Fuel Cell Cooling Control for Short Shutdown Degradation

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Solution Overview

Problem

Fuel cell systems experience degradation due to startup and shutdown, which is exacerbated by shorter shutdown durations, leading to reduced service life.

Innovation Solution

A method that predicts future shutdown time periods and operates the cooling system to reduce fuel cell temperature before restart, using either fuel cell power or an auxiliary power source, to minimize degradation within a predetermined time window.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the fuel cell system is shut down for short durations, then energy consumption is reduced, but degradation increases due to frequent startup/shutdown cycles

Engineering Contradiction:
Improveenergy consumptionVSAvoidfuel cell degradation
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system performs preliminary cooling action before a predicted shutdown to ensure the fuel cell temperature is reduced in advance. This preliminary action prevents degradation during subsequent startup/shutdown cycles while still allowing the system to remain shut down for energy savings, thus resolving the contradiction between energy consumption and reliability.

Inventive Principle:
Principle #10Preliminary action

2Temperature

If the cooling system is operated continuously, then fuel cell temperature is maintained, but energy consumption increases

Engineering Contradiction:
Improvefuel cell temperatureVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

Instead of continuous operation, the cooling system operates periodically based on predicted shutdown events. The system activates cooling only when a shutdown is predicted within the degradation time window, maintaining appropriate temperature only when necessary, thus reducing overall energy consumption while still protecting the fuel cell.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The cooling system is activated in advance before predicted shutdown events to proactively reduce fuel cell temperature. This preliminary cooling action ensures temperature control is achieved only when and where needed, avoiding continuous operation and the associated energy waste.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the fuel cell system is restarted after short shutdown periods, then productivity is maintained, but degradation increases due to high temperature restart

Engineering Contradiction:
Improvesystem availabilityVSAvoidfuel cell degradation
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary cooling before predicted short-duration shutdowns to ensure the fuel cell temperature is reduced in advance. This allows the system to be restarted after short shutdowns without suffering from high-temperature degradation, thus maintaining productivity while protecting reliability.

Inventive Principle:
Principle #10Preliminary action

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

Reduces fuel cell degradation by proactive cooling, extending service life and ensuring efficient energy usage.

Implementation Method 1

a cooling system with a cooling fluid for cooling the one or more fuel cells during use

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP4412853B1A method for operating a fuel cell system
Publication Date: 2025.08.27 VOLVO TRUCK CORP
  • EP4412853B1 patent drawingFigure 1~2
  • EP4412853B1 patent drawingFigure 3~5
  • EP4412853B1 patent drawingFigure 6

AI summary

The invention relates to a method for operating a fuel cell system (1) comprising one or more fuel cells (10) and a cooling system (20) with a cooling fluid for cooling the one or more fuel cells during use, the method comprising: - obtaining (S1) a shutdown request for the fuel cell system (1); - predicting (S2) a future shutdown time period; - in response to detecting that the future shutdown time period is shorter than a predetermined degradation time window (TW) for the one or more fuel cells (10), operating (S3) the cooling system so as to reduce the temperature of the one or more fuel cells (10). The invention also relates to a control unit (30), a fuel cell system (1), a vehicle (100), a computer program and to a computer readable medium.