Performance Prediction for Counter-flow Desiccant Wheels Using an Approximate Solution

An analytical model has been developed to predict the performance of desiccant wheels. This model is based on an approximate solution derived from a set of linearized governing equations, with the assumption that the desiccant temperature and moisture concentration change over time according to trigonometric functions. The model predicts the outlet conditions of air streams in a silica gel desiccant wheel under typical operating conditions, and the results are compared with those obtained from a numerical model. It is found that the maximum absolute error is ±1.5 K in dry bulb temperature and ±0.6 g/kg in humidity ratio within the ranges of 0.5≤Cr≤1, 1≤Ntu₀≤5, 10^-2≤Cr*≤10.