Service life of aluminum alloy cable
Firstthere are mainly two kinds of corrosion of Conductor: chemical corrosion and electrochemical corrosion.
◆Chemical corrosion: corrosion of metals in the atmosphere with oxygen, chlorine, sulfur dioxide, hydrogen sulfide and other gases.
Metal surfaces react with oxygen to form different metal oxides.
Aluminum oxide can form a dense surface film with certain hardness.
The oxide structure of iron is loose and easy to fall off, and continues to penetrate and diffuse into the metal and destroy materials.
Copper oxide, commonly known as green copper, is a toxic substance between them.
◆Electrochemical corrosion: when the metal and medium are made up of a primary battery, the corrosion process of metal is formed. When the metal phase of two different electrode potentials is connected, and when there is water or other electrolytes, the two metals will produce a current to form a primary battery, one of which is in positive potential and the other in negative. Potential, the metal at negative potential is continuously accumulated in the ionic state through the electrolyte to the metal at the positive potential. The metal at negative potential is gradually damaged and destroyed, resulting in electrochemical corrosion. The larger the difference of the electrode potentials between the two metals, the stronger the electrochemical corrosion. The higher the temperature, the more serious the corrosion of the metal.
Different metals have different electrode potentials. The electrode potential sequence of commonly used metals is: metal Ag (silver) Cu (Cu) Pb (lead) Sn (TIN) Fe (iron) Zn (zinc) A1 (aluminum). The greater the potential of the potential +0.8+0.334-0.122-0.16-0.44-0.76-1.33 electrode is, the stronger the trend of turning into the electrolyte, that is, the more vulnerable to corrosion. The negative value of the electrode potential of aluminum is large, but the corrosion resistance of aluminum can be improved because there is often a protective layer of oxide film on its surface.
Rare earth aluminum alloy material is added in aluminum rare earth elements, it can play a purification, improve purity, fill the surface defects, refine the grain. To reduce the segregation and eliminate the effect of local corrosion, it also brings negative shift of the electrode potential of aluminum, which has the effect of cattle anode and excellent conductivity, thus greatly improving the corrosion resistance of aluminum. For the corrosion problems of C1 - in marine environment, S, H2S + C02 in petroleum and chemical environment, this kind of material has a unique anti-corrosion mechanism. The strong reducibility of rare earth metals can be effectively combined with the strong oxidation of S, H2S and C1- to produce stable compounds (C1- and rare earth aluminum alloys produce stable coordination compounds), and the oxidation and reduction processes in the chemical reactions are organically unified and interacted with the oxygen of S, H2S, C1- and other corrosive media from the root. The corrosion damage caused by chemical activities has completely solved the problem that the developed countries including the United States, including the United States, have not been well solved. The analysis of the testing and engineering examples of the national inspection departments, such as the Beijing Nonferrous Metals Research Institute, shows that the chlorine ion, the sea water, the ocean atmosphere, the salt fog environment (alternate wet and dry) Under saturated HzS, sulphur and high temperature and high pressure environment, the annual corrosion rate of rare-earth aluminum alloy is zero or almost zero.
Second、Insulation part
◆The current carrying capacity of power cables refers to the maximum current allowed by cable conductors at the highest allowable temperature. When the cable is designed, the heat of the loss of all parts of the cable shall not exceed the maximum allowable temperature of the cable. In most cases, the transmission capacity of the cable is determined by the maximum temperature of the cable. The maximum allowable temperature of the cable depends on the thermal aging performance of the insulation material used because of the cable work. When the temperature is too high, the aging of insulation materials will accelerate and the life span of cables will be greatly shortened. If the cable runs above the most permissible temperature, the cable will work safely for 30 years.
◆XLPE is the abbreviation of the English name of XLPE. Polyethylene is a linear molecular structure and can be easily deformed at high temperature. The crosslinked polyethylene process makes it form a network structure. This structure has strong deformation resistance even at high temperatures.
◆The excellent anti aging properties and super heat resistant deformation of XLPE determine that large current can be allowed under the condition of normal operating temperature (90C) short time failure (130C) and short circuit (250C). Because it runs at a temperature 20 C higher than PVC, it has excellent heat resistance, increased insulation aging resistance, and greatly increased life.
Economic performance
◆Direct purchase cost
The price comparison between aluminum alloy cable and copper core cable: aluminum alloy cable has superior safety, electrical performance, mechanical performance and longer service life, the price of aluminum alloy cable is only about 75% of the copper cable.
◆ Reduce the cost of installation
Save installation cost: aluminum alloy cable is easy to install because of its good bending performance and light weight.
Anhui Nanyang Cable Group Co., Ltd. owns advanced production equipment and testing equipment, which guarantees the stability of product quality and the timeliness of delivery.