微波加热过程中圆柱型包装食品的温度分布研究

Study on the Temperature Distributions in Cylindrically Packaged Food during Microwave Heating

从实验和理论上考察介电特性(介电常数、介电损失率)对圆柱型食品温度分布形态形成的影响。实验中以凝胶琼脂为实验样品,通过对样品添加NaCl来改变样品的介电特性,采用液晶感温片测得样品直径面的温度分布。结果表明,添加NaCl可提高样品的表面加热性,使样品的温度分布高温区由中心部向着项角部转移。为了从理论上对该现象加以描述,采用数学模型对样品中的温度分布进行了计算,结果表明,计算值与实验值有着良好的一致性。

In this study, the effect of the dielectric properties (dielectric constant、 rate of dielectric loss factor) on the temperature distributions of cylindrical foods was investigated in both experimental and theoretical bases. The agar gel was used as experimental samples, through the addition of sodium chloride ( NaCl ) change the dielectric properties of samples. The temperature distributions of samples section was measured by liquid crystal sheet. The results showed that the surface heating property could be incresced by adding NaCl, the high temperature zone of sample was moved from the center of the cylinder to the top corner. To describe these phenomena theoretically, the temperature distributions in the samples were calculated using the mathematical model. The result showed that the calculated results accorded closely with the experimental values.