Corrugated Header Sheet Coupling for Fin Tube Brazing Gaps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat exchangers face issues with increased gaps between headers and fin tubes due to manufacturing tolerances, leading to high brazing defect rates and low structural stability, as well as difficulties in assembly, especially with numerous fin tubes passing through narrow insertion holes.
Innovation Solution
A heat exchanger design featuring a header with a sheet having corrugated portions and slits, where fin tubes are inserted and compressed to reduce gaps and improve adhesion, enhancing brazing quality and structural stability, and facilitating assembly by increasing the interval between corrugated portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If slotting processing or wire cutting is used to form insertion holes in the header, then fin tubes can be inserted into the header, but gaps between the header and fin tubes increase due to manufacturing tolerances, leading to high brazing defect rates
Solution Approach 1:
The sheet is divided into multiple corrugated portions with slits, where each corrugated portion independently engages with a fin tube. This segmentation allows each insertion point to be optimized separately, reducing the impact of manufacturing tolerances on the overall gap size.
Solution Approach 2:
The sheet is formed with corrugated portions having curved surfaces that conform to the cylindrical shape of fin tubes. This curvature enables better surface contact and reduces gaps compared to flat insertion holes, improving brazing quality while maintaining ease of insertion.
2Area of stationary object
If multiple fin tubes pass through narrow insertion holes, then the header can be compact, but the assembly process becomes difficult due to narrow intervals between insertion holes
Solution Approach 1:
The corrugated portions are arranged in a pattern that optimizes both space utilization and accessibility. By considering the three-dimensional arrangement of corrugated portions on the sheet, the design achieves compact header area while maintaining sufficient clearance for assembly operations.
3Manufacturing precision
If the gap between header and fin tube is reduced through precise machining, then brazing quality improves, but the structural stability of coupling between components remains low
Solution Approach 1:
The corrugated portions with curved surfaces provide both tight gap control for brazing and enhanced mechanical interlocking with the fin tubes. The curved geometry creates a friction fit that improves structural stability while maintaining the reduced gap necessary for quality brazing.
Solution Approach 2:
The coupling mechanism combines brazed joints (metallic bond) with mechanical interference fit from the corrugated portions (physical interlocking). This composite coupling approach provides both the precision of brazing and the structural stability of mechanical engagement.
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
The design reduces refrigerant leakage, improves brazing quality, and enhances structural stability, making assembly easier and more reliable by minimizing gaps between the header and fin tubes and using a filler metal to secure the connection.
Implementation Method 1
the corrugated portion of the sheet is compressed, a gap between the header and the fin tube is reduced to thereby increase adhesion between the sheet and the fin tube
Data Source
AI summary
The present invention relates to a heat exchanger comprising: a plurality of fin tubes which have heat transfer fins integrally formed with tubes in which a refrigerant flows; and a header which is coupled to the respective one end portions of the plurality of fin tubes. The header may comprise: a header main body which has one side opened; and a sheet which is disposed on the open one side of the header main body, has formed therein a plurality of slits having the respective one end portions of the plurality of fin tubes respectively inserted therein, and forms a plurality of corrugated portions by being bent into a corrugated shape. Accordingly, the respective one ends of the fin tubes are inserted into the sheet having the corrugated portions formed, and then the corrugated portions of the sheet are compressed, thereby enabling the narrowing of gaps between the fin tubes and the header, and thus, by increasing tight adhesion between the fin tubes and the sheet, tolerance may be reduced, and a leakage of the refrigerant may be reduced. In addition, when inserting the fin tubes, intervals between the corrugated portions formed on the sheet are widened so as to enable the fin tubes to be easily inserted, and thus an advantage is also achieved of enabling easy product assembly.