Abstract:

Humid air handling process is a key part of the air-conditioning system. Air handling units using liquid desiccant or desiccant wheel are the common air humidity control devices using desiccants. Based on the basic air handling process using desiccants, similarity between the dehumidification units using liquid desiccant and desiccant wheel is analyzed in present research. Uniformity coefficient ξ is used to describe the uniformity of the driving force between air and desiccants for heat and mass transfer, then to investigate the diversity between liquid desiccant dehumidification and desiccant wheel. It is found that, for the desiccant wheel, distribution of the driving force are relatively uniform throughout the whole wheel. As to the liquid desiccant process, the uniformity characteristic of the driving force is significantly influenced by the relative position of the inlet air and solution states. Only when the inlet air and solution states are along the iso-relative-humidity line, the distribution of the driving force is uniform, with a uniformity coefficient ξ close to 1. Analysis on different air handling processes indicate that the distribution characteristic of the driving force offers an effective guidance for constructing an optimized actual process for air dehumification.

Key words: liquid desiccant, desiccant wheel, uniformity coefficient, driving force distribution, process optimization

摘要：

空气湿度处理是空调系统的基本组成环节,溶液式、转轮式空气处理装置是常见的采用液体或固体吸湿剂对空气进行湿度处理的设备。从采用吸湿剂的基本空气处理过程出发,分析了溶液式与固体转轮式空气湿度处理方式之间的相似性。针对传热、传质过程驱动力的沿程分布特性进行研究,采用不均匀性系数ξ描述空气与吸湿剂之间传递过程驱动力的均匀性,刻画了固体转轮与溶液除湿方式之间的差异性。分析表明:转轮方式沿程参数较为均匀;溶液除湿方式受空气与溶液进口相对位置的影响显著,只有当二者进口状态沿等相对湿度线时,驱动力分布均匀,不均匀性系数ξ接近1。对不同空气处理流程的分析表明,驱动力特性分析能够为实际流程构建提供有效指导。

关键词: 溶液除湿, 转轮除湿, 不均匀性系数, 驱动力分布, 流程优化