逆向求解估算热风干燥对流传质系数

利用逆向求解Fick扩散定律，比较胡萝卜切片热风干燥试验数据与数值模拟计算结果，确定胡萝卜切片试样表层局部干基含水率，联合平均值理论对不同温度、不同相对湿度热空气及不同厚度胡萝卜切片试样条件下的热风干燥对流传质系数进行迭代估算。结果表明：胡萝卜切片试样厚度、平均干基含水率、热空气温度和相对湿度对胡萝卜切片热风干燥对流传质系数估算值大小几乎没有影响。干燥末期，胡萝卜切片热风干燥对流传质系数估算值出现陡增，这是由于在热风干燥末期，胡萝卜切片试样表层局部干基含水率接近其平衡干基含水率，测算公式中分母数值趋于0所致。

Estimation of Hot Air Drying Convective Mass Transfer Coefficient by the Inverse Solution Method

Fick diffusion law is solved as a inverse problem, comparing the numerical simulation results to the hot air drying test data, the surface local moisture content of carrot slice samples were determined. Combined with the average theory, the convective mass transfer coeffi-cients were iteratively estimated under different temperature, relative humidity of hot air and different thickness of carrot slice samples. The re-sults showed that the thickness and the moisture content of carrot slice, temperature and relative humidity of hot air have hardly effect on the estimated values of the convective mass transfer coefficients. At the end of drying, the estimated values of the convective mass transfer coeffi-cients increased sharply due to the surface local moisture content of carrot slice samples close to their equilibrium moisture content, resulting in the value of the denominator close to zero in the estimated equation.