Thermal performance evaluation of various nanofluids with non-uniform heating for parabolic trough collectors

Abed, Nabeel; Afgan, Imran; Cioncolini, Andrea; Iacovides, Hector; Nasser, Adel; Mekhail, Tarek

doi:10.1016/j.csite.2020.100769

Cited by 49 publications

(18 citation statements)

References 46 publications

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“…Lin et al 20 found that injecting metallic/water nanofluid significantly enhances the thermal conductivity of the resultant mixture. According to a study conducted by Abed et al 21 various nanofluids (e.g., CuO-water, Ag-water, Al 2 O 3 -water, and TiO 2 -water) with varying nanoparticle concentrations were employed to improve heat transfer in a concentric annular pipe with the results revealing that the Al 2 O 3 /water nanofluid at Ra = 104 had little effect on improving heat transfer. For example, it has been found that the thermal conductivity of Al 2 O 3 -water and CuO-water nanofluids with a 5% nanoparticle volume fraction is 29% and 60% greater than the pure fluid, respectively.…”

Section: Introductionmentioning

confidence: 99%

Computational optimum design of natural convection in a concentric and eccentric annular cylinder using nanofluids

Azzawi

Hasan

Yahya

2022

Proceedings of the Institution of Mechanical Engineers, Part A:

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Free convection of various nanofluids inside concentric and eccentric annular cavity with internal heat flux, fully filled with porous media is studied numerically and its heat transfer rate and pressure drop are examined. The impact of inner cylinder inclination angles (βecc = 45°, 135°, 225°, and 270°) and nanofluids (Al2O3/water, CuO/water and SiO2/water) for different heat flux (1000, 2000, 3000, and 4000 w/m2) on the heat transfer rate are evaluated. Initially, a validation process has been implemented to ensure that the predicted results obtained from this model are accurate. Results indicate that Al2O3 Nanofluid provides a better enhancement in the heat transfer rate when compared to SiO2 and Cu Nanofluids. Furthermore, the heat transfer coefficient increased with the inclination angle of βecc = 225°, and maximum heat transfer occurred at a heat flux of 4000 W/m2, which was roughly 6% greater than the concentric annular cylinder. The findings also indicated that while increasing the eccentricity has a minor impact on the heat transfer rate for convection-dominated flows (high heat flux), on the other hand, it has a significant impact on the heat transfer rate for conduction-dominated flows (low heat flux).

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Section: Introductionmentioning

confidence: 99%

Computational optimum design of natural convection in a concentric and eccentric annular cylinder using nanofluids

Azzawi

Hasan

Yahya

2022

Proceedings of the Institution of Mechanical Engineers, Part A:

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“…Over the last few decades, several studies investigating different aspects of thermalhydraulics components and various modeling approaches related to nuclear power plants have been conducted [4][5][6][7][8][9][10][11][12][13][14][15][16]. However, the safety of nuclear reactors and various incident plans has not received the required numerical consideration to reduce MCCI and the various factors affecting it [17].…”

Section: Introductionmentioning

confidence: 99%

Thermochemical Modeling of Metal Composition and Its Impact on the Molten Corium–Concrete Interaction: New Insights with Sensitivity Analysis

2022

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The characterization of molten corium–concrete interaction (MCCI) has increasingly become a cause of concern because, in the case of a severe nuclear accident, the core could meltdown and release radiation into the environment. The objective of this study was to determine the thermochemical impact of metal content in the corium and analyze the effect of corium metal content on ablation depth, corium temperature, its viscosity and surface heat flux, and production of hydrogen, carbon monoxide, and carbon dioxide. The governing heat transfer equations were solved while considering the various thermochemical reactions in the existing numerical code in a comprehensive way. The developed MCCI model in CORQUENCH was validated against the data available in the literature. Our findings showed that the composition of corium, especially its metal content, has a noticeable effect on mitigating or aggravating the ablation depth and nuclear reactor integrity. We observed that during molten corium–concrete interaction, zirconium plays a significant role and its presence can increase the ablation depth exponentially from 18.5 to 139 cm in the investigated case study. It was found that the presence of zirconium in the corium instigated various thermochemical reactions continuously, and thus the injected water, instead of quenching the molten corium, enhances the temperature by facilitating exothermic reactions. Additionally, due to the presence of zirconium, the production of hydrogen and carbon monoxide increases by 45 and 52 times, respectively and the generation of carbon dioxide becomes zero because the zirconium reacts with carbon dioxide continuously, converting it to carbon monoxide.

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“…The use of nanofluids is a promising technique to improve the thermal conductivity, as it enhances the Nusselt number (the ratio of convective to conductive heat transfer across a boundary), thermal efficiency and exergy efficiency. More information about nanofluids and its application can be found in [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ].…”

Section: Introductionmentioning

confidence: 99%

“…After obtaining the optimum strip height and angle, the number of strips were increased stepwise from one to four. The results were then examined with the presence of a nanofluid using 6% of SiO 2 nanoparticles mixed in Therminol ® VP-1, as this was the best candidate proposed by Abed et al [ 13 ]. It is important to mention that all case studies were assumed to be steady-state, incompressible and three dimensional, using Therminol ® VP-1 as a heat transfer fluid with an inlet temperature of 400 K. The heat flux distribution was taken as a realistic profile by applying the output of the Monte Carlo ray tracing (MCRT) model in the circumferential direction.…”

Section: Introductionmentioning

confidence: 99%

Thermal-Hydraulic Analysis of Parabolic Trough Collectors Using Straight Conical Strip Inserts with Nanofluids

et al. 2021

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In this study, we numerically investigated the effect of swirl inserts with and without nanofluids over a range of Reynolds numbers for parabolic trough collectors with non-uniform heating. Three approaches were utilized to enhance the thermal-hydraulic performance—the variation of geometrical properties of a single canonical insert to find the optimized shape; the use of nanofluids and analysis of the effect of both the aforementioned approaches; the use of swirl generators and nanofluids together. Results revealed that using the straight conical strips alone enhanced the Nusselt number by 47.13%. However, the use of nanofluids along with the swirl generators increased the Nusselt number by 57.48%. These improvements reduced the thermal losses by 22.3% for swirl generators with nanofluids, as opposed to a reduction of only 15.7% with nanofluids alone. The investigation of different swirl generator designs showed various levels of improvements in terms of the overall thermal efficiency and thermal exergy efficiency. The larger swirl generator (H30mm-θ30°-N4) with 6% SiO2 nanofluids was found to be the optimum configuration, which improved the overall collector efficiency and thermal exergy by 14.62% and 14.47%, respectively.

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Thermal performance evaluation of various nanofluids with non-uniform heating for parabolic trough collectors

Cited by 49 publications

References 46 publications

Computational optimum design of natural convection in a concentric and eccentric annular cylinder using nanofluids

Computational optimum design of natural convection in a concentric and eccentric annular cylinder using nanofluids

Thermochemical Modeling of Metal Composition and Its Impact on the Molten Corium–Concrete Interaction: New Insights with Sensitivity Analysis

Thermal-Hydraulic Analysis of Parabolic Trough Collectors Using Straight Conical Strip Inserts with Nanofluids

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