Thermal Modeling of Remote Radio Head Units

Thermal modeling of concealed Remote Radio Head (RRH) units which are placed on a cell tower is the main interest of this paper. RRH units which dissipate fixed amount of heat are modeled in higher ambient temperature. The effect of creating an enclosure on the open air assembly of RRH units is studied. The aim of this study is to analyze if concealment of the RRH units is possible under natural convection for cooling under boundary conditions with inlet temperature 55°C, solar loading and wind. Also, the study has been made to investigate if stacking of one, two, or three concealed sections is possible under natural convection cooling process. Various configurations were modeled and analyzed using a computational fluid dynamics (CFD) tool. Different temperature profiles are reported. An enclosure has been created and the operating temperatures of the enclosed model and an open model are compared. After studying the air flow pattern in the model, specific design modifications, like placing baffles on top of each RRH unit, are suggested for proper air flow management thereby facilitating efficient thermal management inside the enclosure. Also, addition of baffles helped in removing the hot spots in the model. Stacking concealed sections poses a challenge since hot exhaust air from a lower section may enter the air inlets of top sections. Thereby, higher surface temperatures on RRH units in the upper sections are observed. Orientation of the upper section has been changed to address this issue. Results show that with proper airflow management and arrangement of sections, it is possible to have three sections one on top of the other.