Heat pump dehydrator is a modern technology to conserve energy and improve quality of dried products. Compared with conventional drying technologies, this technique consumes less fossil fuel and electricity to produce dried products, while reducing the temperature of the air used in the drying process. Moreover, this technology can also recover latent heat and sensible heat from the waste exhaust gas of the dryer (Hawlader et al., 2003).
However, despite the advantages of heat pump drying, its applicability has not yet been widely accepted in sub-Saharan Africa. This article aims to explore the potential of the heat pump as a drying system in this region, with emphasis on the evaluation of its performance.
The evaluation of the performance of the heat pump as a drying device is difficult because it is not a simple energy consumer. The heat pump only produces a small amount of electrical energy during operation; the rest of its energy is obtained from the thermal energy contained in the dried air, which has a high calorific value.
Thus, the evaluation of the performance of a heat pump for a drying application must consider the total energy consumption of the entire drying process. In order to calculate this, the efficiency of the system may be defined as a product of its COP and SMER.
The SMER of a heat pump is defined as the ratio of the electrical energy consumed by the heat pump to the amount of water evaporated. A good SMER is a significant factor in the evaluation of the performance of a heat pumps for drying applications. In addition, the SMER of a heat pump can be improved by adjusting the heating and cooling parameters. heat pump dehydrator