A Welding Process for Outlet Wires of Air Internally Cooled Turbogenerator

Abstract

The invention provides a welding process for the outgoing line of an air inner-cooled turbine generator. The outgoing line comprises a connecting round pipe, and an upper connecting head and a lower connecting head connected to the two ends of the connecting round pipe in a welding manner, during welding, two sets of intermediate frequency induction heating equipment are adopted for heating at different powers, so as to enable workpieces to be heated uniformly, and manual stuffing is performed in circumferential soldering seams between the connecting round pipe and the upper connecting head and between the connecting round pipe and the lower connecting head, so as to increase a welding area. Due to the adoption of the welding process for the outgoing line of the air inner-cooled turbine generator, welding quality conforms to design requirements, defects of cracks, through welding, slag inclusion, exhaust holes and the like can be avoided, the welding intensity is relatively high, and the welding qualified rate is high.

Description

technical field [0001] The invention relates to a welding process for the lead wire of an air-cooled turbo generator, and belongs to the technical field of welding process for the lead wire of the generator. Background technique [0002] The lead-out line of the 350MW air-internal cooling turbogenerator includes the upper connector, the lower connector and the connecting pipe, which are assembled and welded in three parts. The connecting round pipe is Φ125×20, and the material is TU1 oxygen-free copper; the upper connector and the lower connector are bent into a U shape with TU1 oxygen-free copper plate, and there is a Φ126mm counterbore with a depth of 9mm at the bottom welding place. The size of the preset annular silver solder piece is Φ125×20. In addition to carrying its own gravity load, the generator lead-out wire also bears a strong vibration load when the generator is running, which requires high welding strength at the weld. During welding, the temperature at the ...

AI Technical Summary

Problems solved by technology

Because traditional welding cannot evenly heat the bottom of the counterbore of the connector, it is prone to defects such as incomplete fusion and incomplete penetration

And when filling the circumferential direction of the brazing seam, due to uneven heating, the brazing seam will appear oxidized and peeled, which will reduce the welding quality and joint strength of the welding place

If vacuum furnace brazing is used, manual filling cannot be performed during welding. The welding area is the molten pool area of ​​the annular silver solder piece, and the penetration rate of the welding place is extremely high. However, due to the copper material of the upper connector and the lower connector The thickness is different, the heating time is timely and the temperature is difficult to control, there is a phenomenon that the solder on the side of the thick copper material is not fully fused, and the solder on the side of the thin copper material is liquefied and flows, corroding the workpiece, the welding pass rate is low, and the reject rate is high. This is the existing technology. deficiencies

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