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I have seen anecdotal testing of fuel cell stacks. Intended to demonstrate that their power output can be improved through the addition of a centrifugal blower.

What are the limits associated with turbocharging a fuel cell stack?

Is fuel cell power output principally limited by fuel supply, or the stack itself?

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  • $\begingroup$ Did you search for "fuel cell thermodynamics"? I found several sources on the internet that are discussing it. Having said that, a centrifugal blower moves large amounts of gases at a low pressure differential. What you would need is small volumes to be pressurized at high pressure (probably tens, if not hundreds of times normal pressure). Unless you already have access to high pressure gases (e.g. in a spacecraft), creating that pressure is a losing proposition because it will take more energy than you will gain from the fuel cell. $\endgroup$
    – FlatterMann
    Commented Jan 16 at 21:12
  • $\begingroup$ That's more or less what I'm investigating. Traditionally you might just burn the fuel and oxidizer in a turbine. But in this case there is a special need to use electric turbines so as to not have exhaust gases blowing in peoples faces. $\endgroup$
    – Slartibartfast
    Commented Jan 16 at 22:36
  • $\begingroup$ The correct vernacular helped substantially in locating the necessary information. intechopen.com/chapters/70166 $\endgroup$
    – Slartibartfast
    Commented Jan 25 at 4:09
  • $\begingroup$ I might edit the question to better reflect what I was ultimately trying to resolve. $\endgroup$
    – Slartibartfast
    Commented Jan 25 at 4:10

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I ultimately found the answer buried in a very informative paper on fuel cell thermodynamics. My takeaway is that while a direct reaction of Hydrogen and Oxygen, i.e. combustion; occurs at a blistering pace. The expedience of the reaction is attributable to the fact. That every mole of reactant is in direct contact with every mole of co-reactant.

Fuel cells are therefore inherently limited to the total surface area on which the reaction can occur. Higher pressures are still potentially of some benefit for the purpose of supplying additional reactant. But only where the reactive surface of the fuel cell membrane scales accordingly. Pursuant to the requirement for higher reaction surface areas. The channels through which reactants must flow become narrower. Higher pressures may thus be still useful if only for the purpose of overcoming the higher dynamic viscosity that results.

https://www.intechopen.com/chapters/70166

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  • $\begingroup$ The operation of a fuel cell is different from that of direct combustion. In a fuel cell we are moving electrons to extract electrical power. In combustion we do not. $\endgroup$
    – FlatterMann
    Commented Jan 25 at 5:16
  • $\begingroup$ That was my point. A direct reaction represents the highest rate at which that reaction can occur. So it is the reactive surface area of the membrane that is the limiting factor. $\endgroup$
    – Slartibartfast
    Commented Jan 25 at 5:18
  • $\begingroup$ It's not the same reaction. You have to include the electrons into the stoichiometry. They are gaining energy in the electrical field of the cell. $\endgroup$
    – FlatterMann
    Commented Jan 25 at 5:21
  • $\begingroup$ To actually design the cell I do. In the interim I'm just interested in knowing what was the limiting factor in terms of power output. $\endgroup$
    – Slartibartfast
    Commented Jan 25 at 5:27
  • $\begingroup$ If the fuel cell is not even a fuel cell than the question makes no sense. If you are increasing the gas pressure in a combustion reaction, then it speeds up just as well. $\endgroup$
    – FlatterMann
    Commented Jan 25 at 5:32

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