening (low-temperature charging, etc.) and double-opening conditions with sufficient heat, the second temperature and pressure sensor 351 collects the outlet temperature and pressure signals of the battery pack heat exchange plate 321. According to the signals, the outlet supercooling degree of the battery pack heat exchange plate 321 can be obtained. If the outlet supercooling degree is higher than the preset target supercooling degree, the first electronic expansion valve 311 increases the opening degree. If the outlet supercooling degree is lower than the preset target supercooling degree, the first electronic expansion valve 311 decreases the opening degree until the outlet supercooling degree is consistent with the preset target supercooling degree. According to the signals, the outlet pressure of the battery pack heat exchange plate 321 can also be obtained. If the outlet pressure is higher than the target pressure, the second electronic expansion valve 331 increases the opening degree. If the outlet pressure is lower than the preset target pressure, the second electronic expansion valve 331 decreases the opening degree until the outlet pressure of the battery pack heat exchange plate 321 is consistent with the preset target pressure, so as to realize the working temperature and temperature difference requirements of the battery pack.

[0190] In the double-opening heat deficiency working condition, the outlet temperature and pressure signals of the battery pack heat exchange plate 321 are collected by the second temperature and pressure sensor 351, and the outlet supercooling degree of the battery pack heat exchange plate 321 is obtained according to the signals. However, at this time, the first electronic expansion valve 311 is limited to a small opening degree to limit the heat supply to the battery heat management branch 3, because the system needs to preferentially provide heat to the air conditioning heat management branch 2. At this time, if the condensing pressure of the battery pack heat exchange plate 321 is not controlled, the gaseous refrigerant will be lost too quickly in the battery pack heat exchange plate 321, so that some battery cells in the battery pack are heated, and the other battery cells are not heated, resulting in a large temperature difference of the battery pack. Therefore, the opening degree of the second electronic expansion valve 331 is controlled to regulate the condensing pressure of the battery pack heat exchange plate 321, so as to reduce the condensing temperature in the battery pack heat exchange plate 321, increase the range of gaseous refrigerant flowing through, reduce the proportion of liquid refrigerant, and enhance the battery temperature uniformity. The plate exchange 421 is connected to the refrigerant flow channel on one side, and exchanges heat with the PTC heater 411 on the other side, so that the refrigerant is completely converted into a superheated saturated gas.

[0191] According to a fifth aspect of the present disclosure, a vehicle is provided, which comprises the heat management system in any of the above embodiments. The vehicle has all the beneficial effects of the heat management system, which will not be repeated here.

[0192] The vehicle can be a new energy vehicle such as a pure electric vehicle, a plug-in hybrid electric vehicle, or a range-extended hybrid electric vehicle, which is not specifically limited in the present disclosure.

[0193] The present disclosure adjusts the working temperature of the battery pack heat exchange plate through the throttling device electronic expansion valve and the temperature and pressure sensor. In the cooling and heating process, the temperature of the battery and the passenger compartment can be controlled according to the system capacity and the respective thermal load, so as to adapt to the different needs of the two, adjust the temperature difference of the battery pack, and improve the battery pack temperature uniformity.

[0194] The present disclosure installs temperature and pressure sensors and electronic expansion valves before and after the battery pack heat exchange plate. The control of each component is simple and easy to develop, and the temperature and pressure of each part of the battery can be easily monitored, so as to adjust the temperature distribution. The electronic expansion valve of the throttling device can raise or lower the temperature of the battery pack heat exchange plate, which avoids the risk of safety caused by the too low or too high temperature of the local battery cell in the direct cooling and direct heating process, such as lithium precipitation and thermal runaway.

[0195] In the description of the present disclosure, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" can explicitly or implicitly include one or more features. In the description of the present disclosure, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0196] In the above embodiments, the description of each embodiment is focused on, and the part not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0197] The embodiments, implementation manners and related technical features of the present disclosure can be combined or replaced with each other without conflict.

[0198] The above is only a preferred embodiment of the present disclosure, and does not limit the present disclosure in any form. Although the present disclosure has been described in examples, the description of each embodiment is focused on, and the part not described in detail in a certain embodiment can be referred to the related description of other embodiments. Any brief introduction, modification, equivalent change and modification of the above embodiments made according to the technical essence of the present disclosure without departing from the technical solution content of the present disclosure still belong to the scope of the technical solution of the present disclosure.

Claims

1. A battery thermal management branch (3), characterized by, The battery thermal management branch comprises: a first throttling device (31), a battery pack heat exchange device (32) and a second throttling device (33) connected in sequence along a heat exchange medium transmission direction; the first throttling device and the second throttling device are used for adjusting the pressure of the battery pack heat exchange device; the battery pack heat exchange device is used for heat exchange of the battery pack.

2. The battery thermal management branch of claim 1, wherein, The first throttling device comprises a first electronic expansion valve (311), and / or the second throttling device comprises a second electronic expansion valve (331).

3. The battery thermal management branch of claim 1 or 2, wherein, The battery thermal management branch further comprises: a first temperature and pressure sensor (341) and a second temperature and pressure sensor (351); the first temperature and pressure sensor is arranged between the outlet of the first throttling device and the inlet of the battery pack heat exchange device; and the second temperature and pressure sensor is arranged between the outlet of the battery pack heat exchange device and the inlet of the second throttling device.

4. A battery thermal management method, characterized by, The battery thermal management method is applied to the battery thermal management branch of any one of claims 1 to 3; the battery thermal management method comprises: controlling the throttling opening of the first throttling device and the second throttling device according to the heat exchange requirement of the battery pack heat exchange device and the supply heat exchange amount of the battery thermal management branch.

5. The battery thermal management method of claim 4, wherein, The controlling the throttling opening of the first throttling device and the second throttling device according to the heat exchange requirement of the battery pack heat exchange device and the supply heat exchange amount of the battery thermal management branch comprises: when the supply heat exchange amount of the battery thermal management branch is less than a first preset heat exchange amount, detecting the inlet pressure and the outlet pressure of the battery pack heat exchange device, and controlling the throttling opening of the first throttling device and the second throttling device according to the inlet pressure and the outlet pressure.

6. The battery thermal management method of claim 5, wherein, The first preset heat exchange amount comprises a preset refrigeration amount, and the controlling the throttling opening of the first throttling device and the second throttling device according to the heat exchange requirement of the battery pack heat exchange device and the supply heat exchange amount of the battery thermal management branch comprises: when the heat exchange requirement of the battery pack heat exchange device is refrigeration requirement, and the supply refrigeration amount of the battery thermal management branch is less than the preset refrigeration amount, detecting the inlet pressure and the outlet pressure of the battery pack heat exchange device; if the inlet pressure is greater than a first preset inlet pressure, reducing the throttling opening of the first throttling device; after adjusting the throttling opening of the first throttling device, if the outlet pressure is less than a first preset outlet pressure, reducing the throttling opening of the second throttling device.

7. The battery thermal management method of claim 5 or 6, wherein, The first preset heat exchange amount comprises a preset heating amount, and the controlling the throttling opening of the first throttling device and the second throttling device according to the heat exchange requirement of the battery pack heat exchange device and the supply heat exchange amount of the battery thermal management branch comprises: when the heat exchange requirement of the battery pack heat exchange device is heating requirement, and the supply heating amount of the battery thermal management branch is less than the preset heating amount, detecting the inlet pressure and the outlet pressure of the battery pack heat exchange device; if the inlet pressure is greater than a second preset inlet pressure, then reducing the throttling opening of the first throttling device; after adjusting the throttling opening of the first throttling device, if the outlet pressure is greater than a second preset outlet pressure, then increasing the throttling opening of the second throttling device.

8. The battery thermal management method of any one of claims 4 to 7, wherein, The control of the throttling openings of the first throttling device and the second throttling device according to the heat exchange demand of the battery pack heat exchange device and the supply heat exchange amount of the battery thermal management branch includes: detecting the inlet pressure and the outlet pressure of the battery pack heat exchange device when the supply heat exchange amount of the battery thermal management branch is greater than a second preset heat exchange amount; if the inlet pressure is less than a third preset inlet pressure, then increasing the throttling opening of the first throttling device; after adjusting the throttling opening of the first throttling device, if the outlet pressure is greater than a third preset outlet pressure, then increasing the throttling opening of the second throttling device; or, after adjusting the throttling opening of the first throttling device, if the outlet pressure is less than the third preset outlet pressure, then reducing the throttling opening of the second throttling device.

9. The battery thermal management method of any one of claims 4 to 8, wherein, The control of the throttling openings of the first throttling device and the second throttling device according to the heat exchange demand of the battery pack heat exchange device and the supply heat exchange amount of the battery thermal management branch includes: detecting the inlet pressure and the outlet temperature of the battery pack heat exchange device when the supply heat exchange amount of the battery thermal management branch is greater than a third preset heat exchange amount; if the inlet pressure is less than a fourth preset inlet pressure, then increasing the throttling opening of the first throttling device; after adjusting the throttling opening of the first throttling device, if the heat exchange demand of the battery pack heat exchange device is refrigeration demand and the outlet superheat degree corresponding to the outlet temperature is greater than a preset superheat degree, then increasing the throttling opening of the first throttling device, if the heat exchange demand of the battery pack heat exchange device is refrigeration demand and the outlet superheat degree corresponding to the outlet temperature is less than the preset superheat degree, then reducing the throttling opening of the first throttling device; or, after adjusting the throttling opening of the first throttling device, if the heat exchange demand of the battery pack heat exchange device is heating demand and the outlet subcooling degree corresponding to the outlet temperature is greater than a preset subcooling degree, then increasing the throttling opening of the first throttling device, if the heat exchange demand of the battery pack heat exchange device is heating demand and the outlet subcooling degree corresponding to the outlet temperature is less than the preset subcooling degree, then reducing the throttling opening of the first throttling device.

10. The battery thermal management method of any one of claims 4 to 9, wherein, The battery thermal management method further includes: detecting the inlet pressure and the inlet temperature of the battery pack heat exchange device; detecting the throttling effect of the first throttling device and the second throttling device according to the inlet pressure, the inlet temperature, the system target pressure and the system target temperature of the battery pack heat exchange device.

11. The battery thermal management method of any one of claims 4 to 10, wherein, The inlet pressure and the inlet temperature of the battery pack heat exchange device are obtained by a first temperature and pressure sensor, and the outlet pressure and the outlet temperature of the battery pack heat exchange device are obtained by a second temperature and pressure sensor.

12. A thermal management system characterized by, The thermal management system includes the battery thermal management branch and the main circuit (1), the air conditioning thermal management branch (2) of any one of claims 1 to 3. The outlet of the main circuit is connected with the inlet of the first throttling device and the inlet of the air-conditioning heat management branch respectively, and the inlet of the main circuit is connected with the outlet of the second throttling device and the outlet of the air-conditioning heat management branch respectively; The main circuit is used for providing energy required by heat management to the battery heat management branch and the air-conditioning heat management branch respectively.

13. The thermal management system of claim 12, wherein, The main circuit comprises a third temperature and pressure sensor (161), an electric compressor (111), a first electromagnetic valve (121), a condenser (131) and a pressure sensor (151) connected in sequence. The third temperature and pressure sensor is arranged between the outlet of the second throttling device and the inlet of the electric compressor, and the pressure sensor is arranged between the outlet of the condenser and the inlet of the first throttling device.

14. The thermal management system of claim 13, wherein, The main circuit further comprises a second electromagnetic valve (141) arranged between the inlet of the first electromagnetic valve and the outlet of the condenser.

15. The thermal management system of any one of claims 12 to 14, wherein, The air-conditioning heat management branch comprises an evaporator (211), a thermal expansion valve (221) and a third electromagnetic valve (231) connected in sequence. The outlet of the evaporator is connected with the inlet of the main circuit, and the inlet of the third electromagnetic valve is connected with the outlet of the main circuit.

16. The thermal management system of any one of claims 12 to 15, wherein, The heat management system further comprises a heating circuit (4) comprising a PTC heater (411) and a plate exchanger (421). The plate exchanger is arranged between the outlet of the second throttling device and the inlet of the main circuit. The PTC heater is connected with the plate exchanger and is used for heat exchange with the plate exchanger.

17. A method of controlling a thermal management system, the method comprising: The heat management system control method is applied to the heat management system according to any one of claims 12 to 16, and comprises: According to the output heat exchange amount of the main circuit and the heat management working condition, the supply heat exchange amount provided to the battery heat management branch and the air-conditioning heat management branch is controlled respectively.

18. The thermal management system control method of claim 17, wherein, According to the output heat exchange amount of the main circuit and the heat management working condition, the supply heat exchange amount provided to the battery heat management branch and the air-conditioning heat management branch is controlled respectively. When the output heat exchange amount of the main circuit is greater than the fourth preset heat exchange amount and the heat management working condition is the battery and air-conditioning double-opening working condition, the supply heat exchange amount of the battery heat management branch and the air-conditioning heat management branch is increased respectively.

19. The thermal management system control method of claim 17 or 18, wherein, According to the output heat exchange amount of the main circuit and the heat management working condition, the supply heat exchange amount provided to the battery heat management branch and the air-conditioning heat management branch is controlled respectively. When the output heat exchange amount of the main circuit is less than the third preset heat exchange amount and the heat management working condition is the battery and air-conditioning double-opening but air-conditioning priority working condition, the supply heat exchange amount of the air-conditioning heat management branch is increased and the supply heat exchange amount of the battery heat management branch is decreased. ​ 20. The thermal management system control method of any one of claims 17-19, wherein, The heat management system further comprises a heating circuit connected between the outlet of the second throttling device and the inlet of the main circuit; the heat management system control method further comprises: when the heat exchange demand of the battery heat management branch and / or the air conditioner heat management branch is a heating demand, starting the heating circuit to heat the heat exchange medium flowing therethrough.

21. The thermal management system control method of any one of claims 17-20, wherein, The heat management system control method further comprises: detecting the inlet pressure and the inlet temperature of the electric compressor in the main circuit; determining the return gas superheat degree of the electric compressor according to the inlet pressure and the inlet temperature of the electric compressor; determining the liquid knock risk size of the electric compressor according to the return gas superheat degree of the electric compressor.

22. A vehicle characterized by comprising: The vehicle comprises the heat management system according to any one of claims 12 to 16.

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