To investigate the drying characteristics of multi-layer-arrangement cabbage seeds with heat pump drying

a cabbage seed heat pump drying model was built in this paper. It consists of the heat and mass transfer model of both drying air and cabbage seeds. The model was used to simulate the drying characteristics of cabbage seeds with three-layer orderly arrangement. The mean moisture content and temperature of overall cabbage seeds

internal moisture content and temperature of cabbage seeds were calculated and analyzed. Results show that seeds in the top layer dry faster than those in the bottom layer. So

the moisture content of different seeds rises gradually

while temperature decreases both along and across the flow direction of drying air. The moisture contents of seeds in the top layer rise from 12.67% to 12.80% along the flow direction of dry air in 3000 s

with temperatures decrease from 39.8℃ to 39.5℃. And the moisture contents of seeds in the eighth column rise from 12.73% to 12.78% across the flow direction of dry air in 3000 s

with temperatures decrease from 39.7℃ to 39.5℃.