A medium size power station is used to produce 30 MW net power for a refinery. The station uses steam as the operating fluid and operates according to the Carnot cycle between the pressure limits of...

A medium size power station is used to produce 30 MW net power for a
refinery. The station uses steam as the operating fluid and operates
according to the Carnot cycle between the pressure limits of 0.4 bar and
35 bar. Steam enters the boiler as a saturated liquid and leaves it as a
dry saturated vapour.

(i) List the name of the four processes in a generic Carnot cycle and
state what type of energy transfer (work/heat) can be neglected
in each process.

(ii) Determine the dryness fraction of the steam that is fed to the
condenser, and the specific enthalpy values at the four key points of
the cycle.

(iii) Calculate the specific heat provided to the boiler, the specific
work extracted from the power station and the mass flow rate of
the steam circulating in the cycle, then, determine the thermal efficiency of the cycle.