CN105655040A

CN105655040A - Method for preventing single-core power cable from heating

Info

Publication number: CN105655040A
Application number: CN201410713985.2A
Authority: CN
Inventors: 张成斌; 赵久长; 贾丹江; 廖晓斌; 毛玉峰
Original assignee: Angang Steel Co Ltd
Current assignee: Angang Steel Co Ltd
Priority date: 2014-12-01
Filing date: 2014-12-01
Publication date: 2016-06-08

Abstract

The invention provides a method for preventing a single-core power cable from heating, which is characterized in that an aluminum trapezoidal cable bridge is manufactured and adopted, the single-core cable is grounded at one end of a high-voltage cabinet, a 40-60 mm grounding wire is arranged at the joint of the cable bridge, a 40-60 mm grounding wire is adopted between each cable bridge bracket and the bridge for connection, all cables are laid on the same layer of cable bridge in a single layer and are arranged in a straight line in A, B, C three phases, and the central distance between every two adjacent cables is 1 time of the outer diameter of the cable. The invention solves the heating problem of the single-core cable, and can ensure that the operating temperature of the cable is below 60 ℃ and is less than the standard value of the maximum temperature of 90 ℃ of the cable in long-term operation, thereby prolonging the service life of the cable, reducing the operating cost and ensuring the long-term safe and stable operation of the cable.

Description

A kind of method preventing single core power electric cable heating

Technical field

The invention belongs to electric protection device field, it is specifically related to a kind of for preventing the method for single core power electric cable heating.

Background technology

Single core power cable meeting and cable shield generation electromagnetic induction in operational process that cross section is bigger, thus produce induced current at screen layer, the material usually selected due to cable testing bridge is irony, it is easy to produce eddy-current heating on crane span structure. When single-core cable working current is bigger, very big current can be produced at screen layer, make electric cable heating serious, and cause eddy-current heating. To sum up two kinds of reasons, cause cable work and envrionment temperature higher than the highest long-term permission working temperature 90 DEG C of standard values of cable, and long-time running can damage cable insulation, causes short circuit, blows out, even presence of fire accident, and equipment forms great potential safety hazard.

For 1580mm hot rolling dynamic passive compensation system, there is following defect in its TCR cable running:

1, the type selecting of cable testing bridge is groove formula cable testing bridge, and this specification cable testing bridge radiating effect is poor, and groove formula cable testing bridge shield effectiveness is better simultaneously, it is easy to produces induced current, causes eddy-current heating, be not suitable for and lay the bigger power cable of working current.

2, the material of cable testing bridge is irony, when the cable current that inside is laid is bigger, it is easy to produce bigger inductive emf on cable testing bridge, thus produces bigger induced current.

3, cable testing bridge is without obvious ground connection, and stake resistance is bigger.

4, cable testing bridge inside cable is that Multi-stacking compaction is put, and is unfavorable for the heat radiation of cable.

When TCR electric current is bigger, TCR cable prevailing temperature is at 110 DEG C, and cable testing bridge temperature is at 130 DEG C, and the highest transient temperature in poor position of dispelling the heat reaches more than 200 DEG C, and the highest permission working temperature of cable long-time running is 90 DEG C, and cable insulation causes very big destruction.

Summary of the invention

Prevent the method for single core power electric cable heating it is desirable to provide a kind of, thus reduce the heating of single-core cable, make cable operate in less than 60 DEG C, extend cable work-ing life, it is ensured that cable long-term safety steady running.

For reaching this object, this invention takes following technical solution:

A kind of method preventing single core power electric cable heating, it is characterised in that:

1, make aluminium matter ladder-shaped cable bridge: cable testing bridge is made up of side plate, backboard, crossbeam and rivet, is provided with crossbeam between two side plates, side plate length direction by backboard together with rivet interlacement.

2, single-core cable is taked high pressure tank end one place ground connection, and the induction voltage reducing the generation of single-core cable screen layer is poor.

3,40��60mm grounding wire is installed in cable testing bridge junction, and adopts 40��60mm grounding wire to be connected between each bridge support for electric cable with crane span structure.

4, taking individual layer to lay on whole cable to be placed on same layer cable testing bridge, and press A, B, C three-phase and arrange in a word side by side, adjacent Liang Gen cable center distance is 1 times of outside diameter of cable.

The useful effect of the present invention is:

The invention solves the heating problem of single-core cable, can ensure that the operating temperature of cable is below 60 DEG C, be less than the standard value of cable long-time running top temperature 90 DEG C, thus extend cable work-ing life, reduce running cost, it is ensured that cable can the stable operation of long-term safety.

Accompanying drawing explanation

Fig. 1 is cable testing bridge structural representation;

Fig. 2 is that cable is put and grounding connection mode schematic diagram.

In figure: the indirect ground wire 8 of side plate 1, crossbeam 2, rivet 3, backboard 4, bracket 5, three-phase cable 6, junction grounding wire 7, bridge.

Embodiment

The present invention prevents the concrete grammar of single core power electric cable heating from being:

1, make and adopt aluminium matter ladder-shaped cable bridge. As seen from Figure 1, described aluminium matter ladder-shaped cable bridge specification is 2000 �� 600 �� 60mm, adopts the thick aluminium sheet of 3mm as side plate 1, connects and adopt aluminium matter rivet 3, and crane span structure connects the white steel screw of employing. Being provided with crossbeam 2 between two side plates 1, side plate length direction is fixed together by backboard 3 and rivet 3.

Owing to the original zinc-plated crane span structure of groove formula is replaced by the trapezoidal crane span structure of aluminium matter, and aluminum metal is nonferromagnetic material, and during single-core cable operation at rating, cable testing bridge there will not be eddy-current heating phenomenon. Owing to aluminum metal is high thermally conductive material, its thermal conductivity is 237W/mK, and the thermal conductivity of iron is 80W/mK, cable contacts with crane span structure after normally generating heat, aluminium matter crane span structure can play the effect of scatterer, and trapezoidal crane span structure adds the contact surface of cable and air, enhance radiating effect when identical ventilation heat exchange.

2, single-core cable is taked high pressure tank end one place ground connection. Changing single core power cable into high pressure tank end one place ground connection by original high pressure tank end and equipment end two ground connection, the induction voltage reducing the generation of single-core cable screen layer is poor, avoids producing circulation at cable shield, reduces electric cable heating.

3,40��60mm junction grounding wire 7 is installed in cable testing bridge junction, and be connected with adopting the indirect ground wire 8 of 40��60mm bridge between cable testing bridge at each bridge support for electric cable 5, improving the reliability of cable testing bridge ground connection, through measuring, the resistance between crane span structure and crane span structure counterpoise grounding is 0 ohm.

4, taking individual layer to lay on whole cable to be placed on same layer cable testing bridge, and press A, B, C three-phase cable 6 and arrange in a word side by side, adjacent Liang Gen cable center distance is 1 times of outside diameter of cable, strengthens radiating effect under ventilation state.

Claims

1. one kind prevents the method for single core power electric cable heating, it is characterised in that:

(1) make aluminium matter ladder-shaped cable bridge: cable testing bridge is made up of side plate, backboard, crossbeam and rivet, is provided with crossbeam between two side plates, side plate length direction by backboard together with rivet interlacement;

(2) single-core cable is taked high pressure tank end one place ground connection, and the induction voltage reducing the generation of single-core cable screen layer is poor;

(3) 40��60mm grounding wire is installed in cable testing bridge junction, and adopts 40��60mm grounding wire to be connected between each bridge support for electric cable with crane span structure;

(4) taking individual layer to lay on whole cable to be placed on same layer cable testing bridge, and press A, B, C three-phase and arrange in a word side by side, adjacent Liang Gen cable center distance is 1 times of outside diameter of cable.