For the power cycle described in Problem 8.37, determine the cycle efficiency if the pressure at state 6 is 600 psia and at state 7 it is 100 psia.
For the ideal power cycle shown in Fig. 8.37, assume the steam leaving the boiler at state 5 is at 1200 psia and 1000°F with a mass flux of 50 lbm/s. Steam is removed at state 6 at 400 psia and sent to an open feedwater heater. The remaining steam leaves the high-pressure turbine at state 7 at 200 psia and is reheated to 800°F. This steam is sent back to the low-pressure turbine and leaves this turbine at 4 psia. Plot this cycle on a T-s diagram and determine:
i) The steam flux extracted to go to the feed-water heater
ii) The total heat addition by the boiler
iii) The power output of the turbine
iv) The quality, or temperature, of the steam leaving the turbine
v) The heat loss from the condenser
vi) The total horsepower of the two pumps
vii) The thermodynamic efficiency of the cycle
Figure 8.37

Boiler 5 P1) 53 Heater P2 Condenser