陈皮热泵干燥动力学模型构建和特性分析

Construction and Characteristic Analysis of Drying Kinetic Model of Pericarpium Citri Reticulatae Heat Pump

为了研究陈皮热泵干燥过程和特性,提高干燥后品质,减少干燥时间,针对柑皮在干燥温度(40、50、60℃)、出风速度(1、2、3m/s)、切片长度(10、20、30mm)的干燥条件下,分析干燥特性、干燥曲线、水分扩散系数和活化能。通过对不同干燥动力学模型进行研究,对陈皮干燥过程中的干燥曲线进行拟合,建立干燥温度、出风速度和切片长度与模型参数的定量关系。研究表明:陈皮热泵干燥以降速干燥为主,升速干燥的时间较短。对于试验结果进行模型非线性拟合研究,建立陈皮热泵干燥模型与试验结果进行比较,分析得出:Weibull分布函数适用于陈皮的热泵干燥工艺中;干燥温度和出风速度对水分比和干燥速率均有显著影响,切片长度对水分比和干燥速率有较小的影响;陈皮在热泵干燥中水分的有效扩散系数范围为9.69×10^(-6)~14.05×10^(-6)m^(2)/s;陈皮热泵干燥的活化能为13.221kJ/mol。研究可为陈皮热泵干燥构建动力学模型提供技术依据。

In order to study the drying process and characteristics of Chenpi heat pump,improve the quality after drying and reduce the drying time,the object of this paper is to analyse and study the drying characteristics,drying curve,moisture diffusion coefficient and activation energy.The drying curves during the drying of peel were fitted by studying different drying kinetic models to establish the quantitative relationships between drying temperature,air outlet speed and slice length and the model parameters.The study shows that the drying time of Chenpi is mainly at the descending speed and the ascending speed is shorter.The research shows that:the heat pump drying of Chenpi is mainly at a reduced speed,and the drying time of ascending speed is shorter;for the experimental results,a model non-linear fitting study was conducted,and a heat pump drying model of Chenpi was established to compare with the experimental results,and the analysis concluded that the Weibull distribution function is applicable to the heat pump drying process of Chenpi;the drying temperature and air outlet speed have obvious effects on the moisture ratio and drying rate,and the slice length has less effect on the moisture ratio and This study provides a technical basis for the construction of a kinetic model for the heat pump drying of Chenpi.