微波加热沥青混合料传热模型研究

RESEARCH ON HEAT TRANSFER MODEL OF MICROWAVE HEATING ASPHALT MIXTURES

为了得到沥青混合料通过微波加热后表面的温度分布情况,通过Maxwell方程建立了沥青混合料内电场的分布情况,提出了一种沥青混合料内传热模型的解法,分析了理论求解传热模型的局限性与困难性。使用仿真和实验的方法,结果表明:第一,理论仿真得到的沥青混合料表面温度高于实验所测得的温度;第二,沥青混合料在加热过程中,加热区域边界处热量散失明显;第三,沥青混合料被加热区域表面温度梯度明显,且仿真所得到的温度分布梯度比实验得到的温度分布梯度大;第四,被加热区域沥青混合料最高温度达到了120℃左右也不会出现明显的焦化现象。

In order to achieve the surface temperature distribution of the asphalt mixture by microwave heating, the equation is established by the Maxwell distribution of the electric field within the asphalt mixture. We propose a solution within the asphalt mixture transfer model. The limitations of the model are solved by analyzing the results in theory. The simulation and experimental methods are used to obtain the temperature distribution on the surface of the asphalt mixture. The theoretical reasons difference between simulation and experimental results are obtained by comparative analysis. Firstly, theoretical simulations on the surface of the asphalt mixture temperature are higher than the measured temperature by experiments. Secondly, during the heating process of asphalt mixture, the heat loss significantly at the heating zone boundary. Thirdly, temperature gradient is evident in the heated zone of the asphalt mixture＇s surface. Finally, the heated area of asphalt mixture about 120 ℃ does not appear significant coking phenomenon.