Development of Simulator for Microwave Thawing and Heating

目前，冷冻食品迅速增加，用微波炉解冻，加热不均匀。在微波加热或蒸煮的情况下，由于食物的受热度随盐浓度的变化而变化，可能会出现受热不均匀的情况。为了控制食品在微波加热过程中的温度分布不均匀，本研究开发了用于预测食品微波加热过程温度分布的模拟器。2003财年，开发了具有可选介电性能的模型食品，并建立了数学模型，以获得在不定形状态下的内部温度分布。在2004会计年度，根据2004会计年度的结果进行了以下审查。首先，2003财年开发的数学模型假设加热和烹饪温度在0℃以上，没有考虑解冻过程。加热与解冻的较大区别在于，比热、导热系数等物理性质发生较大变化，在凝固点产生潜热。本研究采用外观比热模型建立数学模型，该模型不需要考虑冻结层和熔化层，可以使用一般的热传导方程。并利用Hayakawa等人的预测方程对具有温度依赖性的物性进行估计。然后，利用该数学模型开发了仿真器，并用有限元法进行了求解。在模拟器中，在个人电脑屏幕上输入以下数据，并制作计算所需的数据文件：(1)样品形状，(2)制作元件的坐标数据，(3)解冻过程存在的信息，(4)各元件的介电特性，(5)热物性值。使用此数据文件计算温度分布。该模拟器的计算结果与模型食品的实测值吻合较好，证明了该模拟器的有效性。少

At present, the frozen food has been rapidly increased, and it is thawed by the microwave oven which causes uneven heating. In the case of microwave heating or cooking, since the heating-ness of food is changed with the salt concentration, the uneven heating may be occurred. In this research, in order to control the uneven heating, the simulator for predicting the temperature distribution during microwave heating of the food was developed.In the 2003 fiscal year, the model food with optional dielectric properties was developed, and the mathematical model was developed in order to obtain internal temperature distribution even in the indeterminate form state. In the 2004 fiscal year, the following was examined based on the result in 2004 fiscal year. First of all, the mathematical model developed in the 2003 fiscal year assumed heating and cooking over 0℃, and the thawing process was not considered. Large difference of heating and thawing is that the physical properties such as specific … More heat and thermal conductivity greatly changes and that the latent heat generates at freezing point. In this study, mathematical model was developed using the appearance specific heat model, which does not need to consider frozen and melting layers, and it is possible to use the general heat conduction equation. And the predictive equations of Hayakawa et al. were used in the estimation of physical property with temperature dependence.Next, the simulator was developed using this mathematical model, and was solved using finite element method. In the simulator, following data is input on the personal computer screen, and the data file necessary for the calculation is made, (1)The shape of sample, (2)The coordinate data for making the element, (3)Information of the thawing process existence, (4)The dielectric characteristic of each element, (5)The thermophysical property values. Temperature distribution was calculated using this data file.It was confirmed that this simulator was effective, because calculated result by this simulator and measured value, which was obtained using model food, agreed well. Less