Theoretical investigation of heat and mass transfer for hollow fibre integrated evaporative cooling system

Abstract

Due to the advantages of light weight, corrosive resistant and low cost, hollow fibres have been studied as the substitute for metallic materials. A novel hollow fibre integrated evaporative cooling system, in which the hollow fibre module constitutes as the humidifier and evaporative cooler, is proposed. This novel hollow fibre integrated evaporative cooling system will provide a comfortable indoor environment for hot and dry area. Moreover, the water vapour can permeate through the hollow fibre effectively, and the liquid water droplets will be prevented from mixing with the processed air. A mathematical model, which takes into account of the heat transfer between incoming air and the circulating water inside the fiber, and the water evaporation through the fibre, is developed and analyzed. The variations of incoming air velocity, fibre inside diameter, the incoming air temperature and humidity on the evaporative cooling effectiveness were discussed in this paper. The results showed that as the incoming air velocity increased from 0.2m/s to 0.8m/s, the saturation efficiency was between 0.52 and 0.84. The theoretical investigation revealed that this novel hollow integrated evaporative cooling system is compact, which offers relatively high heat and mass transfer performance.