Fuel Cell Oxidant Bypass Valve for Motor Failure Redundancy
Solution Overview
Problem
Conventional fuel cell systems face issues where a motor-driven upstream-side valve failure, such as wire breakage or disconnection, prevents the supply of oxidant gas to the fuel cell stack, rendering a fuel cell vehicle unable to perform escape running or pull over.
Innovation Solution
Incorporating an upstream-side bypass passage and bypass valve that allows oxidant gas to bypass the upstream-side valve, enabling the supply of oxidant gas to the fuel cell even if the upstream-side valve fails, with the bypass valve being a solenoid or relief valve that opens when a predetermined pressure is reached.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a motor-driven upstream-side valve is used to control oxidant gas supply, then the valve can be precisely controlled during normal operation, but the system loses reliability when wire breakage or disconnection occurs
Solution Approach 1:
The system is divided into two independent pathways: the main oxidant gas supply passage with the motor-driven upstream-side valve for normal operation, and a bypass passage with a bypass valve for emergency operation. This segmentation allows the system to maintain functionality even when one pathway fails.
Solution Approach 2:
The bypass passage and bypass valve are prepared in advance as a backup system. When the motor-driven valve fails due to wire breakage or disconnection, the bypass valve can be opened to allow oxidant gas to flow through the bypass passage, cushioning against the failure and maintaining system operation.
2Reliability
If a bypass passage with bypass valve is added to the system, then reliability is improved by providing alternative oxidant gas supply path, but device complexity increases
Solution Approach 1:
The gas supply system is segmented into a main pathway and a bypass pathway, each with its own valve. This segmentation adds redundancy for improved reliability while keeping each segment relatively simple in structure.
Solution Approach 2:
The bypass passage acts as an intermediary pathway that can activate when the main pathway fails. The bypass valve serves as a mediator that redirects oxidant gas flow from the compressor to the fuel cell stack when the upstream-side valve cannot open properly.
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
Ensures that a fuel cell vehicle can perform escape running or pull over even if the upstream-side valve fails, by providing a redundant pathway for oxidant gas supply, thereby ensuring operational safety and mobility.
Implementation Method 1
one of the valve seat and the valve element is provided with a seal member configured to seal between the valve element and the valve seat during non-operation of the drive mechanism
Implementation Method 2
a compressor provided in the oxidant gas supply passage and configured to supply the oxidant gas to the fuel cell
Implementation Method 3
the bypass valve being a solenoid or relief valve that opens when a predetermined pressure is reached
Data Source
AI summary
In a fuel cell system, each of an inlet sealing valve and an outlet integration valve is provided with a valve seat including a valve hole and a seat surface formed on a circumferential edge of the valve hole, a valve element formed, on its outer periphery, with a seal surface corresponding to the seat surface, and a motor to move the valve element away from the valve seat upon receipt of electric power supplied from outside. The valve seat is provided with a seal member to seal between the valve element and the valve seat during non-operation of the motor. In an inlet-side bypass passage connected to an air supply passage by detouring around the inlet sealing valve, there are arranged an inlet-side bypass passage and an inlet bypass valve.