Session: 12-06-01: Boiling Heat Transfer and Flow Instabilities

Paper Number: 166477

Subcooled Flow Boiling Heat Transfer Characteristics of a Novel Micro Pin-Fin Heat Sink 

Recent advancements in micro-electro-mechanical systems (MEMS) and silicon-based technologies have paved the way for the development of highly efficient electronic devices. The increasing integration of electronic components has further driven miniaturization. However, this miniaturization leads to more heat generation within electronic circuits and devices, making thermal management a critical aspect of their design. Consequently, there is a growing need for cooling systems to stabilize electronic chips and high-power devices by dissipating the generated heat. Among various passive cooling solutions, flow boiling in microchannel heat sinks is an attractive option for cooling high-power electronic devices. The high surface area density of microchannels allows for more efficient heat dissipation compared to traditional channels. Additionally, advanced microchannel systems are essential for the effective miniaturization of electronic devices and circuits. Flow boiling in microchannel heat sinks shows great promise as a solution for cooling electronic devices by utilizing the latent heat of vaporization to dissipate substantial amounts of thermal energy. In comparison, single-phase microchannel cooling systems only dissipate sensible heat. Utilizing the phase change process, flow boiling achieves more efficient heat transfer rates even at reduced flow rates. Moreover, flow boiling ensures a more consistent surface temperature than single-phase methods. Micro pin-fin heat sinks (MPFHSs) offer advantages such as exceptional heat transfer capabilities, large surface area per unit volume, compact dimensions, and low fluid requirements compared to other heat sinks. The micro pin-fins can effectively disrupt the flow and boundary layer, thereby enhancing flow mixing and regenerating the thermal and hydraulic boundary layers.
In this study, we propose a novel micro pin-fin heat sink, where each micro pin-fin is designed with a single inclined opening, angled from the inlet to the outlet direction. The inclined opening in the micro pin-fins of the novel heat sink shows promising potential to enhance heat transfer by increasing the surface area and directing flow towards the heat sink base. They also create additional vapor bubble sites and offer the potential to mitigate flow reversal during boiling. These findings provide a comprehensive framework for future modeling and optimization of advanced micro pin-fin heat sink designs for high-performance thermal management applications. The length of the heat sink is 14.5 mm, the width is 15 mm, and the pin-fin has a length of 0.5 mm, a width of 0.5 mm, a height of 1 mm, diameter of the inclined opening is 0.25 mm, and an angle of inclination of 45 degrees. Critical heat flux, heat transfer coefficient, and pressure drop, as well as flow characteristics in novel micro pin-fin heat sink were investigated by conducting subcooled flow boiling experiments. This observation effectively accounted for a broad range of flow conditions. Additionally, the results were compared with previous correlations. The comparison with previous correlations was carried out using various error metrics, such as mean absolute error, the percentage of data points within 30% and 50% absolute error, and mean relative error.

Presenting Author: Sang-Woo Lee Sung-Min Kim

Presenting Author Biography: sungkyunkwan university

Authors:

Sang-Woo Lee Sung-Min Kim
Santhosh Senguttuvan sungkyunkwan university
Won-Woo Choi sungkyunkwan university
Gyeong-Jae Park sungkyunkwan university
Sung-Min Kim sungkyunkwan university