Enhanced Heat Transfer Tube Surface via Groove and Protrusion Tooling
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Solution Overview
Problem
Existing heat transfer surfaces in industries such as refrigeration and petrochemicals face challenges in enhancing heat transfer performance due to clogging by impurities and non-uniform voids, requiring complex and costly manufacturing processes to create effective boiling or evaporating surfaces.
Innovation Solution
The development of heat transfer surfaces with a plurality of cavities and protrusions formed using a tool with a mirror image of grooves and cutting/lifting edges, which creates additional paths for fluid flow and increases surface area for heat exchange, allowing for enhanced turbulence and improved heat transfer performance without removing metal from the tube surface, thus avoiding debris-related issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a porous layer is formed by sintering, radiation-melting or edging methods to enhance boiling or evaporating, then heat transfer performance is improved, but impurities in the boiling liquid clog the small voids or cells impairing heat transfer performance
Solution Approach 1:
The invention creates a surface with locally differentiated features: protrusions with cavities at their tips and grooves between them. The cavities provide larger openings resistant to clogging, while the grooves guide fluid flow. This local differentiation allows the surface to maintain heat transfer performance while resisting impurity clogging that affects uniform porous layers.
Solution Approach 2:
The surface is segmented into discrete protrusions and grooves rather than forming a continuous porous layer. This segmentation creates isolated cavities that are less susceptible to complete clogging, as fluid can still access heat transfer surfaces through multiple separate pathways rather than a single interconnected porous network.
2Reliability
If a porous layer is formed by sintering, radiation-melting or edging methods, then heat transfer performance is improved, but the voids or cells are non-uniform in size or dimension causing varying heat transfer performance along the surface
Solution Approach 1:
The invention uses a forming tool with a predetermined pattern of protrusions and grooves to create the surface geometry before the tube is put into service. This preliminary formation ensures uniform cavity sizes and distributions along the surface, eliminating the non-uniform void structures that result from sintering or radiation-melting processes.
Solution Approach 2:
The invention changes the geometric parameters of the surface structure from random porous voids to controlled protrusions with specific cavity dimensions. By defining specific parameters for protrusion height, cavity size, and groove spacing, the surface achieves uniform heat transfer characteristics along its length.
3Reliability
If multiple steps or passes with tools are used to create the final surface, then heat transfer performance can be enhanced, but manufacturing complexity and cost increase
Solution Approach 1:
The invention combines multiple surface features (protrusions, cavities, and grooves) into a single integrated structure that can be formed in one manufacturing pass. The forming tool simultaneously creates all these features by rotating against the tube surface, eliminating the need for multiple sequential steps required by conventional methods.
4Reliability
If metal is removed from the tube surface to create enhanced heat transfer surfaces, then heat transfer performance is improved, but debris is generated which can damage equipment
Solution Approach 1:
Instead of removing metal to create the enhanced surface, the invention inverts the approach by adding material through plastic deformation. The forming tool pushes metal forward to create protrusions and cavities, generating no debris while achieving the same heat transfer enhancement that would traditionally require material removal.
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 solution significantly enhances heat transfer performance by reducing transition time between phases and increasing fluid flow paths, leading to improved efficiency and cost-effectiveness in manufacturing, suitable for various industrial applications.
Implementation Method 1
a tool, which also can be easily added to existing manufacturing equipment, having a cutting edge to cut through the surface of tube and a lifting edge to lift the surface of the tube to form protrusions
Implementation Method 2
The cavities create additional paths for fluid flow within the tube and thereby enhance turbulence of heat transfer mediums flowing within the tube
Implementation Method 3
Protrusions creating cavities also provide extra surface area for additional heat exchange
Data Source
AI summary
The invention relates to enhanced heat transfer surfaces and methods and tools for making enhanced heat transfer surface. Certain embodiments include a boiling surface that include a plurality of primary grooves, protrusions and secondary grooves to form boiling cavities. The boiling surface may be formed by using a tool for cutting the inner surface of a tube. The tool has a tool axis and at least one tip with a cutting edge and a lifting edge. Methods for making a boiling surface are also disclosed, including cutting through the inner surface of a tube to form primary grooves, then cutting and lifting the inner surface to form protrusions and secondary grooves.