Enhancement and integration of desiccant evaporative cooling system model calibrated and validated under transient operating conditions

Desiccant cooling systems provide new possibilities in air conditioning technology through the use of either solid or liquid sorption air dehumidification. Such systems can be more reliable and environmental friendly than the conventional systems. The focus of current study is to enhance the existing ideal system component models of the desiccant evaporative cooling system (DEC) developed in an equation-based object-oriented modeling and simulation program, Dymola/Modelica to address the real component operation. Initially, the enhanced component models are calibrated and validated through the transient measurements obtained from the real DEC system installation. Afterward, using the validated physical models of individual components, complete system model has been experimentally calibrated and validated. The obtained results are in good agreement with the actual measurements at the both component and system levels. At the system level, in terms of specific enthalpy of supply air, the resulting maximum and minimum root mean square error (RMSE) and mean percentage error (MPE) between the simulated and measured transient performance is 0.96 kJ/kg and 1.53%. The results show that the enhanced system model is able to predict the performance of the real desiccant cooling system with good accuracy. As such, the current paper contributes to the efforts of bringing simulations closer to performance of real systems under building operating conditions. (C) 2014 Elsevier Ltd. All rights reserved.