Posted: March 10th, 2017

Draw a T-s diagram for the isentropic and actual process. c) (6 points) The mass flow rate of the working fluid (steam). Compare to the answer you got in problem I. Is it less, the same or greater? d) (6 points) The actual thermal efficiency of the cycle.

We add superheat and reheat to the cycle above. Steam enters the first turbine stage at 8 MPa, 480oC, and leaves at 0.7 MPa. It is reheated to 440oC and enters the second turbine stage, where it is expanded to 0.008 MPa. Saturated liquid leaves the condenser at 0.008 MPa. The turbines and pump again have isentropic efficiencies of 85%, and the plant has 100 MW net power. Find: a) (6 points) Draw a system diagram and label all the components. Number the flow, starting with a 1 at the pump inlet. b) (6 points) Draw a T-s diagram for the isentropic and actual process. c) (6 points) The mass flow rate of the working fluid (steam). Compare to the answer you got in problem I. Is it less, the same or greater? d) (6 points) The actual thermal efficiency of the cycle. Compare to the answer you got in problem I. Is it less, the same or greater? e) (6 points) Calculate the mass flow rate of the cooling fluid (assume subcooled water with a Cp of 4.184 kJ/kgK) ) if this cooling fluid enters the condenser at 15oC and leaves at 25oC.