Numerical simulation of membrane humidifier with different flow fields for medical application

Abstract

Medical humidifier is one of the vital instruments for a respiratory patient in hospital, which is used to humidify the required oxygen for respiratory patients. The conventional type of humidifier, bubble humidifier, has some technical problems, including the need to drain condensed water and a lack of accurate control of air or oxygen required by the patient. In contrast, Membrane humidifier has exciting advantages, including the simplicity of the system, the absence of moving parts, very low noise, and the ability to control temperature and humidity. In this study, three configurations, including parallel, cross, and serpentine of a single module of a membrane humidifier according to the person's weight and breathing rate (the range of 10–28 SLPM) are numerically investigated. For validation of numerical models, a membrane humidifier experimental setup test is used. The obtained results indicated that the crossflow configuration for membrane humidifier has a minimum Dew Point Approach Temperature (DPAT) (2<DPAT<5), which confirms that this flow field has better performance than other flow fields. The results show that increasing the volume flow rate increases the DPAT for membrane humidifiers and Water Vapor Temperature Recovery (WVTR). Furthermore, with an increase of 7 ​L/min of the gas mixture, the relative humidity has decreased by about 30%. This decrease was most outstanding in the cross-flow field and less in the serpentine flow field.

Keywords

• Membrane humidifier
• 3D multiphase model
• Relative humidity
• Temperature
• Medical