Performance Analysis of a Solid Desiccant Air Dehumidifier

Abstract

A desiccant air dehumidification system is widely used in many applications such as refrigeration, crops drying, food industries, pharmaceutical and air-conditioning. The thermal effectiveness is often used to represent the performance of the system. Its value depends on the psychrometric properties of the incoming air and several other parameters. This article presents an experimental study to determine the thermal performance of a compact solid desiccant air dehumidifier. The effects of percent opening combination of the control valve for the process and regeneration air ducting on the thermal performances of the dehumidifier was investigated. An experimental rig was fabricated for these purposes. It consists of a solid desiccant air dehumidifier, process and regeneration air ducts, instrumentation and data acquisition system. Experimental data were acquired under a steady-state operating condition, for three cases of control valve opening combinations. It was found that the thermal effectiveness of the air dehumidifier decreases with increasing flow velocity of the process air. At a given process air flow velocity, the thermal effectiveness for case 1 is higher than that for case 3. The difference in the thermal effectiveness between the two cases becomes smaller as the process air flow velocity increases.