Experimental investigation on the phase change liquid cooling characteristics in the offset grooved microchannel heat sink

Abstract

Improving chip integration and computing power leads to serious local overheating and high energy consumption in data centers. An innovative heat sink with offset triangular grooves is introduced to solve heat dissipation issue and improve energy efficiency of the cooling system. The flow boiling properties in the new configuration are examined by visualization experiment for a flow rate of 3 ∼ 15 ml/min and heat flux of 4.58 ∼ 100.66 W/cm². The influence of groove arrangement on the flow evolution, boiling curve, heat transfer rate, pump power, coefficient of performance, and temperature features is explored in detail. The new findings include that: compared to the rectangular microchannel, the offset grooves induce boiling with a 16.8 ℃ lower temperature and 10.52 times higher heat transport efficiency, attributing to the increased nucleation sites and enhanced liquid film vaporization. For low heat flux, the heat transport rate of offset grooves is 2.87 times larger than the symmetrical one because of the efficient steam removal. For high heat flux, the symmetrical grooves present superior thermal performance due to stronger flow disturbance. Moreover, the pump power for the offset grooves is dropped by 71.47 % and 14.23 % compared to the smooth one and symmetrical counterpart, respectively. The temperature stability and uniformity of the offset grooves are also better than those of other heat sinks. The effect of groove arrangement on the flow boiling features is revealed thoroughly, and the optimal configuration under different operating conditions is obtained. The innovative configuration achieves heat dissipation enhancement while reducing pump power with a significantly improved coefficient of performance. In addition, the interaction between flow evolution and heat transfer is elucidated by bubble dynamics analysis. The new design has a better application prospect for chip-scale cooling in data centers because of the improved boiling stability, increased heat transport efficiency, reduced pump power, and favorable temperature performance.