Vehicle Thermal Loop Layout for Secondary-Refrigerant Heat Pumping

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Solution Overview

Problem

Existing thermal management systems for vehicles face challenges with a large number of parts, complex loops, and an inability to adapt to refrigerants needing secondary loops, leading to inefficiencies and increased complexity.

Innovation Solution

A refrigerant circulation system with independent heat exchangers and parallel expansion valves, combined with a cooling liquid circulation system, allows for environmentally-friendly refrigerants to exchange heat through parallel loops, reducing the need for additional electric heaters and simplifying the system structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a heat pump function is added based on a refrigerant circulation loop to increase heating efficiency, then heating efficiency is improved, but the structure becomes more complex and cost increases due to additional auxiliary components

Engineering Contradiction:
Improveheating efficiencyVSAvoidstructure complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The refrigerant circulation loop is designed to serve multiple functions: it can act as a heat pump for heating the passenger compartment, cool the battery, and provide dehumidification. The same refrigerant loop and heat exchangers are used across different seasons and conditions, eliminating the need for separate heating-specific components and reducing overall system complexity despite the added multi-functionality

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

Solution Approach 2:

The patent merges the heating function with the existing refrigerant circulation loop used for cooling and battery thermal management. Instead of adding a completely separate heating system, the refrigerant loop is configured to provide heating through the outdoor heat exchanger acting as a condenser, combining multiple thermal management functions into a single integrated system

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If motor stalling is used for heating as a heat source of a heat pump system, then heating function is provided, but heating efficiency is very low and permanent magnet synchronous motors cannot achieve motor stalling

Engineering Contradiction:
Improveheating function availabilityVSAvoidheating efficiency
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The system uses the motor's own operational characteristics to provide heating. During regenerative braking or motor deceleration, the motor acts as a generator and the refrigerant circulation loop captures the waste heat from the motor and transmission oil through the oil-to-refrigerant heat exchanger, converting waste energy into useful heating without requiring separate heating components or inefficient motor stalling

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If a battery heating system and passenger compartment heating system are provided with two sets of auxiliary high-voltage electric heaters, then heating functions are completed, but system cost increases and vehicle layout becomes less friendly

Engineering Contradiction:
Improveheating function coverageVSAvoidnumber of components
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The refrigerant circulation loop serves as a universal thermal management system that can simultaneously or independently heat the passenger compartment, heat the battery, cool the battery, and provide dehumidification. The system uses a single refrigerant loop with configurable flow paths to replace multiple dedicated heating systems, reducing the number of high-voltage electric heaters needed while maintaining comprehensive heating coverage

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

Solution Approach 2:

The system dynamically configures the refrigerant flow paths using flow path switching components (four-way valves) to adapt to different operational requirements. The same refrigerant loop can be directed to different heat exchangers based on real-time thermal management needs, allowing a single system to replace multiple static heating systems with different component configurations

Inventive Principle:
Principle #15Dynamics

4Object-affected harmful factors

If R290 refrigerant is used, then environmental compliance is improved, but a secondary loop is required due to flammability, increasing system complexity

Engineering Contradiction:
Improveenvironmental complianceVSAvoidloop complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The refrigerant circulation loop is designed as a universal system that handles both flammable (R290) and non-flammable refrigerants through the same configuration. The system uses the refrigerant loop for multiple purposes: passenger compartment cooling, battery thermal management, and heating through heat pump operation. This multi-functional design eliminates the need for separate secondary loops for flammable refrigerants, as the same loop that provides cooling and heating functions also safely manages the flammable refrigerant through controlled containment and proper heat exchanger design

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

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

The system effectively cools or heats the passenger compartment and battery by controlling refrigerant flow direction, reduces part count, and enhances energy utilization, while maintaining reliability and efficiency without high-speed rotating components.

Implementation Method 1

a refrigerant circulation system, wherein the refrigerant circulation system includes a compressor, a first heat exchanger, a first expansion valve, a second heat exchanger, a third heat exchanger

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a first expansion valve, a second expansion valve arranged in parallel; a first end of the refrigerant channel of the first heat exchanger is respectively connected with a first end of the first expansion valve and a first end of the second expansion valve

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP4596271A1Thermal management system of vehicle, and vehicle
Publication Date: 2025.08.06 SAIC MOTOR
  • EP4596271A1 patent drawingFigure 1~2
  • EP4596271A1 patent drawingFigure 3~4
  • EP4596271A1 patent drawingFigure 5~6

AI summary

Disclosed in the present invention are a thermal management system of a vehicle, and a vehicle. The thermal management system includes a refrigerant circulation system and a cooling liquid circulation system. The refrigerant circulation system includes a compressor, a first heat exchanger, a first expansion valve, a second heat exchanger, a third heat exchanger, a second expansion valve and a first flow path switching component. The first heat exchanger has a refrigerant channel and an electric drive cooling liquid channel which are independent and capable of transferring heat; the second heat exchanger has a refrigerant channel and a passenger compartment cooling liquid channel which are independent and capable of transferring heat; and the third heat exchanger has a refrigerant channel and a battery cooling liquid channel which are independent and capable of transferring heat. The cooling liquid circulation system includes a passenger compartment cooling liquid circulation system and an engine room cooling liquid circulation system. The passenger compartment cooling liquid circulation system includes a first water pump and a cold-hot core. The engine room cooling liquid circulation system includes an electric drive circulation loop, a battery circulation loop and a second flow path switching component. The thermal management system is applicable to a refrigerant needing a secondary loop, and the system has a small number of parts.