Fuel Cell Separator Groove Design for Joining Strength and Cooling

Solution Overview

Problem

Fuel cell stacks face challenges in maintaining joining strength between separators while minimizing coolant pressure loss, which affects the cooling performance.

Innovation Solution

The fuel cell stack design includes specific groove width variations in the separators to enhance joining strength and reduce coolant pressure loss, with wide and narrow portions in the fluid and coolant grooves that are strategically positioned to create a common coolant flow path and optimize fluid flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the groove width of the gas groove portion is partially increased in one of the two separators to ensure joining strength, then the joining strength between separators is improved, but the groove width of the adjacent coolant groove portion is narrowed, causing increased pressure loss of coolant

Engineering Contradiction:

Improvejoining strength between separatorsVSAvoidpressure loss of coolant

Core Design Contradiction:

StrengthVSLoss of energy

Solution Approach 1:

The patent applies local quality by creating wide portions in gas groove portions and corresponding narrow portions in coolant groove portions at specific locations. The wide portions (increased groove width) are strategically positioned to enhance joining strength between separators, while the narrow portions are confined to non-critical cooling zones. This localized modification allows the separators to be joined more effectively without significantly impacting overall coolant flow and pressure loss.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces asymmetry by making the groove widths unequal in specific regions - the gas groove portions have wide portions while the adjacent coolant groove portions have narrow portions. This asymmetric design breaks the uniform groove width pattern, allowing optimized joining strength in gas flow regions while maintaining adequate cooling capacity through the asymmetric distribution of groove width variations.

Inventive Principle:

Principle #4Asymmetry

2Strength

If the groove width of the gas groove portion is partially increased to improve joining strength, then the area of the joining portion is increased, but the groove width of the adjacent coolant groove portion is narrowed, degrading cooling performance

Engineering Contradiction:

Improvejoining strength between separatorsVSAvoidcooling performance

Core Design Contradiction:

StrengthVSTemperature

Solution Approach 1:

The patent applies local quality by creating wide portions in gas groove portions and corresponding narrow portions in coolant groove portions at specific locations. The wide portions (increased groove width) are strategically positioned to enhance joining strength between separators, while the narrow portions are confined to non-critical cooling zones. This localized modification allows the separators to be joined more effectively without significantly impacting overall coolant flow and pressure loss.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10854892B2Fuel cell stack having improved joining strength between separators

Publication Date: 2020.12.01 TOYOTA JIDOSHA KK

AI summary

A fuel cell stack includes: a membrane electrode assembly; and first and second separators joined to each other, wherein first and third fluid groove portions face each other in a stacking direction in which the membrane electrode assembly and the first and second separators are stacked, second and fourth fluid groove portions face each other in the stacking direction, and first and second coolant groove portions face each other in the stacking direction and define a common coolant flow path.