학술논문
Supersonic two-phase flow of CO2 through converging–diverging nozzles for the ejector refrigeration cycle
Document Type
Article
Source
Subject
*CARBON dioxide
*TWO-phase flow
*EJECTOR pumps
*THERMODYNAMIC cycles
*SUPERSONIC nozzles
*ISENTROPIC expansion
*REFRIGERATION & refrigerating machinery
*PHYSICS experiments
*THERMAL properties
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Language
ISSN
0140-7007
Abstract
Abstract: CO2 is environmentally friendly, safe and more suitable to ejector refrigeration cycle than to vapor compression cycle. Supersonic two-phase flow of CO2 in the diverging sections of rectangular converging–diverging nozzles was investigated. The divergence angles with significant variation of decompression were 0.076°, 0.153°, 0.306° and 0.612°. 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°C were used to resemble ejector nozzles of coolers and heat pumps. For inlet temperature around 37°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°, decompression curves for inlet temperature above 35°C approached IHE curves. For divergence angles smaller than 0.306° or for nozzles with inlet temperature below 35°C, IHE had no solution. [Copyright &y& Elsevier]