Vehicle Battery Refrigerant Loop for Lightweight Thermal Management

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Solution Overview

Problem

Existing liquid cooling systems for vehicle batteries, particularly in electric vehicles, face challenges due to increased weight, which affects vehicle performance, and there is a need for an efficient thermal management system that maintains battery efficiency and lifespan.

Innovation Solution

The use of various refrigerants, including natural, hydrofluorocarbon (HFC)-based, hydrofluoroolefin (HFO)-based, hydrochlorofluorocarbon (HCFC)-based, hydrocarbon-based, halon, and perfluorocarbon (PFC)-based refrigerants, for controlling battery temperature through a thermal management system that includes a battery cooling system and an air conditioning system, with a bypass pipe for refrigerant circulation based on temperature thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a liquid cooling system is used for battery thermal management, then cooling efficiency is improved, but system weight increases

Engineering Contradiction:
Improvebattery cooling efficiencyVSAvoidcooling system weight
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

The refrigerant circulation system serves dual functions: it cools the battery during high-temperature conditions and provides air conditioning for the passenger compartment. The system uses a single refrigerant loop that can selectively cool either the battery or the cabin based on operational requirements, eliminating the need for separate dedicated cooling systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the battery cooling function with the air conditioning system by integrating the refrigerant circulation paths. The evaporator and expansion valve components are shared between the battery cooling mode and the air conditioning mode, reducing overall system weight and component count while maintaining effective cooling capability.

Inventive Principle:
Principle #5Merging (Combining)

2Temperature

If a liquid cooling system is used for battery thermal management, then cooling performance is improved, but system volume increases

Engineering Contradiction:
Improvebattery cooling performanceVSAvoidcooling system volume
Core Design Contradiction:
TemperatureVSVolume of moving object

Solution Approach 1:

The refrigerant circulation system serves dual functions: it cools the battery during high-temperature conditions and provides air conditioning for the passenger compartment. The system uses a single refrigerant loop that can selectively cool either the battery or the cabin based on operational requirements, eliminating the need for separate dedicated cooling systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically switches between different operational modes (battery cooling mode and air conditioning mode) based on real-time temperature conditions and operational requirements. The expansion valve and circulation paths are dynamically adjusted to optimize cooling efficiency while minimizing system volume utilization.

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If refrigerant circulation is controlled based on temperature thresholds, then energy efficiency is improved, but system complexity increases

Engineering Contradiction:
Improveenergy efficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The control system continuously monitors battery temperature and refrigerant conditions, using this feedback to dynamically adjust the expansion valve opening degree and refrigerant circulation rate. This closed-loop control ensures optimal energy efficiency by matching cooling capacity to actual thermal requirements while maintaining relatively simple control logic based on temperature threshold comparisons.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces the weight and volume of the cooling system while maintaining high-efficiency battery cooling performance, enabling rapid cooling or heating and improving heat exchange efficiency by selectively controlling refrigerant circulation paths.

Implementation Method 1

a battery chiller configured to perform heat exchange between the coolant pipe and the refrigerant pipe

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

enabling rapid cooling or heating and improving heat exchange efficiency by selectively controlling refrigerant circulation paths

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP4711433A1Refrigerant for thermal management of vehicle battery, and method and apparatus for thermal management thereof based on the refrigerant
Publication Date: 2026.03.18 SK INNOVATION CO LTD
  • EP4711433A1 patent drawingFigure 1
  • EP4711433A1 patent drawingFigure 2
  • EP4711433A1 patent drawingFigure 3

AI summary

Disclosed are a use of a refrigerant, a method, and an apparatus for thermal management of a vehicle battery. The refrigerant comprises at least one of a natural refrigerant; a hydrofluorocarbon (HFC)-based refrigerant; a hydrofluoroolefin (HFO)-based refrigerant; a hydrochlorofluorocarbon (HCFC)-based refrigerant; a hydrocarbon-based refrigerant that is not a natural refrigerant; and a halon or a perfluorocarbon (PFC)-based refrigerant, and can be used for thermal management of the vehicle battery by controlling a temperature of said vehicle battery.