Nuclear Steam Generator Cleaning Solution Reuse
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for reusing cleaning solutions in thermal power plants, particularly for vessels like boilers and steam generators, face challenges with high concentrations of reducing agents, chelants, and corrosion inhibitors, leading to increased corrosion and instability during transition from reducing to oxidizing conditions, which complicates the removal of iron oxide and copper deposits.
Innovation Solution
The method involves transferring the spent cleaning solution to an external vessel for reconstitution and reformulation, where residual reducing agents are scavenged and oxidizing conditions are established, allowing for the injection of copper removal chemicals, thereby reducing corrosion and enhancing deposit removal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cleaning solution is reused with high concentrations of reducing agents and chelants, then deposit removal capability is maintained, but corrosion of vessel components increases
Solution Approach 1:
The patent changes the chemical parameters of the cleaning solution by adjusting pH levels and adding specific chemicals during the transition from reducing to oxidizing conditions. This allows the solution to maintain deposit removal capability while reducing corrosion through controlled chemical transformation.
Solution Approach 2:
The patent introduces intermediary chemicals and controlled transition conditions that mediate between the reducing and oxidizing states. These intermediaries facilitate the transformation while protecting vessel components from excessive corrosion during the chemistry change.
2Productivity
If cleaning solution chemistry is changed for different deposit types, then removal efficiency for specific deposits improves, but solution stability during transition deteriorates
Solution Approach 1:
The patent performs preliminary actions by gradually adjusting chemistry and pre-conditioning the solution before full transition. This staged approach maintains solution stability while enabling efficient removal of different deposit types through controlled chemical transformation.
Solution Approach 2:
The patent employs periodic action through staged chemistry transitions and repeated cycles of condition adjustment. This allows the solution to adapt to different deposit types while maintaining stability through controlled, incremental changes rather than abrupt transitions.
3Device complexity
If conventional cleaning methods are used without reformulation, then process simplicity is maintained, but waste disposal costs and cleaning time increase
Solution Approach 1:
The patent applies discarding and recovering by reformulating and reusing the cleaning solution rather than discarding it after single use. This extends the solution's lifecycle and reduces waste disposal costs while maintaining operational efficiency through controlled chemistry adjustments.
Solution Approach 2:
The patent makes the cleaning solution universal by enabling it to handle multiple deposit types through reformulation. The same base solution can be adapted for iron oxide, copper, or other deposits, reducing the need for multiple specialized solutions and decreasing overall cleaning time.
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 approach minimizes waste disposal costs, reduces cleaning time, and stabilizes dissolved metal complexes, enabling effective reuse of cleaning solutions with reduced corrosion and improved deposit removal capabilities.
Implementation Method 1
dissolving and removing deposits from vessels
Implementation Method 2
removal of iron oxide and copper deposits
Data Source
AI summary
An aqueous cleaning solution that has been previously used to remove deposits from a nuclear steam generator (or other vessel) is reused after being transferred from the steam generator into an external vessel. The spent cleaning solution may be reconditioned and reused in a further cleaning of the same steam generator or a different steam generator. The different cleanings being accomplished by the cleaning solution may be of the same type or different types (e.g., iron oxide removal and/or copper removal).