Experimental study on mechanism of boiling heat transfer of surface-mounted evaporative cooling system

ABSTRACT

The Boiling heat transfer technology has been applied to the field of heat dissipation of power electronic equipment. Due to the complexity of the boiling heat transfer mechanism, its heat transfer mechanism is still unclear, which limits the further improvement of the cooling efficiency of power electronic equipment. This study aimed to obtain the characteristics of boiling heat transfer in the liquid box of a self-circulating evaporative cooling system and establish an accurate calculation model for boiling heat transfer. To this end, we studied the boiling heat transfer process in a liquid box with a cross-sectional area of 180 mm × 20 mm. The experimental results reveal that bubble flow, Churn flow, and mist flow appear successively in the liquid box with an increase in thermal load. A new correlation for boiling in the liquid box is proposed by introducing a new dimensionless number X_new, and the predicted boiling heat transfer coefficient and experimental data show agreement within 8%. This correlation further improves the calculation accuracy of the boiling heat transfer coefficient and provides a useful reference for engineering applications of the surface-mounted evaporative cooling system.

KEYWORDS:

• Boiling
• two phase
• self-circulating
• flow pattern
• dimensionless number
• correlation

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under Grant [number 51777201].

Notes on contributors

Yitao Shi

Yitao Shi is currently pursuing his Ph. D. degree at the university of chinese academy of sciences. His major research direction: Evaporative cooling technology for electronic equipment.

Rui Cao

Rui Cao received herMaster degree in Beijing Jiaotong University, Beijing, China, in 2010. She joined the Institute of Electrical Engineering Chinese Academy of Sciences, where she is currently a ResearchAssistant. Her research interests is heat dissipation of electronic equipment.

Lin Ruan

Lin Ruanreceived her Ph. D. degree in electric machines and electric apparatus from the Institute of Electrical Engineering Chinese Academy of Sciences, Beijing, China, in 2004. She joined the Institute of Electrical Engineering Chinese Academy of Sciences, where she is currently a researcher. Her research interests include research of evaporative cooling technology for electrical and electronic equipment and Two-phase flow and phase-change thermal technology.