Embossed Copper Tube

What are the advantages of using embossed copper tube in heat exchangers

Structure and technical features of embossed copper tubes
Embossed copper tubes are made by mechanically embossing the surface of the tube through a special mold on the basis of traditional smooth copper tubes to form regular protrusions or grooves. This structural design not only improves the surface area of ​​the copper tube, but also significantly enhances its heat exchange capacity with fluid media (such as air, water, refrigerant, etc.). The surface texture can effectively break the boundary layer, so that the fluid will produce micro-turbulence when flowing inside or outside the tube, improve the heat transfer coefficient, and improve the energy efficiency of the overall system.
Advantages of using embossed copper tubes in heat exchangers
1. Improve heat transfer efficiency
The core of the heat exchanger is to achieve efficient heat transfer between media. Embossed copper tubes greatly increase the heat transfer rate by increasing the surface area and turbulence effect. According to industry data statistics, under the same conditions, the heat transfer efficiency of embossed copper tubes can be increased by 15% to 30% compared with light tubes, and their application in equipment such as air conditioners, refrigerators, condensers and evaporators is particularly significant.
2. Reduce the amount of refrigerant, green and environmentally friendly
Thanks to the high heat exchange capacity, embossed copper tubes can use smaller diameter or shorter length pipes while maintaining the same performance, which helps to reduce the overall volume of the system and reduce the refrigerant, in line with the development direction of green energy saving and environmental protection.
3. Enhance structural strength and pressure resistance
Because the surface embossing process changes the force distribution mode of the copper tube, the embossed copper tube is better than the ordinary light tube in pressure resistance. It is especially suitable for high-pressure and high-load operation scenarios, such as commercial air-conditioning systems or industrial heat pump equipment.
4. Extend service life
The embossed copper tube produces a disturbed flow on the fluid, which helps to reduce the adhesion of scale and dirt and reduce the risk of corrosion. In addition, Zhejiang Jingliang Copper-Tube Products Co., Ltd uses high-purity copper raw materials and precision extrusion technology to ensure that the product has excellent thermal conductivity and corrosion resistance, significantly improving the operating life and long-term stability of the system.

What are the welding performance and process precautions of embossed copper tube?

Analysis of welding characteristics of embossed copper tube
The main material of embossed copper tube is still high-purity copper, which has good thermal conductivity and ductility, so it has excellent weldability in theory. However, several characteristics brought by its surface embossed structure make the welding process more complicated:
Surface unevenness
Embossed causes continuous concave and convex textures on the surface of the copper tube, which will affect the spreading of the brazing material and the integrity of the weld, especially in automatic welding, it is easier to form weld nodules or cold welds.
Uneven local heat input
The metal thickness of the embossed area changes slightly, and the heat conduction rate is slightly different under high temperature, which may lead to uneven heating during welding. It is necessary to use zone heating or control the shape of the flame mouth.
Increased oxidation risk
The surface area of ​​the copper material after embossing increases. If it is not controlled, it is easy to form an oxide layer before or during welding, affecting the strength and density of the welded joint.
Precautions for welding process
1. Pre-welding treatment is crucial
Before welding, the surface of the copper tube must be thoroughly degreased and deoxidized. Zhejiang Jingliang uses multiple cleaning and bright annealing processes to effectively ensure the clean surface of the copper tubes leaving the factory, providing a good foundation for customers' subsequent welding.
2. Choose the right solder
It is recommended to use low-temperature and high-wetness silver-based solder (such as BAg series) or phosphor copper solder (such as BCuP series), and decide whether to contain silver according to the stress of the welding part. For applications with high structural sealing requirements, such as condenser systems, silver-containing solder performs better.
3. Control heating method
Oxygen-acetylene flame is often used for manual welding. The flame should be adjusted to a neutral flame to prevent oxidation and keep the welding temperature within the range of 650℃ to 850℃; for mass production, automatic brazing equipment can be heated by infrared or electric induction, which is more conducive to the control of weld consistency.
4. Ensure fusion depth
If the embossed area is close to the weld, avoid contacting the solder only at the convex point. Zhejiang Jingliang recommends that customers use flared plug-in or sleeve welding when designing the connection structure to improve welding strength and anti-leakage performance.
5. Post-weld cleaning and testing
After welding, the weld should be cleaned and tested for air tightness. It is recommended to use nitrogen pressurization or water pressure testing process to ensure that the product meets the pressure resistance and sealing requirements.

How to detect the inner and outer surface quality defects of embossed copper tube

Common inner and outer surface defect types of embossed copper tube
Due to the influence of mechanical pressure and heat treatment during the forming process, embossed copper tube is more likely to produce the following typical surface defects:
Surface scratches and abrasions
Due to the contact between the pipe and the equipment parts during the transmission, rolling or handling process, it is very easy to leave obvious scratches on the raised lines.
Uneven embossing and deformation
If the embossing process is not properly controlled, some areas may be under- or over-deeply pressed, affecting the appearance and functionality.
Oxidation spots and surface stains
If the protective atmosphere is not strictly controlled during annealing or cooling, oxidation spots or spots are likely to appear on the surface of the copper tube.
Inner wall burrs or residues
Pulling chips, lubricants or oxide scales that have not been cleaned up may remain in the inner hole, affecting subsequent welding and fluid flow.
Pinholes, cracks and sand holes
Mostly originate from the quality of the ingot, extrusion stress or metal structure defects, which are extremely dangerous quality risks.
Detection methods and technical processes of embossed copper tubes
1. Manual visual inspection + strong light auxiliary inspection
This is the most basic and irreplaceable first line of quality defense. Zhejiang Jingliang has a special appearance inspection area. All embossed copper tubes must be inspected by professional quality inspectors in a 360-degree rotation under strong light to screen for obvious defects such as scratches, spots, and embossing deviations, and use high-definition magnifying glasses or digital images to strengthen the confirmation of doubts.
2. Laser profile scanning detection system
In order to realize the automated detection of embossing depth and shape consistency, Zhejiang Jingliang introduced a laser three-dimensional profiler, which can perform non-contact measurement on the surface of each section of the copper tube, and model and compare the geometric parameters of the embossing (such as peak distance, embossing depth, and repetition rate) in real time to ensure compliance with process standards.
3. Eddy Current Testing Technology
For fine cracks, pinholes and inclusions on the inner and outer surfaces of copper tubes, eddy current testing technology shows high sensitivity and efficiency. Eddy current testing can realize online fully automatic continuous testing, which is suitable for Zhejiang Jingliang's high-speed production line and has excellent recognition capabilities for microcracks, corrosion spots and welding defects.
4. Inner wall high-definition endoscope inspection
For embossed copper tubes with larger diameters, the inner wall defects are scanned using industrial video endoscopes, which can effectively detect invisible defects such as burrs, poor welds, and inner wall scratches. Zhejiang Jingliang is equipped with an original German imported high-definition probe system to ensure that there is no dead angle inspection inside the pipeline.
5. Color difference and surface uniformity analysis
The surface color of the copper tube is digitally monitored using a high-precision colorimeter to ensure that the product color is uniform after annealing. For export customer orders with high appearance requirements, the company customized an online spectral color difference comparison system to improve the product appearance grade.
6. Water pressure air tightness test and vacuum tightness test
For embossed copper tubes used in heat exchangers and condensers, water pressure and air tightness tests are required to detect whether there is microporous leakage. Zhejiang Jingliang has multiple special air tightness testing equipment, which can perform 100% testing on product batches to ensure that there is no leakage risk.