(Solved): Problem 2: Steam undergoes an adiabatic expansion in a piston-cylinder assembly (closed system) fr ...

Problem 2: Steam undergoes an adiabatic expansion in a piston-cylinder assembly (closed system) from 100 bar, $$640^{?}\mathrm{C}$$ to 1 bar, $$160^{?}\mathrm{C}$$. (a) Calculate work in $$\mathrm{kJ}$$ per $$\mathrm{kg}$$ of steam for the adiabatic expansion process and the amount of entropy produced, in $$\mathrm{kJ}/\mathrm{kg}?\mathrm{K}$$ for the process. $$(15)$$ (b) Sketch the process on a carefully proportioned T-s diagram (5) (c) What is the magnitude of the maximum theoretical work that could be obtained from the given initial state $$(100$$ bar, $$640^{?}\mathrm{C})$$ to the same final pressure $$(1$$ bar)? (15) (d) An inventor claims that he can obtain steam at a quality of $$50\%$$ at the end of this expansion process. Evaluate his claim with suitable thermodynamic arguments (5)