Modeling and Analysis of Cooling Coil for Control System Design Using Gray Box Approach

Abstract

The purpose of the study is to design a method analyzing dynamic behavior of cooling coil in order to be applicable in online simulations. Coils account for the highest energy consumers among other components in an Air Handling Unit (AHU). Essential data as input-output of neural network is provided using energy and mass conservation equations. An implicit numerical method is used to solve dynamic equations of coil. The results of mathematical methods are applied in the output of neural network to design an online model. The proposed model is based on an active coil used in Heating, Ventilation and Air Conditioning (HVAC) systems of clean rooms in Iran Pasteur Institute. Since in active air handlers, input and outputs are not measured, here we model air conditioning systems generally. The results in comparison with actual system data indicate an acceptable performance of the proposed method, so that combination of numerical results with a nonlinear autoregressive exogenous model (NARX) makes it possible to control system effectively by saving a significant amount of time.