弓型毛細結構之毛細泵吸環路於1U伺服器熱性能理論預測與實驗設計

Design and Prediction of the CPL Thermal Performance with Semi-arc Porous Structure in One Unit Server

林鴻文(Hung-Wen Lin)

指導教授 ： 林唯耕

國立清華大學/原子科學院/工程與系統科學系/博士(2007年)

https://doi.org/10.6843/NTHU.2007.00183

摘要

This research aims to study the capillary pumped loop (CPL) pipe line temperature distributions. A simple axial heat transfer method was developed to predict the pipeline temperature from evaporator outlet to evaporator inlet.

CPL is a high efficiency two-phase heat transfer device. Since it does not need any other mechanical force such as pump, furthermore, it might be used to do the thermal management of high power electronic component such as spacecraft, notebook and computer servers. It is a cyclic circulation pumped by capillary force, and this force is generated from the fine porous structure in evaporator. A novel semi-arc porous evaporator to CPL in 1U server was designed on the ground with a horizontal position and scale down the whole device to the miniature size.

Reservoir was designed and set up in the liquid head. The influence of reservoir upon thermal resistance was also analyzed. The thermal resistance for CPL with reservoir could keep almost a constant value from low to high thermal loading. On the contrary, the thermal resistance became stable at higher power when the CPL without reservoir. In addition, the thermal resistance of CPL with reservoir was much lower than that without reservoir. It was indicated that reservoir was helpful to maintain a stable CPL performance.

From the experimental results, the CPL could remove heat 110W in steady state and keep the heat source temperature about 80oC. At theoretical results, condenser inlet temperature; condenser outlet temperature; condenser base temperature; fin number demand; fin heat removal ability and mass flow rate could be calculated from the theoretical model. A good agreement between the theoretical results and experimental values had been achieved.

In summary, the CPL has already been turned into the electronics cooling device of new generation. Semi-arc inner evaporator structure provides designer a new design direction and an axial heat transfer method allow designer more freedom.

關鍵字

Capillary Pumped Loop ； Semi-arc ； Axial Heat Transfer Model ； Reservoir

參考文獻

[3].J. Yun, d. Wolf, E. Kroliczek, T. Hoang, “Multiple Evaporator Loop Heat Pipe”, ICES, July, 2000

[5].L. Ottenstein, D. Butler, J. Ku, K. Cheung, R. Baldauff, T. Hoang, “Flight Testing of the Capillary Pumped Loop 3 Experiment”, Space Technology and Applications International Forum, Feb., 2003

[6].E. Bazzo, R. R. Riehl, “Operation Characteristics of Small-Scale Capillary Pumped Loop”, Applied Thermal Engineering, vol. 23, pp. 687-705, 2003

[7].Y. F. Maydanik, “Review: Loop Heat Pipe”, Applied Thermal Engineering, vol. 25, pp. 635-657, 2005

[13].I. Muraoka, F. L. Ramos, V. Vlassov, “Experimental and Theoretical Investigation of a Capillary Pumped Loop with a Porous Element in the Condenser”, International Communications in Heat and Mass Transfer, 25 (8), pp.1085-1094, 1998