高效填料型除湿器新传质关联式实验研究

New Experimental Correlations for the Mass Transfer of a High-efficiency Packed-type Dehumidifier

填料作为溶液除湿器的重要部件,其传质特性直接关系到整个溶液除湿空调系统性能的好坏。本文搭建了逆流填料型溶液除湿实验台,以Li Cl溶液为除湿溶液,对高比表面积波纹纤维规整填料(650 m2/m3)进行了除湿实验研究。以气液界面的水蒸气分压差为传质驱动力,获得了新的传质系数实验关联式和除湿效率实验关联式。并对该填料的除湿效果与文献中的不同填料进行对比。结果表明:该填料具有最高的单位体积传质系数,且填料的单位体积传质系数随着填料比表面积的增加而增大。传质系数实验关联式计算值与实验值相对偏差在±20%以内,除湿效率实验关联式计算值与实验值相对偏差在±15%以内。新的传质关联式可以比较精确的计算除湿器的传质性能。

The packing is a crucial part of a liquid-desiccant dehumidifier,and its mass-transfer characteristics have a great impact on the overall performance of liquid-desiccant-based air-conditioning systems. An experimental test rig was built to study the performance of a counter-flow packed-type liquid-desiccant dehumidifier that employs cross-corrugated cellulose-structured packing with a high specific surface area( 650 m2/m3). A Li Cl aqueous solution was used as the desiccant solution. The water-vapor pressure difference between the gas and liquid interface was considered as the mass-transfer-driven force. New experimental correlations for the mass-transfer coefficient and the dehumidification effectiveness were developed. The performance of this type of packing was compared with other types of packing in the literature. The results show that this type of packing has the highest volumetric mass-transfer coefficient. In addition,the volumetric mass-transfer coefficient is found to increase with the specific surface area of the packing. The deviations between the experimental data and the predicted data using the experimental correlation for the mass-transfer coefficient are within ± 20%,and within ± 15% for the dehumidification effectiveness. This indicates that the two new correlations can be used to accurately predict the mass-transfer performance of a dehumidifier.