Thermo-Economic Analysis of Organic Rankine Cycle with Different Working Fluids for Waste Heat Recovery from Coal-based Power Plant

Abstract

The utilization of waste heat from power plants, which is generally lost to the atmosphere, can reduce energy waste significantly. Heat recovery systems can be integrated with power plants to utilize the waste heat, improving plant energy efficiency and reducing fossil fuel consumption and carbon emissions. The current study is focused on harnessing waste heat through the Organic Rankine Cycle (ORC) from 500 MWe supercritical power plant with CO2 capture. The simulation flow sheet program “Cycle-Tempo” models and simulates different plant layouts. This study considered five different working fluids for ORC, such as R245fa, Benzene, Methanol, Ethanol, and Acetone. The ORC generates additional electricity of 9.91 MWe for R245fa, 14.11 MWe for Benzene, 13.71 MWe for Methanol, 14.04 MWe for Ethanol and 13.97 MWe for Acetone. The thermodynamic study concludes that ORC based on benzene is the best, and the economic analysis discloses that ORC based on ethanol is the best among all working fluids with a payback period of 0.869 years and cost of electricity of Rupees 1.101 per kWh. This study also concludes that the novel technique used in the present study is economically viable, contributing to a more energy-efficient and environmentally friendly power generation system.