gui chao cable news: comparison of corrugated aluminum sheath argon arc welding and extrusion process-非凡电子娱乐

the metal corrugated aluminum sheath in the high voltage cable has cable short circuit current,

radial waterproofing and the role of lateral pressure resistance,

the production process includes two forms: longitudinal, argon arc welding and continuous extrusion.

technology of argon arc welding aluminum sheath

1: argon arc welding process is the use of aluminum foil after the uniform thickness of aluminum,

after cleaning, fine cutting, longitudinal package, welding, online testing, rolling process to achieve;

the argon arc welding process is under the protection of argon and helium,

the tungsten electrode is a positive electrode, which is welded by a low voltage and high current.

tungsten welding head diameter of only 2mm, and the protective gas continuous blow to the solder joint,

take away the heat quickly, make the welding parts evenly and quickly cooling,

at the same time, the structure of the cable can not be affected by any adverse effects.

2: the use of advanced argon arc welding technology, and equipped with ultrasonic and other on-line detection device,

to ensure the tightness of the welding, in order to check whether there is leakage welding,

the production plant has added an intermediate inspection device,

air tightness test of the whole welding cable, and one hundred percent of the inspection.

through several years of production, use and operation, the production technology is stable and reliable.

3 shanghai electric cable research institute carries on the mechanical strength test,

the tensile strength of the weld (78n/mm2)

slightly higher than the tensile strength of aluminum alloy (76n/mm2),

and slightly higher than the tensile strength of aluminum sheath itself (75n/mm2),

after the xi'an jiaotong university and the metallographic experts discussion and discussion,

this phenomenon is reasonable, the strength of the welding material is higher than the original material,

because the metallographic structure of the welded material changes.

the lateral pressure test is carried out by using the hollow aluminum sleeve,

lateral pressure test is 90 degrees apart and separated by a distance of 180 degrees,

the load deformation curve is basically the same.

4 the experimental study of the temperature distribution of the corrugated aluminum sheathed cable is also carried out in shanghai cable research institute,

when the temperature reaches 700 deg c.,

the three points of the temperature of the water resistance of the aluminum sleeve are respectively divided into a temperature of 90, 43, and 37 deg c, respectively, by a thermocouple, respectively, at a temperature of 69,

the 34, 26, and 27 deg c are respectively under the water resisting layer, because the aluminum sleeve is a little heated welding,

although the temperature is high, but the energy is not large, aluminum heat dissipation and soon,

so the temperature of the cable insulation is very low, at the same time,

the numerical calculation of the welding temperature field of the cable aluminum sheath is carried out in the insulation research laboratory of xi'an jiaotong university,

the temperature near the insulating layer is about 40 degrees centigrade.

the experimental results of the two research institutions are basically the same.

5 because of the corrugated welding aluminum sheathed cable temperature is very low,

there is no barrier to hurt the possible insulation or insulation,

the gap between the aluminum sleeve and the cable is very small, so the water resistance structure of the cable can be realized,

at the same time, the cable can be used as the buffer layer,

not difficult to design and calculate,

the expansion of the insulating radius of the domestic 220kv cable is about 1.5mm,

it can be absorbed by the water resisting layer, so the structure of the cable is very compact and reasonable,

in case of damage to the aluminum sleeve, the cable will not be flooded due to the role of the water layer.

two: continuous extrusion aluminum sheath technology

continuous extrusion aluminum sheath process is the use of the pressure machine production equipment of aluminum ingots,

the aluminum is continuously extruded on the cable insulation core in a semi molten state,

extrusion temperature up to 460 deg c,

may adversely affect the internal structure of the cable and reduce the service life of the cable.

1: aluminum sheath extrusion device to squeeze large, much energy,

extrusion at high temperature of about 600 deg c, the insulation may hurt yang,

affect the quality of cable products, in addition to some old enterprises,

in the new business is rarely added aluminum machine device,

the production of aluminum pressing machine is decreasing day by day,

the world's most stringent aeic cs7-93 cable standard in the united states

it is recommended to use corrugated welded aluminum sleeve,

or welded copper and steel sheathed cables,

without mentioning the need to squeeze the aluminum sheathed cable.

2: in order to reduce the squeeze aluminum sheathed cable may hurt yang,

copper wire woven fabric

blocking the heat source in the process of the aluminum sleeve and insulation,

but to the expansion of the insulation room,

there is a great gap between the aluminum sheath and the insulation,

once the cable is in water, the cable insulation will be completely immersed in water,

bring great loss to power supply line.

3: extrusion aluminum sheath is made of extrusion process,

if the control is not easy to cause uneven thickness of aluminum sheath,

easy to produce microporous, trachoma and other phenomena,

this makes aluminum sheath strength is very uneven,

reduction of radial waterproof property of aluminum sheath.

three: with the development of welding technology,

there are more and more people's understanding of the reliability of the use of corrugated welded aluminum sheathed cables,

in the near future, to replace aluminum sheathed cable extrusion trend.