- #1
ruiwp13
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Homework Statement
A compressor processes 1.5kg/min of air in ambient conditions (1 bar and 20ºC). The compressed air leaves at 10bar and 90ºC. It is estimated that the heat losses trough the walls of the compressor are of 25kJ/min. Calculate:
a) The power of the compressor
b) The variation of specific entropy of the air crossing the compressor
c) Verify if this process is possible, if it obeys to the 2nd Law of Thermodynamics
Homework Equations
1)ΔS = Q1/T1 - Q2/T2
2)ΔSuniverse=ΔSair+ΔSneighbours
3)Δs=cp*ln(T2/T1)-R*ln(P2/P1)
The Attempt at a Solution
For a I am a little bit stuck. Can I assume that the power of the compressor is all the work done by it?
In b) I think I just need to use the 3) equation.
For c) I need to use the 2) equation being ΔSneighbours=Q/Tneigh ⇔ ΔSneighbours=25kJ/min/20 and ΔSair the variation of entropy calculated in b)
Is this correct? And if it is can you help me in a)?
Best Regards,
Much appreciated!