高海拔特高压输电线路开式沙尘天气模拟实验平台

发布时间：2018-07-04 09:53

本文选题：沙尘天气 + 实验平台　；参考：《华北电力大学》2017年硕士论文

【摘要】：特高压输电由于输电能力强、路线能耗小等优势具有广阔的发展前景。然而,西北地区高海拔和沙尘环境会影响特高压输电线路的电晕特性,进而影响电网的安全有序运行。因此,研制沙尘天气模拟实验平台可为实验研究输电线路电晕特性奠定物质基础。本文阐述了气固两相流的基本理论,根据电晕实验对沙尘环境的需求确定了其实验参数,在此基础上设计了自由落沙、旋流扩散和类平抛扩散三种方案下的沙尘天气模拟实验平台。采用理论分析和数值模拟相结合的方法,对上述方案在不同风速及颗粒粒径下的颗粒扩散区域进行了对比分析,以探寻既能满足实验需求又操控方便的方案并确定之。从缩短管路总长和降低管路压损两个角度,对已初步确定的旋流扩散方案实验平台进行了优化设计;并对该优化后实验平台在不同的给沙率、颗粒粒径和风速下的颗粒扩散情况进行了研究,以获得实验区域的沙尘浓度特性;对该优化后实验平台中的风机和给料器以及控制、测量和支撑等装置进行选型设计以利其工程化,并实验研究了给料器的给料特性。研究结果表明:1)旋流扩散方案的实验平台既满足实验需求且又操控方便;2)优化后实验平台其上下直管长度均为2m,前后导流器开度均为30?,给料管距前级导流器的轴向距离为0.5m,给料口纵向位于风管轴心,此时压损系数与未优化前相比减小0.25;3)优化后实验平台可满足不同工况下距风管出口4m,纵向标高为6.72m的实验区域3?3m2的沙尘覆盖,且沙尘浓度精确可控;4)在给沙率、风速和颗粒粒径分别为(0.005~0.03)kg/s、(6~9)m/s和(0.125和0.25)mm的情况下,优化后实验平台在实验区域内的沙尘浓度随风速增加先增后减,且0.125mm和0.25mm粒径下的拐点对应风速分别为7m/s和8m/s;沙尘浓度增幅随给沙率增加而增加;5)给料器给料率与给料器频率基本呈线性关系。
[Abstract]:UHV transmission has a broad development prospect because of its strong transmission capacity and low energy consumption. However, the high altitude and dust environment in Northwest China will affect the corona characteristics of UHV transmission lines, and then affect the safe and orderly operation of the power grid. Therefore, the development of sand and dust weather simulation experimental platform can lay a material foundation for the experimental study of corona characteristics of transmission lines. In this paper, the basic theory of gas-solid two-phase flow is described, and the experimental parameters are determined according to the requirements of the corona experiment for the sand and dust environment. On this basis, the free sediment dropping is designed. The experimental platform of sand and dust weather simulation under three schemes of swirl diffusion and flat throwing diffusion. By using the method of theoretical analysis and numerical simulation, the particle diffusion regions under different wind speeds and particle sizes are compared and analyzed in order to find out a scheme that can meet the experimental requirements and control conveniently. From two angles of shortening the total length of pipeline and reducing the pressure loss of pipeline, the experimental platform of swirl diffusion scheme that has been preliminarily determined has been optimized and designed, and the experimental platform has been optimized for different sand feeding rates after the optimization. The particle size and particle diffusion under wind speed were studied to obtain the dust concentration characteristics in the experimental area, and the fan and feeder in the optimized experimental platform and its control were obtained. The measuring and supporting devices were selected and designed for engineering, and the feeding characteristics of the feeder were studied experimentally. The results show that the experimental platform of the swirl diffusion scheme not only meets the experimental requirements but also has convenient operation. The optimized experimental platform has a straight tube length of 2 m, an opening of both front and rear conductors, and a feed tube distance from the axis of the front stage guide. The direction distance is 0.5 m, the feed port is located longitudinally on the axis of the air pipe, At this time, the pressure loss coefficient is reduced by 0.25m3 compared with that before optimization. After the optimization, the experimental platform can satisfy the dust coverage of 3?3m2 in the experimental area with a longitudinal elevation of 6.72m and 4m from the outlet of the wind pipe under different operating conditions, and the dust concentration is accurately controlled. When the wind speed and particle size were (0.005 ~ 0.03) kg / s, (6 ~ 9) m / s and (0.125) mm, respectively, the dust concentration in the experimental area increased first and then decreased with the increase of wind speed. The inflection points of 0.125mm and 0.25mm particle size are 7m/s and 8m / s, respectively, and the increase of dust concentration increases with the increase of sand feed rate. (5) the feed rate of the feeder has a linear relationship with the frequency of the feeder.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM75

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