A Novel Approach to Modeling of Cooling Coils for Control and Optimmization of Hvac Systems

ABSTRACT A cooling coil unit (CCU) is nonlinear in nature. Existing CCU models for control and optimization are either linear approximations around working point or very complex nonlinear ones, resulting in difficulties for real time applications. Therefore, a simple yet accurate CCU engineering model is very important to obtain a better performance for Heating, Ventilating, and Air-Conditioning (HVAC) systems. In this paper, a technique for developing a simple yet accurate engineering CCU model is presented. The modeling technique is based on energy balance and heat transfer principles. Commissioning information is then used to estimate up to maximum three model parameters by either linear or non-linear least-squares method. Experiment shows that the method is robust and gives a good match to the real performance over the entire operating range compared with methods presented in the literature. This model is expected to have wide applications in control and optimization of HVAC systems. The modeling methodology can also be extended to other heat exchangers.