Predictive Equation Proposal for Condensation Heat Transfer Coefficient of Pure Refrigerants in Horizontal Micro-Fin Tubes.

Condensation Heat Transfer of Pure Refrigerants in Microfin Tubes

Experimental Investigation of the Condensation Heat Transfer Coefficient of R134a inside Horizontal Smooth and Micro-Fin Tubes

The condensation heat transfer coefficient of R134a was experimentally studied inside two smooth and four micro-fin tubes. The working conditions and structural parameters of the test tubes were selected as the influencing factors, and the experiment was conducted under mass velocities of 400–1100 kg·m−2·s−1, condensation temperatures of 35–45 ◦C and water-testing Reynolds numbers of 8000–22,00...

Experiments on Flow Boiling Heat Transfer of Pure CO2 and CO2-Oil Mixtures in Horizontal Smooth and Micro-Fin Tubes

Experiments on the flow boiling heat transfer of almost pure CO2 and CO2-oil mixtures in horizontal smooth and micro-fin tubes have been carried out. The smooth tube is a stainless steel tube with an inside diameter of 3mm, and the micro-fin tube is a copper tube with a mean inside diameter of 3.04mm. Experiments were carried out at mass velocities from 190 to 1300kg/(ms), saturation temperatur...

Analysis of variance of nanofluid heat transfer data for forced convection in horizontal spirally coiled tubes

In the present study, an experimental study is carried out to investigate the effect of adding Al and Cu nanoparticles to the base fluid (water) on the heat transfer rate in a spirally coiled tube. The spirally coiled tube is fabricated from the straight copper tube with the inner and outer coil diameters of 100 and 420 mm, respectively. The experiments have been done for water and two types of...

Optimized heat transfer correlations for pure and blended refrigerants

Refrigerant blends and pure refrigerants have wide applicability in thermal engineering. One of the critical parameters in the design and evaluation of thermal equipment is the heat transfer coefficient, which can be difficult to determine for refrigerants that undergo phase change within the equipment. For pure refrigerants, classical experimental relations developed by Gungor and Winterton (G...