Fayi Yan^*, Xuejian Pei, He Lu, Shuzhen Zong

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 287-304, 2024, DOI:10.32604/fhmt.2023.045038

Abstract As compact and efficient heat exchange equipment, helically coiled tube-in-tube heat exchangers (HCTT heat exchangers) are widely used in many industrial processes. However, the thermal-hydraulic research of liquefied natural gas (LNG) as the working fluid in HCTT heat exchangers is rarely reported. In this paper, the characteristics of HCTT heat exchangers, in which LNG flows in the inner tube and ethylene glycol-water solution flows in the outer tube, are studied by numerical simulations. The influences of heat transfer characteristics and pressure drops of the HCTT heat transfers are studied by changing the initial flow velocity, the helical middle diameter, and… More >

D. S. Martínez^†, J. P. Solano, J. Pérez, A. Viedma

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-10, 2011, DOI:10.5098/hmt.v2.3.3002

Abstract Non-Newtonian flow and heat transfer in tubes of heat exchangers with reciprocating insert devices have been numerically investigated. The heat exchanger is mechanically assisted by a reciprocating cylinder, which moves the scraping rods inserted in the tubes. An array of semi-circular elements is mounted on each rod, with a pitch p=5D. These elements fit the internal diameter of the tubes. During the reciprocating motion, they scrape the inner tube wall, avoiding fouling. Additionally, the movement of the inserted device generates macroscopic displacements of the flow, which continuously mix core regions with peripheral flow. A power law model with temperature dependent… More >

P. V. Ramana, Arunn Narasimhan^*, Dhiman Chatterjee

Frontiers in Heat and Mass Transfer, Vol.3, No.2, pp. 1-6, 2012, DOI:10.5098/hmt.v3.2.3007

Abstract The present experimental study investigates the effect of tube-to-tube porous interconnectors on the pressure drop and heat transfer (Nu) of tube banks. A copper wire mesh porous medium connects successive tubes of the in-line and staggered arrangement of six rows of tubes. The tubes are subjected to constant and uniform heat flux and cooled by forced convection using water as a cooling fluid in the laminar flow range (100 < ReDuct < 625). The inline configuration with the tube-to-tube porous medium inter-connectors provides marginal enhancement of heat transfer and 12% reduction in the pressure drop penalty respectively, compared to tube… More >

Weiting Jiang^1,*, Lei Zhao^1,*, Chongyang Wang², Tingni He¹, Weiguo Pan¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2597-2611, 2023, DOI:10.32604/fdmp.2023.027504

Abstract When a brazed plate heat exchanger is used as an evaporator, the working mass in the channel may undergo solidification, thereby hindering the refrigeration cycle. In this study the liquid solidification process and its optimization in a brazed plate heat exchanger are investigated numerically for different inlet velocities; moreover, different levels of corrugation are considered. The results indicate that solidification first occurs around the contacts, followed by the area behind the contacts. It is also shown that dead flow zones exist in the sharp areas and such areas are prone to liquid solidification. After optimization, the solidification area attains its… More >

Ravi Datt^a,b , Anil Kumar^c,*, Mangal Singh Bhist^d , Alok Darshan Kothiyal^e , Rajesh Maithani^f

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-19, 2019, DOI:10.5098/hmt.12.26

Abstract This work presents a review of the research recent results concerning the augmentation of hydrodynamic and thermal performance of various twisted tape inserts in heat exchanger tubes. The thermal and hydrodynamic correlations for various twisted tape elements have been summarized. A comparative study of thermal and hydrodynamic performance of numerous twisted elements has also been reported to understand the result of applications of twisted tape inserts in heat exchanger tubes. The literature review found that multiple twisted tapes heat exchanger tube shape enhanced hydrodynamic and thermal performance than other comparable twisted tape inserts heat exchanger tube shapes. The review of… More >

Ida Bagus Alit, I Gede Bawa Susana^*

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-7, 2021, DOI:10.5098/hmt.17.15

Abstract Rice husk is a cheap fuel source and it is abundantly available in Indonesia. The heat exchanger mechanism was used in other to, the dried material was not contaminated by the combustion gases. The drying system consists of three components which include the furnace, heat exchanger pipe, and drying chamber. The heat exchanger pipe connects the furnace with the drying chamber and transfers the heat generated from rice husk burning to the drying chamber. The drying chamber was the section for drying the jackfruit dodol. It consists of 4 shelves and is equipped with an exhaust fan. The results showed… More >

Vikas Gulia, Anirban Sur^*

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-10, 2022, DOI:10.5098/hmt.18.40

Abstract Over the past few decades, the world is moving towards miniature products owing to the technological developments in variegated industrial domains such as aerospace, biomedical, electronics, etc. This has led to the exponential growth of efficient micro cooling systems which are light in weight and have effective thermal performance. Microchannel Heat Sinks and Microchannel Heat Exchangers are the widely adopted solutions for such efficient micro cooling systems. This paper comprehensively reviews the recent developments in the field of Microchannel Heat Sinks and Microchannel Heat Exchangers. Initially, the concept of microchannel cooling is discussed. Further, a comprehensive review of materials, fabrication… More >

Scott Wahlquist^a, Amir Ali^a,b,*, Su-Jong Yoon^c, Piyush Sabharwall^c

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.35

Abstract The heat transfer performance of a novel tube configuration that combines the swirling velocity induced by oval-twisting and secondary flow generated by a helical geometrical flow path is presented. The Nusselt number (Nu) and friction factor (f) are compared for the laminar flow regime (Re = 250- 2000) under isothermal wall conditions. Under the same flow and boundary conditions, the oval-twisted helical tube increased the Nu and slightly increased the f over the circular helical tube. The best performance with the highest Nuand lowest f occurs at the coil curvature ratio (d_h/D) of 0.17. The quantified enhancement performance factor (h)… More >

Ida Bagus Alit, I Gede Bawa Susana^* , I Made Mara

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-7, 2022, DOI:10.5098/hmt.19.25

Abstract The study compared solar dryers with hot air from a heat exchanger double furnace during the drying of white turmeric. Solar drying is the process of drying the product in the sun. The hot air dryer consists of two furnaces with heat exchanger pipes and a drying chamber with six vertical shelves. During the test, the use of rice husk energy in a constant amount of 35 kg. Temperature and drying rate are higher in hot air dryers. Tests carried out for 420 minutes resulted in a change in moisture content from 88% to 35.88% and an average temperature of… More >

Peter van den Engel^1,*, Michael Malin², Nikhilesh Kodur Venkatesh¹, Luigi Antonio de Araujo Passos¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 783-805, 2023, DOI:10.32604/fdmp.2022.021962

Abstract This research evaluates the performance of a Phase Change Material (PCM) battery integrated into the climate system of a new transparent meeting center. The main research questions are: a. “Can the performance of the battery be calculated?” and b. “Can the battery reduce the heating and cooling energy demand in a significant way?” The first question is answered in this document. In order to be able to answer the second question, especially the way the heat loading in winter should be improved, then more research is necessary. In addition to the thermal battery, which consists of Phase Change Material plates,… More > Graphic Abstract