A thermal management system for an electric vehicle

Abstract

The utility model relates to the field of automobile manufacturing, concretely relates to a thermal management system of electric automobile. It includes passenger cabin refrigeration subsystem, electric drive thermal management subsystem, battery thermal management subsystem, passenger cabin heating subsystem, the utility model discloses through three -way water valve + check valve combination, through the system design check valve both sides pressure difference, thereby realizes the mixed heat reduction, reduces low temperature working condition and high temperature working condition, heat loss, the system through manual and after -sales filling method, combines automatic emptying method and can solve the phenomenon that some subsystem bubble is too much even to lack cooling medium after long -time operation of system, avoids the emergence heat management function degradation even breakdown.

Description

Technical Field

[0001] This utility model relates to the field of automobile manufacturing, and specifically to a thermal management system for electric vehicles. Background Technology

[0002] The thermal management system for pure electric vehicles includes a passenger compartment thermal management subsystem (passenger compartment heating and cooling), an electric drive thermal management subsystem, and a battery thermal management subsystem. Current pure electric vehicle thermal management technologies have low integration levels between the battery pack and heating systems, failing to achieve integrated thermal management of just two subsystems. This results in incomplete functionality and limited cost-benefit improvements. Existing technology arranges the water pump, water PTC, heater core, and piping of the passenger compartment thermal management subsystem separately; the water pump, battery pack cooler, water PTC, and piping of the battery pack thermal management subsystem are also arranged separately. The water PTC is shared by both the passenger compartment and battery pack thermal management systems.

[0003] The crew compartment thermal management system and the battery pack thermal management system share a water-based PTC for heating. Existing technologies include: Option 1: using a water-to-water heat exchanger and a three-way water valve for heat exchange between the two systems; Option 2: using a three-way water valve to heat the battery pack via a warm air water circuit. Option 1 suffers from increased PTC energy consumption due to heat conduction, convection, and radiation from the water-to-water heat exchanger; Option 2, due to the presence of a bridging pipe, also experiences increased PTC energy consumption due to heat conduction, convection, and radiation. Existing technologies cannot solve this problem. Current integrated systems and methods lack active venting, which can lead to insufficient cooling medium in some circuits and unstable auxiliary water tank levels under extreme conditions, resulting in failure modes such as no heating, no cooling, no warming function, or related functional degradation. Utility Model Content

[0004] To solve the above problems, this utility model proposes a thermal management system for electric vehicles. The specific technical solution is as follows:

[0005] A thermal management system for an electric vehicle includes a passenger compartment cooling subsystem, an electric drive thermal management subsystem, a battery thermal management subsystem, and a passenger compartment heating subsystem.

[0006] The crew cabin refrigeration subsystem consists of a compressor, condenser, pressure sensor, shut-off valve, electronic expansion valve, thermostatic expansion valve, battery pack cooler, evaporator, and temperature and pressure sensor. The compressor passes through the pressure sensor and condenser, and then returns to the compressor via a three-way valve, a shut-off valve, thermostatic expansion valve, evaporator, and another three-way valve. The other three-way valve returns to the compressor via the electronic expansion valve, battery pack cooler, temperature and pressure sensor, and another three-way valve.

[0007] The electric drive cooling subsystem consists of an electric drive water pump, an N-in-one unit, a motor, an electric drive radiator, and an electric fan connected in series. A T-junction is provided at the rear end of the electric drive water pump to connect to the electric drive auxiliary water tank.

[0008] The battery pack thermal management subsystem consists of a battery pack water pump, a battery pack inlet water temperature sensor, a battery pack, a three-way water valve, and a battery pack auxiliary water tank. The three-way water valve is equipped with ports V4, V3, and V2. The battery pack water pump, battery pack inlet water temperature sensor, battery pack, ports V4 and V2 of the three-way water valve, and battery pack cooler are connected in series. A three-way valve is provided between the battery pack water pump and the battery pack cooler to connect to the battery pack auxiliary water tank.

[0009] The crew cabin heating subsystem consists of a crew cabin electronic water pump, a water PTC, and a heater core connected in series.

[0010] The three-way water valve has ports V3 and V2 connected to the crew compartment heating subsystem via a three-way valve.

[0011] Furthermore, the electric drive radiator, electric fan, and condenser constitute the front-end module.

[0012] Furthermore, the angle of the three-way water valve is infinitely adjustable, with an adjustment range of 110 degrees to 200 degrees.

[0013] The media flow of this invention is as follows: When the passenger compartment is cooled in an independent circuit, the compressor drives the refrigerant to first pass through the pressure sensor, then the condenser, the shut-off valve opens, and it undergoes heat exchange in the evaporator before finally returning to the compressor. At this time, the electronic expansion valve is closed, and the refrigerant does not pass through the battery pack cooler. When the battery pack is cooled in an independent circuit, the compressor drives the refrigerant to first pass through the pressure sensor, then the condenser, the shut-off valve closes, and it undergoes heat exchange in the battery pack cooler before finally returning to the compressor. At this time, the shut-off valve is closed, and the refrigerant does not pass through the evaporator. When the passenger compartment and battery pack are cooled simultaneously, the compressor drives the refrigerant to first pass through the pressure sensor, then the condenser, the shut-off valve opens, and it undergoes heat exchange in both the battery pack cooler and the evaporator before finally returning to the compressor. By adjusting the shut-off valve and the opening of the electronic expansion valve, the refrigerant flow through the evaporator and battery pack cooler can be adjusted to meet different cooling needs of the battery pack and passenger compartment.

[0014] When the electric drive needs cooling, the electric drive water pump drives the coolant through the N-combination unit, then through the motor to absorb the N-combination unit and finally through the electric drive radiator for cooling. The electric drive auxiliary water tank ensures that the cooling system is a closed space and regulates the pressure and replenishes the coolant.

[0015] When the battery pack is cooled, the battery pack water pump drives the coolant through the battery pack and then through the three-way water valve (V4-V2). The coolant continues to pass through the battery pack cooler, where the refrigerant is in a flowing state on one side, cooling the coolant. The cooled water then returns to the water pump. When the battery pack is heated, the battery pack water pump drives the coolant through the battery pack and then through the three-way water valve (V4-V3). The hot water in the passenger compartment gradually increases the opening of the three-way valve (V4-V3) and flows into the battery pack circuit. After mixing with the battery pack coolant, the temperature rises and the coolant continues to pass through the battery pack cooler, where the refrigerant is in a non-flowing state on one side. The heated coolant finally returns to the water pump to heat the battery pack.

[0016] When the passenger compartment is heated, the passenger compartment water pump drives the coolant through the water PTC, and the coolant temperature rises. Then it passes through the heater core, where the coolant exchanges heat with the passenger compartment air. The coolant temperature in the heater core decreases, and the air temperature in the passenger compartment rises.

[0017] This invention utilizes a single water-cooled PTC for heating the passenger compartment and battery pack, employing a three-way water valve to distribute heating power between the two. Compared to a combined air-cooled PTC and battery pack water-cooled PTC heating system, this approach is more cost-effective and requires less investment. The use of a three-way water valve and a check valve isolates the battery pack circuit from the heating air circuit by different pressures on either side of the check valve, effectively reducing heat mixing issues. The three-way valve is a proportional valve, allowing for stepless adjustment of the heating power for both the battery pack and passenger compartment, resulting in more stable target temperatures for the battery pack and simpler control. This invention also shares a single auxiliary water tank, a single water supply pipe, and a single vent pipe for both the passenger compartment and battery pack, effectively reducing the number of auxiliary water tank components and pipes. By controlling the water valve to open multiple circuits, this system enables the low-temperature, low-pressure system to complete both filling and emptying in a single operation, allowing for active degassing of the thermal management system and improving system reliability. Attached Figure Description

[0018] Figure 1 This utility model's 1A mode operation diagram;

[0019] Figure 2 The 1B mode operation diagram of this utility model;

[0020] Figure 3 This utility model's 2B mode operation diagram.

[0021] Figure label:

[0022] 1100 - Crew compartment refrigeration subsystem, 1101 - Compressor, 1102 - Condenser, 1103 - Pressure sensor, 1104 - Shut-off valve, 1105 - Electronic expansion valve, 1106 - Thermal expansion valve, 1107 - Battery pack cooler, 1108 - Evaporator, 1109 - Temperature and pressure sensor, 1300 - Electric drive cooling subsystem, 1301 - Electric drive water pump, 1302 - All-in-one system, 1303 - Motor, 13 04-Electric drive auxiliary water tank, 1305-Electric drive radiator, 1306-Electric fan, 1400-Battery pack thermal management subsystem, 1401-Battery pack water pump, 1402-Battery pack inlet water temperature sensor, 1403-Battery pack, 1404-Three-way water valve, 1405-Battery pack auxiliary water tank, 1500-Crew compartment heating subsystem, 1501-Crew compartment electronic water pump, 1502-Water PTC, 1503-Heat air core. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] A thermal management system for an electric vehicle includes a passenger compartment cooling subsystem 1100, an electric drive thermal management subsystem 1300, a battery thermal management subsystem 1400, and a passenger compartment heating subsystem 1500.

[0025] The crew cabin cooling subsystem 1100 consists of a compressor 1101, a condenser 1102, a pressure sensor 1103, a shut-off valve 1104, an electronic expansion valve 1105, a thermal expansion valve 1106, a battery pack cooler 1107, an evaporator 1108, and a temperature and pressure sensor 1109. The compressor 1101 passes through the pressure sensor 1103 and the condenser 1102, and then returns to the compressor 1101 via a three-way valve, passing through the shut-off valve 1104, the thermal expansion valve 1106, and the evaporator 1108. The other three-way valve returns to the compressor 1101 via the electronic expansion valve 1105, the battery pack cooler 1107, the temperature and pressure sensor 1109, and the three-way valve.

[0026] The electric drive cooling subsystem 1300 consists of an electric drive water pump 1301, an N-in-one unit 1302, a motor 1303, an electric drive radiator 1305, and an electric fan 1306 connected in series. The electric drive water pump 1301 is connected to the electric drive auxiliary water tank 1304 at the rear end of the system.

[0027] The battery pack thermal management subsystem 1400 consists of a battery pack water pump 1401, a battery pack inlet water temperature sensor 1402, a battery pack 1403, a three-way water valve 1404, and a battery pack auxiliary water tank 1405. The three-way water valve 1404 is provided with ports V4, V3, and V2. The battery pack water pump 1401, the battery pack inlet water temperature sensor 1402, the battery pack 1403, ports V4 and V2 of the three-way water valve 1404, and the battery pack cooler 1107 are connected in series. A three-way connection is provided between the battery pack water pump 1401 and the battery pack cooler 1107 to the battery pack auxiliary water tank 1405.

[0028] The crew cabin heating subsystem 1500 consists of a crew cabin electronic water pump 1501, a water PTC 1502, and a heater core 1503 connected in series.

[0029] The three-way water valve's ports V3 and V2 are respectively connected to the crew compartment heating subsystem 1500 via a three-way valve.

[0030] Furthermore, the electric drive radiator 1305, the electric fan 1306, and the condenser 1102 constitute a front-end module.

[0031] Furthermore, the 1404 three-way water valve has an infinitely adjustable angle, with an adjustment range of 110 degrees to 200 degrees.

[0032] The media flow in this invention is as follows: When the crew compartment is cooled via an independent circuit, the compressor 1101 drives the refrigerant to first pass through the pressure sensor 1103, then the condenser 1102, with the shut-off valve 1104 open. The refrigerant then undergoes heat exchange through the evaporator 1108, and finally returns to the compressor 1101. At this time, the electronic expansion valve 1105 is closed, and the refrigerant does not pass through the battery pack cooler 1107. Conversely, when the battery pack is cooled via an independent circuit, the compressor 1101 drives the refrigerant to first pass through the pressure sensor 1103, then the condenser 1102, with the shut-off valve 1104 closed. The refrigerant then undergoes heat exchange through the battery pack cooler 1107, and finally returns to the compressor 1101. When the compressor is in position 1101, the shut-off valve 1104 is closed, and the refrigerant does not pass through the evaporator 1108. When the passenger compartment and battery pack are cooled simultaneously, the compressor 1101 drives the refrigerant to first pass through the pressure sensor 1103, then through the condenser 1102, and the shut-off valve 1104 is open. The refrigerant then undergoes heat exchange through the battery pack cooler 1107 and the evaporator 1108, and finally returns to the compressor 1101. By adjusting the shut-off valve 1104 and the opening of the electronic expansion valve 1105, the refrigerant flow through the evaporator 1108 and the battery pack cooler 1107 can be adjusted to meet the different cooling needs of the battery pack and the passenger compartment.

[0033] When the electric drive needs cooling, the electric drive water pump 1301 drives the coolant through the N-combiner and then through the motor 1303 to absorb the coolant. The N-combiner 1302 and the motor 1303 are then cooled by the electric drive radiator 1305. The electric drive auxiliary water tank 1304 ensures that the cooling system is a closed space and regulates the pressure and replenishes the coolant.

[0034] When the battery pack is cooled, the battery pack water pump 1401 drives the coolant through the battery pack 1402 and then through the three-way water valve 1404, which is in the V4-V2 state. The coolant continues to pass through the battery pack cooler, where the refrigerant is in a flowing state on one side, cooling the coolant. The cooled water returns to the water pump 1401. When the battery pack is heated, the battery pack water pump 1401 drives the coolant through the battery pack 1402 and then through the three-way water valve 1404, which is in the V4-V3 state. The hot water in the passenger compartment gradually increases the opening of the three-way valve V4-V3 and flows to the battery pack circuit. After mixing with the battery pack coolant, the temperature rises and the coolant continues to pass through the battery pack cooler 1107, where the refrigerant is in a non-flowing state on one side. The heated coolant finally returns to the water pump 1401 to heat the battery pack 1402.

[0035] When the passenger compartment is heated, the passenger compartment water pump drives the coolant through the water PTC1502, and the coolant temperature rises. Then it passes through the heater core 1503, where the coolant exchanges heat with the passenger compartment air. The coolant temperature in the heater core decreases, and the air temperature in the passenger compartment rises.

[0036] The three-way water valve 1404, by adjusting the angle of its V4-V3 ports (V4-V2 110 degrees, V4-V3 200 degrees), increases the opening of the valve, thereby increasing the flow of hot water from the passenger compartment to the battery pack circuit. This hot water mixes with the coolant in the battery pack circuit, achieving the required heating inlet water temperature for the battery pack 1403. Its mode settings are shown in the table below:

[0037]

[0038]

[0039] The passenger compartment heating / cooling and battery pack cooling-only -1A mode operation status is as follows: Figure 1 The operation status of the crew cabin heating and battery pack proportional heating in mode 1B is as follows: Figure 2 The passenger compartment heating and battery pack maximum heating - 2B mode operation status is as follows: Figure 3This system enables the battery pack and passenger compartment to share PTC heating via a three-way water valve 1404. It has few parts, simple control, and effectively prevents heat mixing via a one-way valve 1504. Pressure analysis was performed on both sides of the one-way valve 1504. P1 represents the inlet pressure of the battery pack cooler, and P2 represents the outlet pressure of the heater core. The three-stage operation is shown in the table below:

[0040]

[0041] This system, by adjusting the three-way water valve 1404 and combining it with the water pump duty cycle, establishes a corresponding after-sales refill mode, greatly increasing the amount of coolant added during after-sales refilling, as detailed in the table below:

[0042]

[0043]

[0044] Power-on degassing mode:

[0045] Each time power is applied, the PTC outlet water temperature is >55℃, the three-way water valve opening is 110 degrees, the battery pack water pump runs at 90% for 10 seconds;

[0046] PTC outlet water temperature ≤ 55℃, three-way water valve opening degree 155 degrees, battery pack water pump running at 20%, warm air water pump running at 90%, time 10s; after 10s, three-way water valve opening degree 110 degrees, battery pack water pump running at 90%, time 10s.

[0047] The system uses a combination of a 1404 three-way water valve and a 1504 one-way valve. By designing a pressure difference on both sides of the one-way valve, heat mixing is reduced, thus minimizing heat loss under both low and high temperature conditions. For example, when the battery pack does not require heating, heat leakage from the warm air circuit to the battery pack circuit is prevented. This system, through manual and after-sales refilling methods combined with automatic evacuation, can solve the problem of excessive air bubbles or even lack of cooling medium in a certain subsystem after long-term operation, avoiding degradation or even failure of thermal management functions.

[0048] The preferred embodiments of this patent have been described in detail above. However, this patent is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this patent.

Claims

1. A thermal management system for an electric vehicle, characterized in that: It includes a crew cabin cooling subsystem, an electric drive thermal management subsystem, a battery thermal management subsystem, and a crew cabin heating subsystem; The crew cabin refrigeration subsystem consists of a compressor, condenser, pressure sensor, shut-off valve, electronic expansion valve, thermostatic expansion valve, battery pack cooler, evaporator, and temperature and pressure sensor. The compressor passes through the pressure sensor and condenser, and then returns to the compressor via a three-way valve, a shut-off valve, thermostatic expansion valve, evaporator, and another three-way valve. The other three-way valve returns to the compressor via the electronic expansion valve, battery pack cooler, temperature and pressure sensor, and another three-way valve. The electric drive cooling subsystem consists of an electric drive water pump, an N-in-one unit, a motor, an electric drive radiator, and an electric fan connected in series. A T-junction is provided at the rear end of the electric drive water pump to connect to the electric drive auxiliary water tank. The battery pack thermal management subsystem consists of a battery pack water pump, a battery pack inlet water temperature sensor, a battery pack, a three-way water valve, and a battery pack auxiliary water tank. The three-way water valve is equipped with ports V4, V3, and V2. The battery pack water pump, battery pack inlet water temperature sensor, battery pack, ports V4 and V2 of the three-way water valve, and battery pack cooler are connected in series. A three-way valve is provided between the battery pack water pump and the battery pack cooler to connect to the battery pack auxiliary water tank. The crew cabin heating subsystem consists of a crew cabin electronic water pump, a water PTC, and a heater core connected in series. The three-way water valve has ports V3 and V2 connected to the crew compartment heating subsystem via a three-way valve.

2. The thermal management system for an electric vehicle according to claim 1, characterized in that: The electric drive radiator, electric fan, and condenser constitute the front-end module.

3. The thermal management system for an electric vehicle according to claim 1, characterized in that: The angle of the three-way water valve is infinitely adjustable, with an adjustment range of 110 degrees to 200 degrees.

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