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

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.

[1]  Weilin Zhuge,et al.  Review of Expander Selection for Small-Scale Organic Rankine Cycle , 2014 .

[2]  Rémi Daccord,et al.  Cost to benefit ratio of an exhaust heat recovery system on a long haul truck , 2017 .

[3]  Vincent Lemort,et al.  Positive displacement expanders for Organic Rankine Cycle systems , 2017 .

[4]  Antonio Giuffrida,et al.  Improving the semi-empirical modelling of a single-screw expander for small organic Rankine cycles , 2017 .

[5]  Martijn van den Broek,et al.  Turn waste heat into electricity by using an Organic Rankine Cycle, part 1 , 2011 .

[7]  Mauro Venturini,et al.  Design, Analysis and Optimization of a Micro-CHP System Based on Organic Rankine Cycle for Ultralow Grade Thermal Energy Recovery , 2014 .

[8]  Vincent Lemort,et al.  Reciprocating Expander for an Exhaust Heat Recovery Rankine Cycle for a Passenger Car Application , 2012 .

[9]  Tomasz Z. Kaczmarczyk,et al.  A review of expanders for power generation in small-scale organic Rankine cycle systems: Performance and operational aspects , 2016 .

[10]  Saffa Riffat,et al.  Expanders for micro-CHP systems with organic Rankine cycle , 2011 .

[11]  Vincent Lemort,et al.  Experimental investigation of a reversible heat pump/organic Rankine cycle unit designed to be coupled with a passive house to get a Net Zero Energy Building , 2015 .

[12]  Vincent Lemort,et al.  Modelling of organic Rankine cycle power systems in off-design conditions: An experimentally-validated comparative study , 2017 .

[13]  Andreas Brümmer,et al.  Investigating a Small Oil-Flooded Twin-Screw Expander for Waste-Heat Utilisation in Organic Rankine Cycle Systems , 2017 .

[14]  Andreas P. Weiß,et al.  VOLUMETRIC EXPANDER VERSUS TURBINE - WHICH IS THE BETTER CHOICE FOR SMALL ORC PLANTS? , 2015 .

[15]  Ahmed Kovacevic,et al.  Steam as the working fluid for power recovery from exhaust gases by means of screw expanders , 2011 .

[16]  Vincent Lemort,et al.  Experimental performance of a piston expander in a small- scale organic Rankine cycle , 2015 .

[17]  Olivier Dumont.  Investigation of a heat pump reversible in an organic Rankine cycle and its application in the building sector , 2017 .

[18]  Vincent Lemort,et al.  Importance of the reconciliation method to handle experimental data in refrigeration and power cycle: application to a reversible heat pump/organic Rankine cycle unit integrated in a positive energy building , 2016 .

[19]  Martijn van den Broek,et al.  Low-order models of a single-screw expander for organic Rankine cycle applications , 2015 .

[20]  Vincent Lemort,et al.  Experimental investigation of an ORC system for a micro-solar power plant , 2014 .

[21]  Vincent Lemort,et al.  Extrapolability and limitations of a semi-empirical model for the simulation of volumetric expanders , 2017 .

[22]  Jenny Welander,et al.  Master of science in mechanical engineering , 2015 .

[23]  Kim Choon Ng,et al.  A thermodynamic model for the analysis of screw expander performance , 1990 .

[24]  Sylvain Quoilin,et al.  Sustainable energy conversion through the use of Organic Rankine Cycles for waste heat recovery and solar applications , 2011 .

[25]  Li Zhao,et al.  A review of working fluid and expander selections for organic Rankine cycle , 2013 .

[26]  V. Lemort.  Contribution to the Characterization of Scroll Machines in Compressor and Expander Modes , 2008 .

[27]  Ahmed Kovacevic,et al.  Review of Mathematical Models in Performance Calculation of Screw Compressors , 2011 .

[28]  L. Guillaume.  On the design of waste heat recovery organic Rankine cycle systems for engines of long-haul trucks , 2017 .