A Simplified Model of Desiccant Wheel and Implementation in a Design Tool

Abstract

A new class of heat and mass transfer model for a desiccant wheel has been presented and implemented in a design tool. Having studied the behavior of the system in different conditions and sensitivity studies, two physical parameters have been chosen to make simplified models or correlations. Using 1500 data of model solutions, two correlations have been made by an optimization routine in Matlab. These equations correlate outlet air conditions of a desiccant wheel to inlet air conditions of air streams and also the wheel and air speeds. The correlations are limited to be used only in the given range of air conditions and wheel speed. However, the range covers the practical situation that usually happens according to the weather data. The behavior of air conditions in Mollier diagram shows that the error for simulation of a typical cooling cycle to calculate supply air conditions is reduced with a factor of almost 3 times smaller. This shows that even in those ranges with low accuracy the correlations are useful. These simplified equations will be used in the design tools as has been presented in details in this paper.