Research On Heat And Mass Transfer Experiment Device And Heat And Mass Coupling Of Asphalt Pavement Based On Microwave Heating

As a new type of heating energy,microwave is widely used in various fields.And when it is introduced to the asphalt pavement heating repair,the asphalt is used as a porous material,placed in the microwave field,under the action of microwave,the polar molecules inside the asphalt(including polar water molecules)rotate rapidly,collide and rub each other,producing a lot of heat.The heat is softened by the inside and outside to achieve the purpose of repairing the road surface.In order to improve the efficiency of repairing asphalt pavement and improve the quality of asphalt pavement,it is necessary to study the heat transfer phenomena in the heating process.The following work has been done in this article:(1)In order to study the heat and mass transfer mechanism of microwave heating asphalt pavement,first of all,the physical parameters of the asphalt pavement material were consulted.The physical parameters,such as porosity and specific surface,which affect the effect of microwave heating,are compared and analyzed,then the research method of asphalt pavement,the theory of heat transfer and the mass transfer theory are discussed.(2)According to the research purpose,a heat transfer and mass transfer experiment device for microwave heating asphalt pavement was designed.The equipment is weighed on the heated asphalt by weighing instrument.the surface temperature of asphalt pavement was measured by infrared thermometer,the distance between the heating chamber and the surface of asphalt pavement by the gear lifting mechanism to adapt to the experimental study of asphalt pavement with different thickness.(3)In order to establish the thermal coupling model of asphalt pavement under microwave action.After analyzing the internal composition of asphalt pavement and the heating process of microwave heating asphalt pavement,the basic assumptions are combined,the heat transfer model and mass transfer model of the asphalt pavement are obtained respectively,and the two models are finally obtained by combining the two models,and the three models are simulated numerically.(4)COMSOL Multiphysics is used to simulate the thermal coupling model,the effects of different thickness,aggregate and humidity on the microwave heating effect were analyzed.In this paper,the simulation results are compared and analyzed,and the reasons for the error between experiment and simulation are discussed.