环境湿度对浸金属碳滑板磨损及温升的影响

Influence of Environment Humidity on Wear and Temperature Rise of Metal-impregnated Carbon Strip

为探究环境湿度对弓网摩擦副载流滑动过程中电弧放电能量、浸金属碳滑板温升及滑板磨损量的影响,采用环-块式高速载流摩擦磨损试验台,对比不同湿度条件下,电弧能量、滑板温升及滑板磨损量随滑动速度、电流强度、法向力的变化情况。试验结果表明:不同环境湿度下,滑动速度和电流强度的增大均会导致电弧能量及滑板温升急剧增大;电弧热是导致温升的主要热源;增大法向力对于抑制电弧放电、降低滑板温升均有显著效果,而对于滑板磨损量变化的影响,不同湿度情况则截然相反;高湿度环境下接触副附着的水膜改善了接触状况和散热情况,电弧能量及滑板温升都小于低湿度环境;低湿度环境下滑板表面受到更严重的机械摩擦,其表面状态相比高湿度更差;在平均湿度较高的夏季适当增加升弓压力,在平均湿度较低的冬季适当降低列车行驶速度可以减少浸金属碳滑板磨损。

In order to explore the influence of ambient humidity on the arc discharge energy,the temperature rise and strips wear of the metal-impregnated carbon strip during the sliding process of a catenary-pantograph system,the ringblock high-speed current-carrying friction and wear test bench was used to study the arc energy,the temperature rise of the strip and strip wear with the sliding speed,current and normal force in different humidity conditions.It is found that the arc energy and strip temperature rise increase sharply with the increase of sliding velocity and current under different ambient humidity.Arc heat is the main heat source leading to temperature rise of strip.Increasing the normal force has significant effects on restraining arc discharge and decreasing the temperature rise of the strips,but the effect on the wear of the strips is completely opposite under different humidity conditions.In the high humidity environment,the water film attached to the contact pair improves the contact condition and heat dissipation,and the arc energy and temperature rise of the strips are less than those in the low humidity environment.In the low humidity environment,the strip surface is subjected to more serious mechanical friction,and its surface condition is worse than that in high humidity environment.The wear of the metalimpregnated carbon strip can be reduced by appropriately increasing the normal force in summer when the average humidity is high,and appropriately decreasing the train speed in winter when the average humidity is low.