solution

Figure P7.84 shows liquid water at 80 lbf/in.2 , 300 F entering a flash chamber through a valve at the rate of 22 lb/s. At the valve exit, the pressure is 42 lbf/in.2 Saturated liquid at 40 lbf/in.2 exits from the bottom of the flash chamber and saturated vapor at 40 lbf/in.2 exits from near the top. The vapor stream is fed to a steam turbine having an isentropic efficiency of 90% and an exit pressure of 2 lbf/in.2 For steady-state

operation, negligible heat transfer with the surroundings, and no significant kinetic and potential energy effects, determine the

(a) power developed by the turbine, in Btu/s.

(b) rates of entropy production, each in Btu/s R, for the valve, the flash chamber, and the turbine. Compare.