LiCl-CaCl_(2)混合溶液表面水蒸气分压力测量及模型修正

Measurement and model modification of water vapor pressure of LiCl-CaCl_(2) mixed solution

溶液除湿系统循环工质中,对液体干燥剂(氯化锂和氯化钙单(多)组分溶液)的饱和水蒸气分压力进行研究,实验测量2种除湿工质的单组分溶液及不同配比的混合溶液饱和水蒸气分压力,并改进理论模型。在进行实验测量并与理论计算模型对比后发现,单组分溶液饱和水蒸气分压力使用Conde给出的方法计算较为准确。对于混合溶液,当溶液质量分数和温度较高时,简单混合模型和NRTL模型的混合溶液饱和水蒸气分压力计算值与实验结果都相差较大,需对模型进行修正。修正后的简单混合模型和NRTL模型对计算LiCl-CaCl_(2)混合溶液表面蒸汽压力更为精准。研究结果对采用LiCl-CaCl_(2)混合溶液进行除湿/再生的理论模拟提供了更为精确的物性预测模型。

The saturated vapor pressures of the single-component(multi-component)liquid desiccant,lithium chloride and calcium chloride as well as their mixture were studied,which are most widely used in the liquid desiccant system.The saturated vapor pressures of two kinds of working medium and their mixtures with different ratios were measured experimentally,and the theoretical models were improved.By comparing the experimentally measured values with the calculated values of the model,it was found that the saturated vapor pressure of single-component solution can be calculated precisely using the models given by Conde.As for the mixed solution,when the mass fraction and temperature of the mixed solution were high,the calculated values of the saturated vapor pressure of the mixed solution,no matter in the simple mixing model or in the NRTL model,were greatly different from the experimental results,so the models need to be modified.The modified simple mixing model and NRTL model are more accurate in calculating the saturated vapor pressure of LiCl-CaCl_(2) mixed solution.The results provide a more accurate predicted model of physical property for the theoretical simulation of dehumidification/regeneration using LiCl-CaCl_(2) mixed solution.