Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: scientizscht on 19/05/2020 19:22:53

Title: Are pumps necessary for fuel cells?
Post by: scientizscht on 19/05/2020 19:22:53
Hello

Are pumps necessary for fuel cells?
Or they can be pumpless? What is the benefit of having pumps and how much is it?

Thanks!
Title: Re: Are pumps necessary for fuel cells?
Post by: scientizscht on 23/05/2020 21:04:18
Anyone?
Title: Re: Are pumps necessary for fuel cells?
Post by: Bored chemist on 23/05/2020 21:07:40
No.
Title: Re: Are pumps necessary for fuel cells?
Post by: scientizscht on 25/05/2020 12:43:48
So are they naturally aspirated with oxygen diffused directly from the atmosphere?
Title: Re: Are pumps necessary for fuel cells?
Post by: Bored chemist on 25/05/2020 13:04:01
... or fed from a cylinder.
Title: Re: Are pumps necessary for fuel cells?
Post by: scientizscht on 25/05/2020 16:41:35
Quote from: Bored chemist on 25/05/2020 13:04:01
... or fed from a cylinder.

So the fuel cells in cars have two cylinders, one for hydrogen and one for oxygen?
Title: Re: Are pumps necessary for fuel cells?
Post by: Bored chemist on 25/05/2020 17:59:15
And some have an air pump and a methanol tank.
There are lots of varieties.
If you rely on diffusion you won't get much current.
Title: Re: Are pumps necessary for fuel cells?
Post by: scientizscht on 25/05/2020 21:39:28
What is the multiple between diffusion and pump? Are we talking about a 20% increase in current or 200%?
The pumps will require quite a lot of energy and there will also be quite significant energy losses so I wonder if they are justified by offering a significant boost in current.
Title: Re: Are pumps necessary for fuel cells?
Post by: Bored chemist on 25/05/2020 21:43:24
You might be talking about a thousand fold increase or more.
Diffusion is pretty slow.
Title: Re: Are pumps necessary for fuel cells?
Post by: scientizscht on 26/05/2020 17:16:10
What about fuel cells that run with liquid?
Title: Re: Are pumps necessary for fuel cells?
Post by: scientizscht on 26/05/2020 17:28:59
So you are saying that using pumps in fuel cells turns one naturally aspirated fuel cell into a thousand of them?

Why is diffusion slow as there is no gap in oxygen created when something burns. Oxygen is replenished instantly.
Title: Re: Are pumps necessary for fuel cells?
Post by: Bored chemist on 26/05/2020 18:46:43
Quote from: scientizscht on 26/05/2020 17:28:59
So you are saying that using pumps in fuel cells turns one naturally aspirated fuel cell into a thousand of them?

Why is diffusion slow as there is no gap in oxygen created when something burns. Oxygen is replenished instantly.
I'm saying that a naturally aspirated fuel cell is not generally a good design.
Part of the problem is getting nitrogen out of the way