EP-4741185-A1 - THERMAL MANAGEMENT SYSTEM AND CONTROL METHOD THEREOF, AND VEHICLE

EP4741185A1EP 4741185 A1EP4741185 A1EP 4741185A1EP-4741185-A1

Abstract

Disclosed are a thermal management system, a control method therefor, and a vehicle. The thermal management system includes a battery subsystem. The battery subsystem includes a plurality of heat exchange branches disposed in parallel. The heat exchange branches are configured to exchange heat with a battery. The plurality of heat exchange branches disposed in parallel include a pressure regulation sub-branch and a heat exchange sub-branch. The control method includes: obtaining a battery heating signal; and the thermal management system enters a preheating mode, where in the preheating mode, a total flow rate Q1 of the pressure regulation sub-branch is greater than a total flow rate Q2 of the heat exchange sub-branch.

Inventors

LING, HEPING
HUANG, WEI
MA, RUI
LAI, Feng
LUO, Yili

Assignees

BYD Company Limited

Dates

Publication Date: 20260513
Application Date: 20240703

Claims (13)

A control method for a thermal management system, wherein the thermal management system (100) comprises a battery subsystem (80), the battery subsystem (80) comprises a plurality of heat exchange branches (20) disposed in parallel, the heat exchange branches (20) are configured to exchange heat with a battery, the plurality of heat exchange branches (20) disposed in parallel comprise a pressure regulation sub-branch (21) and a heat exchange sub-branch, and the control method comprises: obtaining a battery heating signal; and entering, by the thermal management system, a preheating mode, wherein in the preheating mode, a total flow rate Q1 of the pressure regulation sub-branch is greater than a total flow rate Q2 of the heat exchange sub-branch.
The control method for the thermal management system according to claim 1, wherein a ratio of the total flow rate Q1 of the pressure regulation sub-branch to the total flow rate Q2 of the heat exchange sub-branch, namely, Q1/Q2, is greater than a third threshold.
The control method for the thermal management system according to claim 1 or 2, wherein at least one of the heat exchange branches (20) comprises a flow regulating valve (16), and controlling valve opening of the at least one of the heat exchange branches to be greater than valve opening of the heat exchange sub-branch.
The control method for the thermal management system according to claim 1, wherein in the preheating mode, controlling the pressure regulation sub-branch to be in an operating state, and controlling the heat exchange sub-branch to be in a non-operating state.
The control method for the thermal management system according to any one of claims 1 to 4, wherein a temperature of the battery reaches a first temperature, the thermal management system enters a normal heating mode, and controlling, in the normal heating mode based on a real-time temperature of the battery, the at least one of the heat exchange branches to be connected to heat the battery.
The control method for the thermal management system according to claim 5, wherein a flow rate of the pressure regulation sub-branch in the preheating mode is greater than a flow rate of the pressure regulation sub-branch in the normal heating mode.
The control method for the thermal management system according to claim 5 or 6, wherein when a minimum value among temperature values of a plurality of positions of the battery reaches a first specified temperature, the temperature of the battery reaches the first temperature.
The control method for the thermal management system according to any one of claims 1 to 7, wherein the heat exchange branch (20) comprises a battery heat exchange module (56) and a throttling element (15) that are connected in series; and adjusting opening of the throttling element based on superheat of a heat exchange medium in the heat exchange branch.
The control method for the thermal management system according to any one of claims 1 to 8, wherein the plurality of heat exchange branches (20) comprise a bottom heat exchange branch and a top heat exchange branch, and the top heat exchange branch is located at the top of the battery, and the bottom heat exchange branch is located at the bottom of the battery; and in the preheating mode, controlling a total flow rate Q1 of the bottom heat exchange branch to be greater than a total flow rate Q2 of the top heat exchange branch.
The control method for the thermal management system according to any one of claims 1 to 9, wherein the thermal management system (100) further comprises a coolant subsystem (60); and the control method further comprises: when obtaining a waste heat recovery command, exchanging, by the coolant subsystem, heat with the battery subsystem; the thermal management system has the normal heating mode; and controlling, in the normal heating mode, each heat exchange branch to heat the battery, wherein a water temperature of the coolant subsystem reaches a third specified temperature, and the thermal management system enters the normal heating mode.
A thermal management system (100), comprising: a compressor (1), the compressor (1) having a suction port and a discharge port; a plurality of heat exchange branches (20) disposed in parallel, the heat exchange branches (20) exchanging heat with a battery, the thermal management system (100) having a battery heating mode, a first end of each heat exchange branch (20) communicating with the discharge port in the battery heating mode, and the plurality of heat exchange branches (20) disposed in parallel comprising a pressure regulation sub-branch (21) and a heat exchange sub-branch; a first heat exchanger (4), a first end of the first heat exchanger (4) being connected to a second end of each heat exchange branch (20) through a throttling element (15), and a second end of the first heat exchanger (4) being connected to the suction port; and a control module, the control module being configured to perform the control method for the thermal management system according to any one of claims 1 to 10.
A vehicle, comprising a thermal management system and a control module, the control module being configured to perform the control method for the thermal management system according to any one of claims 1 to 10.
The vehicle according to claim 12, wherein the control module comprises a storage medium, the storage medium is configured to store executable instructions, and the instructions are used to perform the control method for the thermal management system according to any one of claims 1 to 10.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priorities to Chinese Patent Application No. 2023108106003 and 2023111338843, filed on July 3, 2023 and August 31, 2023, which are incorporated herein by reference in their entireties. TECHNICAL FIELD This application relates to the field of vehicle technologies, and in particular, to a thermal management system, a control method therefor, and a vehicle. BACKGROUND Battery heating in vehicles usually utilizes the gaseous refrigerant discharged by a compressor to exchange heat with a battery. When heating the battery, the gaseous refrigerant cools down and depressurizes, resulting in liquefaction. In related art, when temperature of the battery is low, or heat exchange area of the battery heat exchange is large, or flow resistance of the battery heat exchange module is high, the heat exchange medium experiences excessive heat exchange within the battery heat exchange module. This leads to low suction pressure and low discharge pressure (high pressure side is low) of the compressor. The compressor operates outside an operating range and may be damaged. SUMMARY This application is intended to resolve at least one of technical problems existing in the conventional art. Therefore, this application provides a control method for a thermal management system, to reduce the probability of compressor damage. This application further provides a thermal management system to which the foregoing control method is applied, to reduce the probability of compressor damage. This application further provides a vehicle to which the foregoing control method is applied, to reduce the probability of compressor damage. According to a control method for a thermal management system in an embodiment of this application, the thermal management system includes a battery subsystem. The battery subsystem includes a plurality of heat exchange branches disposed in parallel. The heat exchange branches are configured to exchange heat with a battery. The plurality of heat exchange branches disposed in parallel include a pressure regulation sub-branch and a heat exchange sub-branch. The control method includes: obtaining a battery heating signal; and the thermal management system enters a preheating mode, wherein in the preheating mode, a total flow rate Q1 of the pressure regulation sub-branch is greater than a total flow rate Q2 of the heat exchange sub-branch. According to the control method for the thermal management system in this embodiment of this application, the total flow rate Q1 of the pressure regulation sub-branch is set to be greater than the total flow rate Q2 of the heat exchange sub-branch, to control a heat exchange medium at an outlet end to maintain a specific temperature state. This can increase outlet pressure of a compressor, and prevent the compressor from operating outside its operating range and being damaged. In some embodiments, a ratio of the total flow rate Q1 of the pressure regulation sub-branch to the total flow rate Q2 of the heat exchange sub-branch, namely, Q1/Q2, is greater than a third threshold. In some embodiments, at least one of the heat exchange branches includes a flow regulating valve, and valve opening of the at least one of the heat exchange branches is controlled to be greater than valve opening of the heat exchange sub-branch. In some embodiments, in the preheating mode, the pressure regulation sub-branch is controlled to be in an operating state, and the heat exchange sub-branch is controlled to be in a non-operating state. In some embodiments, a temperature of the battery reaches a first temperature, the thermal management system enters a normal heating mode, and the at least one of the heat exchange branches is controlled, in the normal heating mode based on a real-time temperature of the battery, to be connected to heat the battery. In some embodiments, a flow rate of the pressure regulation sub-branch in the preheating mode is greater than a flow rate of the pressure regulation sub-branch in the normal heating mode. In some embodiments, when a minimum value among temperature values of a plurality of positions of the battery reaches a first specified temperature, the temperature of the battery reaches the first temperature. In some embodiments, the heat exchange branch includes a battery heat exchange module and a throttling element that are connected in series; and opening of the throttling element is adjusted based on superheat of a heat exchange medium in the heat exchange branch. In some embodiments, the plurality of heat exchange branches include a bottom heat exchange branch and a top heat exchange branch, and the top heat exchange branch is located at the top of the battery, and the bottom heat exchange branch is located at the bottom of the battery; and in the preheating mode, a total flow rate Q1 of the bottom heat exchange branch is controlled to be greater than a total flow rate Q2 of the top heat exchange branch. In so