Experimental investigation and optimal performance assessment of four volumetric expanders (scroll, screw, piston and roots) tested in a small-scale organic Rankine cycle system

By O. Dumont, Antoine Parthoens, R. Dickes, Vincent Lemort. Energy, 2018

116 citations recorded by the source corpus.

Abstract The aim of this paper is to facilitate the selection of the expander for a small-scale organic Rankine cycle based on an experimental comparison of a piston, a screw, a scroll and a roots expander. First, based on a literature review, a comparison between these four technologies of volumetric expansion machines is performed. Afterward, four displacement expanders [2–4 kW] are tested on two similar small-scale ORC unit with fluid R245fa. The maximum effective isentropic efficiencies measured are 53% for the piston expander and the screw expander, 76% for the variable-speed scroll and 48% for the roots machine. However, these performances do not reflect the highest efficiencies achievable by each expander: the test-rig presents experimental limitations in terms of mass flow rate and pressure drop (among others) that restricts the achievable operating conditions. The calibration of semi-empirical models based on the measurements allows to overcome this issue and to predict the isentropic efficiency in optimal conditions despite the limitations of the test-rigs. Based on experimental results, extrapolated prediction of the semi-empirical model and practical considerations, some guidelines are drawn to help the reader to select properly a volumetric expander.

Subfields: Mechanical Engineering

View Paper: https://www.semanticscholar.org/paper/92e541882c0a60a43139359a3093a266ca7f94f6