What is the pressure resistance performance of microchannel flat tubes
Information summary:The pressure resistance performance of microchannel flat tubes is generally suitable for mainstream application scenarios such as automotive air conditioning and industrial heat exchange. There is no fixed standard for their pressure resistance value.
The pressure resistance performance of microchannel flat tubes is generally suitable for mainstream application scenarios such as automotive air conditioning and industrial heat exchange. There is no fixed standard for their pressure resistance value. Conventional products meet the requirements of sealing test pressure ≥ 2.5MPa and bursting pressure ≥ 6.0MPa. Customized or optimized products can have a maximum bursting pressure of over 27MPa, which is significantly affected by structural design, materials, and other factors. Details are as follows:
1. Conventional pressure resistance standards and special operating conditions: There are clear basic pressure resistance requirements for microchannel aluminum flat tubes in the industry, and the sealing test pressure is usually not less than 2.5 MPa, and the bursting pressure is not less than 6.0 MPa. For scenarios such as the high-pressure side of air conditioning refrigeration systems that require higher pressure resistance, optimized products can be easily adapted. For example, according to the relevant standards of Zhejiang Jinxin Aluminum Industry, the microchannel aluminum flat tube must undergo a 14MPa pressure test without deformation, leakage, or rupture; A product made of 1100 series aluminum alloy has been calculated to have a burst pressure of 27.05 MPa, which can meet the requirements of harsh high-pressure working conditions.
2. The core impact of structural design on pressure resistance: This factor directly determines the ability of flat tubes to withstand and disperse pressure. The middle reinforcement is the main pressure bearing point, and the thicker and more numerous it is, the stronger its pressure resistance. For example, a 3003 series aluminum alloy flat tube with a middle reinforcement thickness of 0.3mm and 20 pieces has a measured burst pressure of about 15.44MPa; If the thickness of the middle reinforcement is increased to 0.391mm, the blasting pressure can be increased to 27.05MPa. In addition, there are patents that can reduce local pressure concentration and further enhance the compressive strength of the microchannel wall by adding protrusions on both sides of the microchannel wall as reinforcing ribs, or adopting a reasonable flow channel layout of 19 holes, to avoid pipeline deformation and blockage when the refrigerant flow rate increases.
3. The basic supporting role of material strength: Microchannel flat tubes are mostly made of aluminum alloy as raw material, and the tensile strength of the material directly determines the upper limit of pressure resistance. The tensile strength of 3003 series aluminum alloy is about 100MPa, and the corresponding flat tube burst pressure is better than that of 1100 series aluminum alloy products with a tensile strength of 82MPa. If 6XXX series aluminum alloy is selected, it can further enhance the ability to withstand high-pressure gas pressure; The aluminum alloy flat tube formed by horizontal hot extrusion has a denser internal structure, which can avoid defects such as shrinkage and looseness, and reduce the pressure resistance short board caused by material defects.
4. Breakthrough in pressure resistance of special structural products: The new folding microchannel flat tube has achieved a leap in pressure resistance performance through structural innovation. For example, a dual blade microchannel folding tube with internal fins, designed with an inner wall thickness of 0.08mm, an outer wall thickness of 0.2mm, and 19 holes, has a 30% increase in maximum pressure resistance compared to ordinary microchannel tubes. Its simulation and experimental burst values both reach 21.9MPa, and its volume is reduced by 35%. It not only considers pressure resistance but also achieves structural compactness, suitable for high-pressure heat exchange scenarios that require installation space.