疏松混合物材料微波特性分析与应用

发布时间：2018-11-10 08:52

【摘要】：疏松混合物,本文是指将两种或多种物质组成的散粒或粉状物自由地填充到某一固定容器中的堆积状态。应“贫油料微波高功率处理”课题需求,对油砂样品在加热容器中的微波特性进行测量分析,设计出一种提高微波加热效率的手段。本文选择较成熟的TM0n0模式圆柱谐振腔进行物料的复介电常数测量,利用Lichtenecker对数混合物公式计算油砂样品在加热炉内自由堆积状态下的等效复介电常数,并设计了一套能满足工业化需求的加热炉原型机,在常温下做了端口反射的简单测量,与理论比较一致性良好。具体研究成果如下:(1)本文首先针对贫油料在热解过程中的物理特性进行分析,总结出“疏松混合物”的特点,在针对混合物的一系列等效理论中,选择一种有效介质理论作为分析重点;Lichtenecker对数混合物公式得到过理论证明,从而脱离于半经验公式的范畴,利用该公式进行推导,得到混合物料和空气均匀混合下的等效复介电常数表达式;其次,利用CM因子推导了对数公式和其他两种常见公式之间的关系,表明对数公式在实际应用中具有明显优势。(2)随后,根据疏松混合物材料介电特性,提出了利用谐振腔微扰法测量其复介电常数,并制作了TM0n0模式圆柱谐振腔测试系统,搭建了简易的可用于加热的实验平台;然后用石英、聚四氟乙烯和水对测试算法进行校准,在常温下,对两组各10份不同含水率含油率的油砂样品进行测试,分析了测试结果并发现:含油率的高低对测试结果影响不明显,而含水率是影响微波损耗的关键因素。(3)最后,围绕微波加热技术优势展开叙述,应产业化需求,针对915MHz工业微波源,提出利用开放式同轴谐振腔系统作为加热容器的方案,仿真并实际加工了一套同轴腔原型机,常温下分别填充体积分数为0.4、0.5、0.6、0.7的油砂样品,测得端口电压驻波比,与理论值比较发现:同轴谐振腔实测端口反射大于理论值,但变化趋势保持一致,验证了对数公式理论具有一定适用性,最后分析了系统存在的误差项。
[Abstract]:Loose mixture, in this paper, refers to the stacking state in which two or more particles or powders are freely filled in a fixed container. In order to meet the requirement of "microwave high power treatment of lean oil materials", the microwave characteristics of oil sand sample in heating vessel were measured and analyzed, and a method to improve the efficiency of microwave heating was designed. In this paper, the complex dielectric constant of the material is measured with the more mature TM0n0 mode cylindrical resonator, and the equivalent complex dielectric constant of the oil sand sample is calculated by using the Lichtenecker logarithmic mixture formula under the condition of free stacking in the heating furnace. A reheating furnace prototype is designed to meet the needs of industrialization. A simple measurement of port reflection is made at room temperature, which is in good agreement with the theory. The specific research results are as follows: (1) in this paper, the physical properties of lean oil during pyrolysis are analyzed, and the characteristics of "loose mixture" are summarized. A kind of effective medium theory is chosen as the key point of the analysis. The Lichtenecker logarithmic mixture formula has been proved by theory, which is derived from the semi-empirical formula, and the equivalent complex permittivity expression under uniform mixing of mixture material and air is obtained. Secondly, the relationship between logarithmic formula and other common formulas is deduced by using CM factor, which shows that logarithmic formula has obvious advantages in practical application. (2) subsequently, according to the dielectric properties of loose mixture materials, The complex permittivity is measured by the resonator perturbation method, and the TM0n0 mode cylindrical resonator testing system is made, and a simple experimental platform for heating is set up. Then the algorithm was calibrated with quartz, polytetrafluoroethylene and water. Two groups of 10 oil sand samples with different water content were tested at room temperature. The test results are analyzed and it is found that the oil content has no obvious influence on the test results, but the water content is the key factor affecting microwave loss. (3) finally, the advantages of microwave heating technology are described, which should be industrialized. Aiming at 915MHz industrial microwave source, a scheme of using open coaxial resonator system as heating vessel is put forward. A coaxial cavity prototype machine is simulated and processed. The oil sand sample with volume fraction of 0.4g 0.5U 0.60.70 is filled separately at room temperature. The port voltage standing wave ratio is measured and compared with the theoretical value. It is found that the measured port reflection of the coaxial resonator is larger than the theoretical value, but the variation trend is consistent, which verifies the applicability of the logarithmic formula theory. Finally, the error term of the system is analyzed.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB30;TE31

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