Heat exchanger analysis for biomass-powered organic rankine cycle

With ever-growing world energy demand, renewable and alternative energy solutions are more relevant than ever. Organic Rankine cycle (ORC) is a promising technology that offers a number of advantages over conventional power cycles. However, efficiency is relatively low and individual components can be costly. In this paper, we analysed performance of biomass-powered ORC that used benzene as a working fluid with the focus of the degree of superheat. Three superheated cycle scenarios, with max fluid temperature of 250°C, 300°C and 350°C, were considered. Energetic and exergetic performance of three cycles were evaluated and heat exchanger sizing and analysis was carried out. While the overall power produced increases with the higher degree of superheat, the incremental improvement in efficiency requires a significantly larger heat transfer area. The optimal scenario offers a balance between efficiency, power output and the heat exchanger size.