Rack exergy-loss index for analyzing and evaluating the thermal environment of data center

The data center is employed for storing and managing of different data processing equipments, in which the thermal environment has significant impact on the steady, continuous and safe operation of the facilities. Index to evaluate and reflect the condition of the thermal environment is critical to the operation of the data center with high efficiency and energy conservation.Based on the exergy analysis method, a novel evaluating index, Rack Exergy-Loss Index(REI), is proposed in this paper, which is expected to reflect the conditions of airflow and heat transfer in data center. The feasibility of the proposed index is proved in a modeled typical data center by comparing with current commonly used evaluating index, such as Supply Heat Index/Return Heat Index (SHI/RHI), Rack Cooling Index (RCI), and Return Temperature Index (RTI). Factors resulting in the lower cooling efficiency in data center can be obtained by analysis of the REI, measures to improve the thermal environment and the energy efficiency are also put forward in the paper.