EXPERIMENTAL INVESTIGATION OF HEAT TRANSFER ENHANCEMENT IN TUBE IN TUBE HEAT EXCHANGER WITH PERFORATED TWISTED TAPES

Abstract: This article reports an experimental investigation on heat transfer and pressure drop characteristics of turbulent flow in a heating tube equipped with perforated twisted tapes for Reynolds flow rate 1 to 8 LPM. The parameters investigated were the hole diameter ratio (d/W = 0.2, 0.4 and 0.6) and depth ratio (w/W = y/w=2.5, 3.5 and 4.5). A typical twisted tape was also tested for an assessment. Compared to the plain tube, the tubes with TT and PTT heat transfer enhancement up to 168% and 226%, respectively. The evaluation of overall performance under the same pumping power reveal that the PTT with d/W = 0.4 and y/W = 4.5, gave the maximum thermal performance factor of 1.62, as compare to plain tube.

Keywords: Twisted Tapes, Perforated Twisted Tapes, Performance Criteria, Friction Factor.