Dryout Characteristics of R134a in a Vertical Minichannel
Pages : 36-42
From safety and efficiency point of view all practical devices should be operated below their associated critical limits. Deteriorated heat transfer alongwith burnout of the test section is the major penalty for moving beyond these limits. This article reports experimental finding on dryout of R134a in a resistively heated, smooth vertical stainless steel minichannel (1.6mm inside diameter and 245 mm heated length). Experiments were conducted at 27 & 32 oC saturation temperature with 100-500 kg/m2s mass flux and till dryout conditions. Results for mass flux, vapor quality and system pressure are discussed in detail. Experimental findings were compared with various macro and micro scale correlations from the literature, this comparison revealed Wu’s correlation (Z. Wu et al, 2011) as the most accurate one for predicting dryout heat flux for R134a in small channels.
Key words: Correlation, Dryout, Minichannel, R134a
Article published in International Journal of Thermal Technologies, Vol.3, No.2 (June- 2013)