基于Weibull分布函数的枸杞微波干燥过程模拟及应用

为了探究Weibull分布函数中各参数的影响因素及其在枸杞微波热风联合干燥中的应用,以枸杞在不同脉冲比(脉冲比1.5:2 min/1 min;脉冲比1.67:3 min/2 min;脉冲比2:1 min/1 min)、微波功率(185、200、215 W)、微波介入时枸杞含水率(30%,40%,50%)条件下的干燥过程为研究对象,利用Weibull分布函数对其干燥动力学曲线进行模拟并通过建立的Weibull模型对枸杞微波干燥过程中的水分有效扩散系数和干燥活化能进行分析。实验表明:Weibull分布函数能够较好地模拟枸杞的微波干燥过程;尺度参数α与微波脉冲比、微波功率以及含水率均有关,并且随着微波功率的升高而降低,随着微波脉冲比和含水率的升高而升高;而初始含水率、脉冲比和微波功率对形状参数β的影响较小;根据Weibull分布含水分析得到枸杞的水分有效扩散系数为1.7×10~(-5)~3.2×10~(-5)m~2/h以及枸杞的干燥活化能为54.78 k J/mol。

Application and Modeling Microwave Drying of Chinese Wolfberry Based on Weibull Distribution

In order to explore the factors of the parameters in the Weibull distribution function and its application in Chinese wolfberry microwave hot air drying, he drying processes of Chinese wolfberry in different pulse ratios (pulse ratio of 1.5:2 min/1 min; pulse ratio of 1.67: 3min/2 min; pulse ratio of 2: 1 min/1 min), microwave power (185, 200, 215 W) and moisture content of Chinese wolfberry (30%, 40%, 50%) were selected as the study objects The drying kinetics curves were simulated based on the Weibull distribution function, and the effective diffusion coefficient and dry activation energy during the microwave drying of wolfberry were analyzed by the established Weibull model. The results showed that the Weibull distribution function could simulate the microwave drying process of wolfberry well. The scale parameter alpha was related to microwave pulse ratio, microwave power and moisture content, and it decreased with the increase of microwave power, while increased with the increase of microwave pulse ratio and moisture content. The initial water content, pulse ratio and microwave power had less influence on shaping parameter beta. According to the water content analysis of Weibull, the water effective diffusion coefficient of Chinese wolfberry was 1.7×10-5~3.2×10-5 m2/h and the dry activation energy of Chinese wolfberry was 54.78 k J/mol.