Solar driven liquid desiccant dehumidification system: Measurements and annual system simulations

• Published in: Applied thermal engineering 2024-04, Vol.242, p.122485, Article 122485
• Main Authors: Mandow, Wael, Micus, Felix, Völker, Lisa, Fleig, Daniel, Jordan, Ulrike
• Format: Article
• Language: English
• Subjects: Dehumidification; Liquid desiccant; Regeneration; Solar heat; TRNSYS
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2024.122485

•TRNSYS model of liquid desiccant air conditioning system.•Validation of model for steady-state and dynamical operation mode.•System simulation for adiabatic and internally cooled absorber.•Accuracy of system model for moisture removal rate yields 6 %.•Solar energy as heat source for regeneration with solar fraction up to 81 %. Liquid desiccant air conditioning (LDAC) systems are used for dehumidification of air to low dew point temperatures. In the presented study a TRNSYS model of a LDAC unit is developed and validated with laboratory measurements. This model is coupled with a solar thermal system that provides heating water for the regeneration process. With this model dynamic annual system simulations can be carried out to simulate the dehumidification of a building. The solar fraction is evaluated for various infiltration rates of the building and solar collector areas with an internally cooled as well as an adiabatic absorption process. The simulation results reveal that high solar fractions of 70% to 81% can be achieved when dimensioning the solar thermal system to cover the regeneration heat demand on a good summer day. This is due to the good correlation of solar irradiance and dehumidification load. Without internal cooling of the absorption process (adiabatic conditions), the solar fraction is reduced by about 10percent points for the same size and operating conditions.