Integrated thermal management system and method for new energy heavy truck

Abstract

The invention particularly discloses an integrated thermal management system and method for a new energy heavy truck. The system comprises a battery water loop, a motor water loop, a battery refrigerant loop, a Chiller and a four-way water valve. The Chiller is arranged on the battery refrigerant loop and is connected with the battery water loop, so that a refrigerant of the battery refrigerant loop exchanges heat with circulating water in the battery water loop to reduce the temperature of a cooling liquid of the battery water loop; the four-way water valve is arranged on the motor water loop and connected with the battery water loop so that motor waste heat can be recycled to be used for heating a battery pack or a Chiller in the battery water loop can be used for refrigerating a motor. According to the system, the waste heat utilization rate can be increased, all functional modules are finely controlled, and refrigerating and heating requirements of batteries, motors, passenger compartments and the like are comprehensively managed.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle thermal management, and more specifically, to an integrated thermal management system and method for new energy heavy trucks. Background Art

[0002] Currently, new energy vehicle models are gradually penetrating into the commercial vehicle field such as heavy trucks, and the requirements for vehicle thermal management systems are also getting higher and higher. Among them, the heavy truck thermal management system mainly involves motor cooling, battery heating and cooling, and air conditioning systems. For these three subsystems, the industry technical trend is high integration and modularization. Currently, non-integrated designs are still commonly used in the heavy truck industry, where each subsystem works independently, resulting in a low overall thermal efficiency, poor economy, and a large number of scattered components, making maintenance and servicing difficult. The existing water-cooled unit, as an independent unit dedicated to battery thermal management, occupies a large space, cannot store and transfer heat to other subsystems. When heating is required, only high-power PTC heating can be used, and the waste heat of the motor cannot be utilized. When cooling is required, only Chiller refrigeration can be used and the heat is dissipated, and heat cannot be transferred or stored, resulting in large energy losses, directly affecting the vehicle's cruising range. Moreover, due to the need to frequently operate under refrigeration and heating conditions, large refrigeration and heating powers are required, resulting in large volumes and energy consumption. At the same time, the noise and vibration during operation are large, directly affecting the user experience. In addition, since this water-cooled unit is independent of the vehicle's cooling system and motor cooling system, only limited CAN communication can be used for information interaction, making it difficult to achieve refined control of parameters and difficult to achieve high-efficiency collaborative work among subsystems. Therefore, how to provide integrated thermal management to achieve waste heat recovery and refined refrigeration and heating control is of great significance. Summary of the Invention

[0003] The present invention provides an integrated thermal management system and method for new energy heavy trucks, which solves the problems of poor waste heat utilization and difficult high-efficiency collaboration in the thermal management of existing new energy heavy trucks, can improve the waste heat utilization rate, perform refined control on each functional module, and overall manage the refrigeration and heating requirements of the battery, motor, passenger compartment, etc.

[0004] To achieve the above objectives, the present invention provides the following technical solutions:

[0005] An integrated thermal management system for new energy heavy trucks, comprising: a battery water circuit, a motor water circuit, a battery refrigerant circuit, a Chiller, and a four-way water valve;

[0006] The Chiller is arranged on the battery refrigerant circuit and is connected to the battery water circuit, so that the refrigerant in the battery refrigerant circuit exchanges heat with the circulating water in the battery water circuit to reduce the coolant temperature in the battery water circuit;

[0007] The four-way water valve is arranged on the motor water circuit and connected to the battery water circuit to recover the waste heat of the motor for heating the battery pack or use the Chiller in the battery water circuit to cool the motor.

[0008] Preferably, a motor assembly, a motor controller, a low-temperature radiator, and a water pump are provided on the motor water circuit.

[0009] Preferably, the battery refrigerant circuit is provided with a WPTC and a water pump for heating the battery pack.

[0010] Preferably, the battery water circuit is provided with a condenser, a water pump, a low-pressure fan, and an expansion valve.

[0011] Preferably, it further includes: an air-conditioning refrigerant circuit and an air-conditioning warm water circuit;

[0012] The air-conditioning refrigerant circuit is provided with a condenser, an evaporator, a compressor, a low-pressure fan, and an expansion valve. Among them, the condensers corresponding to the air-conditioning refrigerant circuit and the battery refrigerant circuit are arranged together with the low-temperature radiator on the motor water circuit;

[0013] The air-conditioning warm water circuit is provided with a WPTC, a heat exchanger, and a water pump. Among them, the heat exchanger is provided with a blower.

[0014] Preferably, a water kettle is provided in each of the battery water circuit, the motor water circuit, and the air-conditioning warm water circuit.

[0015] Preferably, an integrated thermal management bracket is arranged at the front end of the vehicle frame, and the water kettle, condenser, low-temperature radiator, low-pressure fan, WPTC, Chiller, compressor, water pump, and thermal management controller are all integrated on the thermal management bracket.

[0016] The present invention also provides an integrated thermal management method for a new energy heavy truck, using the above thermal management system, including:

[0017] Obtain the motor outlet water temperature and the radiator outlet water temperature. For the cooling condition of the motor water circuit, after power-on, the water pump runs at the lowest speed, and the water pump speed, low-pressure fan speed are controlled according to the motor outlet water temperature and the radiator outlet water temperature, and it is judged whether the coolant needs to flow through the low-temperature radiator.

[0018] Preferably, it further includes:

[0019] Obtain the battery inlet water temperature, and turn on the WPTC for heating when the battery inlet water temperature is less than the set low-temperature threshold;

[0020] When the temperature of the battery water inlet is greater than the first high-temperature threshold, the four-way water valve is switched to connect the battery return water circuit in series with the motor return water circuit, and the corresponding water pump speed and low-pressure fan speed are controlled according to the temperature of the battery water inlet;

[0021] When the temperature of the battery water inlet is greater than the second high-temperature threshold, the four-way water valve is switched to separate the battery return water circuit from the motor return water circuit, the battery refrigerant circuit is operated, and the refrigerant in the battery refrigerant circuit exchanges heat with the coolant in the battery water circuit through the Chiller to reduce the coolant temperature, thereby cooling the battery pack, where the second high-temperature threshold is greater than the first high-temperature threshold.

[0022] Preferably, it further includes:

[0023] When receiving the cooling demand sent by the air conditioner controller, the low-pressure fan and the compressor of the air conditioner refrigerant circuit are powered on and operate at the lowest speed first, the air conditioner target temperature is obtained, and the speeds of the low-pressure fan and the compressor are controlled according to the air conditioner target temperature;

[0024] When receiving the heating demand sent by the air conditioner, the water pump is powered on and operates at the lowest speed first, the water temperature at the outlet of the air conditioner WPTC and the air outlet temperature of the blower are obtained, and the water pump speed and the operation of the air conditioner WPTC are controlled according to the water temperature at the outlet of the air conditioner WPTC and the air outlet temperature of the blower.

[0025] The present invention provides an integrated thermal management system and method for a new energy heavy truck, which connects the battery water circuit, the motor water circuit, and the battery refrigerant circuit into one body through a four-way water valve and a Chiller, solves the problems of poor waste heat utilization and difficult high-efficiency coordination in the thermal management of existing new energy heavy trucks, can improve the waste heat utilization rate, perform refined control on each functional module, and overall manage the cooling and heating demands of the battery, motor, passenger compartment, etc. Description of the Drawings

[0026] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below.

[0027] Figure 1 It is a schematic diagram of an integrated thermal management system for a new energy heavy truck provided by the present invention. Detailed Embodiments

[0028] In order to enable those skilled in the art to better understand the solutions of the embodiments of the present invention, the embodiments of the present invention will be further described in detail below in conjunction with the drawings and embodiments.

[0029] In view of the problems of poor waste heat utilization and difficulty in efficient coordination in the thermal management of current new energy heavy-duty trucks, the present invention provides an integrated thermal management system and method for new energy heavy-duty trucks, which solve the problems of poor waste heat utilization and difficulty in efficient coordination in the thermal management of existing new energy heavy-duty trucks, can improve the waste heat utilization rate, perform fine control on each functional module, and comprehensively manage the cooling and heating needs of batteries, motors, passenger compartments, etc.

[0030] like Figure 1 As shown, an integrated thermal management system for a new energy heavy truck includes: a battery water circuit, a motor water circuit, a battery refrigerant circuit, a chiller and a four-way water valve. The chiller is arranged on the battery refrigerant circuit and connected to the battery water circuit, so that the refrigerant in the battery refrigerant circuit performs heat exchange with the circulating water in the battery water circuit to reduce the coolant temperature of the battery water circuit. The four-way water valve is arranged on the motor water circuit and connected to the battery water circuit to recover the waste heat of the motor for heating the battery pack or to use the chiller in the battery water circuit to cool the motor.

[0031] Furthermore, the motor water circuit is provided with a motor assembly, a motor controller, a low-temperature radiator and a water pump.

[0032] In practical applications, such as Figure 1 As shown, the all-in-one + MCU is an all-in-one motor controller. A three-way valve, a first temperature sensor T-1, and a second temperature sensor T-2 are also provided in the motor water circuit. The first temperature sensor is used to detect the radiator water outlet temperature of the motor water circuit, and the second temperature sensor is used to detect the motor water outlet temperature of the motor water circuit.

[0033] In one embodiment, the cooling conditions of the motor and the all-in-one motor controller are as follows: after power-on, the water pump runs at the lowest speed, T-1 / T-2 monitors the water circuit temperature, and the fan speed is controlled by T-1 feedback PID. When T-1 ≥ 45°C (all-in-one water inlet limit temperature -15°C), the three-way valve switches to control the coolant to flow through the low-temperature radiator; the water pump speed is controlled by T-2 feedback PID / PWM. When T-2 ≥ 20°C, the water flow rate is greater than the maximum required flow rate of 30L / min (duty cycle), when 20°C>T-2≥10°C, the water flow rate is 10L / min (duty cycle), and when 10°C>T-2≥-35°C, the water flow rate is 5L / min (duty cycle).

[0034] Furthermore, the battery refrigerant circuit is provided with a WPTC and a water pump for heating the battery pack.

[0035] Furthermore, the battery water circuit is provided with a condenser, a water pump, a low-pressure fan and an expansion valve.

[0036] The system further includes: an air-conditioning refrigerant circuit and an air-conditioning warm water circuit; the air-conditioning refrigerant circuit is provided with a condenser, an evaporator, a compressor, a low-pressure fan, and an expansion valve. Among them, the condensers corresponding to the air-conditioning refrigerant circuit and the battery refrigerant circuit are arranged together with the low-temperature radiator on the motor water circuit; the air-conditioning warm water circuit is provided with a WPTC, a heat exchanger, and a water pump. Among them, the heat exchanger is provided with a blower.

[0037] Furthermore, water kettles are provided in the battery water circuit, the motor water circuit, and the air-conditioning warm water circuit.

[0038] Furthermore, an integrated thermal management bracket is arranged at the front end of the vehicle frame, and the water kettle, condenser, low-temperature radiator, low-pressure fan, WPTC, Chiller, compressor, water pump, and thermal management controller are all integrated on the thermal management bracket.

[0039] In practical applications, multiple modes can be set, as shown in Table 1, realizing 10 different working modes. Through algorithm and program fine-grained control, it is integrated into the central control unit, and an interface related to OTA upgrade is reserved. More functions can be realized through software upgrade.

[0040]

[0041] By designing an integrated thermal management module, the refrigeration and heating requirements of the battery, motor, and passenger compartment are integrated, and through fine-grained control, high-efficiency heat transfer and centralized management of heat are achieved.

[0042] It can be seen that the present invention provides an integrated thermal management system for a new energy heavy truck. By connecting the battery water circuit, the motor water circuit, and the battery refrigerant circuit into one body through a four-way water valve and a Chiller, the problems of poor waste heat utilization and difficulty in efficient coordination existing in the thermal management of existing new energy heavy trucks are solved. The waste heat utilization rate can be improved, and fine control can be carried out on each functional module to overall manage the refrigeration and heating requirements of the battery, motor, passenger compartment, etc.

[0043] Correspondingly, the present invention also provides an integrated thermal management method for a new energy heavy truck, using the above thermal management system, including: obtaining the motor outlet water temperature and the radiator outlet water temperature. For the cooling condition of the motor water circuit, after power-on, the water pump runs at the lowest speed, and the water pump speed, low-pressure fan speed are controlled according to the motor outlet water temperature and the radiator outlet water temperature, and it is judged whether the coolant needs to flow through the low-temperature radiator.

[0044] The method further includes: obtaining the temperature of the battery water inlet, and turning on the WPTC for heating when the temperature of the battery water inlet is lower than the set low temperature threshold; when the temperature of the battery water inlet is higher than the first high temperature threshold, converting through a four-way water valve to connect the battery return water path in series with the motor return water path, and controlling the corresponding water pump speed and low-pressure fan speed according to the temperature of the battery water inlet; when the temperature of the battery water inlet is higher than the second high temperature threshold, converting through a four-way water valve to separate the battery return water path from the motor return water path, operating the battery refrigerant circuit, and using the refrigerant in the battery refrigerant circuit to perform heat exchange on the coolant in the battery water circuit through a Chiller to reduce the coolant temperature, thereby cooling the battery pack, where the second high temperature threshold is greater than the first high temperature threshold.

[0045] In practical applications, for the battery heating condition, parking and driving are judged through the vehicle speed signal. The state with a vehicle speed ≤ 5 km / h is parking, and the state with a vehicle speed > 5 km / h is driving. For the battery cooling condition: parking and driving are judged through the vehicle speed signal. The state with a vehicle speed ≤ 5 km / h is parking, and the state with a vehicle speed > 5 km / h is driving.

[0046] Parking charging and heating condition: After the temperature management controller TMS receives the heating requirement sent by the battery management system BMS, the water pump (for the battery) is powered on and runs at the lowest speed, and the temperature of the battery water inlet is detected by T-3; when T-3 ≤ (target water temperature - ΔT), turn on heating + water pump, when (target water temperature - ΔT) < T-3 < (target water temperature + ΔT), maintain the previous state, when T-3 ≥ (target water temperature + ΔT), only turn on the water pump; compare T-3 with the target water temperature to execute the control strategy; control the WPTC (for the battery) and the water pump (for the battery) through the PID of the difference between T-3 and the target water temperature.

[0047] Driving (discharging / regenerative charging) and heating condition: After the TMS receives the heating requirement sent by the BMS, the water pump (for the battery) is powered on and runs at the lowest speed, the third temperature sensor T-3 monitors the temperature of the battery water inlet; the second temperature sensor T-2 monitors the temperature of the motor outlet water, and the first temperature sensor T-1 monitors the temperature of the radiator outlet water. When T-2 > T-3 & T-2 > T-1 & T-1 < (target water temperature + ΔT), the four-way valve converts to connect the motor water path in series with the battery water path, and controls the water pump (for the battery) and the motor (water pump) through the PID / PWM of the difference between T-3 and the target water temperature; when the condition of T-2 > T-3 || T-2 > T-1 || T-1 < (target water temperature + ΔT) is not met, the four-way valve converts to separate the motor water path from the battery water path, and execute the parking charging and heating process.

[0048] Park charging and cooling condition: After the TMS receives the refrigeration demand sent by the BMS, the water pump (battery) is powered on and operates at the lowest speed, and the third temperature sensor T-3 detects the battery inlet water temperature; when T-3 ≥ (ambient temperature + 5°C / 2°C, 5°C is the air-conditioning refrigeration state) & T-3 > (target water temperature - ΔT), the four-way valve switches the battery water circuit and the motor water circuit in series, and controls the water pump (battery), water pump (motor) and fan through the PID / PWM of the difference between T-3 and the target water temperature; when it does not meet T-3 ≥ (ambient temperature + 5°C) || T-3 ≥ (target water temperature - ΔT), the four-way valve switches the battery water circuit and the motor water circuit to be separated, and executes the driving (discharging / charging) cooling process.

[0049] Driving (discharging / charging) cooling condition: After the TMS receives the refrigeration demand sent by the BMS, the water pump (battery) is powered on and operates at the lowest speed, and the third temperature sensor T-3 detects the battery inlet water temperature; when T-3 ≤ (target water temperature - ΔT), only the water pump (battery) is turned on; when (target water temperature - ΔT) < T-3 < (target water temperature + ΔT), maintain the previous state, when T-3 ≥ (target water temperature + ΔT), turn on the refrigeration (battery compressor) + water pump (battery); control the water pump (battery) and fan through the PID / PWM of the difference between T-3 and the target water temperature; control the compressor speed through the refrigerant high-pressure feedback value PID, and control the expansion valve opening through the refrigerant low-pressure feedback value PID.

[0050] Battery internal circulation condition: After the TMS receives the internal circulation demand sent by the BMS, the water pump (battery) is powered on and operates at the lowest speed, and T-3 detects the battery inlet water temperature; control the water pump (battery) through the PID / PWM of the difference between T-3 and the target water temperature.

[0051] The method further includes: when receiving the refrigeration demand sent by the air-conditioning controller, the low-pressure fan and compressor of the air-conditioning refrigerant circuit are powered on and first operate at the lowest speed, obtain the air-conditioning target temperature, and control the speeds of the low-pressure fan and compressor according to the air-conditioning target temperature; when receiving the heating demand sent by the air conditioner, the water pump is powered on and first operates at the lowest speed, obtain the air-conditioning WPTC outlet water temperature and the blower outlet air temperature, and control the water pump speed and the operation of the air-conditioning WPTC according to the air-conditioning WPTC outlet water temperature and the blower outlet air temperature.

[0052] In practical applications, air-conditioning heating condition: After the TMS receives the heating demand sent by the air-conditioning controller, the water pump (air-conditioning) is powered on and operates at the lowest speed, the fourth temperature sensor T-4 detects the WPTC (air-conditioning) outlet water temperature, and controls the water pump (air-conditioning) and WPTC (air-conditioning) through the PID of the difference between the blower outlet air temperature and T-4.

[0053] Air-conditioning refrigeration condition: After the TMS receives the refrigeration demand sent by the air-conditioning controller, the fan is powered on and runs at the lowest speed, and the compressor (air-conditioning) is powered on and runs at the lowest speed. The compressor (air-conditioning) and the fan are controlled by the PID of the difference between the surface temperature of the evaporator and the set temperature. When the air-conditioning and the battery share the compressor, the compressor control gives priority to the battery refrigeration demand. When the battery charging refrigeration demand cannot be met under extreme conditions, the air-conditioning is cut off through the SOV cut-off valve.

[0054] Air-conditioning dehumidification condition: After the TMS receives the dehumidification demand sent by the air-conditioning controller, it executes air-conditioning heating + air-conditioning refrigeration.

[0055] It can be seen that the present invention provides an integrated thermal management method for new energy heavy trucks, which connects the battery water circuit, the motor water circuit and the battery refrigerant circuit into one body through a four-way water valve and a Chiller, solves the problems of poor waste heat utilization and difficult high-efficiency coordination in the thermal management of existing new energy heavy trucks, can improve the waste heat utilization rate, perform refined control on each functional module, and overall manage the refrigeration and heating demands of the battery, motor, passenger compartment, etc.

[0056] The structure, features and effects of the present invention have been described in detail based on the embodiments shown in the drawings. The above is only the preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the drawings. Any changes made according to the concept of the present invention, or modified into equivalent embodiments with equivalent changes, still within the spirit covered by the description and the drawings, shall be within the protection scope of the present invention.

Claims

1. An integrated thermal management system for a new energy heavy truck, characterized in that, including: a battery water circuit, a motor water circuit, a battery refrigerant circuit, a Chiller, and a four-way water valve; The Chiller is disposed on the battery refrigerant circuit and connected to the battery water circuit, so that the refrigerant in the battery refrigerant circuit exchanges heat with the circulating water in the battery water circuit to reduce the coolant temperature in the battery water circuit; The four-way water valve is disposed on the motor water circuit and connected to the battery water circuit to recover the waste heat of the motor for heating the battery pack or use the Chiller in the battery water circuit to cool the motor.

2. The integrated thermal management system of the new energy heavy truck according to claim 1, characterized in that The motor water circuit is provided with a motor assembly, a motor controller, a low-temperature radiator, and a water pump.

3. The integrated thermal management system of the new energy heavy truck according to claim 2, wherein The battery refrigerant circuit is provided with a WPTC and a water pump for heating the battery pack.

4. The integrated thermal management system of the new energy heavy truck according to claim 3, characterized in that, The battery water circuit is provided with a condenser, a water pump, a low-pressure fan, and an expansion valve.

5. The integrated thermal management system of the new energy heavy truck according to claim 4, characterized in that, It further includes: an air-conditioning refrigerant circuit and an air-conditioning warm water circuit; The air-conditioning refrigerant circuit is provided with a condenser, an evaporator, a compressor, a low-pressure fan, and an expansion valve. Among them, the condensers corresponding to the air-conditioning refrigerant circuit and the battery refrigerant circuit are arranged together with the low-temperature radiator on the motor water circuit; The air-conditioning warm water circuit is provided with a WPTC, a heat exchanger, and a water pump. Among them, the heat exchanger is provided with a blower.

6. The integrated thermal management system of the new energy heavy truck according to claim 5, characterized in that, Water kettles are provided in the battery water circuit, the motor water circuit, and the air-conditioning warm water circuit.

7. The integrated thermal management system of the new energy heavy truck according to claim 6, characterized in that An integrated thermal management bracket is provided at the front end of the vehicle frame, and the water kettle, condenser, low-temperature radiator, low-pressure fan, WPTC, Chiller, compressor, water pump, and thermal management controller are all integrated on the thermal management bracket.

8. An integrated thermal management method for a new energy heavy truck, using the thermal management system described in claim 7, characterized in that, including: Obtain the motor outlet water temperature and the radiator outlet water temperature. For the cooling condition of the motor water circuit, after power-on, the water pump runs at the lowest speed, and controls the water pump speed, the low-pressure fan speed, and determines whether the coolant needs to flow through the low-temperature radiator according to the motor outlet water temperature and the radiator outlet water temperature.

9. The integrated thermal management method for the new energy heavy truck according to claim 8, characterized in that It further includes: Obtain the battery inlet water temperature, and turn on the WPTC for heating when the battery inlet water temperature is less than the set low-temperature threshold; When the battery inlet water temperature is greater than the first high-temperature threshold, the battery return water circuit and the motor return water circuit are connected in series through the conversion of the four-way water valve, and the corresponding water pump speed and low-pressure fan speed are controlled according to the battery inlet water temperature; When the battery inlet water temperature is greater than the second high-temperature threshold, the battery return water circuit and the motor return water circuit are separated through the conversion of the four-way water valve, the battery refrigerant circuit is operated, and the refrigerant in the battery refrigerant circuit exchanges heat with the coolant in the battery water circuit through the Chiller to reduce the coolant temperature, thereby cooling the battery pack, where the second high-temperature threshold is greater than the first high-temperature threshold.

10. The integrated thermal management method of the new energy heavy truck according to claim 9, characterized in that, It further includes: When receiving the cooling demand sent by the air-conditioning controller, the low-pressure fan and the compressor of the air-conditioning refrigerant circuit are powered on and first run at the lowest speed, obtain the air-conditioning target temperature, and control the speeds of the low-pressure fan and the compressor according to the air-conditioning target temperature; When receiving the heating demand sent by the air conditioner, the water pump is powered on and first operates at the lowest speed. The water temperature at the outlet of the air conditioner WPTC and the air outlet temperature of the blower are obtained, and the water pump speed and the operation of the air conditioner WPTC are controlled according to the water temperature at the outlet of the air conditioner WPTC and the air outlet temperature of the blower.

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