Experimental investigation of heat transfer enhancement of nanofluids in computer cooling sysyems

Abstract

In this study, cooling performance enhancement of computer liquid cooling systems using hBN-water nanofluids are investigated experimentally. Water based nanofluids are prepared with two step method by using ultrasonication and surface ac tive materials. The particle volume fractions of 0.1-2% are considered at constant flow rates varying from 0.3-2 L/min for experimental systems with two different cold plates. A commercial closed loop liquid cooling system is also tested to examine performance of hBN-water nanofluids at constant pumping power. It is observed that the maxi mum cooling enhancement is obtained with 2% volume concentration of hBN-water nanofluid in all experimental systems and reduction in the thermal resistance of liquid cooling systems and Stanton number are correlated at constant flow rate experiments. Moreover, enhancement rate of cooling performance depends on the flow rate and the cold plate design. The cooling performance increase for the commercial system is ob served to be limited with the reduced flow rate at increasing particle volume fractions. Therefore, cold plates must be optimized to maximize the cooling capacity, considering the increasing viscosity and thermal conductivity of nanofluids.