Feasibility of a two-stage liquid desiccant dehumidification system driven by low-temperature heat and power

Liquid-desiccant dehumidification technology is a promising way to take advantage of low-grade energy to dry air for air conditioning and industrial applications. This paper proposed a two-stage liquid-desiccant dehumidification system driven by low-temperature heat and electric power, which is integrated with a vapor compression refrigeration system that performs deep dehumidification. Air moisture is preliminarily removed by the desiccant solution at environmental temperature in a first-stage dehumidifier and then deeply removed by the desiccant solution cooled to 18 °C by a vapor compression refrigerator. Simulation results show that the new system can decrease power consumption by 30.63% compared with a conventional cooling dehumidification system. The equivalent power-generation efficiency of the proposed system can reach 2.91%. Finally, the power-saving mechanism of the proposed system was illuminated by conducting the exergy analysis and the study of the surface vapor partial-pressure difference in the liquid desiccant dehumidifiers.