铁路隧道微波除冰装置的研制

发布时间：2018-04-21 19:27

  本文选题：电气化铁路隧道 + 微波加热　； 参考：《西南交通大学》2017年硕士论文

【摘要】：在我国东北地区,冬季铁路隧道顶部的渗透水将会冻结成冰锥,容易引发接触网短路,严重妨碍了电气化铁路隧道的供电安全。目前的隧道除冰的方式是在列车通行的时间间隙进行人工打冰。这将给施工人员的除冰作业带来极大的安全隐患,并且在除冰过程中常需要关闭接触网的供电,影响列车的正常通行。因此本文提出一种非接触式的远距离微波加热方案,用以防止低温状态下隧道表面渗水结冰。首先根据微波加热理论、喇叭天线原理、磁控管工作原理、矩形波导理论等,设计了一款适合远距离微波加热的装置,可以安装在隧道两侧的墙壁上,与接触网保持了足够的安全距离。然后建立天线与混凝土的加热模型,通过电磁仿真软件得出混凝土内功率损耗密度。然后通过实验,测量了天线口径面与潮湿混凝土距离为2米时的温升情况,实验中喇叭天线的微波源是功率1kW的磁控管。实验结果表明:90分钟后混凝土表面最高温度从17.5℃上升到30.8,平均每15分钟上升2.2℃;初始的30分钟内温度上升了6.5℃,随后温升速率虽然逐渐降低,但仍然具有明显的上升趋势。在整个加热过程中,初始的环境温度为18.1 ℃,实验结束后的环境温度为20.2℃。该实验证明了远距离微波加热除冰方案具有一定的可行性。最后为了进一步提高隧道顶部对微波的吸收效率,在隧道壁表面喷涂一层吸波材料,既可以增加表面对微波的损耗吸收能力,又可以减小对微波的反射系数。通过有耗传输线理论推导出了涂有吸波材料的潮湿混凝土对微波的反射系数。并在MATLAB中计算,得出以下结论:在相同入射角的条件下,TE_y极化波的反射系数全面小于TM_y极化波;根据某公司提供的吸波材料参数,分别计算出不同厚度吸波材料的反射系数与入射角的关系,并结合软件仿真结果和实际情况分析,2mm厚度的吸波材料最佳;计算出提高吸波材料的相对复介电常数虚部ε"和相对复磁导率虚部μ"对反射系数的影响,得出不同厚度下既对微波有较高的吸收能力,又具备低反射系数的ε"和μ"的取值范围。
[Abstract]:In Northeast China, the permeable water at the top of railway tunnel in winter will be frozen into ice cone, which will easily lead to short circuit of catenary, which seriously hinders the power supply safety of electrified railway tunnel. The current method of deicing in tunnels is to carry out manual icing during the time interval of train passage. This will bring great hidden danger to the deicing operation of the construction personnel, and it is often necessary to close the power supply of the catenary in the deicing process, which will affect the normal passage of the train. In this paper, a non-contact microwave heating scheme is proposed to prevent water seepage and ice formation on tunnel surface at low temperature. Firstly, according to microwave heating theory, horn antenna principle, magnetron working principle, rectangular waveguide theory and so on, a device suitable for long-distance microwave heating is designed, which can be installed on the walls of both sides of the tunnel. Sufficient safety distance is maintained from the catenary. Then the heating model of antenna and concrete is established, and the power loss density of concrete is obtained by electromagnetic simulation software. Then the temperature rise of the antenna is measured when the distance between the aperture of the antenna and the wet concrete is 2 meters. The microwave source of the horn antenna is the magnetron of the power 1kW in the experiment. The results show that the maximum temperature of concrete surface rises from 17.5 鈩，

本文编号：1783796