Experimental Investigation of a Small-Scale Reversible High- Temperature Heat Pump – Organic Rankine Cycle System for Industrial Waste Heat Recovery

Abstract

A reversible system that can function as both a high-temperature heat pump (HTHP) and an organic Rankine cycle system (ORC) can enhance the efficiency of industrial waste heat recovery. The reversible system can either upgrade waste heat to process heat (HTHP mode) or generate power (ORC mode). This paper presents the experimental investigation of a small-scale reversible HTHP-ORC system using an automotive open-drive scroll machine to operate as the compressor (HTHP) and expander (ORC) in the system. The refrigerant R1233zd(E) was selected as the working fluid for both modes of operation. Based on an analysis of the experimental results, the HTHP achieved a COPel of 4.6 at 30 K temperature lift, with the scroll compressor achieving a maximum overall isentropic efficiency of 73.4%. In ORC mode, at a source temperature of 75 °C, the cycle thermal efficiency was 3.8%, and the expander overall isentropic efficiency was 43%.