Thermal management system of plug-in hybrid electric vehicle

Abstract

The utility model discloses a thermal management system of a plug-in hybrid electric vehicle, and belongs to the technical field of plug-in hybrid electric vehicles. The system mainly comprises a motor electric control loop, a passenger compartment heating loop, a passenger compartment refrigerating loop, an engine loop and a battery loop, a warm air core body and a liquid-liquid heat exchanger which are used for heating are arranged in the passenger compartment heating loop, a cooler chiller used for refrigerating is arranged in the passenger compartment refrigerating loop, the motor electric control loop is connected with the passenger compartment heating loop in series, and the motor electric control loop is connected with the engine loop. The warm air core body is connected with the liquid-liquid heat exchanger in parallel and then is communicated with the battery loop; and the cooler chiller is communicated with a battery loop after being connected in series with the liquid-liquid heat exchanger. The motor electric control loop is connected with the passenger compartment heating loop in series, the warm air core and the liquid-liquid heat exchanger are connected into the passenger compartment heating loop and the battery loop in parallel, multi-heat-source cooperative utilization is achieved, heating stability is improved, meanwhile, a PTC or heat pump pipeline is omitted, production cost is reduced, extra energy consumption is greatly reduced, and the energy-saving and environment-friendly effects are achieved. The whole vehicle energy utilization rate is improved.

Description

Technical Field

[0001] This utility model belongs to the field of plug-in hybrid vehicle technology, and more specifically, it relates to a thermal management system for plug-in hybrid vehicles. Background Technology

[0002] As a means of transportation, automobiles need to meet the daily heating needs of the passenger compartment. Compared to traditional gasoline vehicles, plug-in hybrid electric vehicles (PHEVs) cannot utilize engine waste heat to heat the passenger compartment under certain operating conditions, such as when the engine is not engaged (pure electric mode). Therefore, the thermal management system design of PHEVs is generally more complex.

[0003] For example, patent CN218197822U discloses a thermal management system for a hybrid vehicle, including an engine block, engine radiators, and a heating subsystem. The heating subsystem includes a plate heat exchanger, to which a power drive subsystem is connected. The heating subsystem comprises the plate heat exchanger, a PTC water pump, and a PTC heater. The engine block and the PTC heater are connected via a first three-way valve. A liquid passage connecting the PTC water pump and the PTC heater to the engine block is also provided. The power drive subsystem includes a battery cooler, whose outlet is connected to the plate heat exchanger. Another port of the second three-way valve is indirectly connected between the plate heat exchanger and the battery cooler outlet. This design allows for the adjustment of the engine's high-temperature coolant circulation path, thereby optimizing the PTC's operating environment as needed.

[0004] The above-mentioned solution mainly utilizes heat pumps or PTCs to heat the passenger compartment of plug-in hybrid vehicles. Specifically, it uses engine waste heat for heating in hybrid mode and heat pumps or PTCs for heating in pure electric mode. The disadvantages are: 1. Using heat pumps or PTCs for heating results in a thermal management system with multiple components, leading to high costs and complex piping connections, which inconveniences vehicle development; 2. The PTC heater dissipates heat only through the engine coolant circuit. When the engine is not running (pure electric mode) and the PTC is operating under high load, the coolant temperature may continuously rise, causing frequent triggering of the PTC overheat protection, thus affecting heating stability. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a thermal management system for plug-in hybrid vehicles. The system connects the motor control circuit and the passenger compartment heating circuit in series, and connects the heater core and the liquid-liquid heat exchanger in parallel to the passenger compartment heating circuit and the battery circuit. This enables the coordinated use of multiple heat sources, improves heating stability, eliminates the need for PTC or heat pump pipelines, reduces production costs, significantly reduces additional energy consumption, and improves the overall energy utilization rate of the vehicle.

[0006] The aforementioned thermal management system for a plug-in hybrid electric vehicle includes a motor control circuit, a passenger compartment heating circuit, a passenger compartment cooling circuit, an engine circuit, and a battery circuit. The passenger compartment heating circuit is equipped with a heater core and a liquid-liquid heat exchanger for heating, and the passenger compartment cooling circuit is equipped with a chiller for cooling. The motor control circuit is connected in series with the passenger compartment heating circuit, the heater core and the liquid-liquid heat exchanger are connected in parallel and then connected to the battery circuit; and the chiller is connected in series with the liquid-liquid heat exchanger and then connected to the battery circuit.

[0007] Preferably, the motor control circuit includes a water pump, a DC-DC & OBC module, a GCU module, an MCU module, a drive motor, a generator, and a low-temperature radiator, with the cooling channels of the water pump, DC-DC & OBC module, GCU module, MCU module, drive motor, generator, and low-temperature radiator connected in series.

[0008] Preferably, it also includes a motor control circuit water tank, which is connected to the motor control circuit via a three-way valve. A three-way proportional valve is provided between the generator and the low-temperature radiator. Port A of the three-way proportional valve is connected to the cooling channel of the generator, port B of the three-way proportional valve is connected to the low-temperature radiator, and port C of the three-way proportional valve is connected to the passenger compartment heating circuit.

[0009] Preferably, the battery circuit includes a third water pump and a high-voltage battery. The third water pump is connected to the cooling channel of the high-voltage battery. The cooling channel of the high-voltage battery, the liquid-liquid heat exchanger, and the chiller are connected in series. The chiller is connected to the third water pump.

[0010] Preferably, the crew compartment heating circuit further includes a three-way proportional valve two, a three-way proportional valve three, and a water pump two. Port A of the three-way proportional valve three is connected to the water pump two, port B of the three-way proportional valve three is connected to the liquid-liquid heat exchanger, port C of the three-way proportional valve three is connected to the heater core, and the pipeline after the heater core and the liquid-liquid heat exchanger are connected to the water pump two and the engine circuit respectively through the three-way proportional valve two.

[0011] Preferably, port A of the three-way proportional valve two is connected to the motor control circuit and the pipeline after the heater core and liquid-liquid heat exchanger are connected in parallel via a three-way valve; port C of the three-way proportional valve two is connected to the engine circuit and water pump two via a three-way valve.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] 1. The heater core and liquid-liquid heat exchanger are connected in parallel to the passenger compartment heating circuit and the battery circuit, forming a dual heat source and temperature control guarantee. On the one hand, it provides a redundancy solution for passenger compartment heating. Even if one heat source is abnormal, the other heat source can still guarantee heating, improving heating stability. On the other hand, the high-voltage battery is cooled and heated by connecting the chiller and the liquid-liquid heat exchanger in series. The coolant is first initially regulated by the liquid-liquid heat exchanger, and then the chiller precisely controls the temperature, ensuring that the battery is always within the optimal operating temperature range and extending battery life.

[0014] 2. The motor control circuit is connected in series with the passenger compartment heating circuit, fully utilizing the motor's stall-rotor heating characteristics to convert the heat energy generated by the motor into energy for passenger compartment heating and high-voltage battery heating. It also recovers waste heat from the motor's daily operation. Combined with waste heat recovery from the engine circuit, it achieves synergistic utilization of multiple heat sources, thus replacing traditional PTC heating. This eliminates the need for PTC or heat pump piping, reduces components, lowers production costs, significantly reduces additional energy consumption, and improves the overall vehicle energy efficiency, extending driving range while ensuring vehicle comfort.

[0015] 3. Through the coordinated operation of three-way proportional valves one, two, and three, the coolant flow direction and volume are precisely adjusted according to the actual temperature requirements of the motor control system, passenger compartment, and battery. When the motor temperature is low, the coolant flow through the low-temperature radiator is reduced to avoid overcooling; when the temperature rises, heat dissipation is enhanced and heat recovery is guided. Simultaneously, during operation, an intelligent model predictive control strategy is used to rationally allocate energy for motor drive and heating, achieving a dynamic balance between thermal management and vehicle drive, maximizing energy utilization. Attached Figure Description

[0016] Figure 1 This is a system schematic diagram of the present invention;

[0017] Figure 2 This is a schematic diagram showing the distribution of the various components of this utility model.

[0018] In the diagram, 1. Motor control circuit; 101. Motor control circuit kettle; 102. Water pump one; 103. DC-DC & OBC module; 104. GCU module; 105. MCU module; 106. Drive motor; 107. Generator; 108. Three-way proportional valve one; 109. Low-temperature radiator; 2. Engine circuit; 3. Passenger compartment heating circuit; 301. Three-way proportional valve two; 302. Three-way proportional valve three; 303. Water pump two; 304. Heater core; 305. Liquid-liquid heat exchanger; 4. Passenger compartment cooling circuit; 401. Cooler; 5. Battery circuit; 501. Water pump three; 502. High-voltage battery. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings:

[0020] The directional terms used in the detailed description paragraphs are only for the convenience of those skilled in the art to understand the technical solutions described in this application based on the visual orientation shown in the accompanying drawings. Unless otherwise expressly specified and limited, the terms "setting," "installation," "connection," etc., should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0021] A thermal management system for a plug-in hybrid electric vehicle includes five circuits: a motor control circuit 1, an engine circuit 2, a passenger compartment heating circuit 3, a passenger compartment cooling circuit 4, and a battery circuit 5. In the prior art, the passenger compartment heating circuit 3 includes a heater core 304 and a liquid-liquid heat exchanger 305 for heating, and the passenger compartment cooling circuit 4 includes a chiller 401 for cooling; all five circuits operate independently.

[0022] like Figure 1 As shown, the thick dotted line represents the motor control circuit 1, the thin solid line represents the engine circuit 2, the thick solid line represents the passenger compartment heating circuit 3, the thin dashed line represents the passenger compartment cooling circuit 4, and the thick dashed line represents the battery circuit 5. In this embodiment, the engine circuit 2 and the passenger compartment cooling circuit 4 are the same as in the prior art and will not be described again.

[0023] In this embodiment, the motor control circuit 1 is connected in series with the passenger compartment heating circuit 3, enabling the use of the motor stall-rotor heating system to heat both the passenger compartment and the high-voltage battery 502 under certain conditions. The heater core 304 is connected in parallel with the liquid-liquid heat exchanger 305 and then connected to the battery circuit 5, achieving separate heating of the passenger compartment and the high-voltage battery 502 via the heater core 304 and the liquid-liquid heat exchanger 305, significantly improving the stability of passenger compartment heating. Simultaneously, the chiller 401 is connected in series with the liquid-liquid heat exchanger 305 and then connected to the battery circuit 5, enabling the chiller 401 and the liquid-liquid heat exchanger 305 to respectively cool and heat the high-voltage battery 502.

[0024] Specifically, the motor control circuit 1 includes a water pump 102, a DC-DC & OBC module 103, a GCU module 104, an MCU module 105, a drive motor 106, a generator 107, and a low-temperature radiator 109. The cooling channels of the water pump 102, DC-DC & OBC module 103, GCU module 104, MCU module 105, drive motor 106, generator 107, and low-temperature radiator 109 are connected in series, forming a complete cooling chain. The water pump 102 serves as the power source, continuously driving the coolant circulation to promptly remove the large amount of heat generated by components such as the DC-DC & OBC module 103, GCU module 104, MCU module 105, drive motor 106, and generator 107 during operation. The low-temperature radiator 109 dissipates the heat carried by the coolant to the external environment under high-temperature conditions, ensuring that the temperature of each component remains within a safe range.

[0025] The motor control circuit 1 is also equipped with a motor control circuit reservoir 101, which is connected to the motor control circuit 1 via a three-way valve. This reservoir stores and replenishes coolant and stabilizes system pressure. A three-way proportional valve 108 is installed between the generator 107 and the cryogenic radiator 109. Port A of the three-way proportional valve 108 is connected to the cooling channel of the generator 107, port B is connected to the cryogenic radiator 109, and port C is connected to the passenger compartment heating circuit 3. The three-way proportional valve 108 flexibly adjusts the coolant flow direction according to the actual temperature requirements of the motor control system. When the temperature is low, it reduces the amount of coolant flowing through the cryogenic radiator 109 to avoid overcooling; when the temperature rises, it guides more coolant through the cryogenic radiator 109 to enhance heat dissipation, while also transferring some heat to the passenger compartment heating circuit 3 for heat recovery and utilization.

[0026] Battery circuit 5 includes water pump 3 501 and high-voltage battery 502. Battery circuit 5 plays a decisive role in the performance and lifespan of high-voltage battery 502. Water pump 3 501 is connected to the cooling channel of high-voltage battery 502, serving as the power source for coolant circulation and ensuring continuous coolant flow within the cooling channel to promptly remove heat generated during battery charging and discharging. The cooling channel of high-voltage battery 502, liquid-liquid heat exchanger 305, and chiller 401 are connected in series, with chiller 401 connected to water pump 3 501, forming an efficient heat dissipation path. When the temperature of high-voltage battery 502 rises, the coolant first flows through liquid-liquid heat exchanger 305 for initial cooling, and then the temperature is further regulated by chiller 401, ensuring that high-voltage battery 502 remains within its optimal operating temperature range. This prevents performance degradation, shortened lifespan, or even safety issues caused by excessively high temperatures. Meanwhile, in low-temperature environments, the circuit can also use the heat from the crew cabin heating circuit 3 to preheat the battery, ensuring the battery's charging and discharging performance under low-temperature conditions.

[0027] The passenger compartment heating circuit 3 includes a heater core 304, a liquid-liquid heat exchanger 305, a three-way proportional valve 2 301, a three-way proportional valve 302, and a water pump 2 303. The heater core 304 and the liquid-liquid heat exchanger 305 are connected in parallel to provide dual heat sources for heating the passenger compartment. The liquid-liquid heat exchanger 305 can recover the waste heat from the engine circuit 2 or the excess heat from the motor control circuit 1. After heating the coolant, the heat is transferred to the heater core 304 by the water pump 2 303, and then the heater core 304 dissipates the heat into the passenger compartment to achieve winter heating.

[0028] Specifically, port A of three-way proportional valve 302 is connected to port C of water pump 2 303 and three-way proportional valve 1 108 via a three-way valve; port B of three-way proportional valve 302 is connected to liquid-liquid heat exchanger 305; port C of three-way proportional valve 302 is connected to heater core 304; the pipeline connecting heater core 304 and liquid-liquid heat exchanger 305 in parallel is connected to port A of three-way proportional valve 2 301 and motor control circuit 1 via a three-way valve; the other two ports of three-way proportional valve 2 301 are connected to water pump 2 303 and engine circuit 2, respectively.

[0029] Port C of the three-way proportional valve 2 301 is connected to the outlet of engine circuit 2 and water pump 2 303 via a three-way valve; Port B of the three-way proportional valve 2 301 is connected to the inlet of engine circuit 2 and engine coolant reservoir via a three-way valve. By working together, the three-way proportional valve 2 301 and the three-way proportional valve 302 precisely control the direction and flow rate of coolant.

[0030] like Figure 2As shown, during installation, the heater core 304 is located in the air conditioning unit below the passenger dashboard; the chiller is located in the front bulkhead of the engine compartment, i.e., on the passenger side of the vehicle body. The DC-DC & OBC module 103 of the motor control circuit 1 is placed at the bottom of the trunk and fixed to the lower left side of the rear of the vehicle body; the generator 107 is rigidly connected to the rear of the engine by bolts and is horizontally arranged in the front engine compartment, with the GCU module 104 horizontally fixed on top of the generator 107. The drive motor 106 and MCU module 105 are integrated into a single structure, arranged at three centroids (left front, right front, right rear) and fixed to the rear subframe. The high-voltage battery 502 in the battery circuit 5 is laid flat at the bottom of the vehicle body and fixed to the vehicle body from the left and right sides by bolts using battery brackets. The liquid-liquid heat exchanger 305, water pump, three-way proportional valve, and water pipes are arranged between the high-voltage battery 502 and the front subframe and fixed to the bottom of the vehicle body to avoid pipe crossing and make the engine compartment layout simpler.

[0031] Working principle:

[0032] When the motor is stalled, it stops rotating but current still flows. Electrical energy cannot be converted into mechanical energy; instead, it is converted into heat energy. This heat energy can be generated by the motor's own windings, eliminating the need for additional resistance heating elements. This invention utilizes this stall-heating characteristic of the motor to replace PTC heating. The motor thus serves two functions: driving the vehicle and heating the passenger compartment and the high-voltage battery 502. In operation, an intelligent model predictive control strategy can rationally allocate energy between the two functions, achieving both heating control of the vehicle's thermal management system and vehicle driving. This maximizes energy utilization, ensuring vehicle comfort while reducing energy consumption and increasing range.

[0033] like Figure 1 As shown, when the passenger compartment or high-voltage battery 502 requires heating and the drive motor 106 meets the stall condition, the drive motor 106 generates heat during stall, and the motor control circuit 1 quickly reaches a suitable temperature. At this time, port B of the three-way proportional valve 108 closes, and the coolant flows through ports A and C of the three-way proportional valve 108 and enters port A of the three-way proportional valve 302 through the three-way valve. Then, according to actual needs, the opening of the three-way proportional valve 302 is controlled, allowing the coolant to enter ports B and C of the three-way proportional valve 302 respectively, thereby heating the heater core 304 and the liquid-liquid heat exchanger 305, thus completing the heating of the passenger compartment and the high-voltage battery 502. Through this circuit, in addition to utilizing the stall condition of the motor to heat the passenger compartment and high-voltage battery 502, it is also possible to utilize the waste heat from the motor's daily operation. By utilizing the stall temperature of the motor, the waste heat from the motor, and the waste heat from the engine, the purpose of replacing the PTC (Power Transmission Control) system can be achieved.

[0034] Finally, although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A thermal management system for a plug-in hybrid electric vehicle, comprising a motor control circuit (1), a passenger compartment heating circuit (3), a passenger compartment cooling circuit (4), an engine circuit (2), and a battery circuit (5), wherein the passenger compartment heating circuit (3) is provided with a heater core (304) for heating and a liquid-liquid heat exchanger (305), and the passenger compartment cooling circuit (4) is provided with a chiller (401) for cooling, characterized in that: The motor control circuit (1) is connected in series with the crew cabin heating circuit (3), the warm air core (304) is connected in parallel with the liquid-liquid heat exchanger (305) and then connected to the battery circuit (5); and the cooler (401) is connected in series with the liquid-liquid heat exchanger (305) and then connected to the battery circuit (5).

2. The thermal management system for a plug-in hybrid electric vehicle according to claim 1, characterized in that: The motor control circuit (1) includes a water pump (102), a DC-DC & OBC module (103), a GCU module (104), an MCU module (105), a drive motor (106), a generator (107), and a low-temperature radiator (109). The cooling channels of the water pump (102), DC-DC & OBC module (103), GCU module (104), MCU module (105), drive motor (106), generator (107), and low-temperature radiator (109) are connected in series.

3. The thermal management system for a plug-in hybrid electric vehicle according to claim 2, characterized in that: It also includes a motor control circuit kettle (101), which is connected to the motor control circuit (1) via a three-way valve. A three-way proportional valve (108) is provided between the generator (107) and the low-temperature radiator (109). Port A of the three-way proportional valve (108) is connected to the cooling channel of the generator (107), port B of the three-way proportional valve (108) is connected to the low-temperature radiator (109), and port C of the three-way proportional valve (108) is connected to the crew cabin heating circuit (3).

4. The thermal management system for a plug-in hybrid vehicle according to claim 1, characterized in that: The battery circuit (5) includes a water pump (501) and a high-voltage battery (502). The water pump (501) is connected to the cooling channel of the high-voltage battery (502). The cooling channel of the high-voltage battery (502), the liquid-liquid heat exchanger (305) and the cooler (401) are connected in series. The cooler (401) is connected to the water pump (501).

5. A thermal management system for a plug-in hybrid vehicle according to claim 1, characterized in that: The crew cabin heating circuit (3) also includes a three-way proportional valve two (301), a three-way proportional valve three (302), and a water pump two (303). Port A of the three-way proportional valve three (302) is connected to the water pump two (303), port B of the three-way proportional valve three (302) is connected to the liquid-liquid heat exchanger (305), and port C of the three-way proportional valve three (302) is connected to the heater core (304). The pipeline after the heater core (304) and the liquid-liquid heat exchanger (305) are connected in parallel is connected to the water pump two (303) and the engine circuit (2) through the three-way proportional valve two (301).

6. The thermal management system for a plug-in hybrid electric vehicle according to claim 5, characterized in that: The A port of the three-way proportional valve 2 (301) is connected to the motor control circuit (1) and the pipeline after the heater core (304) and liquid-liquid heat exchanger (305) are connected in parallel through the three-way valve; the C port of the three-way proportional valve 2 (301) is connected to the engine circuit (2) and water pump 2 (303) through the three-way valve.

Images