风速对钢心铝绞线红外测温图像质量影响研究

Study on effect of wind speed on quality of infrared temperature measurement images of ACSR

对钢心铝绞线进行红外热巡检时,红外热像图成像质量会因环境风速不同而变化。为研究钢心铝绞线红外测温时,不同载流量下热像图成像质量与风速的关系,本文利用传热学原理,分析了钢心铝绞线表面辐射及红外热像测温模型,提出应用于钢心铝绞线表面的红外对比度表达式及其影响因素。在实验室对LGJ-240/30型钢心铝绞线施加风速为0.5~5.0 m/s、电流为240~600 A,通过实验数据绘制三维散点图并拟合,得到对比度与风速、载流量的表达式,并提出利于肉眼观察的“临界对比度”。最后通过设计野外自然实验,验证实验室结果的准确性及可行性。结果表明,实验室得到的对比度表达式与临界值可以有效判断特定条件下,钢心铝绞线红外热像图质量优劣,对架空输电线路红外热巡检工程具有指导意义。

When the infrared thermal inspection is conducted on ACSR, the quality of the infrared thermal images will vary depending on the ambient wind speed. To study the relationship between the quality of thermal images and wind speed under different currents of ACSR, the surface radiation, and the infrared thermal image temperature measurement model are analyzed by using the principle of heat transfer. An infrared contrast formula applied to the surface of ACSR and their influencing factors is proposed. The ambient wind speeds of 0.5~5.0 m/s and currents of 240~600 A are applied to LGJ-240/30 type ACSR in the laboratory. Three-dimensional discrete data are plotted and fitted by experimental data to obtain a formula for contrast, and a “critical contrast” for visual observation is proposed. Finally, the accuracy and feasibility of the laboratory results are verified by natural tests in the field. The results show that the contrast formula and the critical value obtained in the laboratory can effectively determine the quality of infrared images of ACSR under specific conditions, which is of guiding significance for the infrared thermal inspection engineering of overhead transmission lines.