Fayi Yan^*, He Lu, Shijie Feng

Frontiers in Heat and Mass Transfer, Vol.22, No.5, pp. 1493-1514, 2024, DOI:10.32604/fhmt.2024.055324 - 30 October 2024

Abstract Helically coiled tube-in-tube (HCTT) heat exchangers are widely applied to the process technology because of their compactness and higher heat transfer efficiency. HCTT heat exchangers play an important role in liquified natural gas (LNG) use and cold energy recovery. The heat transfer characteristics, pressure distribution, and degree of vaporization of LNG in HCTT heat exchangers are numerically investigated. By comparing the simulation results of the computational model with existing experimental results, the effectiveness of the computational model is verified. The numerical simulation results show the vapor volume fraction of the HCTT heat exchanger is related… More >

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 - 21 March 2024

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,… 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 - 25 June 2023

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, 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 - 29 September 2022

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… More > Graphic Abstract

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 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 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%… More >

Zhaiyk Tokhtarov^1,*, Vitaly Perov², Vitaly Borisov³, Evgeny Tikhomirov⁴, Olga Grunina⁵, Nadezhda Kapustina^5,6, Elmira Cherkasova⁷, Natalya Suray⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.4, pp. 1015-1024, 2022, DOI:10.32604/fdmp.2022.019534 - 06 April 2022

Abstract After conducting a critical survey of the different categories of existing heat exchangers, the results of several experiments about the behaviour of a two-phase current in an open channel are reported. The results confirm the complexity of the problems induced in heat exchangers by flow maldistribution, especially when two-phase flows are considered in multi-channel systems. It is shown that severe misalignment of heat exchangers can lead to a loss of economic performance of more than 25%. Improper distribution of fluid flow causes longer fluid coils to form, and the liquid cochlea can eventually occupy a 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 More >

Fenwicks Shombe Musonye^1,*, Hiram Ndiritu², Robert Kinyua³

Energy Engineering, Vol.118, No.2, pp. 211-224, 2021, DOI:10.32604/EE.2021.013890 - 23 December 2020

Abstract Pinch Analysis is an attractive solution for reduction of thermal energy costs in thermo-chemical industries. In this approach, maximum internally recoverable heat is determined and a heat exchange network is designed to meet the recovery targets. The thermal performance of a heat exchanger over its lifetime is however a concern to industries. Thermal performance of a heat exchanger is affected by many factors which include the physical properties of the shell and tube materials, and the chemical properties of the heat transfer fluid. In this study, thermal performance of shell and tube heat exchangers designed… More >