Convective boiling of halocarbon refrigerants flowing in a horizontal copper tube – an experimental study

TL;DR: In this article, the subcooled flow boiling heat transfer coefficient of pure n-heptane and distilled water at different operating conditions have been experimentally measured and compared, and it was shown that water is better cooling fluid in comparison with n-hexane.

TL;DR: In this paper, the authors present new flow boiling heat transfer results of R-134a flowing inside a 13.84 mm internal diameter, smooth horizontal copper tube, and the experimental results clearly show that a local minimum heat transfer coefficient systematically occurs within slug flow pattern or near the slug-to-intermittent flow pattern transition.

TL;DR: In this article, the pressure drop of refrigerant R-134a under convective boiling conditions in horizontal smooth and microfinned (grooved) copper tubes was investigated in an experimental set up developed for change of phase studies with a test section made out of 7.0, 7.93, and 9.52 mm external diameter, 1.5 m long copper tubes.

TL;DR: In this article, the experimental results clearly show that the heat transfer coefficients of R134a are always higher than those pertaining to R22 (from a minimum of +6 to a maximum of +45%).

TL;DR: In this paper, the basic models of two-phase flow are discussed and empirical treatments of two phase flow are provided. But the authors focus on convective boiling and condensing.

TL;DR: In this article, a new general correlation for forced convection boiling has been developed with the aid of a large data bank consisting of over 4300 data points for water, refrigerants and ethylene glycol, covering seven fluids and 28 authors.