Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
PRESSURE RATIO INFLUENCE OVER THE PERFORMANCE OF A SCROLL EXPANDER
Submission Author:
Paulo Eduardo Batista de Mello , SP
Co-Authors:
Fernando Vieira de Oliveira, Filipi Martins Fernandes Silva, Paulo Eduardo Batista de Mello
Presenter: Paulo Eduardo Batista de Mello
doi://10.26678/ABCM.COBEM2017.COB17-0232
Abstract
The use of scroll expanders in Organic Rankine Cycle (ORC) and Compressed Air Energy Storage (CAES) systems have been considered as a good alternative by many research studies presented in the last decades. These devices are appropriate for the low power range, usually between 1 and 10 kW. Small distributed generation sites could benefit from using scroll devices. One important finding from previous work is the fact that internal leakages decrease the isentropic efficiency of scroll expanders. Actually, these leakages are the main cause of inefficiency. In this paper, a transient 2D CFD simulation of a scroll expander capable of quantifying the internal leakages was used. The results obtained show that the leakages can influence the point of maximum isentropic efficiency of the device, related to pressure ratio. Normally, this maximum is closely related to expander volume ratio, but high internal leakages tend to reduce the optimum pressure ratio. The computation of other relevant parameters (filling factor and power) support the findings and explains the behavior of the measurements obtained with a scroll prototype.
Keywords
Scroll Expander, CFD simulation, ORC, internal leakage, pressure ratio
