Thermal management unit and control method thereof

Abstract

The invention discloses a heat management unit and a control method thereof. The heat management unit comprises a refrigerant circulating system, a secondary refrigerant circulating system, a water cooling unit controller and a battery management system. The secondary refrigerant circulating system comprises a water pump, a heat exchanger, a cooler and an electric heater which are sequentially communicated from a water outlet of the controlled object to a water inlet of the controlled object, the secondary refrigerant circulating system further comprises an electromagnetic valve, the electromagnetic valve is connected with the heat exchanger in parallel, and the secondary refrigerant circulating system is used for exchanging heat with the controlled object; the battery management system is in communication connection with the water chilling unit controller and is used for sending a control instruction to the water chilling unit controller; the water chilling unit controller is used for controlling the opening state of the electromagnetic valve according to the environment temperature and the water inlet set temperature of the controlled object so as to control whether the secondary refrigerant exchanges heat with air through the heat exchanger or not. The water chilling unit controller is further used for controlling the operation states of the compressor, the water pump, the electric heater and the fan according to the control instruction and the opening state of the electromagnetic valve. The energy consumption of the unit can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of thermal management technology, and in particular to a thermal management unit and a control method thereof. Background Art

[0002] With the continuous development of the new energy vehicle industry, new energy vehicles have begun to enter the commercial vehicle field, and the application scenarios have gradually become wider. The environmental conditions of vehicle thermal management units have become increasingly complex and harsh. At the same time, the battery capacity of commercial new energy vehicles, mainly mining vehicles and heavy trucks, is getting larger and larger, and the demand for cooling and heating of vehicle thermal management units is also increasing. Therefore, the power consumption of the thermal management unit itself is also increasing. How to reduce the energy consumption of the thermal management unit itself is becoming more and more important and urgent. Summary of the invention

[0003] The present invention provides a thermal management unit and a control method thereof, which can reduce the energy consumption of the thermal management unit.

[0004] In the first aspect, an embodiment of the present invention provides a thermal management unit, including: a refrigerant circulation system, a coolant circulation system, a water cooling unit controller and a battery management system; the refrigerant circulation system is used to provide a cold source for the coolant circulation system; the coolant circulation system includes a water pump, a heat exchanger, a cooler and an electric heater which are connected in sequence from the water outlet of the controlled object to the water inlet of the controlled object, and also includes a solenoid valve, which is connected in parallel with the heat exchanger, and the coolant circulation system is used to exchange heat with the controlled object; the battery management system is communicatively connected to the water cooling unit controller, and is used to send a control instruction to the water cooling unit controller; wherein the control instruction includes a cooling instruction or a heating instruction; the water cooling unit controller is used to control the opening state of the solenoid valve according to the control instruction, the ambient temperature and the water inlet set temperature of the controlled object, so as to control whether the coolant exchanges heat with the air through the heat exchanger; the thermal management unit also includes at least one fan, the refrigerant circulation system includes at least a compressor, and the water cooling unit controller is also used to control the operating state of the compressor, the water pump, the electric heater and the fan according to the control instruction and the opening state of the solenoid valve.

[0005] Optionally, the heat exchanger is a parallel flow heat exchanger.

[0006] Optionally, the refrigerant circulation system further includes a condenser, an expansion valve and a cooler; the compressor, the condenser, the expansion valve and the cooler are connected in sequence.

[0007] Optionally, the thermal management unit further includes a box body, and the compressor, condenser, expansion valve, cooler, water pump, fan, solenoid valve, heat exchanger and electric heater are all arranged in the box body, and the box body is provided with heat dissipation holes.

[0008] Optionally, the refrigerant circulation system further includes a fan arranged on one side of the housing close to the condenser and the heat exchanger.

[0009] Optionally, the thermal management unit further includes an ambient temperature sensor, which is connected to the water cooling unit controller and is used to collect ambient temperature.

[0010] In the second aspect, an embodiment of the present invention provides a control method for a thermal management unit, which is used for the thermal management unit provided by any embodiment of the present invention, and the control method includes: obtaining a control instruction sent by a battery management system; wherein the control instruction includes a heating instruction and a cooling instruction; controlling the opening state of the solenoid valve according to the control instruction, the ambient temperature and the water inlet set temperature of the controlled object to control whether the refrigerant exchanges heat with the air through the heat exchanger; controlling the operating state of the compressor, water pump, electric heater and fan according to the control instruction and the opening state of the solenoid valve.

[0011] Optionally, according to the control instruction and the opening state of the solenoid valve, the step of controlling the operating state of the compressor, water pump, electric heater and fan in the refrigeration cycle system includes: when the control instruction is a cooling instruction, the compressor, water pump and fan are controlled to operate, and the electric heater is controlled not to operate; when the control instruction is a heating instruction and the solenoid valve is opened, the electric heater and water pump are controlled to operate, and the compressor and fan are controlled not to operate; when the control instruction is a heating instruction and the solenoid valve is closed, the electric heater, water pump and fan are controlled to operate, and the compressor is controlled not to operate.

[0012] Optionally, the step of controlling the opening state of the solenoid valve according to the control instruction, the ambient temperature and the set temperature of the water inlet of the controlled object to control whether the refrigerant exchanges heat with the air through the heat exchanger includes: when the control instruction is a cooling instruction, and the difference between the set temperature of the water inlet of the controlled object and the ambient temperature is less than the set temperature, the solenoid valve is controlled to open to control the refrigerant not to exchange heat with the air through the heat exchanger; when the control instruction is a cooling instruction, and the difference between the set temperature of the water inlet of the controlled object and the ambient temperature is greater than or equal to the set temperature, the solenoid valve is controlled to close to control the refrigerant to exchange heat with the air through the heat exchanger; when the control instruction is a heating instruction, and the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is less than the set temperature, the solenoid valve is controlled to open to control the refrigerant not to exchange heat with the air through the heat exchanger; when the control instruction is a heating instruction, and the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is greater than or equal to the set temperature, the solenoid valve is controlled to close to control the refrigerant to exchange heat with the air through the heat exchanger.

[0013] Optionally, the temperature is set at 3-5°C.

[0014] The thermal management unit provided by the embodiment of the present invention includes a refrigerant circulation system, a coolant circulation system, a water cooling unit controller and a battery management system. The water cooling unit controller intelligently controls the opening state of the solenoid valve in combination with the control instruction, the ambient temperature and the water inlet set temperature of the controlled object. For example, under the refrigeration instruction, if the difference between the water inlet set temperature of the controlled object and the ambient temperature is less than the set temperature, the solenoid valve is controlled to open, and the coolant does not exchange heat with the air through the heat exchanger. This is because in this case, heat exchange with the air through the heat exchanger may cause the coolant to be heated unnecessarily, affecting the refrigeration effect, and also consuming additional energy to maintain the refrigeration state. When the difference between the water inlet set temperature of the controlled object and the ambient temperature is greater than or equal to the set temperature, the solenoid valve is closed to allow the coolant to exchange heat with the air through the heat exchanger, which can better utilize the low ambient temperature to enhance the refrigeration effect, and is an optimization performed under the condition of reasonable use of energy. When the heating instruction is issued, similarly, when the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is less than the set temperature, the solenoid valve is opened to prevent the refrigerant from losing heat in the heat exchanger, saving the energy required to maintain heating; when the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is greater than or equal to the set temperature, the solenoid valve is closed to use air to promote heat exchange to enhance the heating effect, which is also to achieve energy saving by rationally utilizing energy at the right time. The water-cooling unit controller will also accurately control the operating status of the compressor, water pump, electric heater and fan according to the control instructions sent by the battery management system and the opening state of the solenoid valve. When a cooling instruction is received, only the compressor, water pump and fan are started to perform cooling-related operations, and the electric heater is controlled not to run, avoiding the electric heater from consuming additional electricity to generate heat when cooling is required, interfering with the cooling process and wasting electricity. Similarly, when a heating instruction is received and the solenoid valve is opened, the electric heater and water pump are controlled to run, and the compressor and fan are stopped to prevent the refrigeration cycle from consuming electricity unnecessarily when heating is required. This method of precisely controlling the operation of major energy-consuming components based on actual needs can effectively avoid unnecessary energy consumption.

[0015] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1is a schematic diagram of the system principle of a thermal management unit provided by an embodiment of the present invention;

[0018] Figure 2 It is a three-dimensional stereogram of a thermal management unit provided by an embodiment of the present invention;

[0019] Figure 3 is a flow chart of a control method for a thermal management unit provided by an embodiment of the present invention;

[0020] Figure 4 This is a flow chart of another control method for a thermal management unit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 should fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] Figure 1 Schematic diagram of the system principle of a thermal management unit provided by an embodiment of the present invention. Figure 1 As shown, the thermal management unit includes: a refrigerant circulation system 1, a coolant circulation system 2, a water cooling unit controller 3 and a battery management system 4.

[0024] The refrigerant circulation system 1 is used to provide a cold source for the coolant circulation system 2;

[0025] The refrigerant circulation system 2 includes a water pump 21, a heat exchanger 22, a cooler 23 and an electric heater 24, which are connected in sequence from the water outlet P1 of the controlled object 5 to the water inlet P2 of the controlled object, and also includes a solenoid valve 25, which is connected in parallel with the heat exchanger 22. The refrigerant circulation system 2 is used to exchange heat with the controlled object.

[0026] The battery management system 4 is in communication connection with the water cooling unit controller 3 and is used to send control instructions to the water cooling unit controller 3; wherein the control instructions include cooling instructions or heating instructions.

[0027] The water cooling unit controller 3 is used to control the opening state of the solenoid valve 25 according to the control instruction, the ambient temperature and the water inlet set temperature of the controlled object, so as to control whether the coolant exchanges heat with the air through the heat exchanger 22.

[0028] The thermal management unit also includes at least one fan 7, the refrigerant circulation system 1 includes at least a compressor 11, and the water cooling unit controller 3 is also used to control the operating status of the compressor 11, the water pump 21, the electric heater 24 and the fan 7 according to the control instructions and the opening status of the solenoid valve 25.

[0029] Specifically, the thermal management unit provided by the present invention can be used to heat or cool various controlled objects 5. Exemplarily, the controlled object 5 can be a battery pack. The battery pack includes a plurality of single cells connected in series and / or in parallel.

[0030] The heat exchanger 22 is a component for heat exchange between the coolant and the air. When the solenoid valve 25 is open, the coolant bypasses the heat exchanger 22 and flows directly to the cooler 23; when the solenoid valve 25 is closed, the coolant exchanges heat with the air through the heat exchanger 22, thereby changing the temperature of the coolant, thereby affecting the temperature control effect of the controlled object.

[0031] Optionally, the heat exchanger 22 is a parallel flow heat exchanger. The main structure of the parallel flow heat exchanger includes a header, a porous flat tube and a fin strip. Compared with other types of heat exchangers, it has high heat transfer efficiency, small size, compact structure, small space occupation, and less refrigerant usage.

[0032] Optionally, the electric heater 24 is a device that converts electrical energy into thermal energy. In the refrigerant circulation system 2 of the thermal management unit, when the controlled object 5 needs to be heated, the electric heater 24 works to provide heat for the refrigerant. After the refrigerant absorbs the heat generated by the electric heater, the temperature rises, and then the heat is transferred to the controlled object 5 (such as a battery pack) to achieve the temperature increase of the controlled object 5.

[0033] The embodiment of the present invention does not specifically limit the specific type of the electric heater 24. For example, the electric heater 24 can be an electric heater including a positive temperature coefficient (PTC) thermistor. The resistance value of the PTC thermistor increases with the increase of temperature. When current passes through the PTC thermistor, it starts to heat up. As the temperature rises, the resistance increases, causing the current to gradually decrease. When the heat generation and heat dissipation reach a balance, the temperature will stabilize near a specific value, thereby achieving a stable heating function.

[0034] Optionally, the water cooling unit controller 3 sends instructions to the compressor 11 through the controller area network (CAN) to control the start and stop and speed of the compressor 11, sends pulse width modulation (PWM) instructions to the water pump 21 and the fan 7 to control the start and stop and speed of the water pump 21 and the fan 7, sends instructions to the electric heater 24 to control the start and stop and gear of the electric heater 24, and sends instructions to the solenoid valve 25 to control the opening and closing status of the solenoid valve 25.

[0035] Optionally, the water cooling unit controller 3 may include a microcontroller. Exemplarily, the water cooling unit controller 3 may include a single chip microcomputer, a digital signal processor (DSP) or a field programmable gate array (FPGA).

[0036] The battery management system (BMS) is an electronic system used to manage and control the battery pack, and can monitor the temperature of each single cell in the battery pack in real time.

[0037] When the average temperature of each single cell is greater than or equal to the first setting value, or the highest temperature of each single cell is greater than or equal to the second setting value, the battery management system 4 sends a cooling instruction to the water cooling unit controller 3 (Thermal Management System, TMS). When the average temperature of each single cell is less than or equal to the third setting value, or the lowest temperature of each single cell is less than or equal to the fourth setting value, the battery management system 4 sends a heating instruction to the water cooling unit controller 3. Among them, the first setting value, the second setting value, the third setting value and the fourth setting value can be set according to actual conditions, and the embodiment of the present invention does not specifically limit this.

[0038] In order to further optimize the above technical solution, the cooling agent can be a CaCl2 aqueous solution or a 50% ethylene glycol solution. Of course, the cooling agent can also be salt water, which is not limited in the embodiment of the present invention.

[0039] In some embodiments, when the control instruction is a cooling instruction, and the difference between the set temperature of the water inlet of the controlled object and the ambient temperature is less than the set temperature, the control solenoid valve 25 is opened to control the coolant not to exchange heat with the air through the heat exchanger 22. When the control instruction is a cooling instruction, and the difference between the set temperature of the water inlet of the controlled object and the ambient temperature is greater than or equal to the set temperature, the control solenoid valve 25 is closed to control the coolant to exchange heat with the air through the heat exchanger 22.

[0040] Specifically, when the difference between the set water inlet temperature of the controlled object and the ambient temperature is small, it means that the ambient temperature is relatively high. At this time, if the coolant is allowed to exchange heat with the air through the heat exchanger 22, the coolant may absorb heat and increase the refrigeration burden. By controlling the solenoid valve 25 to open, unnecessary temperature rise of the coolant is avoided, reducing the refrigeration energy consumption.

[0041] When the difference between the set temperature of the water inlet of the controlled object and the ambient temperature is large, it means that the ambient temperature is relatively low. At this time, closing the solenoid valve 25 allows the refrigerant to exchange heat with the air through the heat exchanger 22, and the ambient air, a natural cold source, can be effectively used to reduce the temperature of the refrigerant. This can reduce the dependence on the refrigerant cycle system 1, because the operation of the refrigerant cycle system 1 requires the compressor 11 to consume electrical energy to achieve refrigeration. By utilizing the temperature difference between the ambient temperature and the refrigerant for heat exchange, the workload of the compressor 11 is reduced while meeting the refrigeration demand, thereby reducing the energy consumption of the entire system. For example, if the air temperature is very low in a cold weather environment, using air to cool the refrigerant can reduce the operating frequency of the compressor and reduce the operating time of the compressor 11, thereby saving energy.

[0042] In some embodiments, when the control instruction is a heating instruction, and the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is less than the set temperature, the control solenoid valve 25 is opened to control the coolant not to exchange heat with the air through the heat exchanger 22. When the control instruction is a heating instruction, and the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is greater than or equal to the set temperature, the control solenoid valve 25 is closed to control the coolant to exchange heat with the air through the heat exchanger 22.

[0043] Specifically, when the control instruction is a heating instruction, and the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is less than the set temperature, it means that the current ambient temperature is relatively low. At this time, if the refrigerant is allowed to exchange heat with the air through the heat exchanger 22, due to the relatively low ambient temperature, the refrigerant will release heat to the air during the heat exchange with the air in the heat exchanger 22, causing unnecessary heat loss. If this heat exchange is still performed, the electric heater 24 may need to consume more electrical energy to make up for this part of the lost heat, thereby increasing the overall energy consumption. Therefore, the control solenoid valve 25 is opened so that the refrigerant does not exchange heat with the air through the heat exchanger, which can avoid this unnecessary heat loss and save energy. When the control instruction is a heating instruction and the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is greater than or equal to the set temperature, it indicates that the ambient temperature is relatively high. At this time, the solenoid valve 25 is closed to allow the coolant to exchange heat with the air through the heat exchanger 22. When the coolant temperature is lower than the ambient temperature, the coolant will absorb heat from the air to increase the coolant temperature, rather than simply relying on the electric heater 24 to consume electric energy to increase the coolant temperature. In this way, the heat of the coolant itself can be used to a certain extent to achieve a moderate heat balance with the environment, reducing the electric energy consumed by the electric heater 24 alone to increase the coolant temperature, thereby achieving the purpose of energy saving. Optionally, the set temperature is 3 to 5°C.

[0044] Continue to refer Figure 1 Optionally, the refrigeration cycle system 1 further includes a condenser 12, an expansion valve 13 and a cooler 23. The compressor 11, the condenser 12, the expansion valve 13 and the cooler 23 are connected in sequence. Optionally, the expansion valve 13 can be a thermal expansion valve or an electronic expansion valve.

[0045] The refrigeration cycle process of the refrigerant circulation system 1 is as follows: the compressor 11 compresses the gaseous refrigerant into a high-temperature and high-pressure state, and then sends it to the condenser 12. In the condenser 12, the high-temperature and high-pressure refrigerant exchanges heat with the outside air, and the refrigerant releases heat and condenses into a liquid state. The liquid refrigerant is throttled and depressurized by the expansion valve, and becomes a low-temperature and low-pressure liquid and gas mixture, and enters the cooler 23. In the cooler 23, the low-temperature and low-pressure refrigerant mixture absorbs the heat of the refrigerant, lowering the temperature of the refrigerant, and vaporizes itself into a gaseous state, and then is sucked into the compressor 11 to start a new cycle.

[0046] In some embodiments, when the control instruction is a cooling instruction, the compressor 11, the water pump 25 and the fan 7 are controlled to operate, and the electric heater 24 is controlled not to operate. When the control instruction is a heating instruction and the solenoid valve 25 is opened, the electric heater 24 and the water pump 21 are controlled to operate, and the compressor 11 and the fan 7 are controlled not to operate. When the control instruction is a heating instruction and the solenoid valve 25 is closed, the electric heater 24, the water pump 25 and the fan 7 are controlled to operate, and the compressor 11 is controlled not to operate.

[0047] Specifically, under the cooling instruction, the water cooling unit controller 3 will control the operation of the compressor 11. The compressor 11 is the power source of the refrigerant circulation system 1. It compresses the gaseous refrigerant into a high-temperature and high-pressure state, and drives the refrigerant to circulate in the refrigerant circulation system 1, thereby achieving heat transfer and cooling effect. Whether it is a cooling or heating instruction, the water pump 21 needs to run. In the refrigerant circulation system 2, the water pump 21 is responsible for driving the refrigerant to circulate, so that it can transfer heat between various components, realize heat exchange with the controlled object 5 and heat exchange with the refrigerant circulation system 1. Under the heating instruction, the water cooling unit controller 3 will control the electric heater 24 to operate. The electric heater 25 is used to heat the refrigerant, thereby increasing the temperature of the refrigerant, and then transfer the heat to the controlled object to achieve a heating effect.

[0048] When cooling is required or the solenoid valve 25 is closed to allow the coolant to exchange heat with the air through the heat exchanger 22, the fan 7 works to increase the flow rate of the air around the condenser 12 and the heat exchanger 22, thereby enhancing the heat transfer between the refrigerant or coolant and the air.

[0049] It should be noted that the thermal management unit provided in the embodiment of the present invention can be applied to various devices using battery packs and can be used in various transportation vehicles, for example, electric buses, logistics vehicles, heavy trucks, light trucks and other types of vehicles.

[0050] The thermal management unit provided by the embodiment of the present invention includes a refrigerant circulation system, a coolant circulation system, a water cooling unit controller and a battery management system. The water cooling unit controller intelligently controls the opening state of the solenoid valve in combination with the control instruction, the ambient temperature and the water inlet set temperature of the controlled object. For example, under the refrigeration instruction, if the difference between the water inlet set temperature of the controlled object and the ambient temperature is less than the set temperature, the solenoid valve is controlled to open, and the coolant does not exchange heat with the air through the heat exchanger. This is because in this case, heat exchange with the air through the heat exchanger may cause the coolant to be heated unnecessarily, affecting the refrigeration effect, and also consuming additional energy to maintain the refrigeration state. When the difference between the water inlet set temperature of the controlled object and the ambient temperature is greater than or equal to the set temperature, the solenoid valve is closed to allow the coolant to exchange heat with the air through the heat exchanger, which can better utilize the low ambient temperature to enhance the refrigeration effect, and is an optimization performed under the condition of reasonable use of energy. When the heating instruction is issued, similarly, when the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is less than the set temperature, the solenoid valve is opened to prevent the refrigerant from losing heat in the heat exchanger, saving the energy required to maintain heating; when the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is greater than or equal to the set temperature, the solenoid valve is closed to use air to promote heat exchange to enhance the heating effect, which is also to achieve energy saving by rationally utilizing energy at the right time. The water-cooling unit controller will also accurately control the operating status of the compressor, water pump, electric heater and fan according to the control instructions sent by the battery management system and the opening state of the solenoid valve. When a cooling instruction is received, only the compressor, water pump and fan are started to perform cooling-related operations, and the electric heater is controlled not to run, avoiding the electric heater from consuming additional electricity to generate heat when cooling is required, interfering with the cooling process and wasting electricity. Similarly, when a heating instruction is received and the solenoid valve is opened, the electric heater and water pump are controlled to run, and the compressor and fan are stopped to prevent the refrigeration cycle from consuming electricity unnecessarily when heating is required. This method of precisely controlling the operation of major energy-consuming components based on actual needs can effectively avoid unnecessary energy consumption.

[0051] Figure 2 3D diagram of a thermal management unit provided by an embodiment of the present invention. Figure 1 and Figure 2 The thermal management unit also includes a box body 6, a compressor 11, a condenser 12, an expansion valve 13, a cooler 23, a water pump 21, a solenoid valve 25, a heat exchanger 22 and an electric heater 24 are all arranged in the box body 6, and the box body 6 is provided with heat dissipation holes.

[0052] Continue to refer Figure 1 and Figure 2Optionally, the fan 7 is disposed on one side of the housing 6 close to the condenser 12 and the heat exchanger 22. Optionally, the fan 7 may be a variable frequency fan, so that the speed of the variable frequency fan can be adjusted according to the ambient temperature, thereby adjusting the air volume to improve the heat exchange effect. It is understandable that the number of fans 7 can be set according to the actual air volume required, and the embodiment of the present invention is not limited here.

[0053] Continue to refer Figure 1 Optionally, the thermal management unit further includes an ambient temperature sensor 9, which is connected to the water cooling unit controller 3 and is used to collect ambient temperature.

[0054] Continue to refer Figure 1 Optionally, the refrigerant cycle system 1 also includes at least one needle valve 10, and the at least one needle valve 10 includes a first needle valve and a second needle valve, the first needle valve is arranged between the condenser 12 and the expansion valve 13, and the second needle valve is arranged between the outlet of the cooler 23 and the inlet of the compressor 11.

[0055] Specifically, the needle valve 10 can be used to connect a pressure gauge to measure the system pressure for maintenance, evacuate the refrigeration system, and recharge the refrigerant.

[0056] Continue to refer Figure 1 Optionally, the brine circulation system 2 further includes an expansion water tank 26, which is disposed between the water outlet P1 of the controlled object 5 and the water pump 21. Based on the principle of thermal expansion and contraction of liquid and pressure balance, the expansion water tank 26 provides space for the volume change of the brine, thereby preventing the brine circulation system 2 from being over-pressured or over-pressured due to the temperature change of the brine. At the same time, the brine circulation system 2 is located at a high position in the brine circulation system, so that air is gathered there and discharged through the exhaust port, thereby improving the purity of the brine, ensuring the heat exchange efficiency and stable operation of the system.

[0057] Specifically, during the operation of the refrigerant circulation system 2, when the temperature of the refrigerant increases, the distance between its molecules increases, resulting in volume expansion. The expansion water tank 26 is connected to the refrigerant circulation system 2 to provide a storage space for the expanded refrigerant. For example, when the refrigerant of the thermal management unit rises in temperature during a heating process (such as heating by the electric heater 24 in the heating mode) or during operation due to the absorption of heat, the volume of the refrigerant increases, and the excess refrigerant will flow into the expansion water tank 26. On the contrary, when the temperature of the refrigerant decreases and the volume shrinks, the refrigerant in the expansion water tank 26 will flow back to the refrigerant circulation system 2 under the action of gravity or system pressure difference, replenishing the volume of the refrigerant in the refrigerant circulation system 2 and maintaining the normal operation of the refrigerant circulation system 2.

[0058] Continue to refer Figure 1Optionally, the refrigerant cycle system 1 also includes at least one pressure sensor 14, and the at least one pressure sensor 14 includes a first pressure sensor and a second pressure sensor. The first pressure sensor is arranged on the inlet side of the compressor 11, and the second pressure sensor is arranged on the outlet side of the compressor 11. The water cooling unit controller 3 adjusts the operating frequency of the compressor 11 according to the pressure difference between the inlet side and the outlet side to achieve more efficient refrigeration and more stable system performance.

[0059] Continue to refer Figure 1 Optionally, the refrigeration cycle system 1 further includes at least one temperature sensor 15 , and the at least one temperature sensor 15 includes a first temperature sensor and a second temperature sensor, the first temperature sensor is arranged at the inlet side of the compressor 11 , and the second temperature sensor is arranged at the outlet side of the compressor 11 .

[0060] Specifically, the first temperature sensor monitors the temperature of the refrigerant entering the compressor 11 to prevent the refrigerant with too low a temperature from entering the compressor 11 and causing liquid hammer. Liquid hammer may damage the blades and other internal structures of the compressor 11, seriously affecting the service life and performance of the compressor 11. For example, if the cooler 23 works abnormally, so that a large amount of liquid refrigerant flows to the compressor 11 without completely evaporating, the first temperature sensor detects that the temperature is too low, and the water cooling unit controller 3 can adjust the opening of the expansion valve 12 to prevent liquid refrigerant from entering the compressor 11.

[0061] The second temperature sensor can be used to measure the temperature of the refrigerant discharged from the compressor 11. A too high exhaust temperature indicates that the compressor 11 is working abnormally. For example, it may be caused by excessive friction inside the compressor 11 or too low suction pressure. By continuously monitoring the exhaust temperature of the compressor 11, potential problems of the compressor 11 can be discovered in time to avoid damage to the compressor due to overheating.

[0062] Based on the same inventive concept, an embodiment of the present invention further provides a control method for a thermal management unit, which is used for the thermal management unit provided by any of the above embodiments of the present invention. Figure 3 FIG. 1 is a flow chart of a control method for a thermal management unit provided by an embodiment of the present invention. Figure 3 As shown, the control method includes:

[0063] S101. Obtain a control instruction sent by a battery management system.

[0064] The control instructions include heating instructions and cooling instructions.

[0065] S102, controlling the opening state of the solenoid valve according to the control instruction, the ambient temperature and the water inlet setting temperature of the controlled object to control whether the coolant exchanges heat with the air through the heat exchanger.

[0066] S103, controlling the operating states of the compressor, water pump, electric heater and fan according to the control instruction and the opening state of the solenoid valve.

[0067] Figure 4 This is a flow chart of another control method for a thermal management unit provided in an embodiment of the present invention.

[0068] like Figure 4 As shown, the control method includes:

[0069] S201. Obtain a control instruction sent by a battery management system.

[0070] For example, in an electric vehicle, both TMS and BMS are part of the vehicle electronic system and are connected via a CAN bus. The BMS sends control instructions in the form of data frames to the bus according to the CAN protocol, and the TMS receives these data frames on the bus.

[0071] When the average temperature of each single cell is greater than or equal to the first setting value, or the highest temperature of each single cell is greater than or equal to the second setting value, the battery management system 4 sends a cooling instruction to the water cooling unit controller. When the average temperature of each single cell is less than or equal to the third setting value, or the lowest temperature of each single cell is less than or equal to the fourth setting value, the battery management system sends a heating instruction to the water cooling unit controller.

[0072] S202: When the control instruction is a cooling instruction and the difference between the set temperature of the water inlet of the controlled object and the ambient temperature is less than the set temperature, the solenoid valve is controlled to open to control the refrigerant not to exchange heat with the air through the heat exchanger.

[0073] S203. When the control instruction is a cooling instruction and the difference between the set temperature of the water inlet of the controlled object and the ambient temperature is greater than or equal to the set temperature, the solenoid valve is controlled to close to control the refrigerant to exchange heat with the air through the heat exchanger.

[0074] S204: When the control instruction is a heating instruction and the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is less than the set temperature, the solenoid valve is controlled to open to control the refrigerant not to exchange heat with the air through the heat exchanger.

[0075] S205. When the control instruction is a heating instruction, and the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is greater than or equal to the set temperature, the solenoid valve is controlled to close to control the coolant to exchange heat with the air through the heat exchanger.

[0076] S206: When the control instruction is a cooling instruction, the compressor, the water pump and the fan are controlled to operate, and the electric heater is controlled not to operate.

[0077] S207: When the control instruction is a heating instruction and the solenoid valve is open, the electric heater and the water pump are controlled to operate, and the compressor and the fan are controlled not to operate.

[0078] S208: When the control instruction is a heating instruction and the solenoid valve is closed, the electric heater, the water pump and the fan are controlled to operate, and the compressor is controlled not to operate.

[0079] The control method of the thermal management unit is similar to the technical principle and technical effect of the thermal management unit provided in any embodiment of the present invention. The similarities can be referred to the explanation of the thermal management unit, which will not be repeated here.

[0080] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0081] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermal management unit, characterized in that: include: Refrigerant circulation system, coolant circulation system, water cooling unit controller and battery management system; The refrigerant circulation system is used to provide a cold source for the coolant circulation system; The brine circulation system includes a water pump, a heat exchanger, a cooler and an electric heater which are sequentially connected from the water outlet of the controlled object to the water inlet of the controlled object, and also includes a solenoid valve which is connected in parallel with the heat exchanger. The brine circulation system is used to exchange heat with the controlled object; The battery management system is in communication connection with the water cooling unit controller, and is used to send a control instruction to the water cooling unit controller; wherein the control instruction includes a cooling instruction or a heating instruction; The water cooling unit controller is used to control the opening state of the solenoid valve according to the control instruction, the ambient temperature and the water inlet set temperature of the controlled object, so as to control whether the coolant exchanges heat with the air through the heat exchanger; The thermal management unit also includes at least one fan, the refrigerant circulation system includes at least a compressor, and the water cooling unit controller is also used to control the operating status of the compressor, the water pump, the electric heater and the fan according to the control instruction and the opening status of the solenoid valve.

2. The thermal management unit according to claim 1, characterized in that: The heat exchanger is a parallel flow heat exchanger.

3. The thermal management unit according to claim 1, characterized in that: The refrigerant circulation system further comprises a condenser, an expansion valve and the cooler; The compressor, the condenser, the expansion valve and the cooler are connected in sequence.

4. The thermal management unit according to claim 3, characterized in that: The thermal management unit also includes a box body, and the compressor, the condenser, the expansion valve, the cooler, the water pump, the solenoid valve, the fan, the heat exchanger and the electric heater are all arranged in the box body, and the box body is provided with heat dissipation holes.

5. The thermal management unit according to claim 4, characterized in that: The fan is arranged on a side of the box body close to the condenser and the heat exchanger.

6. The thermal management unit according to claim 1, characterized in that: The thermal management unit also includes an ambient temperature sensor, which is connected to the water cooling unit controller and is used to collect the ambient temperature.

7. A control method for a thermal management unit, characterized in that: For the thermal management unit according to any one of claims 1 to 6, the control method comprises: Obtaining a control instruction sent by the battery management system; wherein the control instruction includes a heating instruction and a cooling instruction; Controlling the opening state of the solenoid valve according to the control instruction, the ambient temperature and the set temperature of the water inlet of the controlled object to control whether the coolant exchanges heat with the air through the heat exchanger; According to the control instruction and the opening state of the solenoid valve, the operating states of the compressor, the water pump, the electric heater and the fan are controlled.

8. The control method of the thermal management unit according to claim 7, characterized in that: The step of controlling the operating states of the compressor, the water pump, the electric heater and the fan in the refrigerant cycle system according to the control instruction and the opening state of the solenoid valve comprises: When the control instruction is the cooling instruction, the compressor, the water pump and the fan are controlled to operate, and the electric heater is controlled not to operate; When the control instruction is the heating instruction and the solenoid valve is open, the electric heater and the water pump are controlled to operate, and the compressor and the fan are controlled not to operate; When the control instruction is the heating instruction and the solenoid valve is closed, the electric heater, the water pump and the fan are controlled to operate, and the compressor is controlled not to operate.

9. The control method of the thermal management unit according to claim 7, characterized in that: The step of controlling the opening state of the solenoid valve according to the control instruction, the ambient temperature and the water inlet set temperature of the controlled object to control whether the coolant exchanges heat with the air through the heat exchanger includes: When the control instruction is a cooling instruction, and the difference between the set temperature of the water inlet of the controlled object and the ambient temperature is less than the set temperature, the solenoid valve is controlled to open, so as to control the coolant not to exchange heat with the air through the heat exchanger; When the control instruction is a cooling instruction, and the difference between the set temperature of the water inlet of the controlled object and the ambient temperature is greater than or equal to the set temperature, the solenoid valve is controlled to be closed, so as to control the coolant to exchange heat with the air through the heat exchanger; When the control instruction is a heating instruction, and the difference between the ambient temperature and the set temperature of the water inlet of the controlled object is less than the set temperature, the solenoid valve is controlled to open, so as to control the coolant not to exchange heat with the air through the heat exchanger; When the control instruction is a heating instruction, and the difference between the ambient temperature and the water inlet set temperature of the controlled object is greater than or equal to the set temperature, the solenoid valve is controlled to close to control the refrigerant to exchange heat with the air through the heat exchanger.

10. The control method of the thermal management unit according to claim 9, characterized in that: The set temperature is 3-5°C.

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