Energy and Exergy Analysis Of a 44-MW Bagasse-based Cogeneration Plant in India

Abstract

In this article, energy and exergy analysis of an ongoing, 44-MW, heat-matched, bagasse-based cogeneration plant of Ugar Sugar Works Ltd (USWL), located in Belgaum, India is presented. In the analysis, exergy methods with more conventional energy analysis are employed to assess the thermodynamic efficiencies and losses. The performance of the plant was estimated, and a detailed break up of energy and exergy losses for the considered plant has been presented. The fuel energy savings ratio of the cogeneration plant is estimated in comparison with separate generation plants. The plant performs with energy and exergetic efficiency of 65% and 25%, respectively. Energy losses mainly occurred in the boiler exhaust and condenser, where 35 MW and 27 MW is lost to environment, respectively. The percentage ratio of the exergy destruction to total exergy destruction was found to be maximum in the boiler system (71%) of fuel exergy input or 45% of the physical exergy input. The total exergy destruction in the plant's components is 58% of physical energy input. The plant's fuel energy savings ratio is 8.2%. Because of its inherent combustion irresistibility, the boiler is the major contributor to the plant's overall inefficiency. The inefficiencies in bagasse-fired boilers can be reduced to some extent by increasing the pre-heated, excess air supply and generating steam at possible high pressure and temperature. In terms of technology development, only cogeneration plants with exergetic efficiency close to that of overall efficiency of the conventional power plant be suggested