Study on the coupled heat and mass transfer coefficients of liquid desiccant dehumidification process

The characteristic of desiccant dehumidification was presented based on the NTU-Le model. It suggested that Lewis Number Le had little effect on air outlet humidity ratio, and according to which a new method called h(D)-Le separative evaluation method was developed for determining coupled heat and mass transfer coefficients between air and desiccant solution. The heat and mass transfer coefficients between air and liquid desiccant were obtained by the new evaluation method and experiment data. Effects of the air flow rate on the Lewis Number, the coupled heat and mass transfer coefficients were investigated. The correlations of the air and desiccant solution parameters on mass transfer coefficients were developed. Finally, the actual NTUs were validated to be less than 0.02. The results would have great value to study nonlinear characteristic of dehumidification process and provided an evaluation method for determining the key coefficients.