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EP-4741184-A1 - THERMAL MANAGEMENT SYSTEM AND CONTROL METHOD THEREOF, AND VEHICLE

EP4741184A1EP 4741184 A1EP4741184 A1EP 4741184A1EP-4741184-A1

Abstract

A thermal management system and a control method therefor and a vehicle are disclosed. The thermal management system includes a battery subsystem, the battery subsystem includes at least one heat exchange branch, the heat exchange branch is configured to exchange heat with a battery, and the control method includes: obtaining a battery heating signal; and entering, by the thermal management system, a preheating mode, where in the preheating mode, a temperature of a heat exchange medium at an outlet end of the at least one heat exchange branch is greater than or equal to a first threshold T1.

Inventors

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

Assignees

  • BYD Company Limited

Dates

Publication Date
20260513
Application Date
20240703

Claims (20)

  1. A control method for a thermal management system, wherein the thermal management system (100) comprises a battery subsystem (80), the battery subsystem (80) comprises at least one heat exchange branch (20), the heat exchange branch (20) is configured to exchange heat with a battery, and the control method comprises: obtaining a battery heating signal; and entering, by the thermal management system, a preheating mode, in the preheating mode, a temperature of a heat exchange medium at an outlet end of the at least one heat exchange branch being greater than or equal to a first threshold T1.
  2. The control method for a thermal management system according to claim 1, wherein a temperature difference ΔT between a temperature of a heat exchange medium at an inlet end of the at least one heat exchange branch and the temperature at the outlet end is less than or equal to T2, and T2 is a second threshold.
  3. The control method for a thermal management system according to claim 1 or 2, wherein the thermal management system enters a normal heating mode when a temperature of the battery reaches a first temperature, and in the normal heating mode, the at least one heat exchange branch is controlled, based on a real-time temperature of the battery, to be turned on to heat the battery.
  4. The control method for a thermal management system according to claim 3, wherein the battery subsystem (80) comprises a plurality of heat exchange branches (20) connected in parallel, the plurality of heat exchange branches (20) are configured to exchange heat with the battery, and the plurality of heat exchange branches (20) comprise a pressure adjustment sub-branch (21); and in the preheating mode, a temperature of a heat exchange medium at an outlet end of the pressure adjustment sub-branch is controlled to be greater than or equal to the first threshold T1.
  5. The control method for a thermal management system according to claim 4, wherein in the preheating mode, a temperature difference ΔT between an inlet end and the outlet end of the pressure adjustment sub-branch is controlled to be less than or equal to T2.
  6. The control method for a thermal management system according to claim 4 or 5, wherein at least one heat exchange branch is configured to exchange heat with a first side of the battery, and at least one heat exchange branch is configured to exchange heat with a second side of the battery.
  7. The control method for a thermal management system according to any one of claims 4 to 6, wherein the plurality of heat exchange branches (20) comprise the pressure adjustment sub-branch (21) and a heat exchange sub-branch; and in the preheating mode, a total flow Q1 in the pressure adjustment sub-branch is greater than a total flow Q2 in the heat exchange sub-branch.
  8. The control method for a thermal management system according to claim 7, wherein in the preheating mode, a ratio Q1/Q2 of the total flow Q1 of heat exchange media in the pressure adjustment sub-branch to the total flow Q2 in the heat exchange sub-branch is greater than a third threshold.
  9. The control method for a thermal management system according to any one of claims 4 to 8, wherein the plurality of heat exchange branches (20) comprise the pressure adjustment sub-branch (21) and the heat exchange sub-branch, and at least some of the heat exchange branches comprise a flow regulating valve (16); and an opening degree of a valve in the pressure adjustment sub-branch is controlled to be greater than an opening degree of a valve in the heat exchange sub-branch.
  10. The control method for a thermal management system according to any one of claims 4 to 6, wherein the plurality of heat exchange branches (20) comprise the pressure adjustment sub-branch (21) and a heat exchange sub-branch; and in the preheating mode, the heat exchange sub-branch is controlled to be in a non-operating state.
  11. The control method for a thermal management system according to any one of claims 3 to 10, wherein when a minimum value of temperature values at a plurality of positions of the battery reaches a first specified temperature, the temperature of the battery reaches the first temperature.
  12. The control method for a thermal management system according to any one of claims 1 to 11, wherein the thermal management system further comprises the normal heating mode, the heat exchange branch comprises the pressure adjustment sub-branch, and a flow in the pressure adjustment sub-branch in the preheating mode is greater than a flow in the pressure adjustment sub-branch in the normal heating mode.
  13. The control method for a thermal management system according to any one of claims 1 to 12, wherein the heat exchange branch (20) comprises a battery heat exchange module (56) and a throttle element (15) that are connected in series; and an opening degree of the throttle element is adjusted based on a degree of superheating of a heat exchange medium in the heat exchange branch.
  14. The control method for a thermal management system according to claim 13, wherein in the preheating mode, that an opening degree of the throttle element is adjusted based on a degree of superheating of a heat exchange medium in the heat exchange branch comprises: decreasing the opening degree of the throttle element when the degree of superheating ΔT4 is less than a first specified value ΔTa; increasing the opening degree of the throttle element when the degree of superheating ΔT4 is greater than a second specified value ΔTb; or maintaining the opening degree of the throttle element when the degree of superheating ΔT4 is greater than or equal to ΔTa and less than or equal to ΔTb.
  15. The control method for a thermal management system according to claim 2, wherein the at least one heat exchange branch (20) comprises a bottom heat exchange branch and a top heat exchange branch, the top heat exchange branch is located at a top of the battery, and the bottom heat exchange branch is located at a bottom of the battery; and in the preheating mode, a temperature difference ΔT between an inlet end and an outlet end of the bottom heat exchange branch is controlled to be less than the second threshold.
  16. The control method for a thermal management system according to any one of claims 1 to 15, wherein the thermal management system (100) further comprises a coolant subsystem (60); and the control method further comprises: when a waste heat recovery instruction is obtained, exchanging, by the coolant subsystem, heat with the battery subsystem.
  17. The control method for a thermal management system according to claim 16, wherein the thermal management system has the normal heating mode, and in the normal heating mode, each of the heat exchange branches is controlled to heat the battery; and the thermal management system enters the normal heating mode when a water temperature of the coolant subsystem reaches a third specified temperature.
  18. A thermal management system (100), comprising: a compressor (1), the compressor (1) having an air inlet and an air outlet; at least one heat exchange branch (20), the heat exchange branch (20) exchanging heat with a battery, the thermal management system (100) having a battery heating mode, and in the battery heating mode, a first end of the heat exchange branch (20) being connected to the air outlet; a first heat exchanger (4), a first end of the first heat exchanger (4) being connected to a second end of the heat exchange branch (20) through a throttle element (15), and a second end of the first heat exchanger (4) being connected to the air inlet; and a control module, the control module being configured to perform the control method for a thermal management system according to any one of claims 1 to 17.
  19. A vehicle, comprising a thermal management system (100) and a control module, the control module being configured to perform the control method for a thermal management system according to any one of claims 1 to 17.
  20. The vehicle according to claim 19, 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 a thermal management system according to any one of claims 1 to 17.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is provided based on Chinese Patent Applications Nos. 2023108106003 and 2023111291550, filed on July 3, 2023 and August 31, 2023, and claims priority to these Chinese Patent Applications, 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 and a control method therefor and a vehicle. BACKGROUND Vehicle battery heating is usually implemented by using a gaseous refrigerant discharged by a compressor to exchange heat with a battery. The gaseous refrigerant exchanges heat with the battery, and when the battery is heated, the gaseous refrigerant is cooled, depressurized, and liquefied. In the related art, when the temperature of a battery is low, the heat exchange area of battery heat exchange is large, or the flow resistance of a battery heat exchange module is large, the heat exchange medium excessively exchanges heat in the battery heat exchange module, causing low intake pressure and low discharge pressure (low high-side pressure) in the compressor, which exceed the operating range of the compressor, and may cause damage to the compressor. SUMMARY This application is intended to resolve at least one of technical problems in the conventional technology. Therefore, this application provides a control method for a thermal management system, to reduce a probability that a compressor is damaged. This application further provides a thermal management system to which the foregoing control method is applied, to reduce a probability that a compressor is damaged. This application further provides a vehicle to which the foregoing control method is applied, to reduce a probability that a compressor is damaged. According to the control method for a thermal management system in embodiments of this application, the thermal management system includes a battery subsystem, the battery subsystem includes at least one heat exchange branch, the heat exchange branch is configured to exchange heat with a battery, and the control method includes: obtaining a battery heating signal; and entering, by the thermal management system, a preheating mode, wherein in preheating mode, a temperature of a heat exchange medium at an outlet end of the at least one heat exchange branch is greater than or equal to a first threshold T1. According to the control method for a thermal management system in embodiments of this application, the temperature of the heat exchange medium at the outlet end of the at least one heat exchange branch is set to be greater than or equal to the first threshold T1, so as to control the heat exchange medium at the outlet end to remain in a specific temperature state, to avoid excessive liquefaction of the heat exchange medium in a heat exchanger, thereby increasing pressure at an outlet of a compressor, and avoiding damage to the compressor caused when the compressor operates outside its operating range. In some embodiments, a temperature difference ΔT between a temperature of a heat exchange medium at an inlet end of the at least one heat exchange branch and the temperature at the outlet end is less than or equal to T2, and T2 is a second threshold. In some embodiments, the thermal management system enters a normal heating mode when a temperature of the battery reaches a first temperature, and in normal heating mode, the at least one heat exchange branch is controlled, based on a real-time temperature of the battery, to be turned on to heat the battery. In some embodiments, the battery subsystem includes a plurality of heat exchange branches connected in parallel, the plurality of heat exchange branches are configured to exchange heat with the battery, and the plurality of heat exchange branches include a pressure adjustment sub-branch. In preheating mode, a temperature of a heat exchange medium at an outlet end of the pressure adjustment sub-branch is controlled to be greater than or equal to the first threshold T1. In some embodiments, in preheating mode, a temperature difference ΔT between an inlet end and the outlet end of the pressure adjustment sub-branch is controlled to be less than or equal to T2. In some embodiments, at least one heat exchange branch is configured to exchange heat with a first side of the battery, and at least one heat exchange branch is configured to exchange heat with a second side of the battery. In some embodiments, the plurality of heat exchange branches include the pressure adjustment sub-branch and a heat exchange sub-branch, and in preheating mode, a total flow Q1 in the pressure adjustment sub-branch is greater than a total flow Q2 in the heat exchange sub-branch. In some embodiments, in preheating mode, a ratio Q1/Q2 of the total flow Q1 of heat exchange media in the pressure adjustment sub-branch to the total flow Q2 in a remaining heat exchange branch is greater than a third threshold