4-E analysis and optimization of a 660 MW supercritical combined Rankine-Kalina cycle coal-fired thermal power plant for condenser waste heat recovery

Abstract

Thermodynamic study of a combined 660 MW supercritical Rankine-Kalina cycle thermal power plant and its optimization is carried out based on 4-E (Energy, Exergy, Environment and Economic) analysis for condenser waste heat recovery using ‘Cycle-Tempo’ computer modelling software. Net energy and exergy efficiencies of the plant are increased by about 0.543% and 0.472% points, respectively, compared to standalone power plant by reducing condenser energy and exergy losses by about 0.773% and 0.418% points, respectively. Variation of key operating parameters, namely, ammonia mass fraction, condenser pressure and evaporator shell pressure, is studied and optimized accordingly. About 2.53 t/h of CO2 emission can be reduced at full load, and the cost of fuel saved is about 6.15 times lower than fuel cost. Levelized cost of electricity (LCoE) generation of the plant is about INR 1.919 per kWh which is marginally higher than the standalone power plant.