Offset Fin Heat Exchanger Asymmetric Corrugation
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Solution Overview
Problem
Conventional offset fin heat exchangers face challenges in increasing heat transfer rates while maintaining a low pressure drop, as the fluid flows linearly, limiting turbulence and heating surface area, which restricts further enhancement of heat transfer efficiency.
Innovation Solution
The heat exchanger incorporates an offset fin design with corrugation structures where fins are inclined at opposite angles, creating a turbulent flow and increasing the heating surface area, thereby enhancing heat transfer rates while maintaining a low pressure drop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If fins are arranged with parallel side walls in conventional offset fin, then manufacturing is simple, but heat transfer rate is limited due to linear fluid flow
Solution Approach 1:
The patent applies asymmetry by inclining side walls of fins at different angles (first side wall at first angle, second side wall at second angle different from first angle) to create asymmetric flow paths. This asymmetric geometry forces the fluid to follow curved trajectories through the fins, generating turbulence and extending the effective heating surface area, thereby significantly increasing heat transfer rates while maintaining manufacturability through standard forming processes
2Productivity
If corrugation structures are offset to create turbulence, then heat transfer rate increases, but pressure drop increases
Solution Approach 1:
The patent applies local quality by creating localized turbulence zones at specific positions where corrugation structures are offset, rather than uniformly disrupting flow throughout. The inclined side walls are strategically positioned to generate turbulence only in critical heat transfer regions, maximizing heat transfer enhancement while minimizing overall pressure drop by avoiding unnecessary flow disruption in other areas
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 significantly increases heat transfer rates by inducing turbulence and expanding the heating surface area, while keeping pressure drops manageable, as demonstrated by analytical models showing higher evaluation indices and efficient heat transfer.
Implementation Method 1
Turbulence occurs in the fluid because corrugation structure 70 is disposed offset from corrugation structure 60 in flow direction D. An acceleration effect produced by the turbulence increases a heat transfer rate.
Implementation Method 2
heat is transferred between side walls 62, 72 of fins 61, 71 and the fluid when the fluid passes through fins 61, 71
Data Source
AI summary
An offset fin for use in a heat exchanger includes a first corrugation structure and a second corrugation structure. The first corrugation structure includes a plurality of first fins aligned in a first direction. The second corrugation structure includes a plurality of second fins aligned in the first direction. The second corrugation structure is disposed in a second direction orthogonal to the first direction, with respect to the first corrugation structure. The first fins and the second fins protrude alternately in a third direction orthogonal to both the first direction and the second direction, and each have a protruding shape cross-section. In the first direction, the second fins are disposed offset from the first fins. Each of the first fins includes a first side wall inclined with respect to the second direction, and each of the second fins includes a second side wall inclined with respect to the second direction, at a side opposite to a side at which the first side wall is inclined.