Liquid water is throttled through avalve from500 kPa and 150oC to300 kPa. A flash chamber is used to separate the liquid from the vapor such that saturated liquid water exits from the bottom of the chamber at 300 kPa while saturated vapor exits from the top at the same pressure. The water vapor (steam) is then expanded in a turbine to a pressure of 10 KPa. The turbine has an isentropic efficiency of 90%. Calculate: (a) the rate of exergy destroyed in the valve and flash chamberper kg of water entering the flash chamber, and (b) the turbine exergetic efficiency.

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.