Study on drying characteristics of yam slices under heat pump-electrohydrodynamics combined drying

The drying characteristics of yam slices using heat pump-electrohydrodynamics (EHD) combined drying were studied under the conditions of the drying temperatures of 50–60 °C, the voltages of 80–100 kV and the wind speeds of 1∼3 m/s. The results show that compared with the single heat pump drying, the combined drying can effectively reduce the drying temperature by approximately 5 °C. This is relatively friendly to heat sensitive materials and can also improve the running performance of the heat pump system. Furthermore, the sensory score is increased by approximately 21.4% and the specific energy consumption of combined drying at the voltage of 100 kV is reduced by approximately 27.8%. Under the later stage of the combined drying, the wind speed can be reduced to save energy consumption. Through the analysis of model parameters, Page model is more consistent with the variation law of drying experimental data. This paper provides practical guidance for optimizing the process of yam slices using heat pump-EHD combined drying.