【作者】 刘砚菊；

【导师】 曹云东；

【作者基本信息】 沈阳工业大学 ， 电机与电器， 2011， 博士

【摘要】 在高压SF6断路器的现代设计研究中,合理控制吹弧气流的运动,形成动静触头区域有利于电弧熄灭的‘环境’成为重点研究问题之一。喷口是实现吹弧气体由亚音速到超音速的转变关键部件。目前,关于喷口结构的各类研究,主要着眼于改变喷口喉部及下游的型面结构和尺寸,达到对气流的控制目的。本论文从改变喷口喉部上游结构出发,提出旋气吹弧新方法。该方法的主要思想是：通过改变喷口上游的结构,使吹弧气流从压气缸到动静触头区域的运动过程中,气流运动方式得到改变。到达电弧区域时,形成轴向吹弧+旋转吹弧运动方式。旋转分量通过‘缠绕’运动,增加了冷气流与电弧的作用；轴向分量保证吹弧气体将电弧能量向下游的逸散,从而实现断路器开断能力的提升。本论文针对旋气吹弧开展的研究工作主要为：1.研究改变喷口上游结构,实现主动式控制气流吹弧的设计理念。开发了两种类型的旋气式喷口上游结构：叶片式旋气结构和槽式旋气结构；2.建立了描述灭弧室内旋转气流运动的三维气流场数学模型。在三维气流场的数学模型研究中,为了更准确地反映电弧运动,提出了三维能量源电弧动态数学模型；为了提高激波扑捉和离散控制方程的守恒性,采用了有限体积法+TVD格式进行方程的离散求解；3.完成了叶片式旋气喷口的设计和研究。进行了不同叶片结构下在断路器的开断过程中气流运动、灭弧室内各物理参数变化规律的研究；在综合灭弧室内速度、气体密度、压力分布等规律的基础上,证明该喷口结构具有最佳叶片数量和角度匹配。4.完成了槽式喷口结构的设计和研究。研究了具有不同槽型、槽数及旋气槽倾角对旋气吹弧气体密度、流速的影响。完成了上述情况下各物理参数随开断行程改变中的变化规律研究；通过空载和短路开断下数值仿真实验的研究,证明该结构喷口存在最佳槽型、槽数和最佳槽倾角的匹配关系；5.针对252 kV高压SF6断路器具体结构,完成了槽式喷口结构的优化设计,实现了样机的试制和开断性能的试验验证,通过了T100S(b)短路开断试验。试验结果表明新型旋气式SF6断路器设计原理正确、可行。本文研究为新型旋气喷口的进一步完善和深入研究提供了理论基础。更多还原

【Abstract】 For studying on modern design for the high-voltage SF6 circuit breaker, it becomes one of key research subjects to control the movement of gas blow reasonably in order to form the advantageous arc-quenching’environment’in stationary and moving contacts region. The nozzle is an important component to realize gas flow from the subsonic speed to the supersonic transformation. At present, for nozzle structure in each kind of research, mainly emphasis is to change nozzle throat and the downstream profile structure and the size in order to achieve the goal of gas flow control. In this dissertation, a new method for rotary-gas arc-blowing is presented according to the change upstream structure of nozzle throat.The main thought of this method is:The mode of gas flow movement is changed in process of arc-blowing gas flow from the gas cylinder to stationary and moving contacts region by the changing upstream structure of nozzle. It forms the movement mode of axial arc-blowing+rotary-gas arc-blowing when gas flow arrives at the arc region. The function between cooling gas flow and arc is enhanced by the’twistable’movement of rotary component. The axial component guaranteed the arc-blowing gas making arc energy escape to the downstream, thus realizes the promotion of interrupting capability for circuit breaker. The study contents for rotary-gas are as follow.1. Research the upstream structure of nozzle to achieve the design idea for actively controlling gas flow arc-blowing. Two kinds of upstream rotary-gas nozzle structures have been developed. 2. Three-dimensional gas flow field mathematical model for the description of rotary gas flow movement has been established. In study on three dimensional gas flow field mathematical model, in order to reflected accurately arc movement, the three-dimensional energy source dynamic arc mathematical model are proposed; The finite volume method +TVD form to carry on the equation the separated solution is used to enhance the shock wave to be seized and the conservation properties of discrete governing equation.3. Design and research on rotary-gas blades structure nozzle are completed. Gas flow movement under different blade structure and various physical parameter change rule in the interrupter are studied. Based on velocity, density of gas, pressure and Mach distribution in the interrupter, the reasonable numbers of blade and the best angle match are obtained.4. Design and research on rotary-gas grooves structure nozzle are completed. The influence on velocity of gas flow and the density of arc-blowing gas are studied for rotary-gas nozzle with different groove shapes, the number of grooves and the inclination angle of rotary-gas grooves. The change rule studies for various physical parameters along with to stroke are finished. Numeric simulation experiment study under no-load state and short-circuit interrupting has proved that this new type structure nozzle exists the match relations among best groove shape, the number of grooves and inclination angle of grooves.5. In view of 252 kV high-voltage SF6 circuit breaker structure, rotary-gas nozzle structure optimized design has completed. The prototypical product has been trial-manufacture and experimental verify for short-circuit interruption, and it passed T100S(b) short-circuit experiment. The test results have shown that the principle for new type of SF6 circuit breaker design with rotary-gas nozzle is correct and feasible. All of research work has provided theoretical basis and further improvement for new type of SF6 circuit breaker nozzle.更多还原