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# First law on fuel cell

## First law on fuel cell

(OP)
Hello everyone. I am trying to learn EES but I am still having troubles with simple tasks.
I want to model a very very simple fuel cell to find out its operating temperature:
H2 and O2 enter my control volume at 25 °C;
Water comes out at temperature T;
Heat is dissipated and there is a power output;

What i did was:

Ph2 = 100 [kPa]
Po2 = 100 [kPa]
W_dot = 2 [kW]
watermass_dot = 1.57*10^(-4) [kg/s]
Q = watermass_dot * h_products + W_dot
T = Q / Ht + 25
Ht = 0.027 [kW/C]
h_products = enthalpy(Water, T = T-273.15, P = Po2)+(-104)+(-285830/18)

My model returns T = 2.37 K. Does anyone know where could be my mistake? (maybe I am using the Enthalpy function wrong, I don't know).
Also, when I change some parameters, like W_dot = 200 kW, EES says that the evaluation of the last line resulted in a logarithm of a number less than or equal to zero.

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