Lightning stroke protection device and method for large-scale strip mine electric shovel

Abstract

The invention discloses a lightning stroke protection device and method for an electric shovel for a large strip mine. The lightning stroke protection device comprises a vehicle body lightning rod, a head sheave lightning rod, a first downlead, a second downlead and a grounding system. The vehicle body lightning rod is used for achieving thunder and lightning strike protection of a vehicle body lightning protection area of the strip mine electric shovel and is installed on the top of an A-shaped frame 1 of the strip mine electric shovel. The head sheave lightning rod is installed on the top of a head sheave of the strip mine electric shovel. The upper end of the first downlead is connected with a lightning rod of the vehicle body, and the lower end is laid along the A-shaped frame 1 and can extend to the bottom of the right platform of the electric shovel; the upper end of the second downlead is connected with the head sheave lightning rod, and the lower end extends to the bottom of the right platform of the electric shovel along a working mechanism big arm of the strip mine electric shovel; the grounding system is arranged in a strip mine electric shovel operation area and is provided with an electric shovel explosion-proof connector, and the resistance of the grounding system is smaller than 10 ohms. Therefore, all-directional lightning stroke protection of the electric shovel for the strip mine can be realized.

Description

Technical Field

[0001] The invention relates to a lightning protection device and method for an electric shovel used in a large open-pit mine. Background Art

[0002] The electric shovel used in open-pit mines is powered by overhead wires and cables. The overhead wires are made of steel-core aluminum stranded wires buried on poles, and cables are used near the electric shovel. A grounding electrode is buried at the pole at the end of the steel-core aluminum stranded wire, which can effectively protect against lightning strikes and induced overvoltages, and avoid damage to the electric shovel's electrical equipment caused by overvoltage.

[0003] The equipotential point is set inside the electric shovel, and the control power is concentrated at the common point of the electric shovel platform, which is beneficial to reduce signal interference. The electric shovel body is made of steel and contacts the ground through the crawler. Due to the working terrain conditions and objective environment, the grounding resistance between the electric shovel body and the ground is relatively large, generally much greater than 10 ohms. The current design lacks protection against direct lightning, that is, the electric shovel body is struck by lightning. Once a direct lightning strike occurs, the current cannot be smoothly introduced into the ground, and the residual potential can instantly damage the equipment connected to the equipotential point, causing serious damage to the equipment.

[0004] In areas with frequent thunderstorms, such as plateaus, especially high-altitude mining steps, the risk of equipment being struck by lightning is very high. The vast terrain of open-pit mines makes it impossible to adopt spatial overall lightning protection, and there is currently no direct lightning protection application for electric shovels. Summary of the invention

[0005] The purpose of the present invention is to provide a lightning protection device and method for an electric shovel used in a large open-pit mine, so as to introduce lightning current into a grounding system through a lightning protection component (lightning rod) under thunderstorm weather conditions, so as to prevent the lightning point from directly striking the open-pit electric shovel and causing devastating damage to the electric control system of the open-pit electric shovel. The device effectively protects the equipment and is suitable for areas with frequent thunderstorms such as the Qinghai-Tibet Plateau.

[0006] In order to achieve the above technical objectives, the present invention will adopt the following technical solutions:

[0007] A lightning protection device for an electric shovel used in a large open-pit mine realizes lightning protection by intercepting lightning strikes of an electric shovel used in an open-pit mine, and comprises a double-needle lightning arrester; the double-needle lightning arrester comprises a vehicle body lightning rod, a sheave lightning rod, a first down conductor, a second down conductor and a grounding system; wherein:

[0008] The vehicle body lightning rod is used to implement lightning strike protection in the vehicle body lightning protection area of ​​the open-pit mining shovel, and is installed on the top of the A-frame of the open-pit mining shovel;

[0009] The sheave lightning rod is used to implement lightning protection in the sheave lightning protection area of ​​an open-pit mine shovel, and is installed on the top of the sheave of the open-pit mine shovel;

[0010] The first down conductor has an upper end connected to the vehicle body lightning rod, and a lower end laid along the A-frame and capable of extending to the bottom of the right platform of the electric shovel;

[0011] The second down conductor has an upper end connected to the sky wheel lightning rod, and a lower end extending along the working mechanism arm of the open-pit mine shovel to the bottom of the right platform of the shovel;

[0012] The grounding system is arranged in the electric shovel operation area of ​​the open-pit mine; the grounding system has an electric shovel explosion-proof connector that can be electrically connected to the first and second down conductors respectively, and the resistance of the grounding system is less than 10 ohms.

[0013] Preferably, the height h1 of the vehicle body lightning rod from the ground satisfies:

[0014]

[0015] The height of the vehicle body lightning rod h 10 satisfy:

[0016]

[0017] Where: h 1x It indicates the height of the body of the open-pit mining shovel from the ground; a2 indicates the horizontal distance from the installation position of the lightning rod on the body to the front edge of the body; b indicates the vertical length of the body.

[0018] Preferably, the vehicle body lightning rod is installed on the top of the A-frame through an electric lifting mechanism.

[0019] Preferably, the grounding system includes an electric shovel working platform and a grounding electrode buried in the electric shovel working platform; the electric shovel working platform is arranged in an electric shovel working area of ​​an open-pit mine, and the resistance of the grounding electrode is less than 10 ohms.

[0020] Preferably, the resistance of the ground electrode is reduced by burying a resistance reducing agent on the ground electrode.

[0021] Preferably, an explosion-proof connector is arranged between the vehicle body lightning rod and / or the sky sheave lightning rod and the grounding system.

[0022] Preferably, a line induction lightning protection device is provided inside the open-pit mining electric shovel.

[0023] Preferably, the first and second down conductors are both made of super-insulating materials.

[0024] Another technical purpose of the present invention is to provide a lightning protection method for an electric shovel for a large open-pit mine, which is implemented based on the above-mentioned lightning protection device for an electric shovel for a large open-pit mine, and includes the following steps:

[0025] Step 1: Build a lightning protection device:

[0026] The lightning protection device is built through the following steps:

[0027] Step 1.1: Divide the lightning protection area:

[0028] The open-pit mining electric shovel is divided into two lightning protection areas as a whole. One lightning protection area is the vehicle body lightning protection area centered on the top of the A-frame, and the other lightning protection area is the working mechanism lightning protection area centered on the top of the sheave.

[0029] Step 1.2: Assemble the lightning rod:

[0030] There are two types of lightning rods, one is the vehicle body lightning rod, and the other is the wheel lightning rod;

[0031] A vehicle body lightning rod is installed on the top of the A-frame. The height of the vehicle body lightning rod can ensure that the lightning protection radius of the vehicle body lightning rod covers the vehicle body lightning protection area.

[0032] A sky wheel lightning rod is installed on the top of the sky wheel, and the lightning protection radius of the sky wheel lightning rod can cover the lightning protection area of ​​the working mechanism;

[0033] Step 1.3: Laying down conductors:

[0034] The down conductor includes the first down conductor and the second down conductor;

[0035] Connect the upper end of the first down conductor to the vehicle body lightning rod, and lay the lower end along the A-frame and extend to the bottom of the right platform of the shovel;

[0036] The upper end of the second down conductor is connected to the overhead sheave lightning rod, and the lower end is extended along the working mechanism arm of the open-pit mining shovel to the bottom of the right platform of the shovel;

[0037] Step 1.4: Arrange the grounding system:

[0038] An electric shovel operation platform is set up near the electric shovel operation area in the open-pit mine, and a grounding electrode is buried in the electric shovel operation platform, and a resistance reducing agent is buried to make the resistance of the grounding electrode less than 10 ohms, and an explosion-proof connector of the electric shovel is connected externally;

[0039] Step 2: Lightning protection:

[0040] Under thunderstorm weather conditions, stop the operation of the open-pit mining shovel, and connect the first and second down conductors to the explosion-proof connectors of the electric shovel respectively to introduce the lightning current into the grounding electrode to prevent the lightning point from directly hitting the open-pit mining shovel.

[0041] Preferably, in step 2, the first and second down conductors are electrically connected to the explosion-proof connector of the electric shovel using an explosion-proof connector.

[0042] Based on the above technical objectives, the present invention has the following advantages over the prior art:

[0043] 1. The present invention designs a double-needle lightning arrester in combination with the external dimensions of an open-pit mining shovel, so as to provide all-round lightning protection for an open-pit mining shovel under thunderstorm weather conditions. Specifically, the double-needle lightning arrester includes two lightning rods, one of which is a vehicle body lightning rod installed on the top of the A-frame, and its lightning protection radius can cover the vehicle body lightning protection area, and the other is a sheave lightning rod installed on the top of the sheave, and its lightning protection radius can cover the working mechanism lightning protection area. Therefore, through the cooperation of the two lightning rods, an open-pit mining shovel can be provided with all-round lightning protection.

[0044] 2. The present invention lays a super-insulated down conductor, buries a grounding electrode on the electric shovel working platform, and connects the lightning arrester (lightning rod) to the grounding electrode through an explosion-proof connector to achieve effective lightning protection. Specifically, the present invention sets an electric shovel working platform near the working area of ​​the open-pit mine electric shovel to bury the grounding electrode, and ensures that the resistance of the grounding electrode is less than 10 ohms, so that when the open-pit mine electric shovel is struck by lightning, the residual voltage can be discharged into the earth through the lightning protection system composed of the vehicle body lightning rod, the sheave lightning rod, the first down conductor, the second down conductor and the grounding system, thereby protecting the open-pit mine electric shovel from lightning strikes.

[0045] 3. The present invention installs a line induction lightning protection device inside the open-pit mine electric shovel. The device is connected to the metal of the electric shovel body, and the grounding electrode down conductor is connected to the electric shovel body. When the induced overvoltage near the lightning strike electric shovel is transmitted to the electric shovel body through the varistor and the oxidative lightning arrester, a current rapid discharge channel is provided to effectively protect the electrical system of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a front view of the lightning protection device for a large open-pit mine electric shovel according to the present invention;

[0047] Figure 2 is a top view of the lightning protection device for a large open-pit mine electric shovel according to the present invention;

[0048] Figure 3 It is a schematic diagram of the structure of an electric shovel for large open-pit mining;

[0049] In the figure: 1-A frame; 2-top sheave; 3-car body lightning rod; 4-top sheave lightning rod; 5-working mechanism arm; 6-right platform of the electric shovel;

[0050] h1: height of vehicle body lightning rod from the ground;

[0051] h 1x : Height of vehicle body from the ground;

[0052] h 10 : Height of the vehicle body lightning rod;

[0053] h2: height of the working mechanism sky wheel lightning rod from the ground;

[0054] h 2x : The height of the working mechanism from the ground target;

[0055] h 20 :Height of the sky wheel lightning rod body;

[0056] a1: The horizontal distance between the installation position of the lightning rod on the vehicle body and the rear edge of the vehicle body;

[0057] a2: The horizontal distance between the installation position of the lightning rod on the vehicle body and the front edge of the vehicle body;

[0058] a3: Horizontal projection of the working mechanism, the distance from the edge of the vehicle body to the farthest horizontal projection;

[0059] b: The vertical length of the vehicle body.

[0060] r x : The maximum distance between the vehicle body and the lightning rod installation position. DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means any limitation to the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise specified, the relative arrangement, expressions and numerical values ​​of the components and steps described in these embodiments do not limit the scope of the present invention. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but in appropriate cases, the techniques, methods and equipment should be regarded as part of the specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0062] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations).

[0063] Example 1

[0064] like Figure 1-2 As shown, the lightning protection device for a large open-pit mining shovel of the present invention realizes lightning protection by intercepting the lightning strike of the open-pit mining shovel, and includes a double-needle lightning arrester. The double-needle lightning arrester is configured according to the external dimensions of the open-pit mining shovel, and includes a vehicle body lightning rod 3, a sheave lightning rod 4, a first down conductor, a second down conductor, and a grounding system; wherein:

[0065] The open-pit mining electric shovel is divided into the vehicle body lightning protection area and the working mechanism lightning protection area according to its appearance characteristics;

[0066] The vehicle body lightning rod 3 is used to realize lightning protection in the vehicle body lightning protection area of ​​the open-pit mining shovel. Due to the structural limitations of the open-pit mining shovel itself, the vehicle body lightning rod 3 cannot be installed on the open-pit mining shovel at the center of the top of the open-pit mining shovel body. Instead, the vehicle body lightning rod 3 can only be installed on the top of the A-frame 1 of the open-pit mining shovel and arranged symmetrically with respect to the working mechanism direction of the shovel. Therefore, in order to ensure the protection radius r of the vehicle body lightning rod 3 x Covering the vehicle body lightning protection area, the protection radius r of the vehicle body lightning rod 3 x It must be larger than the farthest point from the vehicle body when the projection point of the installation position on the horizontal plane is taken, that is: At this time, the height h1 of the vehicle body lightning rod 3 from the ground satisfies: Therefore, in the present invention, the height h of the vehicle body lightning rod 3 is 10 satisfy:

[0067]

[0068] Where: h 1xIt indicates the height of the body of the open-pit mining shovel from the ground; a2 indicates the horizontal distance from the installation position of the lightning rod 3 on the body to the front edge of the body; b indicates the vertical length of the body.

[0069] The sheave lightning rod 4 is used to protect the sheave lightning protection area (or the working mechanism lightning protection area) of the open-pit mining shovel from lightning strikes, and is installed on the top of the sheave 2 of the open-pit mining shovel. 2x for:

[0070] r 2x =h 1x -h 2x +h 20

[0071] Where: h 1x Indicates the height of the open-pit mining shovel from the ground; h 2x Indicates the height of the working mechanism from the ground target; h 20 Indicates the height of the main body of the sky wheel lightning rod 4.

[0072] It can be seen that the protection radius r of the sky wheel lightning rod 4 2x Always meet: r 2x >h 1x -h 2x Therefore, the height of the sky wheel lightning rod 4 itself is not limited, and its protection radius r 2x Can always cover the lightning protection area of ​​the working mechanism.

[0073] The present invention is provided with down conductors for the vehicle body lightning rod 3 and the sheave lightning rod 4, that is, the present invention is provided with a first down conductor for the vehicle body lightning rod 3, so that the upper end of the first down conductor is connected to the vehicle body lightning rod 3, and the lower end is laid along the A-frame 1 and can extend to the bottom of the right platform 6 of the electric shovel; and the sheave body lightning rod is provided with a second down conductor, so that the upper end of the second down conductor is connected to the sheave lightning rod 4, and the lower end is extended along the working mechanism arm 5 of the open-pit mine electric shovel to the bottom of the right platform 6 of the electric shovel. The first and second down conductors are both made of super-insulating materials, and the first and second down conductors are arranged in parallel.

[0074] The grounding system is arranged in the electric shovel operation area of ​​the open-pit mine; the grounding system has an electric shovel explosion-proof connector that can be electrically connected to the first and second down conductors respectively, and the resistance of the grounding system is less than 10 ohms. Specifically, the grounding system includes an electric shovel operation platform and a grounding electrode buried in the electric shovel operation platform. The grounding electrodes are connected in groups and buried with a resistance reducing agent to effectively reduce the resistance of the grounding electrode, so that the resistance of the grounding electrode is less than 10 ohms, and the electric shovel explosion-proof connector is externally connected.

[0075] When in use, the explosion-proof connector is used to connect the explosion-proof joint of the electric shovel to the first and second down conductors respectively, so as to realize lightning protection for the electric shovel used in open-pit mines.

[0076] Example 2

[0077] This embodiment provides a lightning protection method for an electric shovel for a large open-pit mine, which is implemented based on the above-mentioned lightning protection device for an electric shovel for a large open-pit mine, and includes the following steps:

[0078] Step 1: Build a lightning protection device:

[0079] The lightning protection device is built through the following steps:

[0080] Step 1.1: Divide the lightning protection area:

[0081] The open-pit mining electric shovel is divided into two lightning protection areas as a whole, one of which is the vehicle body lightning protection area centered on the top of the A-frame 1, and the other is the working mechanism lightning protection area centered on the top of the sheave 2;

[0082] Step 1.2: Assemble the lightning rod:

[0083] There are two lightning rods, corresponding to the vehicle body lightning rod 3 and the sky wheel lightning rod 4;

[0084] A vehicle body lightning rod 3 is installed on the top of the A-frame 1, and the height of the vehicle body lightning rod 3 itself can ensure that the lightning protection radius of the vehicle body lightning rod 3 covers the vehicle body lightning protection area;

[0085] A sky wheel lightning rod 4 is installed on the top of the sky wheel 2, and the lightning protection radius of the sky wheel lightning rod 4 can cover the lightning protection area of ​​the working mechanism;

[0086] Step 1.3: Laying down conductors:

[0087] There are two down conductors, namely the first and second down conductors;

[0088] The upper end of the first down conductor is connected to the vehicle body lightning rod 3, and the lower end is laid along the A-frame 1 and can extend to the bottom of the right side platform 6 of the electric shovel;

[0089] The upper end of the second down conductor is connected to the overhead sheave lightning rod 4, and the lower end is extended along the working mechanism arm 5 of the open-pit mine shovel to the bottom of the right platform 6 of the shovel;

[0090] Step 1.4: Arrange the grounding system:

[0091] An electric shovel operation platform is set up near the electric shovel operation area in the open-pit mine, and a grounding electrode is buried in the electric shovel operation platform, and a resistance reducing agent is buried to make the resistance of the grounding electrode less than 10 ohms, and an explosion-proof connector of the electric shovel is connected externally;

[0092] Step 2: Lightning protection:

[0093] Under thunderstorm weather conditions, stop the operation of the open-pit mining shovel, and connect the first and second down conductors to the explosion-proof connectors of the electric shovel respectively to introduce the lightning current into the grounding electrode to prevent the lightning point from directly hitting the open-pit mining shovel.

Claims

1. A lightning protection device for an electric shovel used in a large open-pit mine, which realizes lightning protection by intercepting lightning strikes of an electric shovel used in an open-pit mine, characterized in that: It includes a double-needle lightning arrester; the double-needle lightning arrester includes a vehicle body lightning rod, a sheave lightning rod, a first down conductor, a second down conductor and a grounding system; wherein: The vehicle body lightning rod is used to implement lightning strike protection in the vehicle body lightning protection area of ​​the open-pit mining shovel, and is installed on the top of the A-frame of the open-pit mining shovel; The sheave lightning rod is used to implement lightning protection in the sheave lightning protection area of ​​an open-pit mine shovel, and is installed on the top of the sheave of the open-pit mine shovel; The first down conductor has an upper end connected to the vehicle body lightning rod, and a lower end laid along the A-frame and capable of extending to the bottom of the right platform of the electric shovel; The second down conductor has an upper end connected to the sky wheel lightning rod, and a lower end extending along the working mechanism arm of the open-pit mine shovel to the bottom of the right platform of the shovel; The grounding system is arranged in the electric shovel operation area of ​​the open-pit mine; the grounding system has an electric shovel explosion-proof connector that can be electrically connected to the first and second down conductors respectively, and the resistance of the grounding system is less than 10 ohms.

2. The lightning protection device for electric shovel used in large open-pit mines according to claim 1 is characterized in that: The height h1 of the vehicle body lightning rod from the ground meets the following requirements: The height of the vehicle body lightning rod h 10 satisfy: Where: h 1x It indicates the height of the body of the open-pit mining shovel from the ground; a2 indicates the horizontal distance from the installation position of the lightning rod on the body to the front edge of the body; b indicates the vertical length of the body.

3. The lightning protection device for electric shovel used in large open-pit mines according to claim 2 is characterized in that: The vehicle body lightning rod is installed on the top of the A-frame through an electric lifting mechanism.

4. The lightning protection device for electric shovel used in large open-pit mines according to claim 2 is characterized in that: The grounding system includes an electric shovel working platform and a grounding electrode buried in the electric shovel working platform; the electric shovel working platform is arranged in an electric shovel working area of ​​an open-pit mine, and the resistance of the grounding electrode is less than 10 ohms.

5. The lightning protection device for electric shovel used in large open-pit mines according to claim 4 is characterized in that: The resistance of the ground electrode is reduced by burying a resistance reducing agent on the ground electrode.

6. The lightning protection device for electric shovel used in large open-pit mines according to claim 1, characterized in that: An explosion-proof connector is arranged between the vehicle body lightning rod and / or the sky sheave lightning rod and the grounding system.

7. The lightning protection device for electric shovel used in large open-pit mines according to claim 1 is characterized in that: A line induction lightning protection device is arranged inside the open-pit mine electric shovel.

8. The lightning protection device for electric shovel used in large open-pit mines according to claim 1, characterized in that: The first and second down conductors are made of super-insulating materials.

9. A lightning protection method for an electric shovel for a large open-pit mine, implemented based on the lightning protection device for an electric shovel for a large open-pit mine according to claim 1, characterized in that: The steps include: Step 1: Build a lightning protection device: The lightning protection device is built through the following steps: Step 1.1: Divide the lightning protection area: The open-pit mining electric shovel is divided into two lightning protection areas as a whole. One lightning protection area is the vehicle body lightning protection area centered on the top of the A-frame, and the other lightning protection area is the working mechanism lightning protection area centered on the top of the sheave. Step 1.2: Assemble the lightning rod: There are two types of lightning rods, one is the vehicle body lightning rod, and the other is the wheel lightning rod; A vehicle body lightning rod is installed on the top of the A-frame. The height of the vehicle body lightning rod can ensure that the lightning protection radius of the vehicle body lightning rod covers the vehicle body lightning protection area. A sky wheel lightning rod is installed on the top of the sky wheel, and the lightning protection radius of the sky wheel lightning rod can cover the lightning protection area of ​​the working mechanism; Step 1.3: Laying down conductors: The down conductor includes the first down conductor and the second down conductor; Connect the upper end of the first down conductor to the vehicle body lightning rod, and lay the lower end along the A-frame and extend to the bottom of the right platform of the shovel; The upper end of the second down conductor is connected to the overhead sheave lightning rod, and the lower end is extended along the working mechanism arm of the open-pit mining shovel to the bottom of the right platform of the shovel; Step 1.4: Arrange the grounding system: An electric shovel working platform is set up near the working area of ​​the open-pit mine electric shovel, and a grounding electrode is buried in the electric shovel working platform. And buried the resistance reducing agent to make the resistance of the grounding electrode less than 10 ohms, and connected the explosion-proof connector of the electric shovel externally; Step 2: Lightning protection: Under thunderstorm weather conditions, stop the operation of the open-pit mining shovel, and connect the first and second down conductors to the explosion-proof connectors of the electric shovel respectively to introduce the lightning current into the grounding electrode to prevent the lightning point from directly hitting the open-pit mining shovel.

10. The lightning protection method for electric shovels used in large open-pit mines according to claim 9, characterized in that: In step 2, the first and second down conductors are electrically connected to the explosion-proof connector of the electric shovel using an explosion-proof connector.

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