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[tophat22]

So the question reads:
Joe Unidel claims to have invented a steady-state flow device in which the inlet is steam at 300 C and 5 bar, the outlet is saturated steam at 100 C and 1 bar, the device is adiabatic and produces approx. 388 kJ per kg of steam passed through the device. Should be believe this claim?

So this is how I set it up

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My Entropy Balance:
dS/dt = 0 = ^S(in) - ^S(out) + 0/T + Sgen

So I obtained ^S(in) and ^S(out) from the steam tables and got the values 7.5499 kJ/kg K and 7.3549 kJ/kg K respectively. I plugged the values in and obtained -.195 kJ/kg K as my Sgen... and since the Sgen cannot be negative, his invented device will not work.


Did I do this correctly?

Also, I feel like i'm missing something since I didn't use the 388 kJ/kg...