ENHANCING INDIRECT / DIRECT EVAPORATIVE HEAT EXCHANGER IN DATA CENTER COOLING BY USING PHASE CHANGE MATERIAL

Abstract

Electrical usage in data center continues to grow and recent projection estimate that it contributes 2% in the electricity use in the U.S. One method of controlling the electrical usage during cooling is to reduce or eliminate mechanical cooling; however, using indirect/direct evaporative (IDE) cooling system is starting to be quite popular. IDE has limitations and in this paper we will show how phase change material (PCM) can extend the cooling capacity of IDE. The PCM has been used for temperature control operations. Latent heat storage is one of the most efficient ways of storing thermal energy in PCM. The advantage of temperature difference during diurnal and nocturnal time is applied to charge and release the latent heat capacity of the PCM respectively. Unlike the sensible heat storage method, the latent heat storage method provides much higher storage density with a smaller temperature difference between storing and releasing thermal capacity. In this research, extending the temperature control range by utilizing PCM can increase the cooling energy of the IDE cooler and minimize its working hours. That can create an acceptable air supply condition in data center under arid or extreme climate.