Fuel Cell Stack Coolant Temperature Control for Heat Reduction

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Solution Overview

Problem

Existing fuel cell systems face challenges in efficiently managing waste heat, particularly in vehicles where space constraints and cooling system inefficiencies lead to increased fuel consumption and reduced performance.

Innovation Solution

A control system adjusts the target coolant inlet temperature based on power demand, optimizing parameters like cathode air pressure to reduce heat generation and auxiliary power requirements, thereby enhancing fuel efficiency and reducing cooling system load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the coolant inlet temperature is maintained at a constant first target temperature level, then the fuel cell stack operates stably, but excessive heat is generated and wasted during transient operations, reducing system efficiency

Engineering Contradiction:
Improveheat wasteVSAvoidcoolant inlet temperature control
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The patent applies dynamics by transitioning from a static constant temperature control strategy to a dynamic variable temperature control strategy. The coolant inlet temperature is adjusted in real-time based on the fuel cell stack's operating state (current, temperature, duration), allowing the system to adapt to changing conditions and minimize heat waste during transient operations while maintaining stability during steady-state operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the coolant inlet temperature parameter according to different operating conditions. The control method changes the temperature parameter dynamically based on current, temperature, and duration parameters of the fuel cell stack, optimizing heat management across different operational phases rather than maintaining a fixed temperature setting.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the coolant inlet temperature is rapidly adjusted to reduce heat waste, then energy efficiency improves, but thermal stress and temperature fluctuations increase, potentially damaging the fuel cell stack

Engineering Contradiction:
Improveheat waste reductionVSAvoidthermal stress
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by incorporating a duration parameter into the control logic. Before rapidly adjusting the coolant inlet temperature to reduce heat waste, the system evaluates how long the fuel cell has been operating at the current state. This pre-assessment cushions against unnecessary temperature adjustments during brief transient states, preventing thermal stress from rapid changes while still enabling efficient cooling when transients extend long enough to warrant intervention.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent implements feedback by continuously monitoring multiple parameters (current, temperature, duration) and using this information to dynamically adjust the coolant inlet temperature. The control system receives feedback about the fuel cell's operating state and modifies the temperature accordingly, creating a closed-loop system that balances heat waste reduction with thermal stress prevention based on real-time conditions.

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 minimizes heat production, reduces auxiliary power consumption, and improves overall fuel cell system performance and reliability by optimizing coolant inlet temperature and cathode air pressure.

Implementation Method 1

a coolant inlet of the fuel cell stack

Methodology Applied
Scientific EffectHeat absorption: Conduction (thermal)

Implementation Method 2

A system and method for controlling operation of a fuel cell system of a fuel cell vehicle

Methodology Applied
Scientific EffectElectrochemical energy conversion: Fuel Cell

Data Source

PatentEP4439743B1Heat management in a fuel cell system
Publication Date: 2026.04.29 VOLVO TRUCK CORP
  • EP4439743B1 patent drawingFigure 1
  • EP4439743B1 patent drawingFigure 2
  • EP4439743B1 patent drawingFigure 3

AI summary

A system and method for controlling operation of a fuel cell system of a fuel cell vehicle, to reduce an amount of heat generated by one or more heat sources in the fuel cell system, are provided. The method comprises obtaining a value of power output of the fuel cell system, the value indicating a power demand from the fuel cell system during operation of the vehicle; and adjusting a value of a target coolant inlet temperature of a coolant at a coolant inlet of the fuel cell stack to vary between a first target temperature level and a second target temperature level, in dependence on the value of the power output, to optimize a duration of time during which the target temperature is different from the first target temperature level and to optimize a value of one or more parameters related to operation of the fuel cell system.