Thermal Management System

Abstract

Aimed at improving energy efficiency and reducing power consumption, the thermal management system can regulate the temperature of the thermally managed object within the required temperature range through temperature control. The thermal management system includes: a refrigerant circuit for refrigerant circulation; a high-temperature heat transfer fluid circuit for circulating the heat transfer fluid pumped by the first pump after it has received heat dissipated by the refrigerant and reached a high temperature; a low-temperature heat transfer fluid circuit for circulating the heat transfer fluid pumped by the second pump after it has absorbed heat from the refrigerant and cooled down; a temperature-regulating heat exchange unit for regulating the temperature of the thermally managed object; a heat transfer fluid mixing unit connected upstream of the temperature-regulating heat exchange unit for mixing the high-temperature heat transfer fluid in the high-temperature heat transfer fluid circuit and the low-temperature heat transfer fluid in the low-temperature heat transfer fluid circuit according to the target temperature of the thermally managed object; and a branch point connected downstream of the temperature-regulating heat exchange unit for returning the heat transfer fluid flowing through the temperature-regulating heat exchange unit to both the high-temperature and low-temperature heat transfer fluid circuits.

Description

Technical Field

[0001] This invention relates to a thermal management system suitable for electric vehicles. Background Technology

[0002] In order to cool the battery, traction motor, inverter, and other components in an electric vehicle, the thermal management system used in the electric vehicle includes a heat carrier (water) circuit. Based on this heat carrier circuit, after receiving heat from the battery and other thermally managed objects through the heat exchange unit, the heat carrier dissipates the heat to the outside of the vehicle as it flows through the air heat exchange unit (radiator) (see Patent Document 1 below).

[0003] In addition, in order to further cool the battery and other components that have risen to high temperatures during operation, the air conditioning refrigerant circuit and the heat carrier circuit will exchange heat, and the refrigerant circuit will absorb heat to reduce the temperature of the heat carrier after the battery and other components have been cooled (see Patent Document 2 below).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-105942

[0007] Patent Document 2: Japanese Patent Application Publication No. 2018-43741 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] When performing thermal management on the components of electric vehicles, it is necessary not only to cool them, but sometimes also to regulate the temperature to a suitable range.

[0010] The optimal temperature for battery temperature regulation is around 25°C. When the outside temperature is low, an electric heater is used to heat the heat carrier before it flows to the heat exchange unit used by the battery. Therefore, there are problems of low energy utilization efficiency and high power consumption.

[0011] Therefore, using a heating heat pump to heat the heat transfer medium has become a research topic. However, compared to the optimal temperature of the battery (around 25°C), the required outlet air temperature for heating is around 40-60°C. Since the temperature ranges of the two are different, simply using a heating heat pump to heat the temperature-regulating heat transfer medium used for the battery will result in the battery overheating. Furthermore, when regulating the temperature of thermally managed objects other than the battery, it is necessary to adjust the temperature to different ranges depending on the situation. Therefore, when only using a heat pump to heat the heat transfer medium, there is a problem of not being able to set the temperature within an appropriate range.

[0012] The problem this invention aims to solve is how to address the aforementioned issues. Specifically, this invention aims to improve energy efficiency, reduce power consumption, and enable the thermally managed object to be adjusted within the desired temperature range through temperature control.

[0013] Technical solutions adopted to solve technical problems

[0014] To solve the above problems, the present invention has the following structure.

[0015] A thermal management system includes: a refrigerant circuit for supplying refrigerant circulation; a high-temperature heat transfer fluid circuit for circulating a heat transfer fluid pumped by a first pump after receiving heat dissipated by the refrigerant and reaching a high temperature; and a low-temperature heat transfer fluid circuit for circulating a heat transfer fluid pumped by a second pump after absorbing heat from the refrigerant and cooling down. The thermal management system is characterized by comprising: a temperature-regulating heat exchange unit for regulating the temperature of the thermally managed object; a heat transfer fluid mixing unit connected upstream of the temperature-regulating heat exchange unit for mixing the high-temperature heat transfer fluid in the high-temperature heat transfer fluid circuit and the low-temperature heat transfer fluid in the low-temperature heat transfer fluid circuit in proportion to the target temperature of the thermally managed object; and a branch point connected downstream of the temperature-regulating heat exchange unit for returning the heat transfer fluid flowing through the temperature-regulating heat exchange unit to both the high-temperature heat transfer fluid circuit and the low-temperature heat transfer fluid circuit.

[0016] Invention Effects

[0017] Thermal management systems with these characteristics can improve energy efficiency, reduce power consumption, and regulate the thermally managed object within the required temperature range through temperature control. Attached Figure Description

[0018] Figure 1 This is an explanatory diagram showing the basic structure of the thermal management system according to an embodiment of the present invention.

[0019] Figure 2 This is an explanatory diagram illustrating a specific structural example of the thermal management system in an embodiment of the present invention.

[0020] Figure 3 This is an illustrative diagram illustrating an example of the operating mode of a thermal management system.

[0021] Figure 4 This is an illustrative diagram illustrating an example of the operating mode of a thermal management system.

[0022] Figure 5 This is an illustrative diagram illustrating an example of the operating mode of a thermal management system.

[0023] Figure 6 This is an illustrative diagram illustrating an example of the operating mode of a thermal management system.

[0024] Figure 7 This is an illustrative diagram illustrating an example of the operating mode of a thermal management system. Detailed Implementation

[0025] The embodiments of the present invention will now be described with reference to the accompanying drawings. In the following description, the same symbols in different figures represent parts with the same function, and repeated descriptions in various figures have been omitted accordingly.

[0026] like Figure 1 As shown, the thermal management system 1 in this embodiment of the invention includes a refrigerant circuit 10, a high-temperature end heat transfer fluid circuit 20, and a low-temperature end heat transfer fluid circuit 30. The refrigerant circuit 10 is a circuit for refrigerant circulation. Although the circuit shown here is a closed circuit formed by sequentially connecting the compressor 11, condenser 12, expansion valve 13, and evaporator 14 with refrigerant pipes, the refrigerant circuit 10 is not limited to this. For example, it can also be a circuit with an accumulator located upstream of the compressor 11.

[0027] The high-temperature end heat transfer circuit 20 has a high-temperature end heat exchange unit 21 that completes the heat exchange between the heat transfer unit and the refrigerant by integrating with the condenser 12 in the refrigerant circuit 10. When the heat transfer unit 21 is pumped by the first pump 22, it will receive the heat dissipated by the refrigerant at the condenser 12 in the refrigerant circuit 10 and rise to a high temperature before continuing to circulate.

[0028] The low-temperature heat transfer circuit 30 has a low-temperature heat exchange unit 31 that integrates with the evaporator 14 in the refrigerant circuit 10 to complete the heat exchange between the heat transfer unit and the refrigerant. When the heat transfer unit pumped by the second pump 32 flows through the low-temperature heat exchange unit 31, its heat is absorbed by the refrigerant at the evaporator 14 in the refrigerant circuit 10 and cooled down before continuing to circulate.

[0029] The heat transfer fluids that can be used as heat transfer fluids in the high-temperature end heat transfer fluid circuit 20 and the low-temperature end heat transfer fluid circuit 30 include water without any additives or water mixed with additives such as antifreeze and preservatives, as well as liquid heat transfer fluids such as oil.

[0030] The thermal management system 1 includes a temperature-regulating heat exchange unit 40 for regulating the temperature of a thermally managed object M, such as a battery in an electric vehicle. The upstream end of the temperature-regulating heat exchange unit 40 is connected to a heat carrier mixing unit 50, and the downstream end of the temperature-regulating heat exchange unit 40 is connected to a bifurcation point D.

[0031] The heat transfer mixing unit 50 is used to mix the high-temperature heat transfer medium in the high-temperature heat transfer medium circuit 20 and the low-temperature heat transfer medium in the low-temperature heat transfer medium circuit 30 in proportion according to the target temperature of the heat management object M. It is composed of a flow control valve, which uses a control unit (not shown) to control the mixing ratio.

[0032] Bifurcation point D is a branch path used to return the heat transfer fluid flowing through the temperature-regulating heat exchange unit 40 to the high-temperature end heat transfer fluid circuit 20 and the low-temperature end heat transfer fluid circuit 30. Bifurcation point D is connected to the high-temperature end heat transfer fluid circuit 20 at the upstream end of the first pump 22 via a first connection C1, and to the low-temperature end heat transfer fluid circuit 30 at the upstream end of the second pump 32 via a second connection C2.

[0033] Based on this thermal management system 1, the temperature of the thermally managed object M can be regulated by utilizing the heat dissipation and absorption of the heat pump. Therefore, compared with the case of setting up a separate electric heater, this thermal management system 1 can improve energy utilization efficiency and reduce power consumption. In addition, since the high-temperature heat transfer medium in the high-temperature end heat transfer medium circuit 20 and the low-temperature heat transfer medium in the low-temperature end heat transfer medium circuit 30 are mixed in the required proportion and then supplied to the temperature-regulating heat exchange unit 40, the temperature can be regulated within any temperature range according to the target temperature of the thermally managed object M.

[0034] The heat transfer fluid flowing through the temperature-regulating heat exchange unit 40 is diverted at the bifurcation point D, then returns to the high-temperature end heat transfer fluid circuit 20 via the first connection point C1, and returns to the low-temperature end heat transfer fluid circuit 30 via the second connection point C2. Regarding the diversion ratio, no valves or similar devices are needed to allow the heat transfer fluid to return naturally in the corresponding proportion according to the mixing ratio set at the heat transfer fluid mixing unit 50. This simplifies the construction of the heat transfer fluid circuit and enables temperature regulation to achieve the desired temperature range with relatively low power consumption.

[0035] The following is combined Figure 2 A specific structural example of the thermal management system 1 is described below. Here, the objects of thermal management are various components and air conditioning equipment in the electric vehicle. In the figure, the vehicle components subject to thermal management include the battery M1, inverter M2, and motor M3. The air conditioning equipment includes separate air conditioning units M5 and M6, which are located at the main air conditioning unit M4 used for air conditioning the interior space and at the seats, etc., to provide air conditioning for the driver and passengers. Temperature-regulating heat exchange units 41, 42, 43, 44, 45, 46, and 47 are installed at these thermal management objects, and each temperature-regulating heat exchange unit can exchange heat with its corresponding thermal management object.

[0036] As mentioned above, Figure 2The thermal management system 1 shown includes a refrigerant circuit 10, a high-temperature end heat transfer fluid circuit 20, and a low-temperature end heat transfer fluid circuit 30. The upstream ends of the temperature-regulating heat exchange units 41, 44, 45, 46, and 47 are respectively connected to heat transfer fluid mixing units 51, 52, 53, 55, and 54. The temperature of the heat transfer fluid is regulated by mixing the high-temperature heat transfer fluid in the high-temperature end heat transfer fluid circuit 20 with the low-temperature heat transfer fluid in the low-temperature end heat transfer fluid circuit 30 at the heat transfer fluid mixing units 51, 52, 53, 55, and 54 according to the target temperature and a corresponding mixing ratio. The heat transfer fluid is then supplied to each temperature-regulating heat exchange unit 41, 44, 45, 46, and 47. Temperature-regulating heat exchange units 42 and 43, which do not have a set target temperature, are connected to the air-cooled heat transfer fluid circuit 60, which includes an air heat exchange unit (radiator) 61 and a third pump 62. In the structural example of the thermal management system 1, an electric heater 2 may also be added.

[0037] The high-temperature end heat transfer circuit 20, the low-temperature end heat transfer circuit 30, and the air-cooled heat transfer circuit 60 are connected to form the required flow paths via valve devices V1 to V12. Among them, valve devices V1 and V2 are three-way valves, which can selectively switch between the flow paths in three directions, while valve devices V3, V4, V5, V6, V7, and V8 are two-way valves, which can open and close the flow paths.

[0038] In addition, valves V9, V10, and V11 are check valves used to prevent backflow in the flow path.

[0039] For the temperature-regulating heat exchange units 41, 46, and 47 that adjust the temperature after setting the target temperature, there is a bifurcation point D in the flow path at the downstream end. The bifurcation point D is connected to the upstream end of the first pump 22 in the high-temperature end heat transfer circuit 20 through the first connection point C1, and is connected to the upstream end of the second pump 32 in the low-temperature end heat transfer circuit 30 through the second connection point C2.

[0040] An example of the working mode of this thermal management system 1 is described below. Figures 3-7 The circuit states of the thermal management system 1 under various operating modes are shown. The flow paths represented by double lines indicate the flow of a high-temperature heat transfer medium; the flow paths represented by thick lines indicate the flow of a low-temperature heat transfer medium; and the flow paths represented by solid lines indicate the flow of a mixed heat transfer medium (a mixture of high-temperature and low-temperature heat transfer media) or a heat transfer medium that has undergone heat exchange with air. The flow paths represented by dashed lines are those in a non-use state after selecting the flow paths for valve devices V1 and V2, or after selecting the opening and closing of valve devices V3 to V8.

[0041] Figure 3The circuit state shown is the working mode in which the air conditioning equipment provides cooling and the battery M1 is cooled.

[0042] In this example, the high-temperature heat transfer fluid flowing through the high-temperature end heat exchange unit 21 is transported to the inlet on one side of the heat transfer fluid mixing units 51-55, and simultaneously, after branching at the upstream end of the valve device V3, it is transported to the air heat exchange unit 61. At this time, the high-temperature end heat transfer fluid circuit 20 is a circulation loop that flows sequentially through the first pump 22, the high-temperature end heat exchange unit 21, the valve device V3, the air heat exchange unit 61, and the valve devices V1 and V4.

[0043] In addition, the low-temperature heat transfer fluid flowing through the low-temperature end heat exchange unit 31 is transported to the inlet on one side of the heat transfer fluid mixing unit 51-55. The low-temperature end heat transfer fluid circuit 30 is a circulation circuit that flows sequentially through the second pump 32, the low-temperature end heat exchange unit 31, the heat transfer fluid mixing units 52 and 53, the temperature regulating heat exchange units 44 and 45, and the valve device V6.

[0044] The heat carrier, having reached the set temperature through mixing in the heat carrier mixing unit 51, is then transported via valve device V11 to the temperature-regulating heat exchange unit 41 of battery M1, thereby regulating the temperature of battery M1 to the target temperature. The heat carrier flowing through the temperature-regulating heat exchange unit 41 is then split at the branch point D after passing through valve device V7. One branch returns to the high-temperature end heat carrier circuit 20 via the first connection point C1, while the other branch returns to the low-temperature end heat carrier circuit 30 via the second connection point C2.

[0045] Furthermore, the heat carrier that has reached the set temperature by mixing in the heat carrier mixing unit 54 is transported to the temperature-regulating heat exchange unit 47 of the separate air conditioning unit M6, thereby regulating the temperature of the separate air conditioning unit M6 to the target temperature. After the heat carrier flowing through the temperature-regulating heat exchange unit 47 and the heat carrier flowing through the temperature-regulating heat exchange unit 41 converge, they are split at the bifurcation point D. One branch returns to the high-temperature end heat carrier circuit 20 through the first connection point C1, and the other branch returns to the low-temperature end heat carrier circuit 30 through the second connection point C2.

[0046] Furthermore, the heat carriers, after being mixed in the heat carrier mixing units 52 and 53 to reach their respective set temperatures, are transported to the temperature-regulating heat exchange units 44 and 45 of the main air conditioning unit M4. The temperature-regulating heat exchange units 44 and 45 constitute an air conditioning device for cooling, and can function as cooler cores whose temperatures can be set independently.

[0047] Figure 4The circuit state shown is an air conditioning unit consisting of a cooler core and a heater core, which is used to form the main air conditioning unit M4. The battery M1 is cooled by the heat carrier flowing in the air-cooled heat carrier circuit 60.

[0048] In this example, one temperature-regulating heat exchange unit 44 in the main air conditioning unit M4 acts as a cooler core, and another temperature-regulating heat exchange unit 45 acts as a heater core. The high-temperature heat transfer fluid loop 20, based on the existing loop flowing sequentially through the first pump 22, the high-temperature heat exchange unit 21, the valve device V3, the air heat exchange unit 61, and the valve devices V1 and V4, further includes a loop from the high-temperature heat exchange unit 21 to the heat transfer fluid mixing unit 53, through which it flows through the temperature-regulating heat exchange unit 45 (which acts as a heater core) and back to the first pump 22.

[0049] In this example, the heat carrier that has reached the set temperature by mixing in the heat carrier mixing unit 54 is also transported to the temperature-regulating heat exchange unit 47 of the separate air conditioning unit M6, thereby regulating the temperature of the separate air conditioning unit M6 to the target temperature. The heat carrier flowing through the temperature-regulating heat exchange unit 47 is split at the branch point D. One branch returns to the high-temperature end heat carrier circuit 20 through the first connection point C1, and the other branch returns to the low-temperature end heat carrier circuit 30 through the second connection point C2.

[0050] In this example, the temperature-regulating heat exchange unit 41 of battery M1, the temperature-regulating heat exchange unit 42 of inverter M2, and the temperature-regulating heat exchange unit 43 of motor M3 are connected in parallel in the air-cooled heat carrier circuit 60.

[0051] Figure 5 The circuit state shown is in dehumidification and heating mode.

[0052] This example is similar to Figure 4 Similar to the example in the example, one temperature-regulating heat exchange unit 44 in the main air conditioning unit M4 acts as a cooler core, and another temperature-regulating heat exchange unit 45 acts as a heater core. The high-temperature end heat carrier circuit 20 is a circuit that flows through the first pump 22, the high-temperature end heat exchange unit 21, the heat carrier mixing unit 53, and the temperature-regulating heat exchange unit 45 (which acts as a heater core) before returning to the first pump 22. The low-temperature end heat carrier circuit 30 is a circuit that flows through the second pump 32, the low-temperature end heat exchange unit 31, the heat carrier mixing unit 52, and the temperature-regulating heat exchange unit 44 (which acts as a cooler core) before returning to the second pump 32.

[0053] In this example, the high-temperature heat carrier that is not mixed with the low-temperature heat carrier is transported to the temperature-regulating heat exchange unit 47 of the separate air conditioning unit M6 through the heat carrier mixing unit 54. The heat carrier flowing through the temperature-regulating heat exchange unit 47 is split at the branch point D. One branch returns to the high-temperature end heat carrier circuit 20 through the first connection point C1, and the other branch returns to the low-temperature end heat carrier circuit 30 through the second connection point C2.

[0054] The heat exchange unit 41 for temperature regulation of battery M1 and Figure 4 As in the example, it is connected in parallel with the temperature-regulating heat exchange unit 42 of inverter M2 and the temperature-regulating heat exchange unit 43 of motor M3 in the air-cooled heat carrier circuit 60.

[0055] Figure 6 The circuit state shown is the operating mode for heating and preheating the battery.

[0056] In this example, both temperature-regulating heat exchange units 44 and 45 of the main air conditioning unit M4 function as heater cores. The high-temperature end heat carrier circuit 20 is a circuit from the first pump 22 through the high-temperature end heat exchange unit 21, heat carrier mixing units 52 and 53, temperature-regulating heat exchange units 44 and 45 which function as heater cores, and valve device V6, and returns to the first pump 22.

[0057] In contrast, the low-temperature heat transfer circuit 30 is a circuit from the second pump 32 through the low-temperature heat exchange unit 31, valve device V5, air heat exchange unit 61, valve device V1, third pump 62, temperature regulating heat exchange units 42 and 43, and valve device V2 back to the second pump 32. When the heat transfer fluid flowing in the low-temperature heat transfer circuit 30 passes through the temperature regulating heat exchange units 42 and 43, it is heated by receiving heat from the inverter M2 and the motor M3.

[0058] The heat carrier mixing unit 51 provides the heat carrier that has been adjusted to a high temperature to the temperature-regulating heat exchange unit 41 of the battery M1, while the high temperature heat carrier that is not mixed with the low temperature heat carrier is transported to the temperature-regulating heat exchange unit 47 of the separate air conditioning unit M6 through the heat carrier mixing unit 54.

[0059] Figure 7 The circuit configuration shown is a reference example, representing a heating and battery preheating operation mode. An electric heater 2 is added to the high-temperature heat transfer circuit 20. In this example, the refrigerant circuit 10 is stopped, and the high-temperature heat transfer circuit 20 is formed solely by heating with the electric heater 2. The high-temperature heat transfer material is then transported to the temperature-regulating heat exchange units 41, 47, and 45.

[0060] As described above, according to embodiments of the present invention, a thermal management system that effectively utilizes the heat dissipation and heat absorption of a heat pump can be constructed, thereby improving energy utilization efficiency, reducing power consumption, and enabling the thermally managed object to be adjusted within the required temperature range through temperature control.

[0061] Furthermore, since the temperature of the heat carrier flowing in the heat exchanger of the main air conditioning unit M4 and the like can be adjusted by mixing high-temperature water with low-temperature water, and a suitable temperature can be adjusted without the need for a mixing damper, not only can the number of components in the main air conditioning unit M4 and the like be reduced, but the unit can also be made more compact.

[0062] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the specific construction is not limited to these embodiments, and any design changes that do not depart from the spirit of the present invention are included within the scope of the present invention. Furthermore, as long as the above embodiments do not contradict each other or have any problems in terms of their purpose and construction, their techniques can be applied and combined.

[0063] (Symbol Explanation)

[0064] 1: Thermal management system; 2: Electric heater.

[0065] 10: Refrigerant circuit

[0066] 11: Compressor, 12: Condenser, 13: Expansion valve, 14: Evaporator

[0067] 20: High-temperature end heat transfer circuit; 21: High-temperature end heat exchange unit; 22: First pump.

[0068] 30: Low-temperature end heat transfer circuit; 31: Low-temperature end heat exchange unit; 32: Second pump.

[0069] 40-47: Temperature-regulating heat exchange unit; 50-55: Heat transfer fluid mixing unit.

[0070] V1~V12: Valve equipment,

[0071] 60: Air-cooled heat transfer circuit; 61: Air heat exchange unit; 62: Third pump.

[0072] D: Fork in the road, C1: First connection point, C2: Second connection point

[0073] M: Thermal management object, M1: Battery, M2: Inverter, M3: Motor

[0074] M4: Main air conditioning unit; M5 and M6: Separate air conditioning units.

Claims

1. A thermal management system, comprising: Refrigerant circuit, used for refrigerant circulation; A high-temperature end heat transfer circuit is used to circulate the heat transfer fluid pumped by the first pump after it has received heat dissipated by the refrigerant and risen to a high temperature therein; and a low-temperature end heat transfer circuit is used to circulate the heat transfer fluid pumped by the second pump after it has absorbed heat from the refrigerant and cooled therein. The thermal management system is characterized by having: A temperature-regulating heat exchange unit is used to regulate the temperature of the object under thermal management. A heat transfer mixing unit, connected upstream of the temperature-regulating heat exchange unit, is used to mix the high-temperature heat transfer medium in the high-temperature end heat transfer medium circuit and the low-temperature heat transfer medium in the low-temperature end heat transfer medium circuit according to the target temperature of the thermal management object. At the bifurcation point, it is connected to the downstream end of the temperature-regulating heat exchange unit, and is used to send the heat carrier flowing through the temperature-regulating heat exchange unit back to the high-temperature end heat carrier circuit and the low-temperature end heat carrier circuit. At the first connection point, it is connected to the high-temperature end heat transfer circuit on the upstream side of the first pump; The second connection point is connected to the low-temperature end heat transfer circuit on the upstream side of the second pump; A first check valve is disposed between the bifurcation and the first connection. as well as A second check valve is disposed between the bifurcation and the second connection.

2. The thermal management system as described in claim 1, characterized in that: For each of the multiple thermal management objects, a corresponding heat carrier mixing unit is provided.

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