Walking-Beam Furnace Slab Length Planning for Scab Defect Reduction
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Solution Overview
Problem
Existing methods fail to effectively design slab length and charging position in walking-beam heating furnaces to minimize scab defects, which occur due to creep deformation and skid contact, particularly in grain-oriented electrical steel sheets.
Innovation Solution
A method using mixed integer programming to determine slab length and charging position, incorporating constraint equations and evaluation functions to minimize scab defect occurrence probability, considering overhang amounts and skid arrangements in multiple furnaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the slab length is increased to reduce overhang amount, then scab defect occurrence is reduced, but the flexibility in slab length adjustment is limited by upper and lower bounds
Solution Approach 1:
The patent changes the parameters of slab length and charging position to optimize the overhang amount. By adjusting these parameters within defined upper and lower bounds, the method minimizes scab defect occurrence probability while maintaining operational flexibility. The mixed integer programming model systematically explores parameter combinations to find optimal values that balance reliability and adaptability.
2Reliability
If the slab length is adjusted to minimize overhang in one heating furnace, then scab defects are reduced in that furnace, but the same slab length may cause longer overhang and scab defects in other heating furnaces with different skid arrangements
Solution Approach 1:
The patent creates a universal solution that works across multiple heating furnaces with different skid arrangements. The mixed integer programming model simultaneously considers the skid configurations of all furnaces and determines a slab length and charging position that minimizes the maximum scab defect probability across the entire system. This multi-functional approach ensures the solution is adaptable to various furnace configurations.
Solution Approach 2:
The patent segments the problem by considering each heating furnace's skid arrangement as a separate constraint in the optimization model. By dividing the overall system into individual furnace configurations and analyzing their specific overhang requirements, the method finds a compromise solution that performs adequately across all furnaces rather than optimizing for just one.
3Adaptability or versatility
If the overhang amount is increased, then the slab can accommodate different length requirements, but creep deformation increases leading to higher scab defect probability
Solution Approach 1:
The patent optimizes the overhang amount by changing the parameters of slab length and charging position. The mixed integer programming model identifies the optimal overhang amount that is large enough to accommodate different slab length requirements but small enough to minimize creep deformation and scab defect probability. This parameter optimization resolves the contradiction between adaptability and harmful effects.
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
Reduces the probability of scab defects and improves yield rate in walking-beam heating furnaces.
Implementation Method 1
the slab may droop due to creep deformation from the support point to the leading/tail ends
Data Source
Figure 1
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AI summary
A method of determining the slab length and charging position of the slab in a walking-beam heating furnace determines the length of the slab and the charging position of the slab in each heating furnace to minimize a first evaluation function under first constraint conditions, determines the charging position of the slab in each heating furnace to minimize a second evaluation function under a second constraint condition, and uses, as an overhang amount, a lead end overhang amount defined as the distance between a lead end coordinate of the slab in the heating furnace and a second skid coordinate counted from a lead end in a tail end direction, and a tail end overhang amount defined as the distance between a tail end coordinate of the slab in the heating furnace and a second skid coordinate counted from a tail end in a lead end direction.