Tube Inner Electroplating Repair for Expanded Weld Regions
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Solution Overview
Problem
Conventional electroplating repair techniques for tack expansion and seal welding regions in steam generators are inefficient, as they can only repair limited sections at a time, often resulting in stress corrosion cracks and defects due to the roll expansion method used in initially manufactured WEC-type steam generators.
Innovation Solution
An electroplating repair apparatus is designed with a probe body extending a predefined length into the tube, equipped with an electroplating electrode, a sealing member that expands with compressed air to seal the inner surface, and a solution supply line, allowing for simultaneous repair of multiple tubes by positioning the apparatus using a manipulator and extension arm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional electroplating repair techniques are used for tack expansion and seal welding regions, then repair can be performed on limited sections at a time, but operating efficiency is very low and productivity is reduced
Solution Approach 1:
The patent combines multiple electroplating nozzles into a single integrated repair apparatus that can simultaneously repair multiple tubes. The apparatus includes a main body with multiple nozzles arranged to match the tube arrangement, allowing concurrent electroplating repair of several tubes rather than repairing them one at a time, thus dramatically improving productivity while maintaining repair quality
Solution Approach 2:
The repair apparatus is designed with universal functionality to handle multiple tubes simultaneously through its multi-nozzle configuration. The apparatus can be positioned and oriented to repair different sections of multiple tubes in various configurations, making it a versatile tool that replaces multiple single-nozzle devices and significantly enhances operating efficiency
2Strength
If roll expansion method is used in initially manufactured WEC-type steam generators, then tube attachment is achieved, but stress corrosion cracks occur in the expanded part
Solution Approach 1:
The patent applies electroplating to change the surface parameters of the expanded tube portions. By depositing a protective coating through electroplating, the surface properties of the expanded areas are modified to resist stress corrosion cracking, thereby improving reliability without compromising the mechanical attachment strength achieved through roll expansion
Solution Approach 2:
The patent creates a composite structure by adding an electroplated coating layer to the base metal tube. This composite material system combines the mechanical properties of the rolled-expanded tube with the corrosion-resistant properties of the electroplated surface, simultaneously achieving both strong attachment and stress corrosion resistance
3Reliability
If electroplating is applied to repair expanded parts and sealing welds, then stress corrosion cracks are reduced, but the process requires precise positioning and sealing
Solution Approach 1:
The apparatus incorporates sealing members that are positioned and activated before the electroplating process begins. The sealing members are extended to contact the tube inner surfaces in advance, creating sealed chambers that prevent electrolyte leakage before the electroplating current is applied, thereby simplifying the overall operation despite the precision requirements
Solution Approach 2:
The patent uses sealing members as intermediary elements between the electroplating apparatus and the tube interior. These sealing members create isolated working chambers that mediate the electroplating process by containing the electrolyte and ensuring proper current distribution, making the complex positioning and sealing requirements manageable through this intermediary mechanism
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables efficient and high-quality repair of expanded parts and sealing welds across multiple tubes, improving operating efficiency and reducing stress corrosion cracks by allowing for the electroplating of multiple sections simultaneously.
Implementation Method 1
defective expansion and sealing weld may be processed with electroplating (to form an electroplated part 15) to repair and seal the defective part
Implementation Method 2
a sealing member attached to opposite end sides of the probe body to seal a target portion to be electroplated
Data Source
AI summary
Disclosed are an electroplating repair apparatus, an electroplating repair system having the same, and an operating system thereof. The apparatus includes a probe body extending a predefined length in a structure corresponding to an inner diameter part of a tube, an electroplating electrode attached to and surrounding an outer circumferential surface of the probe body, a sealing member attached to opposite end sides of the probe body to seal a target portion to be electroplated, and a solution supply line supplying a solution to the target portion through the inside of the probe body, wherein the apparatus has a structure capable of wholly repairing the inside of the tube including a sealing welding part and an expanded part.