generators and hydrogen gas(boom?)

solarsquirral · February 2015

just wondering if there is any issue with distance of combustable gas generators from battery banks

thanks

BB. · February 2015

Re: generators and hydrogen gas(boom?)

I am a little confused... How far a genset should be installed near a battery bank (which generates hydrogen gas)?

Or do you have some process that is generating flammable gasses and you are worried about near by battery bank?

-Bill

solarsquirral · February 2015

Re: generators and hydrogen gas(boom?)

im just wondering if its dangerous to run a generator close to a battery bank

BB. · February 2015

Re: generators and hydrogen gas(boom?)

Hydrogen gas is known for being explosive over a wide range of mixtures:

https://en.wikipedia.org/wiki/Hydrogen_safety

Hydrogen safety covers the safe production, handling and use of hydrogen. Hydrogen poses unique challenges due to its ease of leaking, low-energy ignition, wide range of combustible fuel-air mixtures, buoyancy, and its ability to embrittle metals that must be accounted for to ensure safe operation. Liquid hydrogen poses additional challenges due to its increased density and the extremely low temperatures needed to keep it in liquid form.

Here is a PDF on the subject from a computer room UPS company:

http://www.apcmedia.com/salestools/SADE-5TNQZQ/SADE-5TNQZQ_R3_EN.pdf

Personally, I am of the opinion that gensets should be separate from battery bank/electronics/inverters--Gensets themselves are frequently the source of fires (fuel leaks, electrical fires, etc.). Just from the point of view if you have a fire, either the genset or the battery bank/inverters are lost--Not both destroyed in the same building.

Hydrogen is very light, so tends to rise away from ignition sources, and hydrogen tends to diffuse pretty quickly (due to small size of molecule). Gasoline and propane fumes are heavy and collect in low spots--A different and possibly worse problem.

-Bill

mike95490 · February 2015

Re: generators and hydrogen gas(boom?)

my battery room has open eves at the top of the roof rafters. Makes it cold, but the chance of explosive accumulation is low. Generator (diesel for low explosive risk) is in the next shed.

vtmaps · February 2015

Re: generators and hydrogen gas(boom?)

solarsquirral wrote: »

just wondering if there is any issue with distance of combustable gas generators from battery banks

As the others have pointed out, there are safety advantages of keeping them separate. There may be other, practical, considerations if you live in a very cold climate... Do you need to keep either the batteries or the generator warm in the winter? Will you have to keep two sheds warm in the winter?

--vtMaps (whose warm, portable generator is carried outdoors when it is needed)

oil pan 4 · February 2015

Re: generators and hydrogen gas(boom?)

Well hydrogen does have the strange ability to remain explosive in any concentration from 1% to 99%.
Other normal gaseous fuels have a much more narrow range, usually some where between 5% and 20%.

ramloui · February 2015

Re: generators and hydrogen gas(boom?)

Actually, the flammability limits of hydrogen in air at standard temperature and pressure (0oC and 1 atm) is 4% to 75% by volume. To put that in perspective, in a room that is 8' x 8' by 8' high, you would need at least 20.5 cubic feet of hydrogen. To produce such quantity, you would need to dissociate about 1 lb of water just to get to the lower flammability limit. Of course, hydrogen being lighter than air, it could reach that concentration faster at the ceiling of that room. As a comparison, gasoline will explode at a concentration of 1.4% in air.

With regular traffic in and out of the room, it may actually be quite difficult to obtain those conditions. I would not loose sleep over that. However, in a tight battery compartment, completely different scenario.

Cheers!

generators and hydrogen gas(boom?)

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