微波照射下玄武岩骨料热响应研究

Research on Thermal Response Mechanism of Basalt under Microwave Irradiation

为探究多模微波照射下玄武岩的热响应机理,采用工业常用频率2.45GHz多模谐振腔,利用其特有的均匀电磁场加热均匀等优点,对圆柱形玄武岩试样进行了不同功率下的微波照射处理。通过谐振腔内部热电偶结合红外热成像仪测量不同时间时试样表面的温度分布,获得微波照射过程中试样的升温特性。通过对测量得到的升温数据和经过微波照射的玄武岩试样外观形貌变化进行观测记录,结合多物理场耦合软件COMSOL Multiphysics分析岩石内部温度以及热应力分布情况。结果表明:采用较低功率照射时,玄武岩吸收能量较少不足以引起宏观裂纹;当采用较高功率对选取试样进行照射时,试样迅速升温,并产生炸裂现象。

Due to its unique uniform electromagnetic field,the multi-mode microwave field has the advantages of uniform heating.In order to explore the thermal response mechanism of basalt under the irradiation of multi-mode microwaves,a common industrial frequency 2.45 GHz multi-mode resonator was used to perform different powers on cylindrical basalt samples.Under the microwave irradiation treatment,the temperature distribution of the sample surface at different times is measured by the thermocouple inside the resonant cavity and the infrared thermal imager to obtain the heating characteristics of the sample during the microwave irradiation process.Through the observation and recording of the temperature rising data obtained by the measurement and the appearance changes of the basalt sample subjected to microwave irradiation,combined with the multi-physics coupling software COMSOL Multiphysics,the internal temperature and thermal stress distribution of the rock are analyzed.The results show that when using lower power irradiation,the basalt absorbs less energy and is insufficient to cause macroscopic cracks;when higher power is used to irradiate the selected bright samples,the sample heats up rapidly and bursts.