Computational Study and Optimization of Wet Cooling Media in Direct Evaporative Heat Exchanger

Abstract

Evaporative cooling media pads are the primary component of importance in direct evaporative cooling units. To increase the overall efficiency of direct evaporative cooling systems, a wet cooling media pad is considered for further optimization in design and operation. An installation technique called ‘staging’ of cooling media pads is examined and evaluated for its incremental cooling, water usage, and operational cooling efficiency. For Staging, a cooling media is divided into multiple vertical sections, and separate water distribution headers control each part. Staging of cooling media can reduce water consumption in data centers and potentially lessen the amount of cooling media required. Increasing the number of stages allows more precise control of humidity and temperature at the discharge. The objective of the present study is to validate a computational model in Computational Fluid Dynamics (CFD) software in predicting the cooling efficiency of wet cooling pads. At the initial level of this project, a CFD model of cooling media will be developed and analyzed. Then, this CFD model will be validated with existing experimental data for GLASdek or CELdek cooling pads. The basic parameters of influence such as pad thickness, flute angle, water flow rate are considered for parametric studies and their impact on cooling media saturation effectiveness, the pressure drop across the media and water consumption will be reported. Also, the degree of increase in cooling capacities as the cooling media wall is scaled/stacked up to accommodate higher cooling unit flow discharge will be investigated. Furthermore, this model will be further modified for ‘staged’ installations and analyzed through the simulations. This information will be helpful in understanding and improving wet cooling media performance.