Energy and Exergy Analysis of a Reheat Regenerative Vapor Power Cycle

The present paper describes the energy and exergy analysis of a reheat regenerative vapor power cycle. The plant consists of one boiler feed pump, one supercritical boiler, two steam turbines with a reheater in between, two feed water heaters (one open and one closed) and a condenser. The energy and exergy balance study has been carried-out for each component of the plant. Energy efficiency, exergy efficiency and the irreversibility results obtained from the simulation has been presented in the form of graphs. The supercritical pressure is varied from 250 to 400 bar in a step of 50 bar and for each supercritical pressure the temperature has been changed from 500 to 800K. The parametric study reveals that the cycle energy and exergy efficiency increases with increase in pressure and temperature. This is due to reduced energetic and exergetic losses at increased pressure and temperature. While estimating the irreversibility and fractional exergy losses of various system components it is found that maximum irreversibility occurs in the boiler which accounts for 46-55% at 350 bar for the given temperature range. The fractional exergy loss in turbine, condenser, BFP, mixing chamber, OFWH and CFWH are found to 20-30%, 13-14%, 1.6 -2%, 0.37 – 0.64%, 1.6-2.8% and 1.252.15% respectively at 350 bar inlet pressure and for the given temperature range. This combined study on energy and exergy analysis thus gives a better insight into the cycle operation with various system components and components requiring operational and design modifications for minimizing losses.