DEVELOPMENT OF SINGLE-PHASED WATER-COOLING RADIATOR FOR COMPUTER CHIP

CHINESE JOURNAL OF MECHANICAL ENGINEERINGVol. 20，No. 2, 2007●77●ZENG PingDEVELOPMENT OF SINGLE-PHASEDCHENG GuangmingWATER-COOLING RADIATOR FOR，LIU JiulongCOMPUTER CHIP*YANG ZhigangCollege of Mechanical Engineeringand Automatizatin,Jilin University,Changchun 130022, ChinaSUN XiaofengAbstract: In order to cool computer chip ftciently with the least noise, a single phase water coolingradiator for computer chip driven by piezoelecric pump with two pall-onnection chambers isdeveloped. The structure and work principle of this radiator is described. Material, processing methodand Automatization,and design principles of whole radiator are also explained. Finite element analysis (FEA) software,Jlin University,ANSYS, is used to simulate the heat distibution in the radiator. Testing equipments for water-coolingradiator are also listed. By experimental tests, influences of flowrate inside the cooling system and fanon chip cooling are explicated. This water-cooling radiator is proved more efficient than curentDepartment of Mechetronics,air-cooling radiator with comparison experiments. During cooling the heater which simulates theJlin Institute of Chemical Technolgy,working of computer chip with different power, the water-cooling radiator needs shorter time to reachJjlin 132022, Chinalower steady temperatures than curent air-cooling radiator.Key words: Computer chip Water-cooling Piezoelecric pump Radiator ANSYS simulationSimulative heaterPENG TaijiangJilin UniversitvChangchun130022, Chinaselected as the material of radiator for its higher heat conduction0 INTRODUCTIONcoefficient and easy machining ability. Heat absorbing layer andThe computer size gets smaller and smaller from the firstheat emission layer are welded together with three pieces of pur-vacuum tube computer to the sixth NN computer, but its capabil-ple copper plates, and the middle one is machined by numericality and computing speed is continuously improved. In 1965, Dr.controlled line cutting machine to form pipeline. Thin purpleMoore predicted that transistors integrated in the molectron wouldcopper plate is welded between heat absorbing and emission layeras fins to strengthen heat transfer effect. Fan is installed on thebe doubled every 18 months, which called Moore law. But itback of radiator to blow cool air to it, and PZT pump is attachedcomes the bigger electricity consumption and greater heat emis-on the side of radiator to pump coolant in the system. After manysion. Heat resulted from improved electricity consumption willcomparison experiments, water is selected as the coolant becausedisable computer chip, even make the computer out of function.of its lower viscosity and higher specific heat.The bulk and quantity of transistors will be limited by heat trans-mission ability. Therefore, efficient heat emission method must bedeveloped in order to ensure chips in function!-l. At present,computer chip power has reached 60~75 W, and rotation speed ofthe fans used on P4 processors is beyond 4 000 r/min which pro-duce insufferable noise. However, by the end of 2005, the heatflux of chip with high performance expects to be 100 W/cm2,what's more, chips will become an uneven heat resource becauseof the decrease of chip core and improved integration. Heat emis-sion power of current air-cooling method has reached its limit, sonew ways to cool computer chip are badly neededb. Pumpedliquid cooling has been implemented in commercial laptop anddesktop computers, in many cases exploring novel electrokineticand electrohydrodynamic pumps'1 DESIGN OF WATER-COOLING RADIATORFig. 1 Structure of integrated water-cooling radiatorFor decreasing the bulk of water- cooling radiator and sim-1. Heat absorbing layer 2. Radiatorrfins3. Lateral planeplifying its usage, integrated radiator is developed which is driven4. Heat emiting layer 5. Radiator outlet/pump inlet6. Radiator inletpump outlet 7. Coolant pipeby piezoeletric (PZT) pump. Fig. 1 ilustrates the structure ofintegrated water-cooling radiator.This system consists of heat absorbing layer 1, radiator fins 1.中国煤化工2, lateral plane 3, heat emitting layer 4, radiator outlet/pump inletFof PZT actuators, which5, radiator inlet/pump outlet 6 and coolant pipe 7. Purple copperis is a kinHCNMHGgPZTdiaphragmastheactuator. Comparea witn raitional pumps, PZT pump is simple,small, light, lower power consuming, noiseless, immune to the●This proet is supported by National Hi-tech Research and Development disturbance of electromagnetism and its output flowrate can beProgram of China (863 Program, No. 2002AA404250) and National Natural controlled through adjusting the voltage or frequency of appliedScience Foundation of China (No. 50575093). Received April 26, 2006; reelectricity. In this water-cooling radiator, PZT pump with dou-ceived in revised form December 18, 2006; accepted December 25, 2006●78.ZENG Ping, et al: Development of single-phased water cooling radiator for computer chipble parallel-connection chambers is selected, and with the help ofRe,Pr d/l <10, Eq. (1) is suitable for the calculation of h. Basedsheet valve, umbrella rubber valve, liquid is transferred when on primary experiments, cooling system inner flow rate is deter-chambers change their volume, which is aroused by the distortion mined to be about 300 mL/min and water inside is learned to beof PZT diaphragm. PZT pump with double parallel-connection 20~30C. When it is 30 C, water has the physical parameters ofchambers (Fig.2) consists ofPZT diaphragm for left chamber1 i= 0.62 W(m. K), u,= 0.79X 106 m/s, ne 78.7 MPa.s,and for right chamber 8, lower pump body 2, valve support plate 3,Prp =5.31, ρ=995.4 kg/m?, nw=764.4 MPa.s, so Re-6.33d apers20 rescarch proiects including several “863 Program" and“National NaturalScience Foundation Program of China”and published over 80 scientific and YANG Zhigang received his PhD degree from Jilin University of Technology,technical papers in recent years. Her research interests include the technology, China, in 1998. He is presently a professor and supervisor of doctoral candidateconstruction and application of piezoelectric materials.in College of Mechanical Engineering and Automatization, Jilin University,Tel: +86-431-5095358; E mail: zengping32l@163.comChina. His research interests include the drive technology of piezoelectric. Hehas supervised over 15 research projects including several “863 Program" andCHENG Guangming received his PhD degree in Jilin University of Technology,"National Narural Science Foundation Program of China", published more thanChina, in 1996. He is presenty a professor and supervisor of doctoral candidate. 100 scientific and technical papers in reent years.China. His research iterets iclude the drive tchology of peiecric and SUN Xiaofeng reived his MS degee from Jili Univesit, China, in 2005.machine design. He has supervised over 15 research projects including severalHe is a teacher in Department of Mechetronics, Jilin Institute of Chemical“863 Program" and“National Natural Science Foundation Program of China"，Technology, China, and now he is a doctoral candidatc in Jilin University, China.published more than 100 scientifi and technical papers in rene years.PENG Taiiang received his MS degree from Jili University, China, in 2003,LIU Jiulong received his MS degree from Jjlin University, China, in 2005. Heand now he is a doctoral candidate in Jilin University, China. He has partici-pated several research projects inchuding“863 Program" and "National Natural"National Natural Science Foundation Programme of China" and published 3 Science Foundation Program ofChina"."中国煤化工MYHCNMHG