Hybrid Vehicle Cooling Circuit Switching for Multi-Loop Thermal Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Hybrid vehicles require a cooling system that efficiently manages the diverse thermal energy needs of internal combustion engines, electric traction motors, and batteries, while minimizing complexity and energy consumption, especially in plug-in hybrid vehicles where components need to be cooled and heated effectively across varying operating conditions.

Innovation Solution

A modular cooling system with multiple operating positions that dynamically routes coolant through different circuits, including a main cooling circuit for the internal combustion engine and electric traction motor, and an additional cooling circuit for the traction battery and power electronics, allowing for needs-based cooling and heating, with separate circuits and controllable distribution systems to optimize thermal management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single cooling circuit is used for all components, then the system design is simple, but the cooling performance for different components cannot be optimized independently

Engineering Contradiction:
Improvecooling system designVSAvoidcooling performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The cooling system is divided into a main cooling circuit for the internal combustion engine and an additional cooling circuit for the traction battery and power electronics. This segmentation allows independent temperature control for each component, optimizing cooling performance while managing system complexity through modular design with controllable connections between circuits.

Inventive Principle:
Principle #1Segmentation

2Reliability

If multiple separate cooling circuits are used for different components, then cooling performance is optimized, but the system complexity increases

Engineering Contradiction:
Improvecooling performanceVSAvoidcooling system design
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cooling system employs controllable connections that allow the main cooling circuit and additional cooling circuit to function independently or in combination. The system can operate in multiple modes: separate circuit operation for specialized cooling, combined operation for heat transfer between circuits, and selective activation based on thermal management needs, thereby optimizing performance while managing complexity.

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

3Loss of energy

If heat transfer between cooling circuits is enabled, then thermal energy utilization is improved, but the control complexity increases

Engineering Contradiction:
Improvethermal energy utilizationVSAvoidcontrol system
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The connection between the main cooling circuit and additional cooling circuit is designed to be controllable and dynamic. The system can adaptively adjust heat transfer between circuits based on real-time thermal conditions, enabling efficient thermal energy utilization while maintaining manageable control complexity through demand-based activation.

Inventive Principle:
Principle #15Dynamics

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 enables efficient cooling and heating of hybrid vehicle components, optimizing performance, reducing energy consumption, and extending the service life of the traction battery by providing precise temperature control, while maintaining a simple and adaptable system design.

Implementation Method 1

the coolant absorbs thermal energy, which is at least partially released back into the ambient air

Methodology Applied
Scientific EffectHeat absorption: Conduction (thermal)

Implementation Method 2

thermal energy, which is at least partially released back into the ambient air in at least one ambient heat exchanger

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3916209B1Hybrid vehicle with a cooling system
Publication Date: 2024.03.13 VOLKSWAGEN AG
  • EP3916209B1 patent drawingFigure 1
  • EP3916209B1 patent drawingFigure 2
  • EP3916209B1 patent drawingFigure 3

AI summary

Motor vehicle with an internal combustion engine comprising an internal combustion engine (2), an electric traction motor (3), a traction battery (4), and a cooling system comprising a main cooling circuit arrangement (8) in which the internal combustion engine (2), a coolant radiator (21), a heater heat exchanger (22), a (first) heater (23), an oil cooler (20), and a distribution system are integrated, wherein: - in a first operating position of the distribution system, coolant is available in a first cooling circuit comprising the heater heat exchanger (22) and the (first) heater (23); - in a second operating position of the distribution system, coolant is available in a second cooling circuit comprising the coolant radiator (21) and the oil cooler (20).- in a third operating position of the distribution system, coolant can be pumped • in the first cooling circuit and • in a third cooling circuit comprising the combustion engine (2) and excluding the coolant radiator (21), and - in a fourth operating position of the distribution system, coolant can be pumped in a fourth cooling circuit comprising • the combustion engine (2) and • the heater heat exchanger (22).