本文選題：電氣化鐵路隧道 + 微波加熱　； 參考：《西南交通大學》2017年碩士論文

【摘要】：在我國東北地區(qū),冬季鐵路隧道頂部的滲透水將會凍結成冰錐,容易引發(fā)接觸網短路,嚴重妨礙了電氣化鐵路隧道的供電安全。目前的隧道除冰的方式是在列車通行的時間間隙進行人工打冰。這將給施工人員的除冰作業(yè)帶來極大的安全隱患,并且在除冰過程中常需要關閉接觸網的供電,影響列車的正常通行。因此本文提出一種非接觸式的遠距離微波加熱方案,用以防止低溫狀態(tài)下隧道表面滲水結冰。首先根據(jù)微波加熱理論、喇叭天線原理、磁控管工作原理、矩形波導理論等,設計了一款適合遠距離微波加熱的裝置,可以安裝在隧道兩側的墻壁上,與接觸網保持了足夠的安全距離。然后建立天線與混凝土的加熱模型,通過電磁仿真軟件得出混凝土內功率損耗密度。然后通過實驗,測量了天線口徑面與潮濕混凝土距離為2米時的溫升情況,實驗中喇叭天線的微波源是功率1kW的磁控管。實驗結果表明:90分鐘后混凝土表面最高溫度從17.5℃上升到30.8,平均每15分鐘上升2.2℃;初始的30分鐘內溫度上升了6.5℃,隨后溫升速率雖然逐漸降低,但仍然具有明顯的上升趨勢。在整個加熱過程中,初始的環(huán)境溫度為18.1 ℃,實驗結束后的環(huán)境溫度為20.2℃。該實驗證明了遠距離微波加熱除冰方案具有一定的可行性。最后為了進一步提高隧道頂部對微波的吸收效率,在隧道壁表面噴涂一層吸波材料,既可以增加表面對微波的損耗吸收能力,又可以減小對微波的反射系數(shù)。通過有耗傳輸線理論推導出了涂有吸波材料的潮濕混凝土對微波的反射系數(shù)。并在MATLAB中計算,得出以下結論:在相同入射角的條件下,TE_y極化波的反射系數(shù)全面小于TM_y極化波;根據(jù)某公司提供的吸波材料參數(shù),分別計算出不同厚度吸波材料的反射系數(shù)與入射角的關系,并結合軟件仿真結果和實際情況分析,2mm厚度的吸波材料最佳;計算出提高吸波材料的相對復介電常數(shù)虛部ε"和相對復磁導率虛部μ"對反射系數(shù)的影響,得出不同厚度下既對微波有較高的吸收能力,又具備低反射系數(shù)的ε"和μ"的取值范圍。
[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，

本文編號：1783796