Submit to Energies Review for Energies Propose a Special Issue

Journal Browser

► Journal Browser

Photo Thermal Conversion and Pool Boiling Heat Transfer of Nanofluid

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 "J: Thermal Management".

Deadline for manuscript submissions: closed (30 September 2022) | Viewed by 16385

Share This Special Issue

Special Issue Editor

Prof. Dr. Honghyun Cho

E-Mail Website
Guest Editor

Department of Mechanical Engineering, Chosun University, Gwangju, Korea
Interests: energy; thermal power; heat transfer; refrigerator cycle technologies

Special Issue Information

Dear Colleagues,

The Guest Editors invite you to submit a Special Issue of Energies on the subject “Photo Thermal Conversion and Pool Boiling Heat Transfer of Nanofluids”. As the importance of renewable energy for replacing fossil fuels has become an issue in the world, the efficient use of energy regarding thermal systems and equipment is required, and thus the use of nanofluids for the increase of efficiency and heat transfer is emphasized. Nanofluids are a major way to improve the poor thermal properties of conventional working fluids such as water, oil, and antifreeze solution. In addition, they can be used in heat energy application fields (especially light–thermal conversion and boiling heat transfer in PTC, CPC, the direct absorption solar heat-collection system, heat pipes, heat exchangers, etc.) because they improve various heat transfer modes such as convection, boiling, and photo-thermal conversion. We therefore invite papers on innovative technical developments, reviews, case studies, analytical papers, as well as assessment papers, from different disciplines, which are relevant to sustainable and renewable energy systems on the applications of nanofluids. The Special Issue will focus on but is not limited to the utilization of light absorption and the boiling heat transfer of various nanofluids.

Prof. Dr. Honghyun Cho
Guest Editor

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

nanofluids
photo-thermal conversion
optical absorption
solar collector
direct absorption solar collector
boiling heat transfer
solar energy
solar collection system
magnetic heat transfer improvement technology

Published Papers (7 papers)

Download All Papers

Research

Jump to: Review

16 pages, 2383 KiB

Open AccessArticle

Evaluation on the Performance of Automobile Engine Using Air Injection Nozzle in the Intake Manifold

by Taejung Kim, Yunchan Shin, Jungsoo Park and Honghyun Cho

Energies 2021, 14(24), 8555; https://0-doi-org.brum.beds.ac.uk/10.3390/en14248555 - 18 Dec 2021

Viewed by 1966

Abstract

In the present study, a nozzle was used to improve the flow performance of an intake manifold, and its effects on the automobile engine output and the exhaust gas were experimentally studied. It was found that the engine output of a vehicle with a mileage of 30,000 km increased by 4.7% and 6.5% when nozzles with diameters of 5 and 2.5 mm were used. In addition, the engine output of a vehicle with a mileage of 180,000 km increased by 3.3% and 13.3% when nozzles with diameters of 5 and 2.5 mm were used compared to those of the same vehicle when no nozzle was used. Thus, using a nozzle for the inflow of outside air created a uniform combustion environment to improve the engine output and reduce harmful exhaust gases, such as hydrocarbon, carbon monoxide, and nitrogen oxides, by generating vortexes inside the intake manifold and increasing the degree of mixing. Furthermore, the smaller nozzle with a diameter of 2.5 mm had greater effects. Full article

(This article belongs to the Special Issue Photo Thermal Conversion and Pool Boiling Heat Transfer of Nanofluid)

► Show Figures

Figure 1

17 pages, 4775 KiB

Open AccessArticle

Comprehensive Experimental Study on the Thermophysical Characteristics of DI Water Based Co_0.5Zn_0.5Fe₂O₄ Nanofluid for Solar Thermal Harvesting

by Tsogtbilegt Boldoo, Jeonggyun Ham and Honghyun Cho

Energies 2020, 13(23), 6218; https://0-doi-org.brum.beds.ac.uk/10.3390/en13236218 - 26 Nov 2020

Cited by 7 | Viewed by 1705

Abstract

The thermophysical properties of water-based Co_0.5Zn_0.5Fe₂O₄ magnetic nanofluid were investigated experimentally. Consequently, the viscosities of 0.25 wt% and 1 wt% Co_0.5Zn_0.5Fe₂O₄ nanofluid were 1.03 mPa∙s and 1.13 mPa∙s, each greater than that of the 20 °C base fluid (water), which were increased by 7.3% and 17.7%, respectively. The Co_0.5Zn_0.5Fe₂O₄ nanofluid thermal conductivity enhanced from 0.605 and 0.618 to 0.654 and 0.693 W/m·°C at concentrations of 0.25 wt% and 1 wt%, respectively, when the temperature increased from 20 to 50 °C. The maximum thermal conductivity of the Co_0.5Zn_0.5Fe₂O₄ nanofluid was 0.693 W/m·°C at a concentration of 1 wt% and a temperature of 50 °C. Furthermore, following a solar exposure of 120 min, the photothermal energy conversion efficiency of 0.25 wt%, 0.5 wt%, 0.75 wt%, and 1 wt% Co_0.5Zn_0.5Fe₂O₄ nanofluids increased by 4.8%, 5.6%, 7.1%, and 4.1%, respectively, more than that of water. Full article

(This article belongs to the Special Issue Photo Thermal Conversion and Pool Boiling Heat Transfer of Nanofluid)

► Show Figures

Figure 1

17 pages, 2458 KiB

Open AccessArticle

Performance Evaluation of Flat Plate and Vacuum Tube Solar Collectors by Applying a MWCNT/Fe₃O₄ Binary Nanofluid

by Minjung Lee, Yunchan Shin and Honghyun Cho

Energies 2020, 13(7), 1715; https://0-doi-org.brum.beds.ac.uk/10.3390/en13071715 - 04 Apr 2020

Cited by 14 | Viewed by 2192

Abstract

This study experimentally investigated the performance characteristics of water and MWCNT/Fe₃O₄ binary nanofluid as a working fluid in a flat plate and vacuum tube solar collectors. As a result, the highest efficiency was 80.3% when 0.005 vol.% MWCNT/0.01 vol.% Fe₃O₄ binary nanofluid was applied to the flat plate solar collector, which was a 17.6% increase in efficiency, compared to that when water was used. In the case of the vacuum tube solar collector, the highest efficiency was 79.8%, which was 24.9% higher than when water was applied. Besides, when the mass flux of MWCNT/Fe₃O₄ binary nanofluid was changed from 420 to 598 kg/s·m², the maximum efficiencies of the flat plate and vacuum tube solar collectors were increased by 7.8% and 8.3%, respectively. When the MWCNT/Fe₃O₄ binary nanofluid was applied to the vacuum tube solar collector, the efficiency improvement was much more significant, and the high performance could be maintained for wide operating conditions, compared with the flat plate solar collector. Full article

(This article belongs to the Special Issue Photo Thermal Conversion and Pool Boiling Heat Transfer of Nanofluid)

► Show Figures

Figure 1

12 pages, 2372 KiB

Open AccessArticle

Thermal Property Measurement of Nanofluid Droplets with Temperature Gradients

by Dong-Wook Oh

Energies 2020, 13(1), 244; https://0-doi-org.brum.beds.ac.uk/10.3390/en13010244 - 03 Jan 2020

Cited by 6 | Viewed by 1838

Abstract

In this study, the 3ω method was used to determine the thermal conductivity of nanofluids (ethylene glycol containing multi-walled carbon nanotubes (MWCNTs)) with temperature gradients. The thermal modeling of the traditional 3ω method was modified to measure the spatial variation of thermal conductivity within a droplet of nanofluid. A direct current (DC) heater was used to generate a temperature gradient inside a sample fluid. A DC heating power of 14 mW was used to provide a temperature gradient of 5000 K/m inside the sample fluid. The thermal conductivity was monitored at hot- and cold-side 3ω heaters with a spacing of 0.3 mm. Regarding the measurement results for the hot and cold 3ω heaters, when the temperature gradient was applied, the maximum thermal conductivity difference was determined to be 3% of the original value. By assuming that the thermo-diffusion of MWCNTs was entirely responsible for this difference, the Soret coefficient of the MWCNTs in the ethylene glycol was calculated to be −0.749 K⁻¹. Full article

(This article belongs to the Special Issue Photo Thermal Conversion and Pool Boiling Heat Transfer of Nanofluid)

► Show Figures

Graphical abstract

17 pages, 5315 KiB

Open AccessArticle

Comparison Study on Photo-Thermal Energy Conversion Performance of Functionalized and Non-Functionalized MWCNT Nanofluid

by Tsogtbilegt Boldoo, Jeonggyun Ham and Honghyun Cho

Energies 2019, 12(19), 3763; https://0-doi-org.brum.beds.ac.uk/10.3390/en12193763 - 01 Oct 2019

Cited by 19 | Viewed by 2292

Abstract

Multiwalled carbon nanotubes (MWCNTs) have attracted attention from researchers because of their superior thermal properties and high optical absorption. In this investigation, the thermal and optical properties of functionalized and nonfunctionalized MWCNT nanofluid based on ethylene glycol/water were experimentally studied and compared. The results indicated that the use of the functionalized MWCNT nanofluid improved the thermal properties and optical absorption performance compared with the nonfunctionalized MWCNT nanofluid. The thermal conductivity enhancement of the functionalized MWCNT nanofluid was higher than that of the nonfunctionalized MWCNT nanofluid. The maximum thermal conductivity enhancement (10.15%) was observed in a functionalized MWCNT concentration of 0.01 wt% at 50 °C compared with the base fluid. In addition, the photo-thermal energy conversion efficiency of the functionalized MWCNT nanofluid was higher than that of the nonfunctionalized one owing to its higher light absorption and thermal conductivity. Full article

(This article belongs to the Special Issue Photo Thermal Conversion and Pool Boiling Heat Transfer of Nanofluid)

► Show Figures

Figure 1

10 pages, 3238 KiB

Open AccessFeature PaperArticle

Assessment of Measurement Accuracy of a Micro-PIV Technique for Quantitative Visualization of Al₂O₃ and MWCNT Nanofluid Flows

by Hanwook Park, Jeonggyun Ham, Honghyun Cho and Sung Yong Jung

Energies 2019, 12(14), 2777; https://0-doi-org.brum.beds.ac.uk/10.3390/en12142777 - 19 Jul 2019

Cited by 2 | Viewed by 2434

Abstract

Nanofluids, which are liquids containing nanoparticles, are used to modify heat transfer performance in various systems. To explain the mechanism of heat transfer modification with nanofluids, many theories have been suggested based on numerical simulations without experimental validation because there is no suitable experimental method for measuring the velocity fields of nanofluid flows. In this study, the measurement accuracy of micro-particle image velocimetry (μ-PIV) is systemically quantified with Al₂O₃ and multi-walled carbon nanotube (MWCNT) nanofluids. Image quality, cross-correlation signal-to-noise ratio, displacement difference, and spurious vector ratio are investigated with static images obtained at various focal plane positions along the beam pathway. Applicable depth is enough to investigate micro-scale flows when the concentrations of Al₂O₃ and MWCNT nanofluids are lower than 0.01% and 0.005%, respectively. The velocity fields of Hagen–Poiseuille flow are measured and compared with theoretical velocity profiles. The measured velocity profiles present good agreement with the theoretical profiles throughout. This study provides the criteria for μ-PIV application and demonstrates that μ-PIV is a promising technique for measuring the velocity field information of nanofluids. Full article

(This article belongs to the Special Issue Photo Thermal Conversion and Pool Boiling Heat Transfer of Nanofluid)

► Show Figures

Graphical abstract

Review

Jump to: Research

33 pages, 12626 KiB

Open AccessReview

Review of the Photothermal Energy Conversion Performance of Nanofluids, Their Applications, and Recent Advances

by Tsogtbilegt Boldoo, Jeonggyun Ham, Eui Kim and Honghyun Cho

Energies 2020, 13(21), 5748; https://0-doi-org.brum.beds.ac.uk/10.3390/en13215748 - 02 Nov 2020

Cited by 38 | Viewed by 3292

Abstract

Nanoparticles have been thoroughly investigated in the last few decades because they have many beneficial and functional qualities. Their capability to enhance and manipulate light absorption, thermal conductivity, and heat transfer efficiency has attracted significant research attention. This systematic and comprehensive work is a critical review of research on the photothermal energy conversion performance of various nanofluids as well as the recent advances in several engineering applications. Different nanofluids used in the photothermal energy conversion process were compared to identify the suitable applications of each nanofluid in thermal systems. An analysis of the previous investigations based on experimental and numerical studies has established that nanomaterials have the potential to increase the efficiency of solar thermal systems. Full article

(This article belongs to the Special Issue Photo Thermal Conversion and Pool Boiling Heat Transfer of Nanofluid)

► Show Figures