Fuel Cell efficiency and heat rejection
Fuel Cell efficiency and heat rejection
(OP)
Hi, my first post, hope you all can help, thanks!
I'm doing a preliminary study on a marine fuel cell installation and am looking at the ventilation requirements for the space. I asked the fuel cell manufacturer what the heat rejection to atmosphere on the fuel cell (250kW) is, and they told me, "Our 125 kW (net) Forza power module has 50% or more efficiency. Therefore, heat rejection to the atmosphere will be approximately 250 kW for 250 kW electric output. Rejected heat will be approximately at 60C."
Does this make sense? For one thing, is heat rejected at a certain temperature, i.e., 60C? If this is correct I need about 26,000 CFM to keep to a 15 degF heat rise (before I even get to solar and other heat loads). Is this the penalty of 50% efficiency?
I'm doing a preliminary study on a marine fuel cell installation and am looking at the ventilation requirements for the space. I asked the fuel cell manufacturer what the heat rejection to atmosphere on the fuel cell (250kW) is, and they told me, "Our 125 kW (net) Forza power module has 50% or more efficiency. Therefore, heat rejection to the atmosphere will be approximately 250 kW for 250 kW electric output. Rejected heat will be approximately at 60C."
Does this make sense? For one thing, is heat rejected at a certain temperature, i.e., 60C? If this is correct I need about 26,000 CFM to keep to a 15 degF heat rise (before I even get to solar and other heat loads). Is this the penalty of 50% efficiency?





RE: Fuel Cell efficiency and heat rejection
Presumably, the 60ºC refers to the highest surface temperature under some condition, which they can't much exceed, since an accessible surface at that temperature can cause skin burns with a long enough exposure. I'll go out on a limb and suggest that the temperature given only applies to a system with 25ºC ambient temperature, so you're dumping the heat load through a 35ºC temperature difference.
TTFN
RE: Fuel Cell efficiency and heat rejection
Water jacket cooling might be an option as well, and a nice way to capture waste heat.
RE: Fuel Cell efficiency and heat rejection
I will talk to the manufacturer about water-cooling, which would certainly be a lot easier. Thanks!
RE: Fuel Cell efficiency and heat rejection
RE: Fuel Cell efficiency and heat rejection