Experimental investigation of a revolving vane expander in a micro-scale organic Rankine cycle system for low-grade waste heat recovery

• Published in: Energy (Oxford) Vol. 253; p. 124174
• Main Authors: Naseri, Ali, Moradi, Ramin, Norris, Stuart, Subiantoro, Alison
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15.08.2022; Elsevier BV
• Subjects: Expanders; Filling factor; Heat recovery; Low temperature; Lubricated volumetric expander; Micro-scale ORC; Oil circulation; Prototypes; Rankine cycle; Revolving vane; Suction; Waste heat; Waste heat recovery; Micro-scale ORC; Oil circulation; Revolving vane; Filling factor; Lubricated volumetric expander
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2022.124174

Organic Rankine cycles (ORCs) are a reliable solution for power generation from low-temperature waste heat. While the ORC is a mature technology in medium to large scale applications, several challenges remain to be solved for its widespread adoption in micro-scale, including the development of a low-cost, reliable, and efficient expander. In this study, a modified revolving vane expander (M-RVE) prototype is experimentally tested in a micro-scale ORC system for the first time. The M-RVE is tested in the range of suction pressures of up to 13.0 bar(a), suction temperatures of up to 63 °C, and shaft speeds of up to 1850 rpm. The M-RVE demonstrated filling factors of 1.2–2.7, an isentropic efficiency of up to 42.5%, and shaft power of up to 134 W. The significant impacts of lubrication on the performance of the M-RVE are discussed. A comparable performance with existing expanders in the literature is achieved, especially at pressure ratios close to the expander built-in volume ratio. The results of this study provide better guidance for further use of the M-RVE in micro-scale ORC systems and provide a benchmark for future improvements of the M-RVE prototype. •A customised micro-scale ORC test bench with a lubrication circuit was developed.•The M-RVE prototype was tested in a micro-scale ORC for the first time.•Non-dimensional analysis was used for the characterisation of the M-RVE prototype.•A comparison between the M-RVE prototype and other expanders was carried out.•A maximum of 42.5% isentropic efficiency was achieved at a pressure ratio of 1.85.