Application of separated heat pipe system in data center cooling

Abstract This paper mainly studies the application of separated heat pipe system on data center cooling. Separated heat pipe system mainly consists of four parts: evaporator, condenser, vapor pipe and liquid pipe. Compared with traditional computer room air conditioning (CRAC) system, which is a kind of room level cooling, heat pipe cooling system is rack level cooling. There are mainly three advantages for separated heat pipe system, firstly, air flow organization is better for there is nearly no hot and cold air mixing, secondly, such system can use cold ambient air as heat sink in winter, thirdly, as the evaporator is placed directly inside the rack, heat generated from IT equipment will be soon absorbed by heat pipe system, thus there is nearly no local hot spots inside the rack. To describe the working condition of the system, there are mainly three parts in this paper. Firstly, operation performance in summer, winter and trans-season is tested. Secondly, as the system can use free cold ambient air to produce chilled water, the time of using free cold ambient air is tested. Finally, T-Q diagram is used to compare the heat transfer process in heat pipe system and traditional CRAC system. The results show that, IT equipment can work in a safe and reliable environment. Besides, the heat sink temperature in heat pipe system is much higher than CRAC system and there is nearly no cold and hot air mixing in heat pipe system. In summary, heat pipe system can save more electrical energy than CRAC system.