Development and investigation on the dehumidification and corrosion resistance performance of a new mixed liquid desiccant

• Published in: International journal of heat and mass transfer 2019-03, Vol.130, p.72-82
• Main Authors: Wen, Tao, Lu, Lin, Nie, Yidan, Zhong, Hong
• Format: Article
• Language: English
• Subjects: Cooling; Cooling systems; Corrosion; Corrosion resistance; Corrosion tests; Dehumidification; Desiccants; Electrochemical test; Energy conservation; Falling film; Heat resistance; Humidity; Liquid desiccant; Lithium chloride; Temperature; Vapor pressure; Wettability; Wetting
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2018.10.066

•A new mixed liquid desiccant was developed with the formula of LiCl/hydroxyethyl urea/water.•The corrodibility of liquid desiccant were identified by electrochemical method firstly.•The dehumidification performance of the mixed liquid desiccant is better caused by greater wetting ratio.•A new correlation for dehumidification effectiveness was proposed. The liquid desiccant cooling system (LDCS) is regarded as a promising alternative for the traditional vapor compression cooling system due to its energy saving potential and accurate control ability of both temperature and humidity. However, metal corrosion of mass exchanger plate caused by the liquid desiccant greatly restricts the application of LDCS. The present study developed a new kind of mixed liquid desiccant to reduce the corrodibility, and the corrodibility of new mixed solution was examined as well as the dehumidification performance. The vapor pressure of the mixed solution was measured by static method firstly, and the corrosion characteristics were tested by electrochemical method and compared with the ones of normal lithium chloride (LiCl) solution. Comparative investigations were also conducted to study the dehumidification performance under various operating conditions. The experimental results indicate that the corrodibility of new mixed solution is far smaller than that of normal LiCl solution, and the dehumidification performance in terms of absolute moisture change and effectiveness has a significant improvement of 8.7–14.3% and 5.8–15.2% for the newly mixed solution compared with LiCl solution because of the excellent wettability of mixed solution on dehumidifier. The wetting area increases from 0.172 m2 for LiCl solution to 0.184 m2 for mixed solution. In addition, a correlation to predict the dehumidification effectiveness of the mixed solution was also proposed with the average mean absolute relative deviation of 4.51%. The newly developed mixed liquid desiccant is a promising alternative for the commercial application of LDCS with small corrodibility and better dehumidification performance.