Question

A basic Rankine cycle is to produce 200 MW of power. The inlet steam pressure can be no higher than 15 MPa, and the outside environment is 15 degrees Celsius. The isentropic efficiency of the turbine is 0.8, and the isentropic efficiency of the pump is 0.75.

(a) Design a basic cycle, specifying state properties at each state, the required mass flow rate of the steam, the thermal efficiency of the cycle, and the required mass flow rate of either cooling water or air in the condenser.

(b) Repeat part a, but the cycle can now contain superheated steam. The steam temperature can be no higher than 600 degrees Celsius. In addition, the steam quality in the turbine cannot fall below 0.85.

(c) Repeat parts a and b, but the cycle should now contain one reheater and one closed feedwater heater. If the pressure of the closed feedwater heater is above 100 kPa, the drains should be cascaded backward; otherwise the drains should be pumped forward.

(d) Repeat parts a through c, but the cycle may now contain an open feedwater heater, up to 2 reheaters, and up to 3 closed feedwater heaters. If the pressure of the closed feedwater heater is above 100 kPa, the drains should be cascaded backward; otherwise the drains should be pumped forward. Attempt to design a system with the highest possible efficiency.

Answer 1

8

Paot d) this task tafes o than 2h to caleulale at tu Stak pains PT Part ⓒ, HPT