Assembling method of upper canopy or lower ring and assembling method of runner

Abstract

The present invention provides an assembling method of upper canopy or lower ring of Francis runner, which restrains welding deformation for preventing large-scale machining and welding defect while the upper canopy or lower ring that are divided into a plurality of members for integrally welding. Particularly, the assembling method of the lower ring (2) of a runner composed of the upper canopy (1), the lower ring (2) and blades (3) in a Francis hydraulic turbine or Francis pump-turbine comprises the following steps: a temporary welding step of performing welding with a welding quantity less than the welding quantity of full groove area of dividing line section and performing surfacing welding next to the crossed part of the blades (3) to a water surface; and a step of grinding and shaping the welding part at the periphery (5a) of the crossed part to the water surface. The upper canopy is assembled similarly.

Description

technical field [0001] The invention relates to an assembly method of the upper crown or lower ring of a Francis type runner such as a Francis type water turbine or a Francis type water pump turbine and the assembly method of the runner, especially relates to dividing the upper crown or the lower ring into multiple Transportation, a method of integrally welding and assembling them on site, and a method of welding the upper crown, lower ring, and blades to assemble the runner. Background technique [0002] In the past, when the runner of the water turbine could not be transported to the power station as a single piece due to problems such as transportation or delivery time, the following method was adopted to make the runner a 2-4 split runner in the joint bolt connection method, and use a single The blade or the upper crown and the lower ring are transported to the vicinity of the power station by means of a body, and the runner is integrated by on-site welding and assembly....

AI Technical Summary

Problems solved by technology

[0021] However, when welding and assembling the blades on-site while keeping the amount of welding to a minimum in order to suppress the welding deformation of the single-body welding on the dividing line between the upper crown and the lower ring, the lower ring will be damaged due to the blade welding and the remaining parts. The deformation near the lower end of the lower ring on the exit side of the runner becomes very large due to the welding of the split line

[0022] Therefore, there are cases where assembly of the runner becomes difficult due to deviation from the allowable size, or the case where the size or shape is deformed greatly deviates from the design value, and there is a problem that there is a large influence such as not achieving performance.

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