Inner Fin Offset Grooves and Projections for EGR Cooler
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Solution Overview
Problem
Conventional inner fins in EGR coolers face issues with high resistance to exhaust gases, easy clogging due to soot and particulate matter accumulation, and increased material costs due to narrow fin pitch, as well as reduced performance from improper assembly and turbulence reduction over time.
Innovation Solution
An inner fin configuration with alternately offset grooves and ridges, featuring inclined first and second projections on the surface, where the second projection is downstream of the first, promotes turbulence and disperses gases effectively without narrowing the fin pitch, and is designed to minimize soot accumulation and ensure easy assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the fin pitch is narrowed to expand heat exchanging area, then heat dissipating performance is improved, but resistance against exhaust gases increases and material cost increases
Solution Approach 1:
The inner fin incorporates projections at specific locations (every other fin in the widthwise direction) rather than uniformly across all fins. This localized modification creates turbulence and enhances heat exchange at critical positions without narrowing the overall fin pitch, thereby improving heat dissipating performance while maintaining low resistance to exhaust gas flow and reducing material consumption.
2Temperature
If the fin pitch is narrowed to expand heat exchanging area, then heat dissipating performance is improved, but soot and PMs accumulation increases causing tube clogging
Solution Approach 1:
Projections are formed on specific fins (every other fin) rather than all fins, creating localized turbulence zones that prevent soot and PMs accumulation. This selective projection configuration disrupts the flow pattern in a way that reduces particulate matter deposition on the inner fin surface, preventing tube clogging while maintaining adequate heat exchange area.
3Temperature
If projections are formed to generate turbulence, then heat dissipating performance is improved, but assembly errors reduce performance and projections accumulate soot over time
Solution Approach 1:
The projections are configured with asymmetric positioning (every other fin has projections while adjacent fins do not) and specific geometric shapes that create directional turbulence. This asymmetric design ensures that the turbulence-generating function is maintained regardless of assembly orientation, preventing performance degradation from assembly errors while the staggered configuration reduces soot accumulation compared to uniform projections.
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
Enhances heat dissipating performance, reduces clogging, and extends product life by creating aggressive turbulence and smooth dispersion of exhaust gases, while maintaining a stable assembly and preventing erroneous installation during fabrication.
Implementation Method 1
the first projection and a second projection, the second projection being disposed downstream of the first projection, are formed for each segment... so that turbulence of exhaust gases are generated in the gas flow path by the projections
Implementation Method 2
a sheet material is formed into an offset configuration in which grooves and ridges are formed alternately in a widthwise direction... to promote heat exchange between the exhaust gases and a cooling fluid
Data Source
AI summary
An object of the invention is to provide an inner fin for a tube used in an EGR cooler which promotes the heat exchange between exhaust gases and cooling fluid, which makes it difficult for the tube to be clogged with soot and which is easy to be assembled at the time of fabrication. There is provided an inner fin (1) configured to be installed in an EGR cooler for cooling exhaust gases, and to be used in a flat tube through which exhaust gases pass, wherein: a sheet material is formed into an offset configuration in which grooves and ridges are formed alternately in a widthwise direction, and the grooves and the ridges are offset laterally at right angles to a gas flowing direction at predetermined length intervals in an alternate fashion; and a first projection (11) and a second projection (12) are formed for each segment (10) surrounded by a pair of left and right side walls, by cutting either an upper surface portion or a lower surface portion and causing the cut surface portion to stand, the first projection (11) being inclined towards an upstream side of the gas flowing direction, the second projection being disposed downstream of the first projection (11) and being inclined towards a downstream side of the gas flowing direction at an angle equal to an angle at which the first projection (11) is inclined.