Questions 1 to 6 refer to the following

A Steam Power Plant is operated on the Rankine cycle, with superheated steam at 6 MPa and

600°C expanded to 20 kPa in an adiabatic turbine with an isentropic efficiency of 81%.

The steam is then condensed to saturated liquid before being pumped back into the boiler.

The power plant operates with a mass flow rate of 24 kg/s.

QUESTION 1

Sketch a schematic diagram of the steam plant, and a T-S state diagram of the Rankine cycle, using

corresponding numbers to indicate the initial and final state for each thermodynamic process.

QUESTION 2

Calculate the specific enthalpy of the steam at the turbine inlet and the turbine outlet.

QUESTION 3

Calculate the net power output of the steam plant.

QUESTION 4

Calculate the individual components of the heat input required to heat the liquid water, to boil the

water, and to superheat the steam, and also calculate the total heat input for the steam plant.

QUESTION 5

Calculate the overall thermal efficiency of the steam plant and explain how this could be improved

by the implementing regenerative feed-water heating.

QUESTION 6

Explain how modifications to the steam plant to include reheat between the high-pressure and low-

pressure stages of the turbine would improve the overall plant performance.