Transient Modeling of the Thermal Behavior of Outdoor Electronic Cabinets

Abstract

This paper presents an investigation into the various factors which influence the peak average inside air temperature of outdoor telephone switching cabinets. The primary goal is to determine which factors are important and to develop a correlation which will predict peak average air temperatures inside the cabinet under a variety of situations. A network of lumped thermal capacitances and resistances is used to model the transient thermal behavior of the electronics enclosure. Energy balances for each element are developed creating a system of ordinary differential equations which are solved using a fourth order Runge-Kutta method. The numerical model is verified by comparison to experimental data. A search of parameters which affect the thermal behavior of telephone switching cabinets is conducted. A sensitivity analysis is performed to determine the important terms. Parametric studies are conducted to develop a correlation which relates the internal cabinet air temperature to the important dimensionless parameters.