Principles and Applications of Gas Separation in Nonfrosting Technology

Abstract

Fan coils in low temperature storage rooms or freezing chambers are usually covered with frost during long-term operation. The fan coils can be installed side-wall or overhead in the freezing chamber, and the coils have cast aluminum fins. The usual solutions for frosting on the surfaces of freezing coils is to heat or spray with water to get rid of the frost periodically. However, these solutions are not only energy-consuming, but they also tends to spoil the refrigerated objects in the chamber. The main idea of this research is to achieve nonfrosting by using the technology of absorption-dehumidification to separate the water vapor from the circulating air in the freezing chamber during operations. Therefore, an experimental determination of nonfrosting technology using absorption principles was employed in this study. In the absorption-dehumidification device, the water vapor was absorbed into the liquid desiccant solution, and the diluted solution was regenerated by using the heat sources combined with waste heat from the freezing machine and major heat from a modified water heater. The dried air from the absorption-dehumidification device was circulated in the freezing chamber. The chamber operated at a temperature of −5 to −10°C. Since most of the water vapor in the circulating air is removed by the absorption-dehumidification device, less water vapor can be condensed on the coils. Therefore, no frosty coils were found in this freezing chamber during long-term operation.