CN110220808A - A kind of anti-explosion box for cable middle connector explosion-proof performance detection method and device based on interface arc burning - Google Patents

Abstract

The invention discloses a method for detecting the explosion-proof performance of an explosion-proof box of a cable intermediate joint based on interface arc combustion, comprising the following steps: S1: making an experimental intermediate joint; S2: installing the intermediate joint and connecting the electrode to a high-voltage power supply; S3: applying a voltage Detonate the intermediate joint; S4: inspection result; the present invention also provides an explosion-proof performance detection device for the explosion-proof box of the cable intermediate joint based on interface arc combustion, including an explosion-proof box and an experimental intermediate joint, and electrodes are arranged at both ends of the experimental intermediate joint. One side of the two groups of electrodes is connected with a wire, and the other end of the two groups of wires passes through the explosion-proof box and is connected to a high-voltage power supply. The invention uses surface discharge to trigger an explosion. The principle is similar to the actual explosion and can simulate the actual cable to the greatest extent. The impact of the explosion of the middle joint on the explosion-proof box; the quantitative control of the explosion energy of the middle joint of the cable; the discharge arc current of the middle joint of the cable that the explosion-proof box can withstand can be obtained.

Description

Explosion-proof performance detection of cable intermediate joint explosion-proof box based on interface arc combustion Method and device

technical field

The invention belongs to the technical field of power grid cables, and specifically relates to a method for detecting explosion-proof performance of an explosion-proof box of an intermediate joint of a cable based on interface arc combustion. At the same time, the invention also relates to a device for detecting explosion-proof performance of an explosion-proof box of an intermediate joint of a cable based on interface arc combustion.

Background technique

With the increasing popularity of power grid cables, cable fire and explosion accidents account for an increasing proportion of electrical accidents. Due to the limitation of the length of a single cable, one line usually requires one or more cable intermediate joints. These intermediate joints are the weakest links most prone to accidents, and are prone to fire and explosion accidents. Explosion and fire accidents at cable joints can easily affect the surrounding cables, causing secondary accidents and expanding the impact of the accident, and the development of cable joint accidents is slow and has no obvious features, making it difficult to monitor.

Installing a fireproof and explosion-proof box on the joint can isolate the joint from the external environment. When the joint fails, the shell of the explosion-proof box can withstand the impact of the explosion and quickly extinguish the flame, effectively preventing the expansion of cable accidents. The fire and explosion-proof performance of the explosion-proof box determines the effectiveness of the explosion-proof box in preventing the expansion of cable joint accidents. The fire-proof performance mainly depends on the flame-retardant performance of the material. There are currently three mainstream methods for the detection of explosion-proof performance: explosive method, phase-to-phase/phase-to-ground short circuit test Current method and weight drop method.

The explosives method is to test the explosion-proof ability of the explosion-proof box through the on-site explosion test. The explosion test uses a specified amount of TNT pellets as the explosion source. Put the pellets into the intermediate joint and assemble them between two simulated cable conductors and detonate them. The technicians observe the samples after the explosion to judge whether the explosion-proof performance of the samples meets the requirements. The explosive method has the advantages of convenient method, quantitative setting of explosion energy, and close to actual results. However, the explosive method requires qualified professional institutions to conduct experiments, and the selection space is small, and the test arrangement is limited by the test institution.

The phase-to-phase/phase-to-ground short-circuit test current method is to artificially make the cable phase-to-ground short-circuit defect and the phase-to-phase short-circuit defect, put the defective cable connector into the explosion-proof box and apply current to it, the effective value of the phase-to-phase short-circuit test current should be greater than or equal to 20kA, and the phase-to-ground short circuit The effective value of the test current should be greater than or equal to 15kA, and it is required that the shell should not be damaged or caught fire during the test. The simulation method of this method is completely inconsistent with the actual operation state of the cable intermediate joint when it explodes, so it is not effective.

The heavy object falling method is to use the impact of a heavy object falling vertically from a certain height to test the impact resistance of the explosion-proof box. The falling weight method is easy to operate and can quantify the impact energy. However, the force on the explosion-proof box under this method is quite different from the actual force when the explosion-proof box explodes, and it can only detect the explosion-proof performance of a single point.

Contents of the invention

The object of the present invention is to provide a method and device for detecting the explosion-proof performance of the cable intermediate joint explosion-proof box based on interface arc combustion, and detect the explosion-proof performance of the explosion-proof box by causing the cable intermediate joint simulation experiment body to discharge along the surface and cause an explosion. This method simulates the impact of the explosion on the explosion-proof box caused by the discharge of the actual cable intermediate joint to the greatest extent, and this method can quantitatively control the arc current and explosion energy when the cable intermediate joint breaks down and explode, so as to solve the problems raised in the above background technology. There is a technical problem.

To achieve the above object, the present invention adopts the following technical solutions:

A method for detecting the explosion-proof performance of an explosion-proof box of a cable intermediate joint based on interface arc combustion, comprising the following steps:

S1: The production of the experimental intermediate joint, the experimental intermediate joint needs to be specially made, which can be divided into two methods: brass tube electrode and conductive rubber electrode:

1) The experimental intermediate joint of the brass tube electrode, the steps are as follows:

a: Take a section of XLPE cable with the same length as the explosion-proof box to simulate the cable of the actual intermediate joint;

b: Put two brass tubes on the cable as electrodes. The two brass tubes are symmetrical to the middle section of the cable. The distance between the two tubes is the preset discharge surface length L, and the brass tube electrodes are connected to the wire. ;

c: Put an insulating rubber cold shrink tube on the outside of the brass tube;

d: Wrap insulating tape on the outside of the cable and the rubber cold shrinkable tube. The cold shrinkable tube and the insulating tape simulate the multi-layer structure of the actual cable intermediate joint;

2) The experimental intermediate joint of the conductive rubber electrode, the steps are as follows:

a: Take a section of XLPE cable with the same length as the explosion-proof box to simulate the cable of the actual intermediate joint;

b: Put a rubber cold shrinkable tube whose main body is made of insulating rubber and has conductive rubber parts at both ends on the cable;

c: Wrap insulating tape on the outside of the cable and the rubber cold-shrinkable tube. The cold-shrinkable tube and the insulating tape simulate the multi-layer structure of the actual cable intermediate joint;

S2: Install the test intermediate connector, connect the electrode to the high-voltage power supply during the test, put the experimental intermediate connector into the sample explosion-proof box, fix the upper and lower halves of the explosion-proof box with bolts, and lead the wires out of the explosion-proof box to connect with the high-voltage power supply, and take pictures after installation Record the surface condition of the explosion-proof box sample;

S3: Apply voltage to detonate the intermediate joint: start the high-voltage power supply, apply high voltage to the experimental intermediate joint, cause the experimental intermediate joint to discharge along the surface and then explode, disconnect the power supply after the explosion, pay attention to the power supply and the operator at an appropriate distance during the test and use an explosion-proof box isolation to ensure safety;

S4: Inspection results: After the explosion, observe the test sample, take photos for comparison, and judge whether it meets the explosion-proof performance requirements of the explosion-proof box;

S5: By changing the length L of the discharge surface and the output of the high-voltage power supply, the discharge arc current and the energy of the explosion can be adjusted, and the above steps S2-S4 are repeated to conduct different experimental tests.

The present invention also provides an explosion-proof performance detection device for an explosion-proof box of a cable intermediate joint based on interface arc combustion, comprising an explosion-proof box and an experimental intermediate joint, the experimental intermediate joint is fixed in the inner cavity of the explosion-proof box, and the two ends of the experimental intermediate joint are All are equipped with electrodes, one side of the electrodes of the two groups is connected with a wire, and the other ends of the wires of the two groups pass through the explosion-proof box and are connected with a high-voltage power supply.

Specifically, the explosion-proof box includes an upper shell and a lower shell, and the upper shell and the lower shell are fixed by a bolt structure.

Technical effects and advantages of the present invention: a method and device for detecting explosion-proof performance of an explosion-proof box of a cable intermediate joint based on interface arc combustion proposed by the present invention, compared with the prior art, has the following advantages:

1. The invention adopts surface discharge to cause explosion, the principle is similar to the actual explosion, and can simulate the impact of the explosion of the actual cable intermediate joint on the explosion-proof box to the greatest extent;

2. This method can quantitatively control the explosion energy of the cable intermediate joint;

3. This method can obtain the discharge arc current of the cable intermediate joint that the explosion-proof box can bear.

Description of drawings

Fig. 1 is a schematic diagram of the experimental principle of the present invention;

Fig. 2 is that the brass sleeve of the present invention is made the experimental middle joint structural representation of electrode;

Fig. 3 is that conductive rubber of the present invention is made the experimental intermediate joint structural representation of electrode;

Fig. 4 is an example diagram of the experimental device of the present invention;

Fig. 5 is a three-dimensional model diagram of the experimental device of the present invention;

Fig. 6 is a three-dimensional model diagram of the experimental device after the explosion-proof box of the present invention is opened.

In the figure: 1. Explosion-proof box; 2. Experimental intermediate joint; 3. Electrode; 4. Wire; 5. High voltage power supply.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. The specific embodiments described here are only used to explain the present invention, not to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The present invention provides a method for detecting explosion-proof performance of an explosion-proof box of a cable intermediate joint based on interface arc combustion as shown in Figures 1-6, comprising the following steps:

S1: The production of the experimental intermediate joint, the experimental intermediate joint needs to be specially made, which can be divided into two methods: brass tube electrode and conductive rubber electrode:

1) The experimental intermediate joint of the brass tube electrode, the steps are as follows:

a: Take a section of XLPE cable with the same length as the explosion-proof box to simulate the cable of the actual intermediate joint;

b: Put two brass tubes on the cable as electrodes. The two brass tubes are symmetrical to the middle section of the cable. The distance between the two tubes is the preset discharge surface length L, and the brass tube electrodes are connected to the wire. ;

c: Put an insulating rubber cold shrink tube on the outside of the brass tube;

d: Wrap insulating tape on the outside of the cable and the rubber cold shrinkable tube. The cold shrinkable tube and the insulating tape simulate the multi-layer structure of the actual cable intermediate joint;

2) The experimental intermediate joint of the conductive rubber electrode, the steps are as follows:

a: Take a section of XLPE cable with the same length as the explosion-proof box to simulate the cable of the actual intermediate joint;

b: Put a rubber cold shrinkable tube whose main body is made of insulating rubber and has conductive rubber parts at both ends on the cable;

c: Wrap insulating tape on the outside of the cable and the rubber cold-shrinkable tube. The cold-shrinkable tube and the insulating tape simulate the multi-layer structure of the actual cable intermediate joint;

S2: Install the test intermediate connector, connect the electrode to the high-voltage power supply during the test, put the experimental intermediate connector into the sample explosion-proof box, fix the upper and lower halves of the explosion-proof box with bolts, and lead the wires out of the explosion-proof box to connect with the high-voltage power supply, and take pictures after installation Record the surface condition of the explosion-proof box sample;

S3: Apply voltage to detonate the intermediate joint: start the high-voltage power supply, apply high voltage to the experimental intermediate joint, cause the experimental intermediate joint to discharge along the surface and then explode, disconnect the power supply after the explosion, pay attention to the power supply and the operator at an appropriate distance during the test and use an explosion-proof box isolation to ensure safety;

S4: Inspection results: After the explosion, observe the test sample, take photos for comparison, and judge whether it meets the explosion-proof performance requirements of the explosion-proof box;

S5: By changing the length L of the discharge surface and the output of the high-voltage power supply, the discharge arc current and the energy of the explosion can be adjusted, and the above steps S2-S4 are repeated to conduct different experimental tests.

High-voltage power supply: The function of the high-voltage power supply is to supply power to the two electrodes of the experimental intermediate joint to cause surface discharge. The high-voltage power supply is connected to the electrode of the experimental intermediate joint through wires. During the test, the high-voltage power supply is placed at a safe distance and isolated from the sample explosion-proof box through a baffle to avoid possible explosion splashes that may cause damage to the power supply and operators. The high-voltage power supply needs to be able to provide a voltage and current sufficient to cause surface discharge of the intermediate joint under test.

The present invention also provides an explosion-proof performance detection device for an explosion-proof box of a cable intermediate joint based on interface arc combustion, comprising an explosion-proof box 1 and an experimental intermediate joint 2, the experimental intermediate joint is fixed in the inner cavity of the explosion-proof box 1, and the two ends of the experimental intermediate joint 2 Both electrodes 3 are provided, and one side of the two groups of electrodes 3 is connected with a wire 4 , and the other ends of the two groups of wires 4 pass through the explosion-proof box 1 and are connected with a high-voltage power supply 5 .

Specifically, the explosion-proof box 1 includes an upper shell and a lower shell, and the upper shell and the lower shell are fixed by a bolt structure.

Working principle: By applying a voltage, surface discharge occurs on the insulating rubber of the cable intermediate joint and then an explosion occurs, simulating the impact of the explosion of the actual cable intermediate joint on the explosion-proof box 1. As shown in Figure 1, put the special experimental intermediate joint 2 into the explosion-proof box 1 and fix it. The external high-voltage power supply 5 is connected to the discharge electrode 3 in the experimental intermediate joint 2. The high-voltage power supply 5 is placed in a safe place and uses a baffle to avoid possible The splashes hurt the power supply and the staff.

The experiment uses a special experimental intermediate joint 2, and two brass cone tubes connected to the high-voltage power supply are placed in the middle of the cross-linked polyethylene (XLPE) cable as electrodes 3. The distance between the two brass electrodes is the test set value L , this distance is also the length along the surface of the discharge when energized; then put an insulating rubber cold shrink tube on the outside of the cable and the brass electrode, as shown in Figure 2; finally wrap the insulating tape on the outside to simulate the middle joint of the actual cable multi-layer structure. In addition to using a brass tapered tube as the electrode 3, conductive rubber can also be used as the electrode 3, and the conductive rubber and insulating rubber are integrally made, as shown in Figure 3.

During the test, connect the electrode 3 to the high-voltage power supply 5, put the experimental intermediate joint 2 into the sample explosion-proof box 1, and then apply high voltage to the electrode 3. The high voltage will cause creeping discharge on the interface between the insulating rubber between the two electrodes 3 and the XLPE cable, and the discharge arc will break down the insulation and release a large amount of heat, causing the experimental intermediate joint 2 to explode. The debris and strong airflow produced by the explosion will impact the explosion-proof box 1, and the explosion-proof performance of the explosion-proof box 1 can be known by observing the situation of the explosion-proof box 1 in the experiment. By changing the length L of the discharge creeping surface and the output of the high-voltage power supply 5, the discharge arc current and the energy of the explosion can be adjusted.

Finally, it should be noted that: the above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still It is possible to modify the technical solutions recorded in the foregoing embodiments, or to perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. within the spirit and principles of the present invention shall be included in the within the protection scope of the present invention.

Claims (4)

1. a kind of anti-explosion box for cable middle connector explosion-proof performance detection method based on interface arc burning, it is characterised in that: packet Include following steps:

S1: testing the production of transition joint, and experiment transition joint needs exclusively carry out production, can be divided into brass pipe electrode and lead Electric rubber electrode two ways:

1) the experiment transition joint of brass pipe electrode, steps are as follows:

A: taking one section of twisted polyethylene cable similar with armored cassette length, simulates the cable of practical transition joint；

B: two brass tubes are covered on cable as electrode, two brass tubes are symmetrical with respect to cable middle section, distance between two pipes Preset electric discharge is taken to be connected along face length, and by brass pipe electrode with conducting wire；

C: upper electro-insulating rubber cold shrink tube is covered outside brass tube；

D: being wrapped with insulating tape outside cable and rubber cold shrink tube, and cold shrink tube and insulating tape simulate in actual cable indirectly The multilayered structure of head；

The experiment transition joint of conductive rubber electrode, steps are as follows:

A: taking one section of twisted polyethylene cable similar with armored cassette length, simulates the cable of practical transition joint；

B: it is that electro-insulating rubber is made, has the rubber cold shrink tube of conductive rubber part at both ends that upper main body is covered on cable；

C: being wrapped with insulating tape outside cable and rubber cold shrink tube, and cold shrink tube and insulating tape simulate in actual cable indirectly The multilayered structure of head；

S2: electrode is connect by installation test transition joint, when test with high voltage power supply, and testing transition joint, to be put into sample explosion-proof In box, armored cassette up and down fixed with bolt by two halves, and conducting wire, which is drawn, to be connected outside armored cassette with high voltage power supply, note of taking pictures after being installed Record armored cassette sample surfaces situation；

S3: apply voltage and ignite transition joint: starting high voltage power supply applies high voltage to experiment transition joint, causes in experiment Between connector creeping discharge and then explode, disconnect power supply after explosion, when test notices that power supply and operator will be in suitable distance And be isolated with armored cassette, guarantee safety；

S4: inspection result: after explosion, test specimen situation is observed, control of taking pictures judges whether to meet armored cassette explosion-proof It can require；

S5: the energy of adjustable electrical discharge arc electric current and explosion, weight are exported along face length L and high voltage power supply by changing to discharge Multiple above-mentioned steps S2-S4 carries out different experiment detections.

2. a kind of anti-explosion box for cable middle connector explosion-proof performance detection based on interface arc burning according to claim 1 Method, it is characterised in that: after the step S2 mesohigh power supply connection, high voltage power supply is placed on safe distance and uses with armored cassette Partition separates.

3. a kind of anti-explosion box for cable middle connector explosion-proof performance detection according to claim 1 based on interface arc burning Device, including armored cassette (1) and experiment transition joint (2), it is characterised in that: the experiment transition joint is located at armored cassette (1) Interior intracavitary fixation, experiment transition joint (2) both ends are equipped with electrode (3), and electrode described in two groups (3) side is respectively connected with Conducting wire (4), conducting wire described in two groups (4) other end both pass through armored cassette (1) and are connected with high voltage power supply (5).

4. a kind of anti-explosion box for cable middle connector explosion-proof performance detection based on interface arc burning according to claim 1 Method, it is characterised in that: the armored cassette (1) includes upper housing and lower case, and bolt is used between upper housing and lower case Structure is fixed.