Solid sorption heat pipe coupled with direct air cooling technology for thermal control of rack level in internet data centers: Design and numerical simulation

Abstract

The utilization of direct/indirect free cooling (natural cold source) method for data center (DC) cooling and thermal management system has great potential in reducing electric energy consumption. Integrating heat pipe indirect and passive heat transfer method with active vapor-compression refrigeration technique is considered as a promising and alternative solution. The proposal of solid sorption heat pipe is expected to alleviate the drawbacks of heat transfer limits in both conventional heat pipe and thermosyphon. Here, a novel dual-mode thermal control system coupled solid sorption heat pipe with direct air convection scheme for rack level cooling of DC is designed and three-dimensional calculation models are set up to simulate the flow and temperature fields for DC room level and rack level, respectively. Experimental results of solid sorption heat pipe with NaBr show that the maximum axial heat flux with different filing amount and different inclination angle are 913.3 kW/m2 and 559.7 kW/m2, respectively. The parameterized simulation results for rack level cooling of DC illustrate that when flow rate of supply air is 2 m/s and heat dissipation of single server reaches 1000 W, this novel dual-mode thermal management scheme could reduce the peak temperature of server from 75.8 °C to 68.8 °C. A case study based on typical DC scale further elaborates that the dual-mode thermal control oriented to rack level is feasible for energy-saving of DC cooling system.