Robotic Sludge Suction in Steam Generator Tube Sheets
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Solution Overview
Problem
Current methods for cleaning and inspecting the top of the tube sheet in steam generators are inefficient and costly, requiring multiple passes and large pumping systems to remove sludge deposits, which can lead to tube degradation and potential radioactive leaks.
Innovation Solution
A robotic system with a moveable sludge suction apparatus and wand assembly that allows for remote, in-bundle vacuuming and inspection of the tube sheet, eliminating the need for high-pressure water and enabling continuous cleaning and real-time visual inspection of sludge removal, using a single air-operated diaphragm pump and a robotic vehicle to navigate through the annulus and tube gaps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high pressure water lancing is used to remove sludge deposits, then cleaning effectiveness is improved, but device complexity and cost increase due to large pumping systems and multiple hoses
Solution Approach 1:
The invention extracts the sludge removal function from the complex high-pressure water lancing system and implements it through a simple vacuum-based robotic apparatus that navigates through the annulus and tube gaps to suction sludge directly, eliminating the need for large pumping systems and multiple hoses
Solution Approach 2:
The invention replaces the mechanical high-pressure water lancing system with a vacuum-based suction system operated by a robotic vehicle, substituting complex hydraulic machinery with a simpler robotic platform that uses vacuum pressure differentials for sludge removal
2Reliability
If multiple passes are performed to ensure satisfactory cleanliness, then cleaning completeness is improved, but loss of time increases
Solution Approach 1:
The robotic vehicle continuously navigates through the annulus and tube gaps in a single continuous operation, performing sludge removal along its entire path without requiring multiple discrete passes, thereby maintaining cleaning completeness while reducing total time
Solution Approach 2:
The robotic system performs preliminary navigation and positioning within the annulus before sludge removal begins, enabling it to access all necessary areas in one continuous operation rather than requiring multiple sequential passes
3Reliability
If high pressure water is delivered from the no tube lane, then sludge removal capability is improved, but ease of operation deteriorates due to the need to push deposits through the tube bundle
Solution Approach 1:
Instead of pushing sludge through the tube bundle from the no tube lane as in conventional systems, the robotic vehicle inverts the approach by navigating through the annulus and tube gaps to suction sludge directly at its source, eliminating the need to push deposits through the bundle and simplifying operation
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 method reduces the time and cost associated with cleaning and inspection by allowing for targeted cleaning and 100% accessible in-bundle tube sheet inspections, improving efficiency and reducing the risk of tube degradation and radioactive leaks.
Implementation Method 1
A robotic system with a moveable sludge suction apparatus and wand assembly that allows for remote, in-bundle vacuuming and inspection of the tube sheet
Implementation Method 2
using a single air-operated diaphragm pump
Data Source
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AI summary
A method and apparatus for manipulating a tool within the secondary side of a steam generator having a tube sheet with a tube bundle having a plurality of heat exchange tubes extending from the tube sheet in rows with an annulus extending around the heat exchange tubes on a periphery of the tube bundle, between the tubes and a wrapper which surrounds the tube bundle. A robot is introduced into the annulus and extends a probe with a tool across selected lanes between the rows of tubes. A method and apparatus is also disclosed for cleaning sludge from the top of a tube sheet that includes introducing a moveable suction apparatus having attached vacuum inlets into either the no tube lane or the circumferential annulus and sludge vacuuming the top of the tube sheet.