Parametric Optimization and Working Fluid Selection of Organic Rankine Cycle (ORC) for Engine Cooling Water Waste Heat Recovery

Abstract

In this paper, aimed to utilize engine cooling waste heat completely, thus promoting engine fuel economy significantly, organic Rankine cycle (ORC) system is proposed and investigated in detail. Considering environmental impact, four promising hydrocarbons, namely butane, isobutane, pentane and isopentane are taken into consideration. The results indicate that butane distinguishes among other fluids for the highest value of output power, and its output power is as large as 6.33kW, besides that its volumetric flow rate is relatively low as well. Pentane and isopentane can acquire a maximum thermal efficiency of 9.5% or more for the whole operating parameters.