Fuel Cell Cathode Cooling via Water Injection

Solution Overview

Problem

Fuel cell systems experience accelerated degradation and reduced lifetime when operated in higher environmental temperatures, as existing cooling components are expensive and space-consuming.

Innovation Solution

A cathode subsystem with a compressor, intercooler, fluid injection system, and electronic processor that controls fluid injection based on temperature measurements to cool and humidify air for the cathode stack, reusing water output from the fuel cell system to enhance cooling and humidification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional cooling components are used to cool the fuel cell system in high environmental temperatures, then the fuel cell system can operate in higher temperatures, but the system cost and space requirements increase significantly

Engineering Contradiction:

Improveoperating temperature rangeVSAvoidcooling system complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The cathode air intake system performs multiple functions: it provides oxygen for the fuel cell reaction, cools the system through evaporative cooling from water injection, and humidifies the air. The compressor and intercooler that were originally dedicated to cooling now serve dual purposes of air supply and temperature control, eliminating the need for separate cooling components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The fuel cell system uses its own water output from the cathode stack to cool itself through evaporative cooling. The water is injected into the air intake line where it evaporates and absorbs heat, providing self-cooling without external cooling systems. This creates a closed-loop self-regulating thermal management system.

Inventive Principle:

Principle #25Self-service

2Temperature

If conventional cooling components are used to cool the fuel cell system, then the fuel cell system can operate in higher environmental temperatures, but the system becomes more expensive

Engineering Contradiction:

Improveoperating temperature rangeVSAvoidsystem cost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The cathode air intake system performs multiple functions: it provides oxygen for the fuel cell reaction, cools the system through evaporative cooling from water injection, and humidifies the air. The compressor and intercooler that were originally dedicated to cooling now serve dual purposes of air supply and temperature control, eliminating the need for separate cooling components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The fuel cell system uses its own water output from the cathode stack to cool itself through evaporative cooling. The water is injected into the air intake line where it evaporates and absorbs heat, providing self-cooling without external cooling systems. This creates a closed-loop self-regulating thermal management system.

Inventive Principle:

Principle #25Self-service

3Temperature

If conventional cooling components are used to cool the fuel cell system, then the fuel cell system can operate in higher environmental temperatures, but the system requires more space

Engineering Contradiction:

Improveoperating temperature rangeVSAvoidsystem volume

Core Design Contradiction:

TemperatureVSVolume of moving object

Solution Approach 1:

The cathode air intake system performs multiple functions: it provides oxygen for the fuel cell reaction, cools the system through evaporative cooling from water injection, and humidifies the air. The compressor and intercooler that were originally dedicated to cooling now serve dual purposes of air supply and temperature control, eliminating the need for separate cooling components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The cooling function is merged with the existing cathode air intake system. The water injection system is integrated into the air intake line, and the intercooler serves both cooling and air preparation functions. This consolidation eliminates the need for separate cooling components and reduces overall system volume.

Inventive Principle:

Principle #5Merging (Combining)

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 effectively mitigates the effects of high temperatures on fuel cell systems by maintaining optimal operating conditions, thereby extending the lifespan and efficiency of the fuel cell system.

Implementation Method 1

an air input line including an intercooler configured to cool air output by the compressor

Methodology Applied

Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

controlling a fluid injection system configured to receive fluid from a fluid output from the cathode stack such that the fluid is injected into an air input line

Methodology Applied

Scientific EffectEvaporative cooling: Evaporative Cooler

Data Source

PatentUS11688866B2Cathode subsystem cooling and humidification for a fuel cell system

Publication Date: 2023.06.27 ROBERT BOSCH GMBH

AI summary

A system and method for cooling and humidifying a cathode subsystem of a fuel cell for an automobile. The system includes a compressor, an air input line including an intercooler configured to cool air output by the compressor, a fluid output line including a fluid injection system, a cathode stack configured to receive air via the air input line and output a fluid to the fluid output line, and an electronic processor. The electronic processor is configured to control the fluid injection system such that the fluid output from the cathode stack is injected into the air input line.