Condensation of R134a outside single horizontal titanium, cupronickel (B10 and B30), stainless steel and copper tubes

Experimental investigation of force balance at vapour condensation on a cylindrical fin

“…Condensation HTC is evaluated from equation (4). Detailed description of the experimental procedures and data reduction algorithms can be found in the present papers of Fernandez-Seara et al [14] and Ji et al [15]. Such type of experiments provides an accuracy of about 15-25 % of the average heat transfer coefficient measurement.…”

Comparison of condensation and evaporation heat transfer on the outside of smooth and enhanced 1EHT tubes

“…Enhanced tubes studied in Chen [16] produce 6-10 times more heat transfer than a plain tube. Ji et al [17] studied horizontal, single tube condensing heat transfer using R134a on the outside of five different three dimensional, enhanced tubes. Additionally, condensation inundation of the tubes was also performed.…”

“…The current study found the same trend with refrigerants at low flowrates. Ji et al [17] used R134a to study condensing heat transfer on horizontal tubes with an enhanced surface structure. They performed an interesting comparison when they studied the performance of copper, titanium, cupronickel (B10 and B30), and stainless steel tubes.…”

“…They go on to conclude that for the same enhanced structure, the tube made from a high thermal conductivity has an appreciably higher condensation heat transfer coefficient (HTC) than the HTC of a tube made from a low thermal conductivity material. Conclusions from [17] state that lower fin efficiency (resulting in a lower condensation heat transfer coefficient) is a result of the low tube material thermal conductivity. Tubes made from a lower thermal conductivity material (with the same enhancement) may have a lower condensation heat transfer coefficient than similar tubes produced from a higher thermal conductivity material.…”

Enhancement of natural and forced convection condensation using three-dimensional extended structures

“…They determined that the reduction of fin efficiency was more evident in the low thermal conductivity brass and bronze tubes as compared to copper tubes. Ji et al [59] compared the heat transfer coefficients of tubes with the same fin structures but with different thermal conductivity materials in R134a refrigerant. They concluded that the enhanced copper tubes have better heat transfer performances than the enhanced tubes made from titanium, cupronickel and stainless steel that are of lower thermal conductivities.…”