Thermodynamic analysis of the partially evaporating trilateral cycle

The potential of Organic Rankine Cycles (ORC) to recover low grade waste heat is well known. The high heat recovery potential is partially attributed to a good match of the temperature profiles between working fluid and waste heat stream in the evaporator. This preferable characteristic is mainly induced by the selection of an appropriate working fluid. However, because of the constant temperature evaporation of the working fluid, the heat recovery potential is restricted. In order to overcome this limitation the trilateral cycle (TLC) has been investigated. A Trilateral cycle (also called Triangular cycle) is a modified Rankine cycle. The main difference is that the working fluid is not evaporated but only heated to the saturation temperature. Compared to the ORC, the heat carrier stream can be cooled further and the thermal efficiency is lower. In this study the effect of partial evaporation of the working fluid is investigated