Fuel Cell Water Management via Electrolysis

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Solution Overview

Problem

Fuel cell systems face inefficiencies due to water accumulation in the stack, which hinders hydrogen flow and degrades power generation performance, and the current methods of purging hydrogen to remove water result in hydrogen loss and potential explosion risks.

Innovation Solution

A fuel cell system with a controller that calculates the maximum residual water in the stack based on output power and time, allowing for accurate real-time water measurement and targeted purging to minimize hydrogen discharge and maintain efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If hydrogen purging is performed to discharge water from the fuel cell stack, then water removal is improved, but hydrogen loss increases

Engineering Contradiction:

Improvewater removalVSAvoidhydrogen loss

Core Design Contradiction:

Quantity of substanceVSLoss of substance

Solution Approach 1:

The patent replaces the mechanical hydrogen purging method with an electrochemical water electrolysis method. Instead of using hydrogen gas flow to mechanically purge water, the system applies electricity to electrolyze water into hydrogen and oxygen, which are then discharged. This substitution eliminates the need to vent large amounts of hydrogen while still achieving water removal from the fuel cell stack.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operational parameters by introducing controlled electrical current to the fuel cell stack. By applying a reverse voltage or exceeding the operating voltage temporarily, the fuel cell operates in electrolysis mode, transforming the electrochemical reaction direction from power generation to water decomposition. This parameter change enables selective water removal without hydrogen loss.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If water is discharged by opening/closing purge valve periodically, then water accumulation is prevented, but hydrogen utilization rate decreases

Engineering Contradiction:

Improvewater accumulation preventionVSAvoidhydrogen utilization rate

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces the mechanical purge valve periodic opening/closing system with an electrochemical electrolysis system. Instead of mechanically opening valves to vent hydrogen-rich gas, the system uses electrical current to decompose water in-situ, eliminating the need for periodic purging and maintaining continuous hydrogen utilization.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent enables continuous water removal through ongoing electrolysis rather than periodic purging. By maintaining a continuous electrolytic process, the system prevents water accumulation without interrupting hydrogen flow or reducing hydrogen utilization, thus achieving continuous useful action without waste.

Inventive Principle:

Principle #20Continuity of useful action

3Power

If large amount of water remains on anodes, then power generation performance degrades, but frequent purging increases hydrogen discharge

Engineering Contradiction:

Improvepower generation performanceVSAvoidhydrogen discharge

Core Design Contradiction:

PowerVSLoss of substance

Solution Approach 1:

The patent substitutes the mechanical hydrogen purging approach with electrochemical electrolysis. By applying electrical current directly to the anode where water accumulates, the system decomposes water into hydrogen and oxygen in-situ, preventing power degradation without requiring hydrogen discharge through purge valves.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces electricity as an intermediary substance to remove water. Instead of using hydrogen gas as the intermediary to carry water out (which causes hydrogen loss), electrical current serves as the intermediary that drives the electrolytic decomposition of water, eliminating the need for hydrogen discharge while maintaining power generation performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 system effectively prevents power degradation by accurately determining when to discharge water, reducing hydrogen loss and enhancing operational efficiency while minimizing risks.

Implementation Method 1

a fuel cell stack that produces electric power and water through an electro-chemical reaction of hydrogen and air

Methodology Applied

Scientific EffectElectro-chemical reaction: Fuel Cell

Data Source

PatentUS11043683B2Fuel cell system and method for controlling the same

Publication Date: 2021.06.22 HYUNDAI MOTOR CO LTD

AI summary

A fuel cell system includes a fuel cell stack that produces electric power and water through an electro-chemical reaction of hydrogen and air. A controller of the fuel cell system calculates an amount of water in the fuel cell stack based on output power of the fuel cell stack and a maximum amount of residual water to which the amount of water in the fuel cell stack converges over time. The fuel cell system may detect the amount of water in the fuel cell stack in real time.