Experimental study of exergetic performance of Al₂O₃ nanofluid in a double‐pipe heat exchanger fitted by a new modified twisted tape

Abstract

The use of nanofluids and surface enhancers today are among the new technologies used to increase heat transfer. In this study, heat transfer phenomena in heat exchanger were investigated using Al2O3 nanoparticles and modified spiral band as flow turbulator. Results are verified with well‐known correlations. The results show that the tube with cross‐hollow twisted tape inserts has the best exergetic performance for different hollow widths of the tape. Clearance, which is defined as the width between the tube and twisted tape, also affects the heat transfer performance. The smaller the clearance, the better is the exergetic performance. The tube can achieve the best exergetic performance when the number of unilateral twisted tapes is four. The results showed that increasing nanofluid concentration improves exergetic performance.

Experimental investigation of heat transfer enhancement in a double pipe heat exchanger with a twisted inner pipe

“…Through passive methods, DPHEs have received many attempts to maximize the heat transfer rates and keep the losses in pressure as minimum as possible. Surveying the literature, heat transfer rate, through passive methods, could be improved either by inserting objects into the inner tube of the DPHE, which may include twisted tapes, coils, fins, using nanofluids combined with turbulators, 5 or changing the shape of the inner tubes which mainly this study concentrates on. More details for the first techniques are given in References [6,7].…”