Flat Oval Heat Exchanger Tubes That Resist Deformation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat exchangers face issues with deformation of flat elliptic heat transfer pipes due to internal pressure, leading to reduced contact with plate-like fins, increased pressure loss, and higher assembly costs, which affect heat transfer performance and ventilation resistance.
Innovation Solution
A heat exchanger design featuring flat-shaped heat transfer pipes with oval sections and D-shaped through holes, bulkhead partitioning, and protruding strips, bonded using pipe-expanding burette balls, maintains pressure capacity and ensures close contact with plate-like fins, reducing deformation and assembly complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a flat elliptic heat transfer pipe with a single through hole is used, then the pipe structure is simple, but the heat transfer pipe is expanded and deformed by internal pressure during operation, deteriorating close contact with the plate-like fin
Solution Approach 1:
The single through hole of the heat transfer pipe is divided into multiple refrigerant flow passages (first and second passages). This segmentation increases the structural rigidity of the pipe wall, preventing deformation under internal pressure while maintaining the flat elliptic shape for good contact with plate-like fins. The multiple passages are arranged symmetrically to balance stress distribution.
Solution Approach 2:
Protruding strips are added locally on the inner wall face of the refrigerant flow passages. These protruding strips create turbulence in the refrigerant flow, enhancing heat transfer performance in specific regions where it is most needed, without affecting the overall pipe shape or contact with fins.
2Temperature
If the heat transfer pipe is made into a multi-hole structure with reduced size and diameter, then heat transfer rate in the pipe is increased, but pressure loss is increased and manufacturing and assembly costs increase due to brazing requirements
Solution Approach 1:
The heat transfer pipe uses multiple refrigerant flow passages with optimized dimensions and arrangements. By changing the parameters of the flow passages (number, size, shape, and distribution), the patent achieves enhanced heat transfer rate while controlling pressure loss. The symmetric D-shaped passages are designed to optimize flow characteristics and minimize pressure drop.
3Temperature
If the heat transfer pipe size and diameter are reduced, then heat transfer performance is improved, but assembling cost is increased since manufacture and mounting are carried out by brazing
Solution Approach 1:
The patent adopts a heat transfer pipe design that can be manufactured and assembled more economically. The multi-hole flat elliptic pipe structure allows for efficient manufacturing processes and simpler assembly methods compared to traditional brazing techniques, reducing assembling costs while maintaining improved heat transfer performance through the optimized multi-passage design.
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 enhances heat transfer performance, reduces ventilation resistance, and increases heat exchange capacity while maintaining reduced pipe size and diameter, with improved assembling efficiency and cost-effectiveness.
Implementation Method 1
bonded to the plate-like fin by expanding diameters of the first and second refrigerant flow passages by a pipe-expanding burette ball
Implementation Method 2
heat transfer pipe inserted in a direction orthogonal to the plate-like fins and through which a refrigerant flows
Implementation Method 3
plate-like fins arranged in parallel with a predetermined interval and a plurality of flat-shaped heat transfer pipes inserted in a direction orthogonal to the plate-like fins and through which a refrigerant flows
Implementation Method 4
one of or both of said first and second refrigerant flow passages have a plurality of protruding strips extending in an axial direction on an inner wall face of the flow passage
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A heat exchanger provided with a plurality of plate-like fins 2 arranged in parallel with a predetermined interval and a plurality of flat-shaped heat transfer pipes 3 inserted in a direction orthogonal to said plate-like fins 2 and through which a refrigerant flows, in which said heat transfer pipe 3 has an outside shape with a flat outer face arranged along an air flow direction and a section substantially in an oval shape and first and second refrigerant flow passages 31a, 31b made of two symmetric and substantially D-shaped through holes having a bulkhead 32 between the two passages inside, which is bonded to said plate-like fin 2 by expanding diameters of said first and second refrigerant flow passages 31a, 31b by a pipe-expanding burette ball.