Underwater local dry laser welding system and welding method thereof

Abstract

The invention provides an underwater local dry laser welding system and a welding method thereof. The system comprises an industrial personal computer, an underwater robot, a SiC laser welding power source, a laser welding head, a micro drainage device, a steam exhaust device, a shielding gas device, a water cooling device, an endoscope and a panoramic camera. The output end of the SiC laser welding power source is connected with the laser welding head; the panoramic camera, the laser welding head and the micro drainage device are arranged on the underwater robot; the laser welding head is positioned in the micro drainage device and is connected with the shielding gas device; the endoscope is positioned in a welding cavity of the micro drainage device; and the steam exhaust device is communicated with the welding cavity of the micro drainage device. According to the system and the method, a surrounding environment image and an internal image of the welding cavity can be obtained, the fine adjustment of a welding path is realized, the welding precision and the welding quality are improved, and the welding system can better adapt to the complex working conditions of nuclear power equipment repair and other underwater welding operations.

Description

technical field [0001] The invention relates to the technical field of underwater laser welding, and more specifically relates to an underwater partial dry laser welding system and a welding method thereof. Background technique [0002] Nuclear power plant reactor pressure vessels and spent fuel pools and other container equipment have been in high-radiation environments for a long time, and are prone to problems such as stress corrosion, cracks and even holes, which seriously threaten the safe operation of nuclear power plants. [0003] The welding work of nuclear power equipment is often carried out underwater, and there are limiting factors such as poor visibility, heavy workload, high operation difficulty and high radiation. Therefore, using welding robots instead of welders can better carry out welding repair work. Local dry welding with a small drainage device to provide a stable gas phase space is convenient and stable, and is the preferred method for robotic underwat...

AI Technical Summary

Problems solved by technology

Local dry welding with a small drainage device to provide a stable gas phase space is convenient and stable, and is the preferred method for robotic underwater laser welding repairs. However, due to the sealing effect of the drainage cover, the current welding state of underwater laser welding equipment It is more difficult to obtain, such as the Chinese utility model patent "Nuclear Power Plant Underwater Welding Robot and Welding System" (public number: CN207735741U), which installs a binocular vision camera on the robotic arm for position acquisition and path planning before welding, but drains water during welding The cover covers the welding area and causes line of sight obstruction, so it is impossible to realize real-time monitoring of welding images, which is not conducive to the improvement of welding quality and the analysis of process influencing factors

[0004] The underwater welding repair work of nuclear capacitors has unfavorable factors such as strong water cooling, submerged flow disturbance, and water film wetting of the workpiece, which cause obvious arc stability problems in the current underwater welding technology that uses arc as the heat source, and due to the underwater environment Affected by the parasitic inductance of long loop cables, arc energy control is difficult, and the quality of welding repair of nuclear power equipment containers cannot be guaranteed

Compared with electric arc, laser has the advantages of high energy density, good stability, and precise positioning. It is relatively less disturbed by adverse factors in the underwater environment. It is an ideal heat source for underwater welding. However, the current laser welding power supply has large fluctuations in driving current. , slow adjustment speed and insufficient self-monitoring ability. For example, the Chinese invention patent "Boost Laser Welding Power Supply System" (public number: CN104242663B) uses Si-based IGBT as the inverter power device, and its switch is used in high-power applications such as welding. The theoretical frequency limit is only 20-30kHz, and the dynamic characteristics are not ideal, resulting in poor output current stability and adjustment response speed, and the corresponding laser quality is difficult to meet the welding requirements of underwater irradiation environment

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