两种常用液体吸湿剂传质性能的比较

分析比较了溴化锂溶液（LiBr）、氯化锂溶液（LiCl）这两种常用的吸湿盐溶液与湿空气之间的传质性能，二者比较的基准是：溶液温度与表面蒸气压分别对应相等。相同状态时，LiBr溶液的密度约是LiCl溶液的1.2倍，比热容约是LiCl溶液的0.8倍，即当LiBr和LiCl溶液的体积流量相同时，二者的热容量大致相等。通过对热质交换过程解析解的分析，得到影响溶液与空气传质效果的核心参数为：空气与溶液的热容量比和传质单元数。在实验测试分别采用LiBr和LiCl溶液的除湿、再生工况性能的基础上，拟合出了传质系数随着空气与溶液进口参数的变化规律。在实验工况范围内，当LiBr与LiCl溶液的体积流量相同时，采用LiBr溶液的传质性能稍优于LiCl溶液，但二者差异不大。

Mass transfer performance comparison of two commonly used liquid desiccants

Mass transfer performance of two commonly used liquid desiccants: LiBr aqueous solution and LiCl aqueous solution was compared at the same solution temperature and surface vapor pressure. The heat capacities of the two desiccants were about the same at the same volumetric flow rate, while LiBr solution had a higher density and a smaller specific heat capacity. The key factors influencing performance were heat capacity ratio of air to desiccant and mass transfer unit, according to the analysis of the analytical solutions of heat and mass transfer processes. The change of mass transfer coefficient with air and desiccant inlet parameters was derived based on the experimental results. The mass transfer performance of LiBr solution was a little better than that of LiCl solution at the same desiccant volumetric flow rate within the experimental operating range.