부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ijrefrig.2009.01.015 Byline: Masafumi Nakagawa (a), Menandro Serrano Berana (a)(b), Akinori Kishine (c) Abstract: CO.sub.2 is environmentally friendly, safe and more suitable to ejector refrigeration cycle than to vapor compression cycle. Supersonic two-phase flow of CO.sub.2 in the diverging sections of rectangular converging-diverging nozzles was investigated. The divergence angles with significant variation of decompression were 0.076[degrees], 0.153[degrees], 0.306[degrees] and 0.612[degrees]. This paper presents experimental decompression phenomena which can be used in designing nozzles and an assessment of Isentropic Homogeneous Equilibrium (IHE). Inlet conditions around 6-9MPa, 20-37[degrees]C were used to resemble ejector nozzles of coolers and heat pumps. For inlet temperature around 37[degrees]C, throat decompression boiling from the saturated liquid line, supersonic decompression and IHE solution were obtained for the two large divergence angles. For divergence angles larger than 0.306[degrees], decompression curves for inlet temperature above 35[degrees]C approached IHE curves. For divergence angles smaller than 0.306[degrees] or for nozzles with inlet temperature below 35[degrees]C, IHE had no solution. Author Affiliation: (a) Department of Mechanical and Structural System Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi City, Aichi 441-8580, Japan (b) Department of Mechanical Engineering, University of the Philippines, Diliman, Quezon City 1101, Philippines (c) Machine Tool Division, Murata Machinery, Ltd., 2 Nakajima, Hashizume, Inuyama City, Aichi 484-8502, Japan Article History: Received 27 July 2008; Revised 15 January 2009; Accepted 19 January 2009