Condenser Copper Tube

What is the role of annealing in the production process of condenser copper tubes

The principle and role of annealing

Annealing is a heat treatment method that eliminates internal stress, improves organizational structure and restores plasticity by heating and slow cooling. In the production process of copper tubes, after multiple drawing, extrusion and precision rolling, a large amount of residual stress will accumulate inside the material, resulting in increased hardness, increased brittleness and reduced ductility. If annealing is not performed at this time, the copper tube will not be able to meet the subsequent process requirements such as bending, flaring or welding, and it will be even more difficult to meet the strict standards of condenser tubes for air conditioning and refrigeration systems.

Through proper annealing, copper tubes can:
Eliminate internal stress and prevent deformation or rupture in the later stage;
Restore plasticity and improve bending and forming performance;
Improve thermal conductivity and ensure heat exchange efficiency;
Stabilize grain structure and improve overall mechanical properties.

The key position of annealing in the production process of condenser copper tubes

Condenser copper tubes are usually used in refrigeration equipment such as air conditioners, refrigerators, and heat pumps, and are required to have good thermal conductivity, corrosion resistance, formability and weldability. Zhejiang Jingliang Copper-Tube Products Co., Ltd. organically combines annealing process with front-end processes such as extrusion, drawing, and finishing rolling in actual production, forming a complete copper tube processing industry chain.
The medium-frequency continuous annealing technology and protective atmosphere annealing furnace system adopted by Jingliang can not only ensure uniform temperature and stable heating, but also effectively prevent oxidation and decarburization, greatly improving the surface quality and service life of copper tubes. This intelligent annealing process reflects the company's development concept of "precision manufacturing, technology first".
The specific impact of annealing process on the performance of condenser copper tubes
1. Improve fatigue resistance
In actual work, copper tubes need to withstand long-term cold and hot cycle shocks and high-frequency pressure changes. After annealing, the copper tubes have uniform grains and dense structure, which can effectively resist material fatigue and extend the overall life of the condenser.
2. Enhance welding and connection performance
Condenser copper tubes often need to be welded with distributors, heat exchangers or other system components. The welding performance of the copper tubes after annealing is significantly improved, and the welding joints are more solid and less prone to leakage.
3. Improve the convenience of forming and installation
Condensers usually need to bend copper tubes for routing according to the equipment structure. Annealed copper tubes have good flexibility and strong fracture resistance, which is convenient for tube bending and assembly, and improves on-site construction efficiency.

What is the main role of condenser copper tubes in refrigeration systems

Functional positioning of condenser copper tubes in refrigeration systems
In a typical refrigeration cycle, the condenser is responsible for cooling the high-temperature and high-pressure gaseous refrigerant output by the compressor into medium-temperature and high-pressure liquid refrigerant. As a heat exchange channel in the condenser, the copper tube plays the following roles:
1. Efficient heat exchange medium
Copper material has extremely high thermal conductivity (about 398 W/m·K). Compared with aluminum, stainless steel and other materials under the same conditions, it can transfer heat energy faster, allowing the refrigerant to quickly condense from gas to liquid, improving the overall system efficiency.
2. Fluid channel
The inside of the condenser copper tube is the main path for the flow of refrigerant. Its finish, inner diameter, bending radius, etc. directly affect the flow rate and pressure drop of the refrigerant, and thus affect the heat exchange capacity and system stability.
3. Corrosion resistance and pressure resistance
Copper naturally has strong corrosion resistance and is suitable for various refrigerants (such as R134a, R410a, R22, etc.) and different operating environments. At the same time, copper tubes have good pressure resistance and can operate safely in high-pressure refrigeration systems.
4. Good formability and weldability
In the design of refrigeration equipment, condenser copper tubes often need to be bent and connected at multiple angles according to structural requirements. Copper has strong ductility and excellent welding performance, which helps to achieve complex pipe layout and improve system compactness and reliability.
Jingliang Copper's product advantages and manufacturing capabilities
Since its establishment in 1994, Zhejiang Jingliang Copper-Tube Products Co., Ltd has always focused on the research and development and manufacturing of high-performance copper tube products, and has accumulated profound technical and industrial chain advantages in the field of condenser copper tubes. The company has now formed a full-process production system covering copper smelting-extrusion-drawing-finishing-annealing-finished product processing to ensure that each condenser copper tube has excellent consistency, stability and applicability.
The company's main products include: condenser copper tubes, evaporator copper tubes, finned copper tubes, square copper tubes, capillaries and conductive copper rods, etc., which are widely used in refrigeration equipment such as air conditioners, refrigerators, heat pumps, and automotive cooling systems, and are exported to international markets such as Europe, America, and Southeast Asia, winning a good brand reputation.
With an annual production capacity of more than 7,500 tons, Zhejiang Jingliang Copper Tube will achieve a total output value of 450 million yuan in 2022, showing excellent market competitiveness. In addition, the company has also been awarded honorary titles such as "Large Taxpayer in the Copper Tube Industry" and "Top Ten Copper Tube Enterprises in China", and technology and production capacity go hand in hand.
The far-reaching impact of condenser copper tube quality on system operation
1. Improve energy efficiency level
The excellent thermal conductivity of high-quality copper tubes can reduce system energy consumption and assist refrigeration equipment to achieve a higher energy efficiency ratio (EER or COP), which is the key support behind the energy efficiency label of air-conditioning products.
2. Extend equipment life
Copper tube materials with low impurities and high uniformity can effectively inhibit corrosion, leakage and other problems, reduce system failure rate and maintenance costs, and increase the life of the whole machine.
3. Optimize system design
Jingliang provides a variety of copper tubes of various specifications and models, including internal threaded tubes, micro tubes, thin-walled tubes, etc., which can be customized according to customer needs to improve the structural integration and performance of refrigeration devices.

What are the connection methods of condenser copper tubes and aluminum fins?

1. Mechanical expansion joint
This is the most common and mature connection method. The process principle is to first put the aluminum fins on the outside of the copper tube, and use the expansion equipment to make the inner diameter of the copper tube slightly plastically expand, so as to tightly press the inner hole of the aluminum fin to achieve good mechanical bonding and thermal contact.
Advantages: low contact thermal resistance, stable structure, suitable for mass production;
Key control: expansion amount, copper tube hardness, fin spacing consistency;
Jingliang advantage: excellent copper tubes can be accurately adapted to different fin inner diameters through annealing treatment and wall thickness precision control, ensuring uniform expansion and no deformation or loosening of the fins.
2. High-Frequency Welding
Through high-frequency induction heating technology, the joints between the copper tube and the aluminum fin are quickly heated and pressed in a short time to form a strong metallurgical bonding layer. This method is mostly used in special structures or equipment with high vibration resistance requirements.
Advantages: Reliable contact, suitable for simultaneous welding of multi-station fins;
Limitations: High equipment requirements, welding consistency needs to be strictly controlled;
Jingliang Application: The company is equipped with advanced automated welding lines, and there are a large number of application cases in the welding of copper fin tubes and aluminum structural components.
3. Aluminum tube plug-in-copper joint conversion method (Hybrid Insert Design)
In some scenarios that are extremely cost-sensitive, a composite structure of "aluminum tube + copper joint" will also be used, with copper tubes as key nodes of the pipeline and aluminum materials used to assist in heat dissipation.
Advantages: Obvious cost control advantages;
Technical challenges: The difference in thermal expansion coefficients of copper and aluminum needs to be solved through explosive welding, cold pressing or intermediate sleeves;
Jingliang technical reserves: The company provides a variety of wall thickness copper tubes, special-shaped copper tubes and special-material interface parts to match customers, and can provide customized composite solutions.
4. Welding + mechanical clamping composite connection
For some industrial heat exchange equipment, the design needs to take into account both the convenience of disassembly and assembly and thermal stability. Some manufacturers use mechanical clamping + local welding to double guarantee contact stability.
Advantages: Suitable for high-intensity operating environments (such as large chillers);
Disadvantages: Complex structure and difficult maintenance;
Jingliang matching: Provide high-strength hard copper tubes and high-precision reducers to meet the needs of complex connection structures.