EML4550HW8ans

# EML4550HW8ans - Problem Plot the power output and...

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Problem: Plot the power output and thermodynamic efficiency against the current density for a fuel cell. Givens: R 1.99 cal mol K := T 298K := F 23060 cal V mol := V oc 1.22V := J L .954 A cm 2 := Δ H 68.320 kcal mol := A s 72cm 2 := p g .21 := p r 1 := ω .25cm := n 2 := σ .625 1 ohm cm := Solution: Current density J .3 A cm 2 .31 A cm 2 , 1.00 A cm 2 .. := J o J ( ) J 1000 cm 2 A := Voltage drop due to chemical polarization at the cathode and anode, Δ V chem_a J ( ) .14V .005V ln J o J () + := Δ V chem_c J ( ) .20V .007V ln J o J + := Voltage drop due to concentration polarization at the anode and cathode, Δ V conc_a J RT nF ln J L J + J L := Δ V conc_c J ln J L J L J := Voltage drop due to the gas side polarization at the air side using the partial pressure, Δ V conc_g ln p r p g

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## This note was uploaded on 10/22/2011 for the course EML 4450 taught by Professor Greska during the Fall '06 term at FSU.

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EML4550HW8ans - Problem Plot the power output and...

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