高功率矩形微波反应器加热效率及均匀性仿真研究

发布时间：2018-05-01 06:26

本文选题：矩形谐振腔 + 电场分布　；参考：《云南师范大学》2015年硕士论文

【摘要】：微波加热具有速度快、效率高、均匀性好、穿透性强、可选择性等独特的优点,被广泛的应用于生产和生活中。微波加热效率和均匀性是衡量微波反应器优劣的重要标准。不同材料和不同尺寸的加热对象在反应腔中将影响电磁场分布,进而出现不同的加热效率和均匀性。因此,探索加载不同加热对象时微波反应腔内的电磁场分布规律有助于微波反应器的优化设计。基于高频电磁仿真软件HFSS,本文分析研究了一种高功率矩形微波反应器加载不同材料、不同形状负载时的加热效率及均匀性,主要工作概况如下:概述分析了微波加热器的理论基础,包括介质的极化、微波加热原理及特点、微波在介质中的传输、矩形谐振腔理论、微扰理论、有限元理论及HFSS在微波加热器设计中的应用。利用HFSS电磁仿真软件,在选定微波反应腔尺寸的基础上,仿真分析了加载粉煤灰和玻璃材料时馈口角度、馈口长度、馈口距离、负载尺寸、距腔体底面距离等设计参数对加热效率的影响。研究结果显示:(1)负载为圆柱体、长方体和球体时,对粉煤灰负载,馈口夹角分别为162?、102?、82?时加热效率最高,对玻璃材料负载,馈口夹角分别为134?、60?、174?时加热效率最高;(2)当馈口长度超过50mm后其对加热效率的影响基本保持不变;(3)加载粉煤灰时,馈口距腔体顶面中心距离在60mm~70mm之间加热效率相对较高,加载玻璃材料时,馈口距腔体顶面中心距离对圆柱体、长方体、球体取值分别为44mm、104mm、63mm时加热效率最高;(4)圆柱体和长方体形状的两种负载厚度在110mm附近均出现较高的加热效率,球体形状的粉煤灰和玻璃材料负载半径分别在60mm和95mm附近出现较高的加热效率;(5)加载粉煤灰时,圆柱体和长方体负载在距腔体底面0~20mm之间,球体负载在50mm附近均出现较高的加热效率,加载玻璃材料时,圆柱体和球体负载距腔体底面距离在10~20mm之间加热效率较高,而长方体负载则为35mm、75mm时加热效率较高。经优化后,加载粉煤灰时,圆柱体和长方体负载的加热效率均超过98%,最高达99.7%,球体负载加热效率达88.82%;加载玻璃材料时,加热效率均超过90%,最高达96.38%。在兼顾加热效率的前提下,亦研究了馈口数量对加热均匀性的影响。对于粉煤灰材料,增加馈口数量可以获得更均匀的电磁能量场分布;对于玻璃材料,增加馈口数量反而导致较差的加热均匀性。
[Abstract]:Microwave heating has been widely used in production and life because of its advantages such as high speed, high efficiency, good uniformity, strong penetration and selectivity. Microwave heating efficiency and uniformity are important standards to evaluate microwave reactor. Different materials and different sizes of heating objects will affect the distribution of electromagnetic field in the reaction chamber, and then the heating efficiency and uniformity will be different. Therefore, it is helpful to optimize the design of microwave reactor to explore the electromagnetic field distribution in microwave reaction cavity under different heating conditions. Based on high frequency electromagnetic simulation software HFSS, the heating efficiency and uniformity of a high power rectangular microwave reactor loaded with different materials and different shapes were studied. The main work is summarized as follows: the theoretical basis of microwave heater is summarized and analyzed, including the polarization of medium, the principle and characteristics of microwave heating, the transmission of microwave in medium, the theory of rectangular resonator, the theory of perturbation, Finite element theory and application of HFSS in microwave heater design. Using HFSS electromagnetic simulation software, on the basis of selecting the size of microwave reaction cavity, the feed angle, feed port length, feed port distance, load size when fly ash and glass material are loaded are simulated and analyzed. The effect of design parameters such as distance from bottom surface of cavity on heating efficiency. The results show that when the load is cylindrical, cuboid and sphere, the feed angle of the fly ash load is 162U 102U 82U? Time heating efficiency is the highest, for the glass material load, the feed angle of the feed port is 134U 60 / 174? When the length of feed port exceeds 50mm, its effect on heating efficiency remains basically unchanged. When fly ash is loaded, the heating efficiency between the feed port and the top surface of the cavity is relatively high between 60mm~70mm and 60mm~70mm, and when the glass material is loaded, the heating efficiency between the feed port and the top surface of the cavity is relatively high. When the heating efficiency of cylinder, cuboid and sphere is 44mm / 104mm / 63mm, respectively) the load thickness of cylinder and cuboid shape has higher heating efficiency in the vicinity of 110mm, while the distance from the feed port to the center of the top surface of the cavity is 44mm / 104mm / 63mm, respectively. When the loading radius of ball shaped fly ash and glass material appears high heating efficiency near 60mm and 95mm respectively, the cylinder and cuboid load are between the bottom surface of the cavity 0~20mm, when the fly ash is loaded with fly ash. The heating efficiency of the spherical load is higher near 50mm. When the glass material is loaded, the heating efficiency between the cylinder and the spherical load is higher between the 10~20mm and the bottom surface of the cavity, while the cuboid load is 35mm / 75mm, and the heating efficiency is higher than that of the cuboid load (35mm / 75mm). After optimization, the heating efficiency of cylinder and cuboid load is over 98 when fly ash is loaded, the highest heating efficiency is 99.7and the heating efficiency of spherical load is 88.82. When the glass material is loaded, the heating efficiency is more than 90, and the highest is 96.388.When the fly ash is loaded with fly ash, the heating efficiency of the cylinder and cuboid is more than 98, the highest is 99.7 and 88.82 respectively. On the premise of taking into account the heating efficiency, the effect of the number of feed ports on the heating uniformity is also studied. For the fly ash material, the more uniform electromagnetic energy field distribution can be obtained by increasing the number of feed ports, and for the glass material, the worse heating uniformity can be caused by increasing the number of feed ports.
【学位授予单位】：云南师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM924.76

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