The current situation of the study on twisted tape inserts in pipe exchangers

Abstract

Heat transfer enhancement is used in many applications including heat exchangers, air conditioning, and refrigeration systems; hence many researchers have conducted experimental and numerical researches on heat transfer enhancement and have developed various techniques and methods. As a passive heat transfer technique, twisted tapes are widely used in various industries for their cost savings, lower maintenance requirements and the fact that they are easily set up. This paper introduces the principle of heat transfer enhancement of twisted tapes and reviews some of the experimental works done by researchers on this technique in recent years. The variously modified twisted tape inserts are widely researched and used to enhance heat transfer efficiency for heat exchangers. Twisted tapes perform better in low Re conditions and in square tubes. However, they could also cause higher pressure drops. Twisted tapes have great potential and profound implications if they can be used in traditional heat exchangers. Besides this, some correlations between the Nusselt number and friction factors are presented in this paper.

Heat transfer and pressure drop characteristics of alternating clockwise and counter clockwise twisted tape inserts in the transitional flow regime

“…A comprehensive literature review on twisted tape inserts indicated that previous studies concentrated mainly on the laminar flow regime for Reynolds numbers between 13 and 3 000 [2,5,15,[37][38][39][40][41][42][43][44][45] or the turbulent flow regime for Reynolds numbers greater than 3 000 [4,29,33,[46][47][48][49][50][51] and not specifically on the transitional flow regime [52][53][54][55]. Up to now, only Wongcharee and Eiamsa-ard [15] (in the laminar flow regime) and Eiamsa-ard and Promvonge [4] (in the turbulent flow regime), considered alternating clockwise and counter clockwise twisted tape (CCCTT)…”

Impact of hyperbolic-cut twisted tape on heat transfer, friction factor and thermohydraulic performance of heat exchanger tube: an experimental study using Internet of Things (IoT) approach

“…Heat exchange tube processes are indispensable in numerous sectors: heating & cooling, refrigeration, automobile radiators, winery, food processing, pharmaceuticals, Petrochemicals, chemicals, oil, steel, agriculture, and manufacturing [1]. Proficient and optimal thermal energy transfer is paramount for the production, preservation, and conveyance of diverse goods.…”

The influence of peripheral u-cut twisted tapes and ring inserts on the heat transfer and pressure drop characteristics in the transitional flow regime

“…A comprehensive literature review on twisted tape inserts indicated that previous studies concentrated mainly on the laminar flow regime for Reynolds numbers between 13 and 3 000 [2,5,15,[37][38][39][40][41][42][43][44][45] or the turbulent flow regime for Reynolds numbers greater than 3 000 [4,29,33,[46][47][48][49][50][51] and not specifically on the transitional flow regime [52][53][54][55]. Up to now, only Wongcharee and Eiamsa-ard [15] (in the laminar flow regime) and Eiamsa-ard and Promvonge [4] (in the turbulent flow regime), considered alternating clockwise and counter clockwise twisted tape (CCCTT) inserts.…”