Question

5. In a turbine, 0.3 kg/s of CO2 expands from 5 bar and 27oC to 1 bar according to 

the polytropic process Pv1.2 = constant, in order to produce cold gases for an 

industrial process. Find the final temperature as well as heat and mechanical 

powers exchanged.

Answer 1

During expansion and compression processes of real gases, pressure and volume are

often related by $PVn = C$, where n and C are constants.

For n = 0, the pressure‐volume relation reduces to P=constant (isobaric process) and the

integral become $W = P(V2-V1).$