Impact of the Lubricant on a Modified Revolving Vane Expander (M-RVE) in an Organic Rankine Cycle System

The expansion device is the critical component of micro-to-small scale organic Rankine cycle (ORC) systems, substantially affecting system efficiency and cost. Low isentropic lubrication requirements are main issues associated with using volumetric expanders in ORC systems. Despite contributing to reducing internal leakages an expander, it may compromise performance by adversely evaporator’s thermal capacity. This study tests a recently developed modified revolving vane expander (M-RVE) micro-scale test rig implementing adjustable oil mass flow rate. impact lubricant on M-RVE prototype investigated within wide range circulation rates (OCR). results demonstrate negligible improvement filling factor for OCRs higher than 1%. Moreover, shaft power not considerably sensitive OCR, while calculated improves OCR. Furthermore, evaporator studied, assuming exact OCR as measured temperature pressure similar pure refrigerant lubricant-refrigerant mixture evaporator. shows that capacity penalized especially values Hence, about 1% good compromise, can be used guideline designing systems without dedicated circuit.