In this study, multi-information including spectrum, high-speed photograph and electrical signal was adopted to explore the coupling mechanism of alternate burning in laser-twin-arc welding process. Laser provides a c...In this study, multi-information including spectrum, high-speed photograph and electrical signal was adopted to explore the coupling mechanism of alternate burning in laser-twin-arc welding process. Laser provides a conductive, stable plasma channel for arcs. Plasma radiation strengthened especially in the center of the arc after hybrid. High temperature plasma erupting from keyhole provides an upward reacting force which can prevent droplet from transfer. The charged particles consisted in high temperature plasma reduce the voltage that maintains arc ignition or burning. The results show that laser can influence the arc shape, prevent droplet transfer, reduce resistivity and stabilize arcs.展开更多
气体绝缘开关设备在电力系统中起着重要的控制与保护作用,内部燃弧故障产生的高温、高压和壳体烧穿效应对设备、建筑物以及工作人员的安全造成了巨大威胁。文中针对252 k V GIS采用流体相平衡中的气体恒压热容CP0、恒容热容CV0修正改进...气体绝缘开关设备在电力系统中起着重要的控制与保护作用,内部燃弧故障产生的高温、高压和壳体烧穿效应对设备、建筑物以及工作人员的安全造成了巨大威胁。文中针对252 k V GIS采用流体相平衡中的气体恒压热容CP0、恒容热容CV0修正改进标准计算法的参数,明确“Kp因子”的取值范围,提出一种计算压升的增强型改进标准计算法和考虑故障切除时间的壳体烧穿概率计算法。研究结果表明:引起压升的能量占电弧能量的比例系数“Kp因子”的取值约为0.78~0.92,显然大于低电压等级开关设备的取值,增强型改进标准法的计算精度高于改进标准法的计算结果,壳体烧穿的概率与故障切除时间成正比,而与电弧移动时间成反比。通过对比实际GIS内部燃弧试验压升和烧穿结果,验证了所提出的增强型改进标准法和烧穿概率计算法的有效性。展开更多
Using highly pure graphite rod and B4C/graphite composite rod as electrods, some macroscopic amounts of boron-doped fullerenes, such as C60-nBn and C70-nBn (n=1,2,3) are syn-thesized by DC arc burning method and extra...Using highly pure graphite rod and B4C/graphite composite rod as electrods, some macroscopic amounts of boron-doped fullerenes, such as C60-nBn and C70-nBn (n=1,2,3) are syn-thesized by DC arc burning method and extracted by o-xylene from the soots under nitrogen for the first time. The boron-doped fullerenes are characterized by FDMS.展开更多
文摘In this study, multi-information including spectrum, high-speed photograph and electrical signal was adopted to explore the coupling mechanism of alternate burning in laser-twin-arc welding process. Laser provides a conductive, stable plasma channel for arcs. Plasma radiation strengthened especially in the center of the arc after hybrid. High temperature plasma erupting from keyhole provides an upward reacting force which can prevent droplet from transfer. The charged particles consisted in high temperature plasma reduce the voltage that maintains arc ignition or burning. The results show that laser can influence the arc shape, prevent droplet transfer, reduce resistivity and stabilize arcs.
文摘气体绝缘开关设备在电力系统中起着重要的控制与保护作用,内部燃弧故障产生的高温、高压和壳体烧穿效应对设备、建筑物以及工作人员的安全造成了巨大威胁。文中针对252 k V GIS采用流体相平衡中的气体恒压热容CP0、恒容热容CV0修正改进标准计算法的参数,明确“Kp因子”的取值范围,提出一种计算压升的增强型改进标准计算法和考虑故障切除时间的壳体烧穿概率计算法。研究结果表明:引起压升的能量占电弧能量的比例系数“Kp因子”的取值约为0.78~0.92,显然大于低电压等级开关设备的取值,增强型改进标准法的计算精度高于改进标准法的计算结果,壳体烧穿的概率与故障切除时间成正比,而与电弧移动时间成反比。通过对比实际GIS内部燃弧试验压升和烧穿结果,验证了所提出的增强型改进标准法和烧穿概率计算法的有效性。
文摘Using highly pure graphite rod and B4C/graphite composite rod as electrods, some macroscopic amounts of boron-doped fullerenes, such as C60-nBn and C70-nBn (n=1,2,3) are syn-thesized by DC arc burning method and extracted by o-xylene from the soots under nitrogen for the first time. The boron-doped fullerenes are characterized by FDMS.
