静水压力对水下电火花放电影响

Study on Influence of Hydrostatic Pressure on Underwater EDM

水下电火花作为大型核反应堆堆内构件维护设备在核电站设备检修、吊篮螺钉更换领域具有重要意义,但由于其工作环境为水下8 m^10 m,环境压力约为水上加工的2倍,压力的改变对水下电火花放电过程的影响研究不足。基于电火花放电原理技术,对水下电火花放电过程中分别研究压力对放电通道形成、气泡膨胀-收缩和气泡运动三个过程进行分析,来得到压力对气泡运动和材料蚀除的影响。而后通过自行研制的水下电火花加工设备在密闭容器中加入与水下10 m相同的压力进行实验,结果显示水下压力的改变对电火花放放电通道形成、气泡的产生和材料的蚀除速率影响不大,而对气泡的膨胀-收缩运动有一定影响;气泡的产生对两极间火花放电稳定性有很重要的影响,由于放电间隙内大部分被气泡占据,在一定范围内压力对电火花蚀除材料过程影响不大,但过大的压力可影响火花放电稳定性,造成材料去除率降低。

Underwater EDM as a large nuclear reactor reactor maintenance equipment in the nuclear power plant equipment maintenance,basket screw replacement field is of great significance,but because of its working environment for the water 8-10 meters,the ambient pressure is about 2 times the water processing,pressure The effect of the change on the underwater EDM process is insufficient. In this paper,based on the principle of EDM,the effects of pressure on bubble motion and material erosion are analyzed by analyzing the pressure generation process,bubble expansion-contraction and bubble motion in the process of underwater spark discharge. And then through the company＇s own underwater EDM equipment installed in a closed container with 10 meters underwater under the same pressure experiments,the results show that changes in underwater pressure on the discharge of electric discharge channels,the formation of bubbles and material corrosion The bubble generation has a certain effect on the spark-discharge stability of the poles. Since the discharge gap is occupied by the bubbles,the pressure is in a certain range EDM material process has little effect,but too much pressure can affect the spark discharge stability,resulting in reduced material removal rate.