Effect of wire coil inserts on heat transfer enhancement and fluid flow characteristics of a double-pipe heat exchanger

The need to reduce energy usage is one of the main issues with creating heat exchangers. This may be accomplished by increasing the heat transfer augmentation which results in the higher thermal performance factor (TPF). The aim of the present study is to experimentally determine the thermal hydraulic performance factor of DPHE with a novel wire coil insert. The experiments were performed in the range of Reynolds number (Re): 5500-15000, and the data were recorded for fifteen different combinations of wire coil (WC) inserts, including five different pitch ratios (P/Dc = 0.625, 1.25, 1.875, 2.5 and 3.125) and three wire diameters (d = 1, 1.5 and 2 mm). The application of WC inserts results in notable enhancement in heat transfer rate as compared to different TT. For the given range of Re, the heat transfer performance was improved to a maximum of 126.7% for pitch ratio (PR) P/Dc = 0.625 at wire diameter (d = 2 mm), while friction was recorded in the range of 2.67-4.71 times higher compared to PT. The TPF (eta) with WC inserts for all combination was recorded greater than unity. The maximum value of TPF (eta) obtained for wire coil inserts is 1.35 with PR (P/Dc = 0.625) and (d = 2 mm). Since TPF(eta) in all cases is greater than 1.0 which shows that it is an effective approach.