果蔬物料变化对微波加热温度特性的影响  

The effect of fruits and vegetables changes on the temperature characteristic during microwave heating

作　　者：张乐道 虞启辉[2] 丁小航 ZHANG Ledao;YU Qihui;DING Xiaohang(School of Life Science and Technology,Inner Mongolia University of Science and Technology,Baotou,Inner Mongolia 014010,China;School of Mechanical Engineering,Inner Mongolia University of Science and Technology,Baotou,Inner Mongolia 014010,China)

机构地区：[1]内蒙古科技大学生命科学与技术学院,内蒙古包头014010 [2]内蒙古科技大学机械工程学院,内蒙古包头014010

出　　处：《食品与机械》2024年第9期29-35,共7页Food and Machinery

基　　金：国家自然科学基金青年科学基金项目(编号:52006109)。

摘　　要：[目的]解决微波加热时,果蔬物料内会出现因局部温度过高而引起的焦化现象。[方法]建立介电特性随温度变化的电磁—热传导耦合模型,通过试验验证了模型的正确性。[结果]当形状为正方体、球体时,介电特性值较大的物料更容易在偏离物料中心处、中心处形成高温聚集区,高温聚集区的温度可比周围温度高10℃以上;若尺寸相同,介电特性越小的物料温度均匀性越高,介电常数减少24.8%可使温度均匀性提高43.8%。[结论]通过调节物料的介电特性和尺寸可有效控制物料温度分布的均匀性。[Objective]This study aimed to solve coking scorch caused by excessive local temperature often occurs when microwave heating of fruit and vegetable materials.[Methods]A coupling model of electromagnetic-heat conduction with dielectric properties varying with temperature was established,and the correctness of the model was verified by experiments.[Results]When the shape is cube,materials with larger dielectric properties are more likely to form a high temperature accumulation zone far from the center,and when the shape is sphere,materials with larger dielectric properties are more likely to form a high temperature accumulation zone in the center.If the size is the same,the temperature uniformity of the material with smaller dielectric properties is higher,and the temperature uniformity is increased by 43.8%when the dielectric constant is reduced by 24.8%.[Conclusion]The temperature distribution uniformity of the material can be effectively controlled by adjusting the dielectric characteristics and size of the material.

关 键 词：介电特性 物料尺寸 温度分布 温度均匀性 微波 

分 类 号：TS255.1[轻工技术与工程—农产品加工及贮藏工程]