Something equivalent to this: http://www.youtube.com/watch?v=DjWZU0hb8Yk (except we’re using a metal-hydride tank). Different school though, and our hydrogen is stored at 125psi instead of generated on the spot.
Our car as-is is considered safe enough for the competition, and actually won a “Best Application of Safety Practices” award at an earlier competition. We just think hydrogen is dangerous (duh) and want to build on our no-compromises approach this year. We’ve already put a lot of work into making sure the car was safer than any other hydrogen-powered vehicle.
I’m building a hydrogen leak detection system with MQ-8 sensors from Hanwei Electronics. If hydrogen is detected, an arduino should cut power to a normally-closed solenoid.
The system’s purpose is to impress judges (we’re optimizing the engineering for a competition, after all), provide me and other students with experience designing and implementing control systems, and give me an excuse to write programs for the arduino.
We’re also going to be designing/building our future cells from scratch, so a properly controlled isolation valve like this could be used to protect our investment.
Thus, the real safety considerations are: reliability of closure, tightness of closure, and compatibility with hydrogen gas.
If we could find one rated for at least “Class 1, Div 2, Group B” service, that would be great. If we could find one that’s explosion-proof, that would be great. However, it has to fit in a small vehicle and be powered by a relatively low voltage DC source (maybe could go up to 24V, but would prefer <=12V DC). So far I haven’t found anything at any price.