Shared Fuel Cell Cooling Circuit for Coolant Pressure Balancing

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Solution Overview

Problem

Existing fuel cell systems face issues with complex, bulky, and expensive cooling systems that require active controlling and regular maintenance due to high pressure differences between coolant, cathode gas, and anode gas, leading to potential damage and performance loss.

Innovation Solution

A single cooling circuit with a pressure equalization device connected to the exhaust of one fuel cell system, allowing for manual height adjustment to balance coolant pressure, reducing pressure differences and simplifying assembly and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate cooling systems are provided for each fuel cell system, then each fuel cell system can be cooled independently, but the overall system becomes bulky and requires more space

Engineering Contradiction:
Improveindependent cooling capabilityVSAvoidcooling system volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent merges the cooling systems of multiple fuel cell systems into a single common cooling circuit. The coolant flows through all fuel cell systems sequentially, allowing one cooling system to serve multiple fuel cell stacks. This reduces the overall cooling system volume while maintaining cooling capability for all systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single cooling circuit is designed to perform the cooling function for multiple fuel cell systems simultaneously. The coolant loop is configured to pass through all fuel cell systems, making the cooling system universal and multi-functional rather than dedicated to a single fuel cell system.

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

2Stress or pressure

If active controlling mechanisms are used to manage coolant pressure, then coolant pressure can be precisely controlled, but the system becomes complex and requires regular maintenance

Engineering Contradiction:
Improvecoolant pressure controlVSAvoidpressure control system complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The patent employs a passive pressure equalization device that automatically balances coolant pressure with exhaust pressure without requiring external control systems. The device uses the inherent pressure differential between the coolant circuit and exhaust system to drive equalization, eliminating the need for active pumps, valves, or control electronics.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex active mechanical pressure control systems (pumps, valves, sensors) with a passive mechanical pressure equalization device. This device uses natural pressure differentials and mechanical equilibrium to maintain pressure balance, substituting complex control mechanisms with a simpler passive mechanical solution.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Temperature

If high pressure differences are maintained between coolant, cathode gas, and anode gas, then cooling efficiency may be improved, but damage and performance loss or leakages occur

Engineering Contradiction:
Improvecooling efficiencyVSAvoidsystem integrity
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent changes the pressure parameter of the coolant by equalizing it with the exhaust pressure. This parameter change ensures that the coolant pressure remains close to the exhaust pressure, minimizing pressure differentials across the fuel cell membranes and preventing damage while maintaining adequate cooling through increased coolant flow rate.

Inventive Principle:
Principle #35Parameter changes

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 solution provides a compact, efficient, and cost-effective cooling system that enhances fuel cell reliability and longevity by minimizing pressure differences, facilitating easy adjustment to individual coolant pressure requirements.

Implementation Method 1

a pressure equalization device for a coolant of the cooling circuit, wherein the pressure equalization device is adapted to be connected to an exhaust of a single one of the fuel cell systems to increase the pressure of the coolant

Methodology Applied
Scientific EffectHydrostatic pressure: Pressure Gradient

Implementation Method 2

the cooling system comprises a height adjustment assembly for adjusting the height of the pressure equalization device. Thereby, the pressure of the cooling circuit may be adjusted in a simple manner

Methodology Applied
Scientific EffectGravitational potential energy: Gravitation

Data Source

PatentEP4560744B1A cooling system with a single cooling circuit for two fuel cell systems and a height-adjustable pressure equalization device and a method of adjusting a coolant pressure
Publication Date: 2025.12.31 VOLVO TRUCK CORP
  • EP4560744B1 patent drawingFigure 1~2

AI summary

A cooling system (1) for at least two fuel cell systems (100, 200), the cooling system (1) comprising a single cooling circuit (10) for the fuel cell systems (100, 200) and a pressure equalization device (20) for a coolant of the cooling circuit (10), wherein the pressure equalization device (20) is adapted to be connected to an exhaust (110) of a single one of the fuel cell systems (100, 200) to increase the pressure of the coolant.