Fuel Cell Stack Separator Protruded Shape Sealing

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Solution Overview

Problem

Conventional fuel cell stacks experience decreased durability due to deformation of separators under pressure differences and thermal loads, which compromises the sealing function.

Innovation Solution

The fuel cell stack design includes alternately stacked cell structures and separators with a protruded shape portion, connecting portions, and fixing portions that prevent direct tensile and shear forces on the sealing members, maintaining the sealing function even under in-plane loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the separator is subjected to pressure difference between the anode side and the cathode side or thermally deformed, then the protrusion of the separator deforms, but this directly applies tensile force or shear force to the sealing member, decreasing its durability

Engineering Contradiction:
Improvesealing functionVSAvoiddurability of sealing member
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent introduces an intermediary structure (the connecting portions with protruded shape) between the separator and the sealing member. This intermediary structure absorbs and distributes the forces, preventing direct transmission of tensile and shear forces to the sealing member, thereby protecting it while maintaining the sealing function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent adds a dimensional feature (protruded shape with connecting portions) to the separator structure. This three-dimensional configuration allows the separator to accommodate in-plane loads through deformation of the protruded shape itself, rather than transmitting forces directly to the sealing member in the original plane.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Strength

If the separator maintains a simple flat structure, then the device complexity is low, but the separator cannot resist in-plane loads from pressure difference or thermal deformation

Engineering Contradiction:
Improveresistance to in-plane loadVSAvoidseparator structure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The separator is segmented into distinct functional portions: the first contacting portion, the connecting portions, and the second contacting portions. This segmentation allows each portion to perform its specific function while collectively providing resistance to in-plane loads without excessive overall complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces curved or protruded geometric features (protruded shape with connecting portions) to the separator structure. These curved elements provide mechanical strength and flexibility to resist in-plane loads while maintaining a relatively simple overall separator design.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP3486986B1Fuel cell stack
Publication Date: 2020.01.15 NISSAN MOTOR CO LTD
  • EP3486986B1 patent drawingFigure 1
  • EP3486986B1 patent drawingFigure 2~3
  • EP3486986B1 patent drawingFigure 4~5

AI summary

A fuel cell stack FS, in which cell structures 3, each of which includes a frame 2 that is disposed at the periphery of the cell structure 3; and separators 4 that are alternately stacked, includes a sealing member S between a peripheral portion of a frame 2 of a first cell structure 3 on one side of one of the separators and a peripheral portion of the separator 4. In each of the separators 4, a first contacting portion 11 in contact with the sealing member S, second contacting portions 12 in contact with a frame 2 of a second cell structure 3 on the other side thereof, and connecting portions 13 that connect the first contacting portion 11 and the second contacting portions 12 are included so as to form a protruded shape portion. Each of the second contacting portions 12 includes a fixing portion fixing with the frame. According to the above, the displacement of the separator 4 attributable to a load caused by pressure difference or thermal deformation is prevented so that the sealing function is maintained.