Experimental study on heat transfer characteristics of closed thermosyphon at different volumes and inclination angles for variable vacuum pressures

Arat, Halit; Arslan, Oğuz; Ercetin, Umran; Akbulut, Ahmet

doi:10.1016/j.csite.2021.101117

Cited by 45 publications

(3 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The uncertainty of the measurement apparatuses for different thermocouple measurement points was calculated based on Eqns. ( 13), ( 14) and (15) [28,29].…”

Section: Uncertainty Analysismentioning

confidence: 99%

Thermal Performance Optimization of Perforated Fins for Flat Plate Heat Sinks Using CFD Approach

Al-Muhsen,

Al-Khafaji,

Ismail

2023

IJHT

View full text Add to dashboard Cite

A comprehensive multi-dimensional computational fluid dynamics (CFD) analysis was conducted on a flat plate heat sink, equipped with four perforated fins. This study aimed to optimize the thermal performance by exploring the effects of the geometry and placement of the perforations within the fins. The heat transfer was modelled under conduction for the heat sink body, and natural convection for the enclosure. The investigation focused on the combined influence of the shape of the fin perforations (circular, square, triangular) and their spatial positioning (bottom, middle, top) on the overall thermal performance. It was observed that the temperature gradients (ΔT) from the bottom to the top of the fins were significantly enhanced with the introduction of perforations. Notably, the smallest ΔT of 2.64℃ was recorded with circular perforations, independent of their placement within the fin matrix. Conversely, the highest ΔT of 12.58℃ was observed when the perforations were triangular in shape. Furthermore, an increase in ΔT was noted when all perforation matrices were relocated from the top to the bottom of the fins. Interestingly, the heat transfer coefficient was found to be higher when the heat sink made use of perforated fins. However, the effect of the perforations' shape and placement on this coefficient was found to be less significant. In conclusion, optimal thermal performance was achieved with circularly perforated fins. The buoyancy effect within the enclosure and in the vicinity of the fins was amplified when the heat sink's fins were top-positioned and circularly perforated. This resulted in a 15.6% increase in ΔT, but also a 29.6% increase in the heat transfer coefficient, indicating an overall enhancement in thermal performance under most tested conditions.

show abstract

“…The uncertainty of the measurement apparatuses for different thermocouple measurement points was calculated based on Eqns. ( 13), ( 14) and (15) [28,29].…”

Section: Uncertainty Analysismentioning

confidence: 99%

Thermal Performance Optimization of Perforated Fins for Flat Plate Heat Sinks Using CFD Approach

Al-Muhsen,

Al-Khafaji,

Ismail

2023

IJHT

View full text Add to dashboard Cite

show abstract

“…The thicknesses of the films obtained in RR0, RR1, RR2, RR3, and RR4 were 360, 345, 355, 330, and 325 nm, respectively. Standard deviation (SD) and uncertainty (U) were calculated like in the previous study [14]. According to this calculation, the standard deviation was determined as 15.2 nm and the uncertainty as 6.8 nm.…”

Section: Structural Analysis Of Cds Filmsmentioning

confidence: 99%

Effects of Sodium Sulphide as an Inhibitor on CdS Films Obtained by Chemical Bath Deposition

Önal

Altıokka

2023

Acta Phys. Pol. A

View full text Add to dashboard Cite

In the present study, CdS thin films were produced on glass substrates by the chemical bath deposition method, and sodium sulfite was used to reduce the reaction rate. Based on the absorbance measurements, it was found that the energy band gaps of the films increased from 2.35 to 2.49 eV depending on the amount of inhibitor. It was also found that when the reaction rate decreased, the crystal structure of the films shifted from the cubic phase to the hexagonal phase in reference to the X-ray diffraction results. When CdS thin films had the hexagonal phase, it was seen in the scanning electron microscope images that pinholes and voids were not seen on the surface of the films. Surface roughness values were calculated using scanning electron microscope images, and these values were found to vary between 22 nm and 9 nm. topics: chemical bath deposition, thin films, CdS, inhibitor

show abstract

“…The results demonstrated that the efficiency of the TPCT for each working fluid under different operating conditions ranged from an average of 30% to 95%, which is consistent with previously published findings. In another study, Arat et al (2021) conducted experiments to assess the heat transfer properties of a 1.5 m long TPCT at various volumes and inclination angles under different vacuum pressures. The findings indicated that the experimentally determined boiling heat transfer coefficients were in good agreement with the correlations reported in the literature.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of the heat transfer characteristics, operating limits, and temperature distribution of a prototypically 3 m long two-phase closed thermosyphon for spent fuel pool passive cooling

Castro,

Kirsch,

Kulenovic

et al. 2024

Exp. Comput. Multiph. Flow

View full text Add to dashboard Cite

The current study investigated the heat transfer performance, operation limits, and temperature distribution of a 3 m prototype model for a large-scale straight two-phase closed thermosyphon with deionized water designed for passive cooling of nuclear spent fuel pools with a filling ratio ranging from 20% to 100% and a heat source temperature ranging from 45 to 80 °C. After the accident at the Fukushima Daiichi nuclear power plant, the need for a reliable cooling system for these pools increased, with thermosyphons emerging as a promising solution for passive cooling. The experimental procedure implemented in this study yielded a comprehensive understanding of the operation and phenomena inside a thermosyphon, providing crucial data for the validation and enhancement of numerical models that simulate relevant phenomena within nuclear power plants, including passive residual heat removal with thermosyphons. The results indicated that the optimal heat transfer performance was achieved at a filling ratio of 30%, where the thermosyphon begins operation at a heat source temperature of 45 °C. Additionally, the temperature distribution along the thermosyphon confirmed the operation limits, including partial dryout at a 20% filling ratio and geyser boiling and flooding (entrainment) limits at 75% and 100% filling ratios, respectively.

show abstract

Experimental study on heat transfer characteristics of closed thermosyphon at different volumes and inclination angles for variable vacuum pressures

Cited by 45 publications

References 21 publications

Thermal Performance Optimization of Perforated Fins for Flat Plate Heat Sinks Using CFD Approach

Thermal Performance Optimization of Perforated Fins for Flat Plate Heat Sinks Using CFD Approach

Effects of Sodium Sulphide as an Inhibitor on CdS Films Obtained by Chemical Bath Deposition

Experimental investigation of the heat transfer characteristics, operating limits, and temperature distribution of a prototypically 3 m long two-phase closed thermosyphon for spent fuel pool passive cooling

Contact Info

Product

Resources

About