Study on Physical Properties of Membranes and Heat and Mass Transfer of a Planar Humidifier

• Main Authors: Yu-Hsuan Chang, 張祐瑄
• Other Authors: Wei-Mon Yan
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/4mz5fx

碩士 === 國立臺北科技大學 === 能源與冷凍空調工程系 === 106 === In this paper, the effects of the physical properties of membrane on the heat and mass transfer characteristics and humidificaion performance of planar humidifiers are investigated experimentally. The physical properties, the air permeability and the water vapor permeability, are used as the indexes to evaluate the mambrane applicability for planar humidifiers. Moreover. the performance of the planar humidifiers with different membranes are evaluated by dew point approach temperature, pressure loss, water flux, water recovery, air pumping power and coefficient of performance. In this work, the experiments can be divided into three parts. In the first part, the air permeability rates of a variety of membranes are measured. The experimental results show that the RO, Nafion and PV membranes have lower air permeability rates under the same degree of vacuum pressure.The air separability of these three types of membrane match the requirement of planar humidifiers In the second part, the measurement of the water vapor permeability of the RO, Nafion and PV membranes are carried out. The results show that the membrane with lower air permeability has lower water vapor permeability. In the third part, the planar humidifiers equipped with the RO, Nafion and PV membranes are tested. The experimental results show that the humidifier with the Nafion membrane has the lowest dew point approach temperature. The water flux and the water recovery rate increase along with the dew point approach temperature. On the other hand, the humidifier with the PV membrane has the lowest pressure loss, which leads to the lowest pump work and the highest coefficient of performance.