The Performance of waste Heat Recovery Systems using Steam Rankine Cycle and Organic Rankine Cycle For Power Generation

Abstract

This paper presents extensive modelling of an Organic Rankine Cycle (ORC) system for a combined cycle power plant and to compare and evaluate the performance of ORC and Steam Rankine Cycle (SRC). In addition, ORC as a second stage waste heat recovery system after SRC too was modelled. Conceptual design of an ORC was made to replace the SRC system used in the power plant and its performance was compared with that of the SRC above. Upon replacing the steam cycle with ORC, the system efficiency is 7.63 %. The total energy destruction is 5140.41 kW. The result shows that ORC delivers very low system efficiency. The steam cycle produces 202.5MW whereas the presented ORC produces just 1.016MW of power. On the other hand, if ORC is implemented on the chimney the system will produce 0.2% of extra power on top the current power production of 675MW. The efficiency of this system is 7.81%. It is recommended to add the ORC at the chimney to tap more useful energy from the otherwise waste energy rejected into the environment.