The Characteristics of Flow Boiling Heat Transfer and Pressure Drop in Small Tube with the Pipe Sections Having Increased Diameters

Abstract:

This study presents an experimental investigation of the characteristics of the flow boiling heat transfer and pressure drop for refrigerant of R134a flowing in a small - diameter evaporative tube with the pipe sections having increased diameters. The experiments were performed at the saturation temperature of 5°C , heat flux of 5.12 ~ 10.96 ( KW/m²), mass flux of 200~600 ( kg/m²s), different length-to-diameter ratios of the test tubes and refrigerant quality of 0.07~0.78, and based on the same surface area of heat transfer. The enhancement performance ratios, θa/s for the tubes with the pipe sections having increased diameters relative to the smooth tube are higher than 1 (about 1.01~1.10). It means that the augmented tubes show the better overall performance than the smooth tube under study.

• Periodical: Advanced Materials Research (Volume 651)
• Pages: 525-529
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.651.525
• Online since: January 2013
• Authors: Mao Yu Wen, Kang Jang Jang
• Keywords: Evaporative Tube with Different Diameters, Flow Boiling, Heat Transfer Coefficient (HTC), Pressure Drop

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