Analysis on energy efficiency of an integrated heat pipe system in data centers

Energy saving in data centers is increasingly important along with the rapidly developing IT industry. This paper proposes an integrated cooling system for data centers which combines a heat pipe cooling cycle and a vapor compression cooling cycle. The operating mode of the system changes with the outdoor temperature. Key problems of the integrated system were solved such as the mix of the refrigerant and lubricant, the match of heat exchange areas and the durability of valves. A thermal equilibrium test was carried out to evaluate the system performance. Thermodynamic analyses based on experimental data show that the PUE (Power Usage Effectiveness) of data centers using the integrated heat pipe system can be 0.3 lower than using the conventional air cooling systems in cold areas like Beijing and Harbin. The energy saving potential of the integrated heat pipe system varies with seasonal and regional climate changes.