Submit to Energies Review for Energies Propose a Special Issue

Journal Browser

► Journal Browser

Enhanced Two-Phase Heat Transfer

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "J1: Heat and Mass Transfer".

Deadline for manuscript submissions: closed (31 December 2023) | Viewed by 9072

Share This Special Issue

Special Issue Editors

Dr. Iztok Golobič

E-Mail Website
Guest Editor

Department of Thermal and Process Engineering, Faculty of Mechanical Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia
Interests: thermal engineering; enhanced heat transfer; phase change; boiling; process engineering; process technology

Dr. Matic Može

E-Mail Website
Guest Editor

Department of Thermal and Process Engineering, Faculty of Mechanical Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia
Interests: heat transfer; phase change; boiling; enhanced heat transfer; surface functionalization; surface engineering; process engineering

Special Issue Information

Dear Colleagues,

With the constant progress in the development of systems requiring efficient cooling for safe operation, heat dissipation techniques also need to be improved to cope with increased thermal loads and heat fluxes. While natural and forced convection might have been the norm in the past, modern applications typically require more intense cooling solutions with heat transfer coefficients several orders of magnitudes above those achievable with single-phase processes. Consequently, two-phase heat transfer, relying on the utilization of the latent heat of vaporization, is currently being intensely researched to both increase the cooling capabilities and further our basic understanding of the associated phenomena.

Even though two-phase convection offers much-improved heat dissipation in comparison with single-phase cooling, some applications are already exceeding the natural limits of its heat transfer intensity. Therefore, many enhancement techniques have been proposed to further intensify heat removal and provide greater safety margins in critical applications. This Special Issue is aimed at exploring the topic of enhanced two-phase heat transfer and publishing the latest knowledge regarding the methods applicable to achieve heat transfer intensification. All papers dealing with the enhancement of heat transfer parameters in processes where two-phase heat transfer takes place will be considered. There include (but are not limited to) pool and flow boiling, dropwise and film condensation, spray cooling, mini-, micro- and nanochannels, heat pipes, and vapor chambers.

Dr. Iztok Golobič
Dr. Matic Može
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

enhanced heat transfer
phase change heat transfer
boiling
condensation
heat pipes
spray cooling

Published Papers (6 papers)

Download All Papers

Research

17 pages, 7135 KiB

Open AccessArticle

Experimental Analysis of an Innovative Electrical Battery Thermal Management System

by Luca Cattani, Matteo Malavasi, Fabio Bozzoli, Valerio D’Alessandro and Luca Giammichele

Energies 2023, 16(13), 5071; https://0-doi-org.brum.beds.ac.uk/10.3390/en16135071 - 30 Jun 2023

Cited by 3 | Viewed by 912

Abstract

The aim of the present work is to develop and test an innovative cooling system for the thermal management of batteries for electric vehicles (EVs). At present, the technology most used for electric propulsion is based on lithium-ion cells. The power supply unit must often deliver a large amount of power in a short time, forcing the batteries to produce a considerable amount of heat. This leads to a high working temperature that can cause a sharp decrease in the battery performance or even a malfunction. Moreover, their working outside of the prescribed temperature range (20–40 °C) or with a significant temperature gradient across the battery meaningfully accelerates their aging or breakage. In this case, a battery thermal management system (BTMS) is necessary to allow the batteries to work as efficiently as possible. In the present work, a pulsating heat pipe with a three-dimensional structure is proposed as cooling technology for a battery pack. At first the performance of the proposed PHP is evaluated in a dedicated experimental setup under different boundary conditions and a wide spectrum of power input values. Then the PHP is tested by applying, as load at the evaporator section, heat power distribution corresponding to three different discharging processes of a battery. These tests, directly referring to an applicative case, show that the proposed 3D PHP has an optimal cooling ability and the possibility to offer a powerful solution for electrical battery thermal management. Full article

(This article belongs to the Special Issue Enhanced Two-Phase Heat Transfer)

► Show Figures

Figure 1

15 pages, 2186 KiB

Open AccessArticle

A Modified Correlative Model for Condensation Heat Transfer in Horizontal Enhanced Tubes with R32 and R410A Refrigerants

by Gangan Zhang, Dehui Du, Le Zhang, Yanlong Xiang, Wei Li, Jiapei Zhang, Jincai Du and David J. Kukulka

Energies 2023, 16(13), 4883; https://0-doi-org.brum.beds.ac.uk/10.3390/en16134883 - 22 Jun 2023

Viewed by 883

Abstract

An experimental study was performed that compared tube side condensation heat transfer characteristics of enhanced tubes (hydrophobic surface tubes (HYD), herringbone micro fin tube (HB), and a composite hydrophobic/herringbone (micro fin) tube (HYD/HB)) to the performance of a smooth tube (ST). The condensation heat transfer coefficient (HTC) was calculated from data that were recorded for smooth and enhanced tubes that had an outer diameter (OD) of 12.7 mm. Data were collected (as a function of mass flow rate) using a couple of refrigerants (R410A and R32), for saturated temperatures of 35 °C and 45 °C, with vapor qualities that ranged from 0.8 to 0.2. Several previously reported smooth tube HTC models were used to calculate values that could be compared to experimentally obtained HTC values. The correlation model that demonstrated the best accuracy (for the conditions considered) was then modified for use with the enhanced tubes from this study. Results from the modified correlation show differences with experimental values that ranged from −10% to +17%; the new modified correlation demonstrates high prediction accuracy. An accurate correlation allows the evaluation of enhanced heat transfer tubes for use in high-efficiency heat exchanger systems. The development of this new model is significant in the study of enhanced heat transfer. Full article

(This article belongs to the Special Issue Enhanced Two-Phase Heat Transfer)

► Show Figures

Figure 1

19 pages, 9744 KiB

Open AccessArticle

Revisiting the Corresponding-States-Based Correlation for Pool Boiling Critical Heat Flux

by Matic Može, Matevž Zupančič, Ivan Sedmak, Klemen Ferjančič, Henrik Gjerkeš and Iztok Golobič

Energies 2022, 15(10), 3524; https://0-doi-org.brum.beds.ac.uk/10.3390/en15103524 - 11 May 2022

Cited by 3 | Viewed by 1564

Abstract

A corresponding-states correlation for predicting the critical heat flux (CHF) in pool boiling conditions is proposed, and only requires knowledge of physical property constants of the fluid at any fluid temperature: molar mass, critical temperature, critical pressure, and the Pitzer acentric factor. If a fourth corresponding equation of state (EoS) parameter is added, a more accurate CHF correlation is obtained and matches Kutateladze–Zuber prediction within ±10% in the reduced temperature range of 0.55–0.95. This way, CHF can be easily predicted for any reduced temperature within the range of correlation’s validity by only knowing basic properties of the fluid. Additionally, two corresponding-states correlations for determining the capillary length are proposed and also do not rely on any temperature- and pressure-dependent fluid properties. A simpler correlation only using the Pitzer acentric factor is shown to be imprecise, and a more complex correlation also accounting for the fourth corresponding EoS parameter is recommended. These correlations are fundamental for further developments, which would allow for accurate prediction of CHF values on functionalized surfaces through further studies on the influence of interactions of fluid properties with other parameters, such as wetting and active nucleation site density. Full article

(This article belongs to the Special Issue Enhanced Two-Phase Heat Transfer)

► Show Figures

Graphical abstract

14 pages, 2515 KiB

Open AccessArticle

Machine Learning for Prediction of Heat Pipe Effectiveness

by Anish Nair, Ramkumar P., Sivasubramanian Mahadevan, Chander Prakash, Saurav Dixit, Gunasekaran Murali, Nikolai Ivanovich Vatin, Kirill Epifantsev and Kaushal Kumar

Energies 2022, 15(9), 3276; https://0-doi-org.brum.beds.ac.uk/10.3390/en15093276 - 29 Apr 2022

Cited by 14 | Viewed by 1928

Abstract

This paper details the selection of machine learning models for predicting the effectiveness of a heat pipe system in a concentric tube exchanger. Heat exchanger experiments with methanol as the working fluid were conducted. The value of the angle varied from 0° to 90°, values of temperature varied from 50 °C to 70 °C, and the flow rate varied from 40 to 120 litres per min. Multiple experiments were conducted at different combinations of the input parameters and the effectiveness was measured for each trial. Multiple machine learning algorithms were taken into consideration for prediction. Experimental data were divided into subsets and the performance of the machine learning model was analysed for each of the subsets. For the overall analysis, which included all the three parameters, the random forest algorithm returned the best results with a mean average error of 1.176 and root-mean-square-error of 1.542. Full article

(This article belongs to the Special Issue Enhanced Two-Phase Heat Transfer)

► Show Figures

Figure 1

12 pages, 4694 KiB

Open AccessArticle

Experimental Analysis of Flow Boiling in Horizontal Annulus—The Effect of Heat Flux on Bubble Size Distributions

by Boštjan Zajec, Leon Cizelj and Boštjan Končar

Energies 2022, 15(6), 2187; https://0-doi-org.brum.beds.ac.uk/10.3390/en15062187 - 17 Mar 2022

Cited by 3 | Viewed by 1487

Abstract

Subcooled flow boiling was experimentally investigated in a horizontal annulus with a temperature-controlled boiling surface and transparent outer pipe facilitating visualization. Boiling occurs on a copper tube with a diameter of 12 mm in an annulus with a 2 mm gap. Refrigerant R245fa is used as a working fluid. The focus of this study is to explore the effect of heat flux variation on the boiling flow patterns at approximately constant inlet flow conditions of the working fluid (fixed mass flux and inlet fluid temperature). Subcooled flow boiling is recorded by a high-speed camera, images are analyzed by a neural network to determine the bubble size distributions and their variation with the heat flux. The experimental setup being a part of the laboratory THELMA (Thermal Hydraulics experimental Laboratory for Multiphase Applications) at the Reactor Engineering Division of Jožef Stefan Institute, analysis methods and measurement results are presented and discussed. Full article

(This article belongs to the Special Issue Enhanced Two-Phase Heat Transfer)

► Show Figures

Figure 1

16 pages, 8123 KiB

Open AccessArticle

Heat Exchanging Grid Structures Based on Laser-Based Powder Bed Fusion: Formation Process and Boiling Heat Transfer Performance

by Bo Qian, Hongri Fan, Jianrui Zhang, Gang Liu and Pei Li

Energies 2022, 15(5), 1779; https://0-doi-org.brum.beds.ac.uk/10.3390/en15051779 - 28 Feb 2022

Cited by 1 | Viewed by 1363

Abstract

Microchannel structures possess high efficiency and high boiling heat transfer coefficient of two-phase flow. In particular, the grid structure has the advantages of a simple pattern, large load capacity, and good surface adaptability. Employing the laser-based powder bed fusion (L-PBF) manufacturing technology, a new method of forming heat transfer grids with a controllable structure is proposed in this study. The formation principle, process, and the reasons for improvements in the boiling heat transfer performance were investigated with stainless steel materials. Laser scanning with varying scan spacings was used to prepare multiple structures with different grid widths and wall heights. On this basis, the porosity and pore morphology of the grid structures were analyzed, followed by pool boiling heat transfer experiments. The results revealed that the grid structure significantly affected the nucleate boiling behavior and increased the critical heat flux (CHF). It was found that the 0.5 mm sample exhibited optimum critical heat transfer performance, with an improvement of 10–27% compared to those of the other four samples (minimum of 63.3 W·cm⁻² and maximum of 93.9 W·cm⁻²). In addition, for samples with a grid width greater than 0.5 mm, the boiling slightly decreased by <5%. When the grid width was further increased, the flow resistance effect and the bubble synapse generation effect tended to converge. In these cases, boiling heat transfer only occurred in a single phase along the direction of the medium wall thickness, thus failing to achieve two-phase heat transfer through bubble growth and collapse. Full article

(This article belongs to the Special Issue Enhanced Two-Phase Heat Transfer)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Enhanced Two-Phase Heat Transfer

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (6 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI