Liquid water at 60 bar and 250°C passes through an adiabatic expansion valve, emerging at a pressure Pf and temperature Tf. If Pf is low enough, some of the liquid evaporates.
(a) If Pf = 10 bar, determine the temperature of the final mixture (Tf) and the fraction of the liquid feed that evaporates (yv) by writing an energy balance about the valve and neglecting ΔEk.
(b) If you took ΔEk into account in Part (a), how would the calculated outlet temperature compare with the value you determined? What about the calculated value of yv? Explain.
(c) What is the value of Pf above which no evaporation would occur?