Fuel Cell Manifold Valve Positioning to Prevent Water Freezing
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Solution Overview
Problem
Conventional fuel cell designs face issues with liquid water entering valves after power generation stops, leading to freezing and operational problems upon reactivation due to inadequate water drainage and management.
Innovation Solution
The fuel cell design includes a gas manifold configuration where the manifold bottom portion is horizontal, with the valve's opening bottom portion positioned above it, and a resin layer to prevent liquid water from flowing into the valve, ensuring effective water retention and prevention of freezing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gas discharge flow path is formed to tilt downward with a larger inclination angle to improve water draining characteristics, then liquid water can be discharged more effectively from the fuel cell, but liquid water may enter the valve after power generation stops and cause freezing in the valve
Solution Approach 1:
The invention introduces a vertical height dimension to solve the water drainage problem. By positioning the bottom portion of the valve opening above the manifold bottom portion in the vertical direction, it creates a height difference that prevents water from flowing into the valve while maintaining effective drainage during operation. This dimensional approach resolves the contradiction between drainage efficiency and valve protection.
Solution Approach 2:
The invention uses the height difference between the manifold bottom portion and the valve opening bottom portion as an intermediary mechanism. This vertical separation acts as a protective barrier that allows water to drain during power generation while preventing water from reaching the valve when the cell is inactive, thus mediating between drainage needs and valve protection.
2Ease of operation
If a valve is provided adjacent to the fuel cell for gas supply and discharge, then gas flow control is improved, but liquid water can enter the valve and cause freezing that prevents reactivation
Solution Approach 1:
The invention applies vertical positioning to protect the valve from water damage. By locating the valve opening bottom portion at a higher vertical level than the manifold bottom portion, the design maintains gas flow control functionality while preventing water from entering the valve, thus ensuring reliable operation after power generation stops.
Solution Approach 2:
The invention implements preliminary protection against water entry by designing the valve opening position to be above the water level in the manifold. This preventive measure stops water from reaching the valve before freezing can occur, thereby maintaining valve reliability during shutdown and restart cycles.
3Reliability
If the manifold bottom portion is positioned at the lowest point for effective water collection, then water drainage is improved, but water may flow into the valve connected to the manifold
Solution Approach 1:
The invention resolves the water collection dilemma by using vertical positioning. The manifold bottom portion is maintained at the lowest horizontal point for effective water collection, while the valve opening is positioned at a higher vertical level, creating a height barrier that prevents water from flowing into the valve even when the manifold is full.
Solution Approach 2:
The invention creates a potential energy barrier by positioning the valve opening above the manifold bottom portion. This height difference establishes a gravitational potential gradient that allows water to collect in the manifold while preventing it from reaching the valve, effectively using gravity to separate water collection from valve protection.
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 prevents liquid water from entering and freezing in the valve, ensuring smooth reactivation and operation by retaining water within the gas manifold and preventing its flow into the valve.
Implementation Method 1
when the fuel cell stack is arranged so that a manifold bottom portion that is a bottom portion extending in the stacking direction in the stacked body manifold is horizontal, a bottom portion of an opening on the valve side in the end plate unit flow path is arranged above the manifold bottom portion
Data Source
AI summary
A fuel cell includes a fuel cell stack having a stacked body with a plurality of stacked unit cells, an end plate unit, and a gas manifold penetrating the stacked body and the end plate unit in a stacking direction for a flow of reaction gas. The fuel cell also includes a valve that is provided between the end plate unit and gas piping and includes an in-valve flow path for communicating the gas manifold and the gas piping and a valve element. The gas manifold includes a stacked body manifold and an end plate unit flow path. When the fuel cell stack is arranged so that a manifold bottom portion is horizontal, a bottom portion of an opening on the valve side in the end plate unit flow path is arranged above the manifold bottom portion.