Film Condensation of Refrigerant-113 and Ethanediol on a Horizontal Tube—Effect of Vapor Velocity

Abstract

Heat transfer measurements are reported for condensation of refrigerant-113 and ethanediol (ethylene glycol) on a single horizontal tube with vertical downflow. For refrigerant-113, vapor velocities up to around 6 m/s were obtained, while for ethanediol, velocities in excess of 100 m/s were obtained at low pressure. The results are compared with those of earlier investigators and with theory.

Thermodynamic optimization of free convection film condensation on a horizontal elliptical tube with variable wall temperature

“…Here, the non-isothermality function is adopted from the experiment of Lee et al [21] for circular tube. Note that 0 6 A 6 1 and the amplitude A largely depends on the ratio of the outside-to-inside heat-transfer coefficients.…”

Turbulent Film Condensation of Pure Vapors Flowing Normal to A Horizontal Condenser Tube - Constant Heat Flux at the Tube Wall

“…The external flow of vapour creates interfacial shear which may enhance the condensation heat transfer coefficient, depending on the direction of flow of vapour. Some important investigations on the external flow of vapour over the condenser tube have been made by several researchers (Shekariladge and Gomeluri, 1966;Fujji et al, 1979;Lee et al, 1984;Memory et al, 1993;and Michael et al, 1989). These investigators were primarily concerned with the estimation of condensation heat transfer coefficients under isothermal conditions of the tube wall.…”

The effect of liquid inundation, vapor shear, and non-condensible gases on the condensation of refrigerants HFC-134a and HCFC-123

“…(2.27) (jr and '77«/ Equation 2.26 satisfies the limiting cases for both large and small vapor velocities and was found by Lee and Rose (1984) to give reasonable results to existing data. At values of G greater than 5 (infinite condensation rate), Equation 2.26 almost duplicates the solutions found using Equation 2.24.…”

“…Both Honda et al (1982) and Lee and Rose (1984) found that these theories tended to overpredict the experimental Nu values for steam at relatively high vapor velocities and underpredict them for CFC-113 data taken at moderate velocities. Noting these discrepencies.…”

“…At values of G greater than 5 (infinite condensation rate), Equation 2.26 almost duplicates the solutions found using Equation 2.24. In the more practical range where G is less than 1.0, Lee and Rose (1984) state that the differences between Equations 2.24 and 2.26 are of the magnitude typical of unceilainties in experimental data. Equations 2.24 and 2.26 do not consider separation, which at high vapor velocities will occur between 82 and 180 degrees from the stagnation point of the tube.…”