Review of insertion scenarios in enhancement performance of double-pipe heat exchanger: Case of cut twist tape

• Double-pipe heat exchangers background: design and configurations, thermal enhancement methods and performance parameters. • A focused literature review of studies that use cut twisted tape inserts as a passive method of enhancing performance of double-pipe heat exchangers. • Analysis of cut twisted tape parameters affecting the hydrothermal performance of double-pipe heat exchanger. • Reducing the twist ratio and width ratio and increasing depth ratio enhances thermal performance but at the expense of hydraulic performance so it is necessary to determine TPF parameter. Double-Pipe Heat Exchanger (DPHX) is used in a wide range of applications including heating and cooling, chemical and food industries as well as a wide range of fields where heat transfer is necessary. This diversity of uses has made it a subject of wide interest to scholars and developers to enhance its performance. Due to ease of application and efficient, the insertion method is considered one of the important passive methods in enhancing the thermal performance of DPHX. This review is the first of its kind to survey and analyze studies that have enhanced DPHX thermal performance using cut Twist Tape (TT) inserts into the inner pipe. Several impact parameters were considered, most notably Twist Ratio (TR), Depth Ratio (DR), and Width Ratio (WR), as well as several performance parameters, most notably the Nusselt number (Nu), friction factor ( f ), and Thermal Performance Factor (TPF). The review results indicate that the thermal performance of DPHX is enhanced at the inserted of cut TT regardless of the difference of the cut geometries, especially with decrease TR and DR and increase WR, but with negative impact on hydraulic performance, which requires consideration of TPF and a wide range of Reynolds number ( Re ). Finally, most studies have shown that cut TT is superior in thermal performance enhancement over plain TT, and this enhancement can be increased when adding other techniques such as the use of nanofluid as heat transfer fluid. This review also provides recommendations that will document the gaps of the cut TT in order to future address.