Ejector Structure for Residual Hydrogen Removal in Fuel Cells
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Solution Overview
Problem
Existing methods for removing residual hydrogen from fuel cell systems are either time-consuming, costly, or pose safety risks during maintenance, such as gas diffusion, air injection, and vacuum pumping, which can lead to fires or explosions.
Innovation Solution
A simple ejector structure combining a nozzle, venturi, and diffuser using compressed air as a driving flow to efficiently suck and remove residual hydrogen without introducing foreign materials or electricity, thereby enhancing safety and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gas diffusion method is used to remove residual hydrogen, then hydrogen concentration is reduced to safe levels, but substantial time is required making it unsuitable during maintenance
Solution Approach 1:
The invention uses pneumatic principles by introducing compressed air into the fuel cell system to create a pressure differential that actively draws out residual hydrogen through existing pathways. This active pneumatic flushing mechanism replaces passive diffusion, reducing hydrogen removal time from an indefinite period to a controlled, rapid process suitable for maintenance operations.
2Reliability
If air injection method is used to remove residual hydrogen, then hydrogen is purged from the system, but oil from air compressor degrades stack performance and requires expensive air filters
Solution Approach 1:
The invention extracts and eliminates the harmful element (oil from air compressors) by replacing the air injection method with an alternative approach using compressed air introduced through existing system pathways. This extraction of the contamination source prevents oil from entering the fuel cell stack, avoiding performance degradation and the need for expensive air filters while maintaining effective hydrogen purging.
Solution Approach 2:
The invention uses compressed air as an intermediary substance to achieve hydrogen removal without direct contact between potentially contaminated air compressor output and the fuel cell stack. By introducing compressed air through existing purge pipes and utilizing the system's own pathways, the method creates an intermediary barrier that prevents oil contamination while maintaining purging effectiveness.
3Reliability
If vacuum pump is used to suck residual hydrogen, then hydrogen is removed from the system, but the vacuum pump is expensive and may cause fire or explosion during operation
Solution Approach 1:
The invention converts the potentially harmful situation of having residual hydrogen present during maintenance into a safe state by using the existing compressed air infrastructure to actively flush out hydrogen. Instead of relying on expensive vacuum equipment that creates ignition risks, the method uses the beneficial compression and flow characteristics of compressed air to rapidly reduce hydrogen concentration to safe levels below the lower explosive limit.
4Ease of operation
If simple structure is used for hydrogen removal device, then device is portable and easy to use, but may not achieve effective hydrogen concentration reduction
Solution Approach 1:
The invention enables the fuel cell system to perform its own hydrogen removal function by utilizing existing components (purge pipes, valves, and control systems) and introducing compressed air through the same infrastructure. This self-service approach eliminates the need for complex external vacuum pumps or specialized equipment, achieving effective hydrogen concentration reduction while maintaining portability and ease of operation during maintenance.
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
The device effectively reduces hydrogen concentration below combustible levels, preventing fires and explosions during maintenance, while being portable, cost-effective, and easy to use, without degrading fuel cell stack performance.
Implementation Method 1
a driving pipe reducing pressure while increasing a speed of a driving flow supplied from a driving flow supply source; and a suction pipe integrally connected to an inlet of the driving pipe to suck and guide a suction flow including the residual hydrogen in a fuel cell system to the driving pipe using energy of the driving flow
Implementation Method 2
a driving pipe reducing pressure while increasing a speed of a driving flow supplied from a driving flow supply source
Data Source
AI summary
Disclosed is a device for removing residual hydrogen in a fuel cell. The device for removing residual hydrogen in a fuel cell sucks residual hydrogen gas in a fuel cell system and easily removes the sucked hydrogen gas so as to prevent a fire, an explosion, and the like which may occur due to residual hydrogen in the fuel cell system during maintenance work of a fuel cell vehicle. In particular, the device may be manufactured as a simple ejector structure in which a nozzle, a venturi, and a diffuser are sequentially combined, the nozzle and the venturi are combined, and the like to use compressed air as a driving flow and use gas inside a fuel cell system as a suction flow and thus easily remove the residual hydrogen.