Innovation, compressor, piezo, electric, refrigeration
In this paper, innovations in refrigeration compressors and their mechanisms which were conceptualised (and some of these were commercialised) at Nanyang Technological University in Singapore over the past twenty years are discussed and presented. These innovations include piezo compressor [1-3], sliding cam compressor , rotaprocating compressor , revolving vane compressor and its variants [6-14], revolving vane expander  and cross-vane mechanism for expander-compressor unit . The revolving vane compressor had won the World Best Technology Showcase, in Arlington, Texas, USA in 2009 and it has licensed to a Japanese compressor company for air-conditioning applications in automobile and private boats sectors, while the patent of the piezo compressor has sold to another Japanese compressor company. In this paper the working principles of each of these innovations, their uniqueness, advantages and challenges in applications will be shown, analysed and discussed. *References* 1. Ooi, K.T., Simulation of a piezo-compressor, Applied Thermal Engineering, v 24, n 4, p 549-62, March 2004. 2. Piezo electric compressor. WO 2004/022/973 A1. International Intellectual Properties organisation (WIPO), international application published under Patent Corporation Treaty (PCT). 3. Piezo electric compressor with displacement amplifier. US 2006/0051232 A1. United State patent application publication, March 9, 2006. 4. Ooi K.T. (2003). A study of a sliding cam compressor. International conference on compressors and their systems IMechE, U.K. 5. Ooi K.T., Wan Thiam Teik. (2000). A Rotaprocating compressor. International compressor Engineering Conference at Purdue (pp. 769-776). 6. Revolving vane compressor, WO2008/004983 A1, Patent Corporation treaty, 10 Jan 2008 7. Revolving vane compressor, US8206140 B2, awarded United State patent, 26 Jun 2012 8. Revolving vane compressor and its method of manufacture, WIPO, PCT, WO2011087457A1, 27 Aug 2009. 9. Revolving vane compressor and its method of manufacture, US patent, 20100310401 A1, 9 Dec 2010. 10. Fixed vane assembly, WIPO, PCT, WO2011087457A1, 21 Jul 2011. 11. Revolving vane compressor, WIPO, PCT, WO2013036203A1, 14 March 2013 (Automotive and private boat applications) 12. Tan KM, Ooi, K T. (2014). Experimental study of fixed-vane revolving vane compressor. Applied Thermal Engineering, 62(1), 207-214. 13. Tan KM, Ooi K.T. (2011). A novel revolving vane compressor with a fixed-vane. International Journal of Refrigeration, 34(8), 1980-1988. 14. Tan K.M., Ooi K.T. (2011). Journal bearings design for a novel revolving vane compressor. International Journal of Refrigeration, 34(1), 94-104. 15. Subiantoro A., Ooi K.T. (2013). Experimental Investigation of the Revolving Vane (RV-I) Expander. Applied Thermal Engineering, 50(1), 393-400. 16. A vane mechanism, WIPO, PCT, WO/2013/162477A1, 21 July 2011.