Plastic Bipolar Plate Layout for Uniform Fuel Cell Cooling
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Solution Overview
Problem
Bipolar plates for fuel cell systems face challenges in optimizing air and coolant guides due to their interdependence, leading to suboptimal temperature distribution and premature aging, as well as complex production processes and waste in current cross-flow and counter-flow designs.
Innovation Solution
A bipolar plate made of plastic with independently designed flow channels on top and bottom shells, combining counter-flow and cross-flow characteristics, allowing for efficient media guidance and thermal exchange without deformation, using thermoplastics that can be machined or embossed independently on each side.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If metal bipolar plates are produced using an embossing process, then the structure is mandatory to provide back side structure, but the air guide and coolant guide become interdependent and cannot be optimized independently
Solution Approach 1:
The bipolar plate is divided into two independent half-shells (top shell and bottom shell) that can be designed and optimized separately. Each shell can have its flow channels independently configured without affecting the other side, allowing independent optimization of air and coolant guides while simplifying the manufacturing process.
Solution Approach 2:
The design transitions from a single-plane embossing process to a three-dimensional assembly of two separate half-shells. This dimensional change allows flow channels on the top shell to be optimized independently from those on the bottom shell, as each shell can be manufactured and designed separately before assembly.
2Productivity
If cross-flow design is used, then active area utilization is good and production waste is little, but cooling performance is sub-optimal due to inhomogeneous temperature distribution
Solution Approach 1:
Different flow channel configurations are applied to different regions and sides of the bipolar plate. The top shell and bottom shell can have locally optimized flow patterns suited to their specific thermal and fluid management requirements, allowing simultaneous optimization of active area utilization and temperature distribution uniformity.
3Temperature
If counter-flow design is used, then cooling performance is advantageous with homogeneous temperature distribution, but distribution structure becomes very complex and production waste is high
Solution Approach 1:
The complex counter-flow distribution structure is segmented into two separate half-shells, each handling one operating medium. This segmentation simplifies the manufacturing process by allowing each shell to be produced independently with simpler tooling, while still achieving the desired homogeneous temperature distribution through optimized flow channel design on each side.
4Reliability
If metal bipolar plates are used, then electrical power conduction is achieved, but flow channel structures on opposite sides are interdependent
Solution Approach 1:
The bipolar plate uses composite construction with two half-shells made from materials comprising plastic. This composite approach allows each shell to be independently designed and manufactured with optimal flow channel configurations, while the assembled structure maintains the necessary electrical power conduction properties through conductive materials or coatings applied to the flow channels.
Data Source
AI summary
The presented invention relates to a bipolar plate (100) for a fuel cell system (700), wherein the bipolar plate (100) is made of a material comprising plastic. The bipolar plate (100) comprises a top shell (200) and a bottom shell (300) with respectively a top side and a bottom side that is opposite the top side, wherein flow channels for guiding a first operating medium through the bipolar plate (100) are formed on the top side of the top shell (200).