Experimental studies on heat transfer performance of a heat exchanger with drilled twisted tape inserts

Abstract Heat exchangers are vital components in various systems where the crucial process of heat exchange takes place. This process typically occurs across the copper wall of a tube, facilitating the transfer of thermal energy between fluids. However, the efficiency of this heat exchange is fundamentally limited by the geometry of the components of the heat exchanger. To enhance the performance and efficiency it is necessary to increase the rate of heat transfer. By optimizing this process, industries can achieve better energy efficiency, reduced operational costs, and improved system reliability. In the present study experimental study of the heat exchanger was accomplished using the drilled twisted tapes. A simple copper tube was equipped with inserts of twist ratios 2.5, 3.33, and 5.0. Additionally, both a classic type insert and a perforated type insert with perforation diameters of 5 mm and 8 mm were fitted inside the copper tube for experimental testing, analysis, and comparison with the heat exchanger without inserts. Overall, the study confirmed that both the classic twisted and perforated inserts can substantially improve heat exchanger performance, with larger perforations being especially effective in optimizing heat transfer. No single combination of the twist ratio and perforation diameter for an insert demonstrated the highest thermal performance factor across all the Reynolds number values. The heat exchanger with an insert featuring a twist ratio of 2.5 and a perforation diameter of 8 mm exhibited a high thermal performance factor in the lower Reynolds number range. In contrast, an insert with a twist ratio of 3.3 and a perforation diameter of 5 mm showed a high thermal performance factor in the higher Reynolds number range. The highest thermal performance factor recorded was 2.37 for the insert with a twist ratio of 2.5 and a perforation diameter of 8 mm.