Numerical simulation and experimental study of heat pump drying characteristics of papaya
To improve the drying uniformity and drying rate of papaya and optimise the drying process,the drying characteristics of papaya heat pump drying were investigated.A one-factor papaya heat pump drying test was conducted,and a numerical model was ab-stracted for simulation study based on the test conditions.The drying uniformity and temperature rise curves of papaya slices under different parameters were obtained by adjusting the parameters of incoming temperature,humidity,speed,and thickness of papaya slices in the model.A comparison of the experimental and simulation results yielded an optimised solution to improve the uniformity and rate of the pa-paya drying process.The uniformity and rate of papaya slices drying can be effectively improved by increasing the air velocity in the range of incoming temperature of 55-70℃,humidity of 15%-30%,and velocity of 0.2-0.8 m/s.The maximum error between the drying inhomogeneity coefficient ε and the predicted value of the model in the test was 0.218,and the average error was 0.064,with the extreme value being 36.75%larger compared with the simulation results.The fit was better in the pre-drying period,and the papaya inhomogeneity coefficient in the middle and late stages of the test was relatively high compared with the simulation results.
papayaheat pump dryinguniformity of dryingdrying ratenumerical simulation