Service life of aluminium alloy cable

Service life of aluminium alloy cable

1. There are two main types of partial corrosion of conductors: chemical corrosion and electrochemical corrosion.

Chemical corrosion: refers to the corrosion of metals in the atmosphere with oxygen, chlorine, sulfur dioxide, hydrogen sulfide and other gases.

The metal surface reacts with oxygen to form different metal oxides.

Aluminum oxide can form a dense surface protective film with a certain hardness.

The structure of iron oxides is loose, easy to fall off, and continue to infiltrate and diffuse into the metal, destroying the material.

Copper oxide, commonly known as copper green, is a toxic substance between the above two.

_electrochemical corrosion: refers to the corrosion process of metals formed after the primary battery is composed of metals and dielectrics. When two metals with different electrode potentials are connected and water or other electrolytes are added between them, a current will be generated between the two metals to form a primary battery. One metal is at positive potential, the other is at negative potential. Potential, the metal in negative potential continuously accumulates to the metal in positive potential through electrolyte in ionic state. The metal at negative potential is gradually lost and destroyed, resulting in electrochemical corrosion. The greater the difference of electrode potential between the two metals, the stronger the electrochemical corrosion. The higher the temperature, the more serious the corrosion of metals.

Different metals have different electrode potentials. The order of electrode potential of several commonly used metals is: Ag (Ag), Cu (Cu), Pb (Pb), Sn (Sn), Fe (Fe), Zn (Zn) A1 (Al). The greater the negative potential of the electrodes, the stronger the tendency of the metal to be ion in the electrolyte, the more vulnerable it is to corrosion. The negative potential of aluminium electrode is larger, but its corrosion resistance can be improved because there is often a protective layer of oxide film on its surface.

Rare earth aluminium alloy material is added rare earth elements in aluminium, which can purify, improve purity, fill surface defects and refine grains. Reducing segregation, eliminating the effect of local corrosion caused by microscopic inhomogeneity, but also bring negative shift of the electrode potential of aluminium, which has the cathode effect and excellent conductivity, thus greatly improving the corrosion resistance of aluminium. For the corrosion problems of C1 - in marine environment, S, H2S + C02 in petroleum and chemical environment, this material has a unique anti-corrosion mechanism. The strong reducibility of rare earth metals can effectively combine with the strong oxidation of S, H2S and C1-to form stable compounds (C1-to form stable coordination compounds with rare earth aluminium alloys). The oxidation and reduction processes in chemical reactions are organically unified and interacted, which ultimately cuts off oxygen in corrosive media such as S, H2S, C1-and so on. Corrosion damage caused by chemical activities has thoroughly solved the problems that developed countries, including the United States, have not been able to solve well in the world. Data analysis of the detection and engineering examples of national detection departments such as Beijing General Institute of Nonferrous Metals Research shows that in chloride ion, sea water, ocean atmosphere and salt fog environment (alternating wet and dry) Under saturated Hz S, sulfur and high temperature and high pressure conditions, the annual corrosion rate of rare earth aluminium alloys is zero or almost zero.

2. Insulation part

_The current carrying capacity of power cable refers to the maximum current allowed by the conductor of the cable at the highest allowable temperature. In the design and selection of cables, the heat loss of each part of the cables should not exceed the maximum allowable temperature of the cables. In most cases, the transmission capacity of the cables is determined by the maximum allowable temperature of the cables. The maximum allowable temperature of the cables mainly depends on the thermal aging performance of the insulating materials used, because the cables work. If the temperature is too high, the aging of insulating materials will accelerate and the service life of cables will be greatly shortened. If the cable operates above the maximum allowable temperature, it will work safely for 30 years.

XLPE is the abbreviation of the English name of crosslinked polyethylene. Polyethylene is a linear molecular structure, which is easily deformed at high temperature. The crosslinked polyethylene process transforms it into a network structure. Even at high temperatures, this structure also has a strong anti-deformation ability.

Excellent aging resistance and super thermal deformation of cross-linked polyethylene determine that high current can be allowed to pass under normal operating temperature (90C), short-term fault (130C) and short-circuit (250C). Because its operating temperature is 20C higher than that of polyvinyl chloride, it has excellent thermal resistance, increases the aging resistance of insulation, and greatly increases its service life.

Economic performance

_Direct Purchasing Cost

Comparing the price of aluminium alloy cable with copper core cable: aluminium alloy cable has superior safety performance, electrical performance, mechanical performance and longer service life, the price of aluminium alloy cable is only about 75% of that of copper cable.

_Lower installation cost

Save installation cost: Aluminum alloy cable is easy to install because of its good bending performance and light weight.