Heat Exchanger Fin Pitch Control Using Cut and Raised Pieces
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Solution Overview
Problem
Conventional heat exchangers face challenges in securing a desired fin pitch between adjacent fins, especially when the thickness of the flat tube is smaller than the required fin pitch, leading to inadequate spacing and ventilation issues.
Innovation Solution
The heat exchanger design includes a cut and raised piece on the inner periphery of the flat tube insertion portion, with a raised portion and a folded portion that contacts an adjacent fin, allowing for a fin pitch that is larger than the thickness of the flat tube by incorporating a cutout portion from the ventilation side, ensuring secure spacing irrespective of the tube thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the cutout remainder portion is bent and raised to form the cut and raised piece, then the fin pitch can be secured, but the length of the cut and raised piece is limited to the width range of the flat tube insertion portion, making it inadequate when flat tube thickness is smaller than the demanded fin pitch
Solution Approach 1:
The invention extends the cut and raised piece formation from solely utilizing the cutout remainder portion (one-dimensional limitation) to include an additional cutout portion formed in the ventilation portion of the fin. This dimensional extension allows the cut and raised piece to achieve a length greater than the flat tube thickness, thereby securing the demanded fin pitch even when the flat tube thickness is smaller than the required fin pitch.
2Manufacturing precision
If the cut and raised piece is formed in the ventilation portion of the fin, then ventilation resistance increases and condensate drainage is reduced, but if formed in the flat tube insertion portion, then the fin pitch cannot be properly secured when flat tube thickness is small
Solution Approach 1:
The invention applies local quality by forming the cutout portion specifically in the ventilation portion of the fin, while the cut and raised piece itself is positioned to contact the adjacent fin for spacing. The cutout portion is strategically located to minimize interference with ventilation and condensate drainage, thus reducing the harmful effects on airflow while still achieving the required fin pitch through the raised structure.
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 design effectively secures a desired fin pitch, improving ventilation and condensate drainage by allowing the cut and raised piece to be larger than the flat tube thickness, thus enhancing the performance of the heat exchanger.
Implementation Method 1
the cut and raised piece has a raised portion of the same length as the fin pitch, and a folded portion that is folded back at the tip of the raised portion and that is in contact with the second fin
Implementation Method 2
heat is exchanged by the plurality of fins, between the refrigerant that flows through the flow path holes inside the flat tubes, and air that passes between the plurality of fins
Implementation Method 3
heat is exchanged by the plurality of fins, between the refrigerant that flows through the flow path holes inside the flat tubes, and air that passes between the plurality of fins
Data Source
AI summary
A heat exchanger includes: a plurality of flat tubes that are stacked in a direction perpendicular to a refrigerant flow direction, and a plurality of fins that have a first flat tube insertion portion into which a first flat tube among the plurality of flat tubes is inserted, and a second flat tube insertion portion into which a second flat tube adjacent to the first flat tube is inserted. A first fin has, formed on the inner periphery of the first flat tube insertion portion, a cut and raised piece for spacing a fin pitch between the first fin and an adjacent second fin. The cut and raised piece has a raised portion of the same length as the fin pitch, and a folded portion that is folded back at the tip of the raised portion and that is in contact with the second fin.