描述了绝热型与内冷型两类平板溶液除湿器的结构特点,在盐溶液竖直降膜与湿空气顺流、充分发展的工况下,基于Navier-Stokes动量方程建立盐溶液与湿空气热、质传递过程耦合数学模型,以LiCl水溶液作为除湿剂,考虑气液界面处的剪切力边界条件,在恒壁温与绝热边界条件下,对两种具有相同尺寸规格的除湿器的除湿过程进行了数值模拟,得到沿高度方向上盐溶液温度、浓度和湿空气温度、含湿量的变化情况,并对两者在相同工况下进行对比,定量描述了两类除湿器在除湿性能上的差异.结果发现内冷型除湿器的出口溶液的温度更低,接近于冷却介质温度,而且处理后的湿空气的含湿量比绝热型除湿器低5.1g·kg^-1,空气的出口温度也要低近10.5℃,但除湿溶液的浓度变化很小,进、出口浓度差不到1%.
This paper describes two configurations of liquid desiccant dehumidifiers-internally cooled and adiabatic dehumidifiers. Based on the Navier-Stokes equation, the processes of heat and mass transfers between air and liquid desiccant were modeled in vertical parallel film laminar flow. Aqueous lithium chloride was used as liquid desiccant, and the dehumidification processes were simulated on the two types of dehumidifiers with the same dimension. The parameters changes of air and liquid desiccant along the direction of plate height were obtained. A comparison between the two dehumidifiers was made under the same operation conditions. The results showed that the temperature of liquid desiccant coming from the internally cooled dehumidifier was much lower, very close to the temperature of the cooling medium, and its outlet air humidity was 5.1 g · kg^-1 less than the one of the adiabatic dehumidifier, and the outlet air temperature was 10. 5℃ lower. On the other hand, the concentration of the liquid desiccant changed little. The concentration difference between inlet and outlet liquid desiccant was less than 1%.