CN212676489U - Mine grounding system - Google Patents

Abstract

The utility model discloses a mine ground system, this system not only are applicable to the opencut district, and more suitable mine is in the pit. Combining the mining section of a mining area or the distribution condition of an underground roadway, drilling and washing holes in a soil-free geological condition at a relative center position near the mining area, pressurizing to inject conductive powder into the holes, penetrating the conductive powder into a rock mass through rock gaps, forming a large good electric conductor between the rock mass and the ground, inserting a metal electric conductor into the holes to be led out of the ground, and connecting a plurality of grounding bodies with each other to form a high-efficiency good and reliable grounding body which is connected with an uncharged shell of electrical equipment through a grounding bus after being integrally formed, thereby protecting the electrical equipment; the system solves the problems that a mine operation surface cannot be provided with a grounding body due to the absence of soil, potential safety hazards exist due to the exceeding of grounding resistance, and a grounding network needs to be laid for a long distance with large investment. The grounding resistor has the characteristics of low installation cost, easy formation of reasonable layout in a mining area, simple, firm and reliable installation and excellent grounding resistance.

Description

Mine grounding system

Technical Field

The utility model relates to a mine operation electrical equipment field, concretely relates to mine ground connection system.

Background

In an electric power system, if electric leakage occurs due to insulation reduction or insulation breakdown of electrical equipment, a part of the electrical equipment which is not supposed to be electrified under normal conditions is suddenly electrified, or a part of low voltage electricity is suddenly changed into high voltage electricity, so that serious vicious accidents of human body electric shock casualties or electric equipment burning are caused. In order to prevent such accidents, the relevant national departments stipulate that the electrical equipment needs to be effectively protected by grounding modes such as IT, TT or TN. According to relevant national regulations such as GB16423-2006 metal and nonmetal mine safety regulations, GB50070-2009 mine electric power design regulations and the like, particularly, an IT grounding mode is required to be adopted underground of a mine to protect and ground all electrical equipment.

Many mines need to be operated underground, and not only are a plurality of tunneling sections, a large range, a long port and a plurality of points of power distribution and supply equipment wide. The underground air humidity is high, the factors such as dust and carbon deposition are not beneficial to the safe operation of electrical equipment, and the possibility of inducing the electric leakage of high-voltage and low-voltage electrical equipment is higher. IT is a necessary basic means for ensuring safe electricity utilization by adopting an IT mode for prevention and protection, so that only one mining area grounding grid can reach tens of thousands of meters or even more than 10 tens of thousands of meters, and the quantity of high-voltage and low-voltage cables, a central substation (station), a substation chamber, a power distribution cabinet, a power distribution box and other electrical equipment which are equipped underground is huge, so that the grounding system investment is huge for ensuring safe production, and a large economic burden is caused to mine enterprises. Because most underground rock structures exist, no geological condition of soil exists, and firstly, the difficulty in installing the grounding body is high; secondly, the grounding resistance of the grounding body is installed, so that the standard requirement is difficult to achieve. There are main, vice sump in part mining area is in the pit, and there is great safe risk in installation earthing pole in the sump: firstly, the water level of the water sump can change, and when the water sump is insufficient or too low, the grounding resistance can be greatly increased or the grounding fails; secondly, when high-voltage electrical equipment (cable) is subjected to insulation breakdown, because the iron plate in the water sump transfers electric energy into the ground through water instead of being grounded, the water in the water sump is electrified, if people work in or around the water sump, the risk of electric shock is great, and if the action sensitivity of a protection device system is poor or the protection device system fails to work, the risk of electric shock is greater. Therefore, the ground body is installed on the ground and then is led into the underground in part of mining areas, a large amount of steel, installation manpower and equipment are required to be consumed when the lead-in distance is long, the damage and fracture risk is high, large amount of resources are invested to erect the ground wire because the lead-in distance is long, the ground resistance can still exceed the standard after the lead-in, the phenomenon is a long-standing problem in the mine industry, particularly the underground operation mine industry, and is also an important inspection and supervision content of the underground mining of the mine by all levels of safety production administrative departments of China, so that the normal production is seriously influenced due to frequent rectification and modification.

Disclosure of Invention

The technical problem to be solved by the utility model is to provide a mine grounding system, which is suitable for open mines, especially has more obvious effect in underground installation of the grounding system in mines, and solves the problems that the existing mines have no soil address condition, the difficulty of installing grounding bodies is high, the grounding resistance of the grounding bodies is difficult to meet the standard requirement, the installation cost is high, and the danger of electric shock exists; the grounding resistor has the characteristics of low installation cost, reasonable layout, standard installation and reliable power supply, has excellent grounding resistance value, and eliminates the safety risk of hurting people or damaging equipment due to electric leakage.

In order to realize the above design, the utility model adopts the following technical scheme: a mine grounding system comprises an underground roadway, wherein a plurality of grounding holes are formed in the underground roadway; the grounding holes are arranged beside a ditch and in a side ditch of the underground roadway; and a grounding body is arranged in the grounding hole.

Preferably, the grounding body comprises a main grounding body and a local grounding body; the main grounding body is arranged in the central radiation area of the mining area. Furthermore, the main grounding body consists of 3-15 grounding holes.

Preferably, the local grounding body consists of 1-2 grounding holes; the local grounding body is arranged in the underground roadway outside the central radiation area according to actual construction requirements.

Preferably, the number of the central radiation areas is not less than one; the underground roadway is divided into a plurality of plate areas according to specific construction requirements and the distribution quantity of electrical equipment, and each plate area is provided with a central radiation area; the total length of the path from the central radiating area to the electrical equipment located anywhere within the panel area is the shortest.

Preferably, the aperture of the grounding hole is 76 mm-91 mm; the hole distance between a plurality of grounding holes of the grounding body is 3 m-6 m, and the hole depth is 5 m-15 m.

Preferably, the grounding body comprises a conductive layer composed of a conductive medium buried inside the grounding hole, and a conductive body penetrating through the conductive layer.

Furthermore, the electric conductor is made of metal materials such as galvanized flat iron or galvanized angle iron.

Preferably, the bottom of the electric conductor is in contact fit with the bottom of the grounding hole; the top of the conductor is higher than the upper surface of the grounding hole, and the length of the part higher than the upper surface of the grounding hole is more than 50 cm; the plurality of conductors are connected to the electrical device by electrical wires.

Further, the conductive medium is conductive powder with the particle size of less than 80 mu m or liquid obtained by stirring and mixing the resistance reducing agent and the purified water; the conductive medium includes a concentration set to 1: 10. 1: 6. 1: 4. 1: 3. 1: 2. 1: 1. 1: 0.8, 1: 0.6, and pouring according to the concentration after dilution during grouting.

Furthermore, after the electric conductor is inserted into the grounding hole, the hole opening of the grounding hole is sealed, and the conducting powder is prevented from being taken away along with flowing water.

The utility model has the advantages that:

the method comprises the following steps of 1, arranging a grounding hole on a rock body in a side ditch of the underground roadway, pressurizing and filling conductive powder slurry into the hole, enabling the conductive powder slurry to fully penetrate into the grounding hole and rock body cracks around the grounding hole, and creating a grounding body in the underground roadway without soil by utilizing a conductive layer formed by the conductive powder slurry and a humid environment in the side ditch, thereby solving the problem of high installation difficulty of the grounding body.

2, the inside landfill of conducting layer has the electric conductor, and the electric conductor top is connected with electrical equipment through the earth connection, makes electrical equipment directly be connected with the ground through the conductor, when having avoided carrying out ground connection through sump etc. through indirect intercommunication in the sump between electrical equipment and the ground to can cause the circumstances that ground resistance changes because of the water level changes, and the electrified potential safety hazard that brings of sump.

And 3, the grounding body consists of a plurality of grounding holes and internal landfill objects, construction is carried out in groups during construction, the grounding resistance test is carried out after each group of construction, the number and the depth of the grounding holes are adjusted through test values, and the grounding resistance of the grounding body can be finely adjusted.

4, the main grounding body is installed by analyzing the quantity and the distribution condition of the electrical equipment in the mining area, so that the consumed material of the grounding grid line for connecting the electrical equipment in the area with the grounding body is minimum, and the resistance value can not exceed the standard due to the overlong distance of the grounding grid; the underground grounding bus, the grounding trunk line, the grounding branch line and the local grounding layer are distinct, and a grounding system with reasonable layout, standard installation and reliable grounding is formed; for a few electrical equipment which is far away and is remote in position, the local grounding body can be installed by the same construction method, so that the installation is very convenient; compared with the existing common method that the grounding body is installed on the ground and then is led to the underground by an extra long distance, the grounding system of the underground grounding system has the advantages that the cost is greatly reduced, the excellent grounding resistance is effectively guaranteed, the grounding network cable is easy to damage and break due to the overlong lead-in distance, the reasonable layout distance of the system is short, and the cost and the difficulty of maintenance and replacement can be greatly reduced.

Drawings

The present invention will be further explained with reference to the drawings and examples.

Fig. 1 is the external structure diagram of the main grounding body of the present invention.

Fig. 2 is a schematic front view of the main grounding body of the present invention.

Fig. 3 is a schematic top view of the main grounding body of the present invention.

Fig. 4 is the distribution diagram of the grounding network cable in the well underworkings of the utility model.

Fig. 5 is the utility model discloses well schematic diagram that electrical equipment and grounding body are connected in the underworkings.

The reference numbers in the figures are: the underground roadway comprises an underground roadway 1, a grounding hole 11, a main grounding body 21, a local grounding body 22, a central radiation area 3, a conducting layer 4, a conductor 5, electrical equipment 6 and a grounding bus 7.

Detailed Description

As shown in fig. 1 to 3, a mine grounding system includes an underground roadway, in which a plurality of grounding holes are formed; the grounding holes are arranged beside a ditch and in a side ditch of the underground roadway; and a grounding body is arranged in the grounding hole.

In a preferred aspect, the ground body includes a main ground body and a local ground body; the main grounding body is arranged in a central radiation area of a mining area and consists of 3-15 grounding holes.

In a preferred scheme, the local grounding body consists of 1-2 grounding holes; the local grounding body is arranged in the underground roadway outside the central radiation area according to actual construction requirements.

In a preferred scheme, the number of the central radiation areas is not less than one; the underground roadway is divided into a plurality of plate areas according to specific construction requirements and the distribution quantity of electrical equipment, and each plate area is provided with a central radiation area; the total length of the path from the central radiating area to the electrical equipment located anywhere within the panel area is the shortest.

In a preferred scheme, the aperture of the grounding hole is 76 mm-91 mm; the hole distance between a plurality of grounding holes of the grounding body is 3 m-6 m, and the hole depth is 5 m-15 m.

In a preferred scheme, the grounding body comprises a conductive layer composed of a conductive medium buried in the grounding hole and a conductive body penetrating through the conductive layer.

In a preferred scheme, the electric conductor is made of a galvanized flat iron or galvanized angle iron and other metal materials.

In a preferred scheme, the bottom of the electric conductor is in contact fit with the bottom of the grounding hole; the top of the conductor is higher than the upper surface of the grounding hole, and the length of the part higher than the upper surface of the grounding hole is more than 50 cm; the plurality of conductors are connected to the electrical device by electrical wires.

In a preferred embodiment, the construction method of the mine grounding system includes the following steps:

s1, drilling: firstly, constructing a main grounding body: drilling holes in the underground roadway side ditch of the selected central radiation area, wherein 3-5 holes are drilled as a group, a group of grounding holes are drilled, each grounding hole is numbered, and water burst, water loss, leakage, hole collapse, block falling, drill sticking, fracture structure, karst development and lithology change conditions in the drilling process are recorded; the deviation of the hole site is not more than 0.5m, and when the hole section meets geological defects such as faults, karsts and the like with large scale, the hole site is readjusted; adopting an anti-inclination measure in the drilling process, wherein the inclination deviation from the hole opening to the hole bottom is less than 0.5 m;

s2, washing: after drilling of a group of grounding holes is finished, carrying out open flushing on residual rock powder in the grounding holes through external clean water, and continuing flushing for 10min after flushing backwater is clarified; measuring and recording the hole depth after the flushing is finished, wherein the thickness of residue at the bottom of the hole is not more than 15 cm; then, flushing the cracks around the inner wall of the grounding hole in a pulsating mode by adopting high-pressure water of 0.9-1.2 MPa, wherein the time interval of high-pressure pulsation and low-pressure pulsation is 5-10 min; after the washing backwater is clarified, continuously washing for not less than 10min, wherein the total washing time is not less than 20 min; after the flushing is finished, a cover plate is adopted to seal the orifice before the next procedure;

and S3, performing a water pressing test after the flushing is finished: introducing pressure water of 1.0-2.0 MPa into the grounding hole, wherein the water pressure of the pressure water is in linear proportional relation with the hole depth of the grounding hole; measuring and reading the pressing-in flow once every 5min after water is supplied, and recording the latest four continuous readings; when the difference between the maximum value and the minimum value in the four readings is less than 10% of the final value, or the difference between the maximum value and the minimum value is less than 1L/min, ending the pressurized water test, and taking the current flow value reading Q as the final value to calculate the rock mass fracture rate Q;

s4, filling conductive powder slurry: adopting inner and outer pipe plugs, circulating in the hole, and continuously drilling and filling the ground hole with conductive slurry from top to bottom or from bottom to top under the filling pressure of 0.5-4 Mpa; grouting the grounding hole in sections at different heights, and gradually increasing grouting pressure from bottom to top; when the grouting pressure of each section is stable, the section is full, and after the section is full, the pressure stable grouting is protected for not less than 5min, so that the conductive powder slurry fully permeates and fills cracks around the grounding hole to form a tree-root-shaped conductive layer radiating to the periphery by taking the hole as the center;

s5, after grouting, inserting the electric conductors into the bottom of the grounding hole, and connecting the tops of the electric conductors with each other through insulated cables; carrying out ground resistance detection on the group of ground bodies subjected to construction through a resistance tester, optionally adding a second group of ground holes and adjusting the hole depth of the second group of ground holes according to a detection result, and repeating S1-S5 until the ground resistance test result meets the requirement;

s6, connecting the electrical equipment in the mining area to the main grounding body after construction by adopting a grounding wire; for electrical equipment with a longer distance, arranging a local grounding body nearby, and connecting the electrical equipment with the local grounding body through a grounding wire; the number of the grounding holes of the local grounding body is 1-2, and the other construction methods are the same as the construction method of the main grounding body.

In a preferred scheme, the conductive powder slurry is a liquid obtained by stirring and mixing conductive powder with the particle size of less than 80 mu m or a resistance reducing agent and purified water; the conductive paste comprises a conductive paste with the concentration set as 1: 10. 1: 6. 1: 4. 1: 3. 1: 2. 1: 1. 1: 0.8, 1: 0.6, and pouring according to the concentration after dilution during grouting.

In a preferred embodiment, after the electrical conductor is inserted into the grounding hole in step S5, the opening of the grounding hole is sealed to prevent the conductive powder from being carried away with the flowing water.

Example 1:

as shown in fig. 4 to 5, a mine grounding system comprises an underground roadway, wherein the underground roadway is divided into 4 main areas according to the distribution condition of electrical equipment, and each area is provided with a central radiation area; the total length of a path from the central radiation area to each electric device in the chip area is shortest, and each central radiation area is internally provided with one main grounding body, and the total number of the main grounding bodies is 4; the rest part is provided with a plurality of local grounding bodies.

The main grounding body is composed of 3-15 grounding holes.

The local grounding body consists of 1-2 grounding holes; the local grounding body is arranged in the underground roadway outside the central radiation area according to actual construction requirements.

In a preferred scheme, the aperture of the grounding hole is 80 mm; the pitch between a plurality of ground holes of the grounding body is 4m, and the hole depth is 12 m.

In a preferred embodiment, the main grounding body and the local grounding body each include a conductive layer formed of a conductive medium buried inside the grounding hole, and a conductive body penetrating through the conductive layer.

In a preferred scheme, the electric conductor is galvanized angle steel.

In a preferred scheme, the bottom of the electric conductor is in contact fit with the bottom of the grounding hole; the top of the conductor is 50cm higher than the upper surface of the grounding hole; the plurality of conductors are connected to the electrical device by electrical wires.

In a preferred embodiment, the construction method of the mine grounding system includes the following steps:

s1, drilling: firstly, constructing a main grounding body: drilling holes in the underground roadway side ditch of the selected central radiation area, wherein 3 holes are a group during drilling, firstly drilling a group of grounding holes, numbering each grounding hole, and recording water burst, water loss, leakage, hole collapse, block falling, drill sticking, fracture structure, karst development and lithology change conditions in the drilling process; the deviation of the hole site is not more than 0.5m, and when the hole section meets geological defects such as faults, karsts and the like with large scale, the hole site is readjusted; adopting an anti-inclination measure in the drilling process, wherein the inclination deviation from the hole opening to the hole bottom is less than 0.5 m;

s2, washing: after drilling of a group of grounding holes is finished, carrying out open flushing on residual rock powder in the grounding holes through external clean water, and continuing flushing for 10min after flushing backwater is clarified; measuring and recording the hole depth after the flushing is finished, wherein the thickness of residue at the bottom of the hole is not more than 15 cm; then, flushing the cracks around the inner wall of the grounding hole in a pulsating mode by adopting high-pressure water, wherein the time interval of high-pressure pulsation and low-pressure pulsation is 5-10 min; the low pressure is 0.9MPa, and the high pressure is 1.2 MPa; after the washing backwater is clarified, continuing to wash for 10min, wherein the total washing time is not less than 20 min; after the flushing is finished, a cover plate is adopted to seal the orifice before the next procedure;

and S3, performing a water pressing test after the flushing is finished: introducing pressure water of 1.5MPa into the grounding hole, measuring and reading the pressing-in flow once every 5min after the water is introduced, and recording the latest four continuous readings; when the difference between the maximum value and the minimum value in the four readings is less than 10% of the final value, or the difference between the maximum value and the minimum value is less than 1L/min, ending the pressurized water test, and taking the current flow value reading Q as the final value to calculate the rock mass fracture rate Q;

s4, filling conductive powder slurry: adopting inner and outer pipe plugs, circulating in the hole, and continuously drilling and filling the ground hole with conductive slurry from top to bottom or from bottom to top under the filling pressure of 0.5-4 Mpa; grouting the grounding hole in sections at different heights, and gradually increasing grouting pressure from bottom to top; when the grouting pressure of each section is stable, the section is full, and after the section is full, the pressure stable grouting is protected for not less than 5min, so that the conductive powder slurry fully permeates and fills cracks around the grounding hole to form a tree-root-shaped conductive layer radiating to the periphery by taking the hole as the center;

s5, after grouting, inserting the electric conductors into the bottom of the grounding hole, and connecting the tops of the electric conductors with each other through insulated cables; carrying out grounding resistance detection on a group of grounding bodies which are constructed through a resistance tester, wherein resistance detection shows that the resistance value exceeds 40%; according to the detection result, 3 grounding holes of the second group are added, the hole depth of the second group of grounding holes is adjusted to be 14m, then S1-S5 are repeated, the detected resistance value reaches the standard, and at the moment, the installation of the grounding body is completed;

s6, connecting the electrical equipment in the mining area to the main grounding body after construction by adopting a grounding wire; for electrical equipment with a longer distance, arranging a local grounding body nearby, and connecting the electrical equipment with the local grounding body through a grounding wire; the number of the grounding holes of the local grounding body is 1, and the other construction methods are the same as the construction method of the main grounding body.

In a preferred scheme, the conductive powder slurry is a liquid obtained by stirring and mixing conductive powder with the particle size of 70 mu m and purified water; the conductive paste comprises a conductive paste with the concentration set as 1: 10. 1: 6. 1: 4. 1: 3. 1: 2. 1: 1. 1: 0.8, 1: 0.6, and pouring according to the concentration after dilution during grouting.

In a preferred embodiment, after the electrical conductor is inserted into the grounding hole in step S5, the hole opening of the grounding hole is sealed with clay to prevent the conductive powder from being carried away with flowing water.

As shown in fig. 5, a plurality of electrical devices at the inner corners of the underground roadway are far away from the main grounding body in the sheet area, so that the local grounding body is installed nearby, a grounding hole is formed in the local grounding body, the hole depth is adjusted to 15m, and the grounding resistance value after installation reaches the standard; wherein the ground strap is connected to the electrical device via a ground branch (not shown).

The above embodiments are merely preferred technical solutions of the present invention, and should not be considered as limitations of the present invention, and the features in the embodiments and the examples in the present application may be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be defined by the claims and the technical solutions described in the claims, including the technical features of the equivalent alternatives as the protection scope. Namely, equivalent alterations and modifications within the scope of the invention are also within the scope of the invention.

Claims (8)

1. The utility model provides a mine ground system, includes underworkings (1), its characterized in that: a plurality of grounding holes (11) are formed in the underground roadway (1); the grounding hole (11) is arranged beside a ditch and in a side ditch of the underground roadway (1); the grounding body is arranged in the grounding hole (11).

2. The mine grounding system of claim 1, wherein: the grounding body comprises a main grounding body (21) and a local grounding body (22); the main grounding body (21) is arranged in the central radiation area (3) of the mining area; the main grounding body (21) is composed of 3-15 grounding holes (11).

3. The mine grounding system of claim 2, wherein: the local grounding body (22) consists of 1-2 grounding holes (11); the local grounding body (22) is arranged in the underground roadway (1) or the underground electrical equipment chamber outside the central radiation area (3) according to actual construction requirements.

4. The mine grounding system of claim 2, wherein: the number of the central radiation areas (3) is not less than one; the underground roadway (1) is divided into a plurality of plate areas according to specific construction requirements and the distribution quantity of electrical equipment, and each plate area is provided with a central radiation area (3); the total length of the path from the main grounding body (21) in the central radiation area (3) to the electrical equipment in each area in the sheet area is shortest.

5. The mine grounding system of claim 1, wherein: the aperture of the grounding hole (11) is 76 mm-91 mm; the pitch between a plurality of grounding holes (11) of the grounding body is 3 m-6 m, and the depth of the holes is 5 m-15 m.

6. The mine grounding system of claim 1, wherein: the grounding body comprises a conductive layer (4) consisting of a conductive medium filled in a grounding hole (11) and a conductive body (5) penetrating through the conductive layer (4).

7. The mine grounding system of claim 6, wherein: the bottom of the electric conductor (5) is in contact fit with the bottom of the grounding hole (11); the top of the conductor (5) is higher than the upper surface of the grounding hole (11), and the length of the part higher than the top is more than 50 cm; the plurality of conductors (5) are connected to the electrical equipment through the connecting wires.

8. The mine grounding system of claim 1, wherein: the hole opening of the grounding hole (11) is provided with a sealing filler, so that conductive powder is prevented from being taken away along with flowing water.

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