Experimental analysis for the determination of the convective heat transfer coefficient by measuring pressure drop directly during annular condensation flow of R134a in a vertical smooth tube.

Author(s) : DALKILIC A. S., TEKE I., WONGWISES S.

Type of article: Article

Summary

This study investigated the direct relationship between the measured condensation pressure drop and convective heat transfer coefficient of R134a flowing downward inside a vertical smooth copper tube having an inner diameter of 8.1 mm and a length of 500 mm during annular flow. R134a and water were used as working fluids on the tube side and annular side of a double tube heat exchanger, respectively. Condensation experiments were performed at mass fluxes of 260, 300, 340, 400, 456 and 515 kg m-2 s-1 in the high mass flux region of R134a. The condensing temperatures were around 40 and 50°C; the heat fluxes were between 10.16 and 66.61 kW m-2. Paliwoda’s analysis, which focused mainly on the determination of the two-phase flow factor and two-phase length of evaporators and condensers, was adapted to the in-tube condensation phenomena in the test section to determine the condensation heat transfer coefficient, heat flux, two-phase length and pressure drop experimentally by means of a large number of data points obtained under various experimental conditions.

Details

  • Original title: Experimental analysis for the determination of the convective heat transfer coefficient by measuring pressure drop directly during annular condensation flow of R134a in a vertical smooth tube.
  • Record ID : 30001169
  • Languages: English
  • Source: International Journal of Heat and Mass Transfer - vol. 54 - n. 4
  • Publication date: 2011/01
  • DOI: http://dx.doi.org/10.1016/j.ijheatmasstransfer.2010.06.057

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