Finned Metal Heat Exchanger Tube With Segmented Evaporation Channels
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Solution Overview
Problem
Existing heat exchanger tubes in refrigeration and air conditioning technologies face inefficiencies in heat transfer during liquid evaporation, particularly due to the limitations of smooth surfaces and conventional finned structures that hinder fluid flow and bubble migration, leading to suboptimal heat exchange performance.
Innovation Solution
The development of a metallic heat exchanger tube with integral ribs and segmented channels, featuring radially outward projections and material projections that limit fluid flow and promote bubble nucleation, enhancing heat transfer by creating local overheating and guiding fluid flow into segments for efficient bubble formation and vapor exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If conventional finned structures are used, then heat transfer area is increased, but fluid flow and bubble migration are hindered
Solution Approach 1:
The channel base is segmented into multiple channels using protrusions that extend radially outward. This segmentation divides the continuous groove into discrete flow paths, allowing controlled fluid distribution while maintaining adequate flow velocity in each channel. The segmentation prevents excessive fluid accumulation and facilitates bubble migration by creating defined flow paths.
Solution Approach 2:
The groove base is equipped with additional structures (protrusions and recesses) at specific locations to enhance local heat transfer. These structures create localized turbulence and extend the liquid film residence time in critical areas, improving heat transfer coefficients without obstructing overall fluid flow through the channel.
2Ease of operation
If smooth tube surfaces are used, then fluid flow is maintained, but heat transfer efficiency during evaporation is insufficient
Solution Approach 1:
The groove base incorporates porous or textured additional structures that promote liquid film formation and retention. These structures create capillary effects that enhance liquid distribution over the heating surface, increasing the effective evaporation area and heat transfer efficiency while maintaining adequate fluid flow through the channel system.
Solution Approach 2:
The invention transitions from a smooth two-dimensional surface to a three-dimensional structured surface with protrusions and recesses. This dimensional enhancement creates additional heat transfer pathways and extends liquid film contact time with the heating surface, significantly improving evaporation efficiency without compromising fluid flow.
3Productivity
If higher projections are added to groove base, then heat transfer is enhanced, but fluid flow in channel is impeded
Solution Approach 1:
The additional structures are designed with optimized dimensions and spacing that adapt to varying flow conditions. The protrusions and recesses create dynamic flow patterns that enhance heat transfer during high flow conditions while minimizing flow resistance during low flow conditions, achieving a balance between heat transfer enhancement and fluid flow maintenance.
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 the heat transfer coefficient, optimizing evaporator performance across a wide range of operating conditions by controlling bubble nucleation and fluid flow, while reducing the cross-sectional area for improved efficiency.
Implementation Method 1
promote bubble nucleation, enhancing heat transfer by creating local overheating and guiding fluid flow into segments for efficient bubble formation and vapor exchange
Implementation Method 2
Evaporation occurs in many areas of refrigeration and air conditioning, as well as in process and energy engineering, in shell-and-tube heat exchangers
Implementation Method 3
liquids of pure substances or mixtures evaporate on the outside of the tube
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to a metal heat exchanger tube (1), comprising integral fins (2) formed on the outside of the tube and having a fin base (3), fin flanks (4), and a fin peak (5), wherein the fin base (3) protrudes radially from the tube wall (10), and a channel (6) having a channel bottom (61) is formed between the fins (2), in which channel additional structures (7, 71, 72) spaced apart from each other are arranged. The additional structures (7, 71, 72) divide the channel (6) between the fins (2) into segments (8). The additional structures (7, 71, 72) locally reduce the cross-sectional area through which flow can pass in the channel (6) between two fins (2) and at least thereby limit a fluid flow in the channel (6) during operation. First additional structures (7, 71) are projections (71) starting from the channel bottom (61) and directed radially outward, each of which are limited in the radial direction by a terminating surface (713) located between the channel bottom (61) and the fin peak (5), thus defining a radial extension of the projections (71). At the location of the projections (71), radially outer material protrusions (72) are arranged as second additional structures (7, 72), which protrusions are formed from the material of the fin flanks (4). The material protrusions (72) are each arranged between a terminating surface (713) and the fin peak (5) in the radial direction, such that the material protrusions (72) are formed about the radial extension of the projections (71) over the channel bottom (61) of the channel (6), lying laterally on the fin flank (4). The material protrusions (72) extend further in the axial and radial direction than in the circumferential direction.