Heat transfer investigation of a flat-plate oscillating heat pipe with tandem dual channels under nonuniform heating

Abstract Flat plate oscillating heat pipe (FP-OHP) is a unique heat transfer device and considered as a promising candidate for effective heat transfer device in electronics industries. A number of theoretical studies and experimental investigations have been carried out on FP-OHP in the past decades after its invention. However, due to the operational characteristics of FP-OHP, the effect of various parameters on the thermal performance of FP-OHP has not been completely revealed so far. This paper attempts to discuss the effect of operational parameters on the thermal performance of FP-OHP. In this study, the FP-OHP was investigated with different charge ratios, orientations, working fluids, and heat loads from 10 W to 150 W. In order to investigate the effect, 18 parallel square channels of 2 × 2 mm2 are machined onto pure copper plate (93 × 70 × 8 mm3) to form FP-OHP. DI water, ethanol, methanol, acetone, and FC-72 are investigated. The measured thermal resistance was strongly dependent on operational parameters. The optimum performance was observed with acetone with a charge ratio of 70% in the vertical orientation. The lowest thermal resistance of 0.39 °C/W is achieved using acetone as a working fluid at 100 W. A Kutateladze number (Ku) was used to compare the experimental data and found to be suitable for prediction of the thermal performance of FP-OHP with standard deviation of 15%.

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A Novel Thermal Solution for Electronics: Alumina Flat-Plate Oscillating Heat Pipe

ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer ◽

10.1115/mnhmt2019-3936 ◽

2019 ◽

Author(s):

Bohan Tian ◽

Hongbin Ma ◽

Yang Deming ◽

Jiujun Xu ◽

Zhiyong Wang ◽

...

Keyword(s):

Heat Transfer ◽

Flat Plate ◽

Heat Pipe ◽

Printed Circuit Boards ◽

Ct Scanning ◽

Working Fluid ◽

Micro Computed Tomography ◽

Two Phase ◽

Oscillating Heat Pipe ◽

Two Phase Cooling

Abstract The heat flux in electronics requires the thermal management of printed circuit boards (PCBs) using two-phase cooling methods. In this study, an integrated ceramic heat transfer device, the alumina flat-plate oscillating heat pipe, is developed. The device was fabricated by pressing and sintering procedures, and the inner serpentine channels were simultaneously formed during sintering without brazing or separated caps. This novel manufacturing process simplifies the fabrication of the macrochannels inside ceramic devices and provides a new method for fabricating ceramic two-phase cooling devices. This paper presents an analysis of the internal channel’s formation mechanism and illustrates the major factors of densification. Micro-computed tomography (Micro-CT) scanning was adopted to assess the macrostructure, and SEM was used to characterize the microstructure of the alumina OHP. Water was charged inside the device as the working fluid. The effects of the power input, orientation, operating temperature and filling ratio on the heat transfer performance were investigated. The experimental results show that the alumina OHP has a high heat transport capability. When the OHP structure is embedded inside the alumina and charged with water, the thermal resistance can be reduced by 97%.

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Fluid flow and heat transfer in flat-plate oscillating heat pipe

Energy and Buildings ◽

10.1016/j.enbuild.2014.01.041 ◽

2014 ◽

Vol 75 ◽

pp. 29-42 ◽

Cited By ~ 17

Author(s):

Xiangdong Liu ◽

Yongping Chen

Keyword(s):

Heat Transfer ◽

Fluid Flow ◽

Flat Plate ◽

Heat Pipe ◽

Oscillating Heat Pipe ◽

Flow And Heat Transfer

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Experimental Investigation of a Flat-Plate Oscillating Heat Pipe With Groove-Enhanced Minichannels

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4047710 ◽

2020 ◽

Vol 12 (6) ◽

Cited By ~ 1

Author(s):

Matthew J. Rhodes ◽

Scott M. Thompson

Keyword(s):

Heat Transfer ◽

Flat Plate ◽

Heat Pipe ◽

Operating Temperature ◽

Operating Conditions ◽

Working Fluid ◽

Oscillating Heat Pipe ◽

Thin Film Evaporation ◽

Film Evaporation ◽

Wide Range

Abstract The thermal and capillary performance of a groove-enhanced, or “microchannel-embedded,” flat-plate oscillating heat pipe (MC FP-OHP) was experimentally investigated while varying heating width, orientation, working fluid and operating temperature. The copper MC FP-OHP possessed two layers of 1.02 × 1.02 mm2 square channels, with the center 14 channels possessing two embedded microchannels (0.25 × 0.13 mm2) aligned coaxially with the primary minichannels. A FP-OHP without embedded microchannels, but with deeper minichannels (DC FP-OHP), was also tested for comparison. The FP-OHPs were filled with Novec 7200 or water (both at 80% ± 2% by volume), and the heating widths were varied between full-width and localized configurations: 38.71 cm2 and 14.52 cm2, respectively. Experimental results demonstrate that the MC FP-OHP is significantly less sensitive to operating orientation and can perform with less detriment as heat flux increases. The MC FP-OHP has a lower startup heating requirement and provides more fluid wetting along the FP-OHP structure—which is advantageous for pumping liquid from the evaporator to the condenser. The MC FP-OHP has enhanced convective heat transfer during operation, as it was observed to have similar or lower thermal resistances to that of the DC FP-OHP for a wide range of operating conditions. The groove-enhanced minichannel within the MC FP-OHP also provides for enhanced heat transfer because there being more thin-film evaporation sites and vapor–liquid mixing between the minichannel and microchannels.

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