Fuel Cell Sealing Member Surface Roughness Control
Solution Overview
Problem
Conventional fuel cell stacks experience unsatisfactory sealing performance due to leakage of high-temperature gases from cathode and anode chambers, leading to reduced heat utilization efficiency and overall efficiency.
Innovation Solution
The fuel cell stack design incorporates a sealing member with a surface roughness of 3.0 μm or less and a reduced undulation standard deviation of 0.2 or less, which is compressed with a preload greater than the fastening load, to effectively prevent gas leakage through the sealing member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional sealing member is used to seal the cathode chamber, then the sealing structure is simple and cost-effective, but gas leakage occurs resulting in unsatisfactory sealing performance
Solution Approach 1:
The invention changes the surface roughness parameter of the sealing member from a conventional value to 3.0 μm or less, and controls the undulation Pa to 1.4 μm or less. This parameter optimization prevents gas leakage through the sealing member while maintaining the simple sealing structure, thereby improving sealing performance without increasing device complexity.
2Loss of energy
If the surface roughness of the sealing member is not controlled, then the manufacturing process is simple, but gas leakage occurs reducing heat utilization efficiency
Solution Approach 1:
The invention specifies that the surface roughness Ra of the sealing member should be 3.0 μm or less and the undulation Pa should be 1.4 μm or less. This precise parameter control prevents gas leakage that would otherwise cause heat loss, thereby improving heat utilization efficiency while maintaining reasonable manufacturing precision requirements.
3Productivity
If a sealing member with higher surface roughness is used, then the manufacturing is easier, but gas leakage occurs reducing overall efficiency
Solution Approach 1:
The invention optimizes the surface roughness Ra to 3.0 μm or less and undulation Pa to 1.4 μm or less for the sealing member. This parameter specification prevents gas leakage that would reduce overall efficiency, while the controls are set at levels that can be achieved through standard manufacturing processes, balancing productivity and manufacturing precision.
Data Source
AI summary
A fuel cell stack including a plurality of electricity generation units fastened by means of a plurality of fastening members. Each electricity generation unit includes a single cell, and a sealing member sandwiched between two other members thereby sealing one of the anode chamber and the cathode chamber. The surface of the sealing member included in at least one electricity generation units, the surface facing either of the two other members, has a surface roughness Ra of 3.0 μm or less.