Fuel Cell Cathode Passage Turn Interval Design

Solution Overview

Problem

Fuel cells experience pressure loss and flooding issues due to the design of expanded metal passages, which affect power generation performance and humidity levels within the membrane electrode assembly.

Innovation Solution

A fuel cell design featuring a serpentine anode passage and a mesh-shaped cathode passage with varying turn intervals and passage widths to balance gas flow and reduce pressure loss, while maintaining humidity levels by overlapping the upstream cathode passage with the anode passage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the gas flows through a mesh-shaped expanded passage, then the gas supply is improved, but pressure loss occurs at bent portions

Engineering Contradiction:

Improvegas supplyVSAvoidpressure loss

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The cathode passage is divided into multiple mesh-shaped expanded passages with different turn intervals. The passage is segmented into regions with first turn intervals (larger) and second turn intervals (smaller), allowing different sections to optimize for either pressure loss reduction or gas supply distribution.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the cathode passage are given different local characteristics. The upstream portion has larger turn intervals to reduce pressure loss, while the downstream portion has smaller turn intervals to improve gas supply distribution to the electrode surface.

Inventive Principle:

Principle #3Local quality

2Productivity

If the turn interval is reduced to improve gas distribution, then gas supply to electrode surface is improved, but pressure loss increases

Engineering Contradiction:

Improvegas distributionVSAvoidpressure loss

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The cathode passage is divided into multiple mesh-shaped expanded passages with different turn intervals. The passage is segmented into regions with first turn intervals (larger) and second turn intervals (smaller), allowing different sections to optimize for either pressure loss reduction or gas supply distribution.

Inventive Principle:

Principle #1Segmentation

3Productivity

If the gas flow direction changes at turn positions, then gas is directed to electrode surface, but water evaporation or penetration occurs causing flooding

Engineering Contradiction:

Improvegas flow direction controlVSAvoidflooding

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

Different portions of the cathode passage are given different local characteristics. The upstream portion has larger turn intervals to reduce pressure loss, while the downstream portion has smaller turn intervals to improve gas supply distribution.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent converts the harmful effect of water accumulation into a beneficial outcome by using the turn positions strategically. The varied turn intervals create controlled flow patterns that prevent excessive water penetration while maintaining necessary gas distribution, effectively managing water removal without causing flooding.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

4Loss of energy

If the pressure loss on gas supply side is reduced, then power generation performance is improved, but gas flow uniformity may be compromised

Engineering Contradiction:

Improvepressure lossVSAvoidgas flow uniformity

Core Design Contradiction:

Loss of energyVSStability of the object's composition

Solution Approach 1:

The cathode passage is divided into multiple mesh-shaped expanded passages with different turn intervals. The passage is segmented into regions with first turn intervals (larger) and second turn intervals (smaller), allowing different sections to optimize for either pressure loss reduction or gas supply distribution.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the cathode passage are given different local characteristics. The upstream portion has larger turn intervals to reduce pressure loss, while the downstream portion has smaller turn intervals to improve gas supply distribution to the electrode surface.

Inventive Principle:

Principle #3Local quality

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 configuration effectively reduces pressure loss, suppresses flooding, and enhances relative humidity within the fuel cell, leading to improved power generation performance.

Implementation Method 1

pressure loss occurs when the gas passes through a bent portion of the passage

Methodology Applied

Scientific EffectPressure loss: Pressure Drop

Implementation Method 2

the evaporation of water from the MEA or the penetration of water into the MEA occurs

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS9799897B2Fuel cell

Publication Date: 2017.10.24 TOYOTA JIDOSHA KK

AI summary

In a fuel cell, a cathode passage extends from an oxidizing gas supply hole to an oxidizing gas discharge hole. A turn interval at which a flow direction of an oxidizing gas returns to an original direction in an upstream-side passage region is different from the turn interval in a downstream-side passage region. A ratio between the turn interval in the upstream-side passage region and the turn interval in the downstream-side passage region is set to 1.1:1 to 3:1. The upstream-side passage region is overlapped with a most downstream-side passage portion of an anode passage with a membrane electrode assembly interposed between the upstream-side passage region and the most downstream-side passage portion.