Numerical Analysis of an Air Humidification System Using Computational Fluid Dynamics

Abstract

Air humidification systems are in demand in many industrial and municipal sectors. Bubble columns are one of the most common forms of laboratory-scale humidifiers. Many operating parameters affect the performance of these systems, such as bubbler geometry, gas flow rate, temperature, the water level in the bubbler, and nozzle type. Since considering all these factors in an experimental system is costly, predicting performance by a computational fluid dynamics model is essential. In the present study, a laboratory-scale bubble column was simulated, and the effect of operating parameters was determined in terms of relative humidity at the outlet. In addition, the hydrodynamic fluid transfer from the nozzle to the outlet was thoroughly evaluated. An acceptable agreement was obtained between the experimental and model data, allowing further investigation on other important variables. Among the geometrical parameters, the ratio of water height to column diameter and nozzle type affected system performance by about 4 % and 20 %. Changing the flow rate and water temperature also affected the humidification process by 15 % and 16 %. The model scheme can be useful in developing and performing humidification systems before practical application.