Question

A large steam power plant operates on a Rankine cycle with regeneration,
The boiler produces steam at 24 MPa, 550EC, the condenser operates at 10 kPa, and the feedwater heater
operates at 3 MPa. These conditions are close to those of the new Keephills 3 supercritical pressure
plant in Alberta.
(a) Calculate the specific work in kJ/kg required for the pump and determine the enthalpy at the
pump outlet. The pump isentropic efficiency is 70%.
(b) Calculate the high pressure turbine specific work in kJ/kg and determine the enthalpy at the high
pressure turbine exhaust (5 in the cycle diagram). The properties of the steam leaving the boiler are
h3 = 3347 kJ/kg, s3 = 6.207 kJ/kg K. The turbine isentropic efficiency is 90%.
(c) Determine the ratio of the extracted mass flow m' E to the mass flow through the boiler m' 1. The
temperature of the water leaving the feedwater heater is T6 = 200EC.
(d) Calculate the specific heat input to the boiler in kJ/kg.
(e) The work produced by the low pressure turbine is 783 kJ/kg, based on the mass flow m' 4.
Determine the net work of the cycle in kJ per kg of mass flow m' 1, and the cycle efficiency. (The real
cycle has an efficiency of 39.5%.)

Answer 1