Inert gasbag sealing support structure and support method for gob along gob-side entry retaining

Abstract

The present invention provides a sealed support structure and a support method for a gob-side entry retaining gob area with flame-retardant inert airbags. The support structure includes at least one support unit capable of isolating and sealing the gob area. Two or more support units are arranged side by side horizontally and are hermetically connected to each other. The support unit includes a first sealed airbag filled with inert gas inside, and at least a pair of magnet pairs that are connected to the first sealed airbag and play a supporting role. The present invention supports the roof by the repulsive force generated between the two magnets of the first sealed airbag and the magnet pair, and uses the first sealed airbag to seal the gob area to play a role in plugging leaks. When the roof caving changes from the original instantaneous caving from a certain height space to the caving after being buffered by the first sealed airbag, the broken roof is controlled to slowly fall, reducing the impact. The present invention combines a magnet and an airbag to form a support unit, which can play a role in closed support, prevent the continued caving of the broken coal and gangue blocks, and play a role in support and sealing.

Description

Technical Field

[0001] The invention belongs to the technical field of goaf support, and particularly relates to a fire-retardant inert airbag sealing support structure and a support method for gob-side entry retaining in a goaf. Background Art

[0002] Due to the non-renewability of coal, in order to improve the coal recovery rate and reduce waste, pillarless mining has become the development trend of coal mining. The gob-side entry retaining technology is a key technology for pillarless mining, that is, during the working face mining process, a support wall and in-gallery support are constructed along the goaf side, and the roadway that has been mined in the working face is retained as a mining roadway for the adjacent working face. Gob-side support is an important part to ensure the success of gob-side entry retaining. In the past, the gob-side supports such as gangue belts, wooden chocks and concrete blocks generally have disadvantages such as slow resistance increase, small bearing pressure, large deformation and poor sealing. And the goaf is one of the places where gas and fire hazards are most likely to occur underground. Such support technologies are not conducive to the maintenance of gob-side entry retaining and the prevention of gas accidents and spontaneous combustion of residual coal in the goaf.

[0003] The most commonly used technology at present is gob-side goaf filling. Gob-side filling can isolate the goaf and cooperate with the roadway support to bear the pressure and maintain the roadway roof. It should have characteristics such as quick setting, high strength and a certain amount of deformability. When the roof breaks in the early stage, the support resistance of the gob-side filling wall should be able to bear the roof cutting resistance, ensure the integrity of the roof in the roadway without delamination, and cut off the roof on the goaf side at the same time. This can balance the support of the gangue accumulated by the goaf caving and the side coal body and the pressure of the top rock layer, and realize the stability of the roadway roof. In addition, a certain amount of deformability of the gob-side filling body can enable the roof rock layer to have a certain adaptability before rotating and sinking to achieve balance, protect the gob-side support body during the rotation and sinking period of the roof rock layer, and realize the transfer of the roof load to the side of the gangue caved in the goaf.

[0004] However, the cost of gob-side goaf filling is relatively high, the on-site workload is large, and the filled materials will be damaged to varying degrees with the roof caving. There are many cracks in the filling body, which will not only cause air leakage, leading to spontaneous combustion of coal in the goaf, but also may cause leakage of goaf gas, and further may lead to the risk of excessive gas in the return air flow of gob-side entry retaining. Therefore, there is an urgent need for a new support structure for sealing the goaf of gob-side entry retaining. Summary of the Invention

[0005] The invention aims to solve the technical problems existing in the prior art. The first object of the invention is to provide a fire-retardant inert airbag sealing support structure for gob-side entry retaining in a goaf. The second object of the present invention is to provide a support method for the fire-retardant inert airbag sealing support structure for gob-side entry retaining in a goaf.

[0006] To achieve the first above-mentioned objective, the present invention adopts the following technical solution: a fire-retardant inert airbag sealing support structure for the gob-side entry retaining gob. The sealing support structure is arranged between the floor and the roof and is used to support the roof of the gob-side entry retaining roadway. The sealing support structure is also arranged between the gob-side entry retaining roadway and the gob and is used to isolate the gob. The sealing support structure includes at least one support unit capable of isolating and sealing the gob. When there are two or more support units, the two or more support units are arranged side by side horizontally and are hermetically connected to each other. The support unit includes a first sealing airbag filled with inert gas inside and at least one pair of magnets connected to the first sealing airbag for supporting. The two magnets of the magnet pair are respectively located on the upper and lower walls of the first sealing airbag and are arranged in corresponding positions. The first sealing airbag is made of a flexible fire-retardant material. The first sealing airbag is connected with an inflation valve and a pressure relief valve. The top and bottom of the first sealing airbag can be respectively abutted and hermetically connected to the roof and the floor. The two magnets of the magnet pair are respectively a first magnet installed on the floor and connected to the bottom of the first sealing airbag and a second magnet connected to the top of the first sealing airbag and capable of generating a repulsive force with the first magnet. The second magnet supports the roof by the repulsive force generated with the first magnet.

[0007] In the above technical solution, by setting the magnet pair and the first sealing airbag, the roof is supported by the repulsive force generated by the first sealing airbag and the two magnets of the magnet pair. The first sealing airbag is used to seal the gob. Utilizing the deformability of the airbag, the first sealing airbag plays a role in plugging leaks after inflation. Moreover, due to the function of the first sealing airbag, when the roof collapses, it changes from instantaneously collapsing from a certain height space to collapsing after being buffered by the first sealing airbag, controlling the slow falling of the broken roof and reducing the impact. The present invention combines the magnet and the airbag to form a support unit, which can play a role in sealing support, prevent the continued caving of the already broken coal gangue blocks, and play a role in support and sealing.

[0008] In a preferred embodiment of the present invention, the first magnet is arranged inside or outside the bottom of the first sealing airbag, and the second magnet is arranged inside or outside the top of the first sealing airbag. When the first magnet is arranged outside the bottom of the first sealing airbag, the outer side of the bottom of the first sealing airbag has a downward concave pit for accommodating the first magnet. When the second magnet is arranged outside the top of the first sealing airbag, the outer side of the top of the first sealing airbag has an upward concave pit for accommodating the second magnet.

[0009] In the above technical solution, two ways of connecting the first magnet, the second magnet and the first sealing airbag are provided, which can be selected according to the actual situation.

[0010] In a preferred embodiment of the present invention, the first magnet and the second magnet are permanent magnets with opposite magnetic poles; or both the first magnet and the second magnet are electromagnets; or one of the first magnet and the second magnet is a permanent magnet and the other is an electromagnet.

[0011] In the above technical solution, the above technical solution provides a way for the first magnet and the second magnet to generate magnetic force, which can be achieved by using permanent magnets or electromagnets, and can be selected according to the actual situation.

[0012] In a preferred embodiment of the present invention, when there are two or more support units, the two or more support units are arranged closely, and the surfaces of the first sealing airbags of two adjacent support units are sprayed with polyurethane material having sealing and flame retardant functions, or the first sealing airbags of two adjacent support units are sealed by flame retardant sealant.

[0013] In the above technical solution, the gap between the two first sealing airbags is sealed by polyurethane material or sealant to ensure closed support.

[0014] In a preferred embodiment of the present invention, when there are two or more support units, the two or more support units are arranged at intervals, and at least one second sealing airbag for sealing the two is provided between two adjacent support units. The second sealing airbag is made of flexible flame retardant material, and the second sealing airbag is connected with an inflation valve and a pressure relief valve.

[0015] In the above technical solution, according to the actual situation and the position of the roof to be supported as needed, multiple support units are arranged at intervals to reduce costs. At this time, the two adjacent support units are sealed by filling the second sealing airbag.

[0016] In another preferred embodiment of the present invention, the surface of the first sealing airbag / second sealing airbag in contact with the second sealing airbag is sprayed with polyurethane material having sealing and flame retardant functions, or the first sealing airbag / second sealing airbag and the second sealing airbag are sealed by flame retardant sealant.

[0017] In another preferred embodiment of the present invention, the support unit and the second sealing airbag are arranged alternately.

[0018] In another preferred embodiment of the present invention, the first sealing airbag is composed of one airbag with internal communication; or the first sealing airbag includes a plurality of airbag compartments arranged side by side horizontally, with communication between the plurality of airbag compartments, and magnet pairs are provided in all or part of the airbag compartments; or the first sealing airbag is composed of two sub-airbags, which are respectively a first sub-airbag located below and a second sub-airbag located above the first sub-airbag. The top of the first sub-airbag abuts and is hermetically connected to the bottom of the second sub-airbag. The first magnet is connected to the first sub-airbag, the second magnet is connected to the second sub-airbag, both sub-airbags are connected with inflation valves, and at least one of the two sub-airbags is connected with a pressure relief valve.

[0019] In the above technical solution, the first sealing airbag is set as a plurality of airbag compartments to improve the overall supporting force of the first sealing airbag and prevent it from collapsing easily; the first sealing airbag is split into two sub-airbags, which is convenient for the installation of the supporting unit, especially when both the first magnet and the second magnet are permanent magnets.

[0020] To achieve the second object, the present invention adopts the following technical solution: a supporting method for a gob-side entry retaining goaf flame-retardant inert airbag sealing support structure, including the following steps:

[0021] S1. Assume that the coal seam and rock stratum are horizontally occurring, simplify the overlying rock stratum of the coal mining face into a multi-layer combined rock beam structure, and obtain the number, thickness, average gravity density and span of the combined rock beam, as well as the weight ratio on the top of the first sealing airbag;

[0022] S2. Calculate the required supporting force

[0023] S3. Set the sharing coefficient 0.5 ≤ σ ≤ 1, and use the formula to obtain the current value I flowing through the coil of the electromagnet;

[0024] S4. According to obtain the pressure P of the first sealing airbag, where Δ is the upper limit parameter of the supporting force, and Δ ≥ 1;

[0025] S5. Maintain the pressure P of the first sealing airbag and pass the current I through the electromagnet to realize the double jacking of the first sealing airbag and the magnet pair;

[0026] Among them, S 气 is the area of the top of the first sealing airbag, i is the rock beam serial number, n is the number of rock beams jacked by the first sealing airbag, m i is the thickness of the i-th rock beam, γ i is the average gravity density of the i-th rock beam, L i is the span of the i-th rock beam, C iis the weight ratio of the \(i\)-th rock beam on the top of the first sealed airbag, \(P\) is the pressure of the first sealed airbag, \(j\) is the serial number of the magnet pair, \(m\) is the total number of magnet pairs, \(\mu_0\) is the vacuum permeability, \(\mu\) is the permeability in air and can take the value of \(\mu_0\), \(N\) is the number of turns of the coil of one electromagnet in the magnet pair, \(I\) is the current value flowing through the coil, \(L\) is the distance between the repulsive surfaces of the two magnets in the magnet pair, and \(S\) 磁 is the area of the magnet repulsive surface of the first sealed airbag.

[0027] In the above technical solution, the top is jointly supported by the first sealed airbag and the magnet pair, adopting a double-lifting structure with the upper limit parameter of the supporting force \(\Delta\geq1\), ensuring the safety of the support. By setting the sharing coefficient, the supporting forces provided by the first sealed airbag and the magnet pair can be adjusted, making the use more flexible. The present invention preferentially sets the supporting force of the magnet pair. On the premise of ensuring the effective support for the roof, the bearing capacity of the first sealed airbag is appropriately reduced, improving the service life and leakage stoppage effect of the first sealed airbag.

[0028] In another preferred embodiment of the present invention, when the roof pressure reaches the high limit of the pressure, the pressure relief valve of the first sealed airbag opens and starts to relieve pressure, and stops relieving pressure when the pressure relief reaches the safe value. During the pressure relief, the pressure is relieved in multiple steps.

[0029] In the above technical solution, the distributed pressure relief can not only resist multiple pressure surges, but also relieve pressure multiple times when the pressure surge is large, ensuring that the roof slowly sinks throughout the process before the airbag fails. At the same time, after the first pressure relief, the pressure relief valve closes, and the first sealed airbag can continue to support the roof. When the roof pressure reaches a certain value, the first sealed airbag relieves pressure again, increasing the effective time of the first sealed airbag.

[0030] Compared with the prior art, the preferred technical solution of the present invention has the following beneficial effects:

[0031] 1) By setting the magnet pair and the first sealed airbag, the present invention supports the roof by the repulsive force generated between the first sealed airbag and the two magnets of the magnet pair. Whether the floor and the roof interacting with the support unit are flat or not, as long as the two magnets can generate repulsive force with each other and the second magnet presses tightly against the roof, the supporting effect can be achieved. Moreover, both the first sealed airbag and the second sealed airbag are deformable. Therefore, when there are protrusions or pits on the surfaces of the floor and the roof, they can still play a role in closed support.

[0032] 2) The first sealed airbag and the second sealed airbag of the present invention have the advantages of simple on-site operation, controllable roof collapse, fast leakage stoppage, convenient transportation, quick and labor-saving installation, low labor intensity, low manufacturing and use costs, etc. Moreover, the first sealed airbag filled with inert gas can also prevent spontaneous combustion in the goaf.

[0033] 3) After the first sealing airbag and the second sealing airbag are placed in place, the inflation time is short, the leakage plugging and support are very fast, no harmful gases are generated, the use process is safe and reliable, the labor intensity of workers is low, and the installation and use speed is fast; moreover, different models of the first sealing airbag can be made according to the size of the roof fall in the working face, which is applicable to roadways under various conditions and has broad application prospects.

[0034] 4) The production cost of the support unit of the present invention is low, while the traditional processes such as reinforcement and filling have a long drilling preparation time, many transportation preparation links, and require a large number of people; the installation and use of the support unit are fast and labor-saving, and only a few people can complete the operation, saving labor cost and bringing obvious economic benefits; at the same time, it is safe and reliable in use, avoiding the occurrence of the situation of the support falling down during support; and it helps to achieve the goal of safe production in mines, has broad application prospects, and has great economic and social benefits.

[0035] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0037] Figure 1 is a schematic structural diagram of gob-side entry retaining of the present application.

[0038] Figure 2 is a first schematic structural diagram of the sealing support structure of Embodiment 1 of the present application.

[0039] Figure 3 is a second schematic structural diagram of the sealing support structure of Embodiment 1 of the present application.

[0040] Figure 4 is a schematic diagram of another connection mode between the magnet and the first sealing airbag.

[0041] Figure 5 is a schematic structural diagram of the first sealing airbag adopting multiple airbag compartments.

[0042] Figure 6 is a schematic structural diagram of the sealing support structure of Embodiment 2 of the present application.

[0043] Figure 7 is a schematic structural diagram of the support unit in Embodiment 3 of the present application.

[0044] The reference numerals in the accompanying drawings of the specification include: floor 1, coal body 2, roof 3, gob-side entry 4, goaf 5, support unit 6, first sealing airbag 61, airbag bin 61a, first sub-airbag 611, second sub-airbag 612, first magnet 62, second magnet 63, second sealing airbag 64. Detailed implementation manners

[0045] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0046] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "vertical", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0047] In the description of the present invention, unless otherwise specified and defined, it should be noted that the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the communication inside two elements. It can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.

[0048] Embodiment 1

[0049] This embodiment provides a gob-side entry goaf flame-retardant inert airbag sealing support structure. Figure 1 The following shows the structural schematic diagram of the gob-side entry of this application. The sealing support structure of the present invention is arranged between the floor 1 (equivalent to the ground) and the roof 3, and is used to support the roof 3 of the gob-side entry 4 on the side of the coal body 2. Moreover, this sealing support structure is also arranged between the gob-side entry 4 and the goaf 5, and is used to isolate the goaf 5, which can avoid the gas leakage of the goaf 5.

[0050] As Figure 2 and Figure 3 shown, in a preferred implementation manner of the present invention, this sealing support structure includes at least one support unit 6 that can isolate and seal the goaf 5. Figure 2 The following shows the setting of one support unit 6, which is applicable to the situation where the connecting port that needs to be filled between the gob-side entry 4 and the goaf 5 is relatively short;Figure 3 As shown, two or more support units 6 are provided. For example, five support units 6 are provided. The two or more support units 6 are arranged side by side horizontally and are hermetically connected to each other, which is applicable to the case where the communication opening that needs to be filled between the reserved roadway 4 and the goaf 5 is relatively long.

[0051] In the present invention, the support unit 6 includes a first sealed airbag 61 filled with inert gas inside, and at least a pair of magnet pairs that play a supporting role and are connected to the first sealed airbag 61. As shown in the figure, a pair of magnet pairs is provided. When multiple pairs of magnet pairs are provided, the multiple pairs of magnet pairs are arranged side by side. The two magnets of the magnet pair are respectively located on the upper and lower walls of the first sealed airbag 61 and are arranged corresponding to each other. The first sealed airbag 61 is made of a flexible flame-retardant material, such as a high-strength rubber material. The first sealed airbag 61 is connected with an inflation valve and a pressure relief valve (not shown in the figure). The gas filled in the first sealed airbag 61 is nitrogen, which has many advantages such as low cost and convenient storage and transportation. In this embodiment, the first sealed airbag 61 is composed of one airbag with internal communication. The upper surface of the top of the first sealed airbag 61 and the lower surface of the bottom can be respectively abutted against and hermetically connected to the roof 3 and the floor 1. The first sealed airbag 61 has a flame-retardant property and will not pose a risk of mine fire. At the same time, the outer wrapping material has high strength characteristics and can effectively prevent the risk of being scratched by gangue during use.

[0052] The two magnets of the magnet pair are respectively a first magnet 62 installed on the floor 1 and connected to the bottom of the first sealed airbag 61, and a second magnet 63 connected to the top of the first sealed airbag 61 and capable of generating a repulsive force with the first magnet 62. The second magnet 63 supports the roof 3 by the repulsive force generated with the first magnet 62.

[0053] In this embodiment, as Figure 2 and Figure 4 shown, the first magnet 62 is provided inside or outside the bottom of the first sealed airbag 61, and the second magnet 63 is provided inside or outside the top of the first sealed airbag 61. For example Figure 2 shown, when both the first magnet 62 and the second magnet 63 are provided inside the first sealed airbag 61, specifically, the first magnet 62 and the second magnet 63 can be directly placed in the first sealed airbag 61; and for another example Figure 4 shown, when the first magnet 62 is provided outside the bottom of the first sealed airbag 61, specifically, a downward concave pit for accommodating the first magnet 62 can be provided on the outside of the bottom of the first sealed airbag 61, and the first magnet 62 can also be directly placed outside the bottom of the first sealed airbag 61; and for another example Figure 4As shown, the second magnet 63 is provided outside the top of the first sealed airbag 61. Specifically, a downwardly concave upper pit for accommodating the second magnet 63 can be provided on the outer side of the top of the first sealed airbag 61, or the second magnet 63 can also be directly placed outside the top of the first sealed airbag 61.

[0054] In this embodiment, both the first magnet 62 and the second magnet 63 are electromagnets; alternatively, one of the first magnet 62 and the second magnet 63 is a permanent magnet and the other is an electromagnet. Generating magnetic force using an electromagnet is a prior art, and its structure and principle will not be elaborated here.

[0055] The first sealed airbag 61 in this embodiment is inflated on-site. First, the uninflated first sealed airbag 61, the first magnet 62, and the second magnet 63 are transported to the empty roadway 4 that needs to be supported and sealed. Then, the first sealed airbag 61 and the first magnet 62 are placed on the floor 1, and the second magnet 63 is stacked on the first magnet 62.

[0056] When the second magnet 63 is provided inside the top of the first sealed airbag 61, an external inflation device that supplies inert gas inflates the first sealed airbag 61 through an inflation valve to make it expand. After the internal pressure of the first sealed airbag 61 reaches a certain value, inflation stops. After the first sealed airbag 61 expands, its top and bottom are respectively pressed against and sealed to the roof 3 and the floor 1, and both sides of the first sealed airbag 61 are also sealed to the side walls of the communication port between the empty roadway 4 and the goaf 5 (when there are gaps between the first sealed airbag 61 and the roof 3, the floor 1, and the side walls of the communication port, a polyurethane material for blocking air used in the art can be sprayed in the gaps). Next, the first magnet 62 and the second magnet 63 are made to work, and a repulsive force is generated between the first magnet 62 and the second magnet 63, causing the second magnet 63 to move upward and press against the roof 3. In this way, the roof 3 can also be supported by the repulsive force generated by the first magnet 62 and the second magnet 63 (the same principle as the levitation of a maglev train).

[0057] When the second magnet 63 is provided outside the top of the first sealed airbag 61, first, the first magnet 62 and the second magnet 63 are made to work, and a repulsive force is generated between the first magnet 62 and the second magnet 63, causing the second magnet 63 to move upward and press against the roof 3. Then, the external inflation device inflates the first sealed airbag 61 through the inflation valve to make it expand. The top and bottom of the first sealed airbag 61 are respectively pressed against and sealed to the roof 3 and the floor 1, and both sides of the first sealed airbag 61 are also sealed to the side walls of the communication port between the empty roadway 4 and the goaf 5.

[0058] The present invention supports the roof plate 3 through the repulsive force generated by the first sealing airbag 61, as well as the first magnet 62 and the second magnet 63. The first sealing airbag 61 is used to seal the gob area 5. By utilizing the deformability of the first sealing airbag 61, the first sealing airbag 61 plays a role in plugging leaks after inflation; moreover, due to the effect of the first sealing airbag 61, when the roof plate 3 collapses, it changes from instantaneously collapsing from a certain height space to collapsing after being buffered by the first sealing airbag 61. When the roof plate 3 collapses and presses on the first sealing airbag 61, the air pressure inside it increases. To prevent damage to the first sealing airbag 61, the pressure relief valve on the first sealing airbag 61 automatically opens to reduce the air pressure inside the first sealing airbag 61. The air pressure inside the first sealing airbag 61 slowly decreases, thereby controlling the slow fall of the broken roof plate 3 and reducing the impact.

[0059] It should be noted that the present invention supports the roof plate 3 through the repulsive force generated between the first magnet 62 and the second magnet 63. If the bottom plate 1 and the roof plate 3 are uneven, with protrusions or pits on the surface, as long as the two magnets can generate repulsive force with each other and the second magnet 63 presses tightly against the roof plate 3, it can play a supporting role; moreover, the first sealing airbag 61 has deformability and can still play a role in sealing and supporting when there are protrusions or pits on the surfaces of the bottom plate 1 and the roof plate 3.

[0060] In this embodiment, the first magnet 62 and the second magnet 63 can both be electromagnets, or one can be a permanent magnet and the other an electromagnet. The electromagnet can be powered by a power supply arranged inside or outside the airbag, and a switching device is arranged on the power supply circuit, and the closing and opening of the switching device can be remotely controlled externally. The power supply can be a battery or an external power supply (such as mains electricity), and the battery can be charged by mains electricity or by wireless charging. It should be noted that there may be gas in the gob-side entry retaining area. Since the basic conditions for gas explosion are that the gas concentration is within the explosion limit, generally 5% - 16%; the oxygen content concentration in the air is not less than 12%; there is an ignition source with sufficient energy, generally referring to an ignition temperature above 650°C - 750°C, such as open fire, smoking, blasting, electric spark, or even impact and friction sparks, etc., which can ignite gas. In this patent application, through gas concentration detection and extraction, it is controlled within a safe range, so it is safe to use an electromagnet.

[0061] As Figure 3 shown, in another preferred embodiment of the present invention, when there are two or more support units 6, the two or more support units 6 are arranged closely. The surfaces of the first sealing airbags 61 of adjacent two support units 6 are sprayed with polyurethane material having sealing and flame retardant functions, or the first sealing airbags 61 of adjacent two support units 6 are sealed by a flame retardant sealing glue.

[0062] In another preferred embodiment, as Figure 5As shown, the first sealing airbag 61 includes a plurality of airbag compartments arranged side by side horizontally, whereby the overall supporting force of the first sealing airbag 61 can be improved and it is not easily collapsible. Specifically, the first sealing airbag 61 includes a bladder body and a number of partition walls disposed vertically inside the bladder body. The number of partition walls divides the inside of the bladder body into a plurality of airbag compartments, and the airbag compartments communicate with each other. Magnet pairs are installed in the front part or some of the airbag compartments.

[0063] Embodiment Two

[0064] The structural principle of this embodiment is basically the same as that of Embodiment One. The difference is that, as Figure 6 shown, in this embodiment, when there are two or more support units 6, the two or more support units 6 are arranged at intervals, and at least one second sealing airbag 64 for sealing the two adjacent support units 6 is provided between the two adjacent support units 6. Figure 6 As shown in, one second sealing airbag 64 is provided between two adjacent support units 6. The support unit 6 and the second sealing airbag 64 are arranged alternately. The second sealing airbag 64 is made of a flexible flame-retardant material. The second sealing airbag 64 is connected with an inflation valve and a pressure relief valve. The second sealing airbag 64 also adopts the on-site inflation method.

[0065] In this embodiment, the surface of the first sealing airbag 61 in contact with the second sealing airbag 64 is sprayed with a polyurethane material having a sealing and flame-retardant function, or the first sealing airbag 61 and the second sealing airbag 64 are sealed by a flame-retardant sealant. It should be noted that when there are two or more second sealing airbags 64 between two adjacent support units 6, the surface of the second sealing airbag 64 in contact with the second sealing airbag 64 is sprayed with a polyurethane material having a sealing and flame-retardant function, or the second sealing airbag 64 and the second sealing airbag 64 are sealed by a flame-retardant sealant.

[0066] In practice, a plurality of support units 6 can be arranged at intervals according to the position of the roof 3 to be supported. At this time, the two adjacent support units 6 are sealed by filling the second sealing airbag 64.

[0067] Embodiment Three

[0068] The structural principle of this embodiment is basically the same as that of Embodiment One and Embodiment Two. The difference is that, as Figure 7As shown in the figure, in this embodiment, the first sealing airbag 61 is composed of two sub-airbags, namely the first sub-airbag 611 located below and the second sub-airbag 612 located above the first sub-airbag 611. The top of the first sub-airbag 611 abuts and is sealingly connected to the bottom of the second sub-airbag 612. The first magnet 62 is connected to the first sub-airbag 611, and the second magnet 63 is connected to the second sub-airbag 612. Both sub-airbags are connected with inflation valves, and at least one of the two sub-airbags is connected with a pressure relief valve.

[0069] In this embodiment, the first magnet 62 is arranged inside or outside the bottom of the first sealing airbag 61, and the second magnet 63 is arranged inside or outside the top of the first sealing airbag 61.

[0070] In this embodiment, both the first magnet 62 and the second magnet 63 are permanent magnets; or both the first magnet 62 and the second magnet 63 are electromagnets; or one of the first magnet 62 and the second magnet 63 is a permanent magnet and the other is an electromagnet.

[0071] When installing the support unit 6, regardless of whether the second magnet 63 is arranged inside or outside the top of the first sealing airbag 61, first make the first magnet 62 and the second magnet 63 work, and a repulsive force is generated between the first magnet 62 and the second magnet 63, so that the second magnet 63 moves upward and abuts tightly against the roof 3, and then an external inflation device inflates the first sub-airbag 611 and the second sub-airbag 612 through the inflation valve to make them expand.

[0072] It should be noted that for the case where both the first magnet 62 and the second magnet 63 are permanent magnets, the magnetic poles of the first magnet 62 and the second magnet 63 are opposite. To avoid being unable to install the support unit 6 due to the repulsive force between the two magnets, a shielding sheet can be arranged between the two sub-airbags first. Thus, when installing the support unit 6, the second magnet 63 can be stacked above the first magnet 62, and then the shielding sheet is removed, and a repulsive force is generated between the first magnet 62 and the second magnet 63, so that the second magnet 63 moves upward and abuts tightly against the roof 3.

[0073] It should be noted that the first sub-airbag 611 and the second sub-airbag 612 in this embodiment can also adopt a structure with multiple airbag compartments arranged side by side. Correspondingly, the first magnet 62 is connected to the airbag compartments of the first sub-airbag 611, and the second magnet 63 is connected to the airbag compartments of the second sub-airbag 612.

[0074] Embodiment 4

[0075] This embodiment provides a support method using the gob-side entry retaining gob fire-retardant inert airbag sealing support structure of the foregoing Embodiment 1, including the following steps:

[0076] S1. Assume that the coal body 2 and the rock stratum are horizontally occurring, simplify the overlying rock stratum of the coal mining face into a multi-layer combined rock beam structure, obtain the number, thickness, average gravity density and span of the combined rock beam, and the weight ratio on the top of the first airtight airbag 61. The foregoing parameters belong to the basic parameters of the rock stratum and can be obtained in the previous geological exploration, which will not be elaborated here;

[0077] S2. Calculate the required supporting force

[0078] S3. Set the sharing coefficient 0.5 ≤ σ ≤ 1, and use the formula to obtain the current value I flowing through the coil of the electromagnet;

[0079] S4. According to obtain the pressure P of the first airtight airbag. Δ is the upper limit parameter of the supporting force, and Δ ≥ 1;

[0080] S5. Maintain the pressure P of the first airtight airbag 61 and pass current I through the electromagnet to realize the double jacking of the first airtight airbag 61 and the magnet pair;

[0081] Among them, S 气 is the area of the top of the first airtight airbag 61, i is the serial number of the rock beam, n is the number of rock beams jacked by the first airtight airbag 61, m i is the thickness of the i-th rock beam, γ i is the average gravity density of the i-th rock beam, L i is the span of the i-th rock beam, C i is the weight ratio of the i-th rock beam on the top of the first airtight airbag 61, P is the pressure of the first airtight airbag 61, j is the serial number of the magnet pair, m is the total number of magnet pairs, μ0 is the vacuum permeability, μ is the permeability in air, and the permeability in air can be taken as μ0. N is the number of turns of the coil of an electromagnet in the magnet pair, I is the current value flowing through the coil, L is the distance between the repulsive surfaces of the two magnets in the magnet pair, and S 磁 is the area of the repulsive surface of the first airtight airbag and the magnet;

[0082] In another preferred embodiment, when the pressure of the roof 3 reaches the high pressure limit, the pressure relief valve of the first airtight airbag 61 opens and starts to relieve pressure. When the pressure relief reaches the safe value, the pressure relief stops, and the pressure relief is carried out in multiple steps. For example, the opening pressure of the pressure relief valve can be associated with the real-time pressure detection system of the first airtight airbag 61 and the real-time pressure detection system of the roof 3. When the pressure of the roof 3 reaches the maximum value, the first pressure relief of the first airtight airbag 61 starts, and the values of the first pressure relief and the second pressure relief are related to the change of the on-site roof pressure. Preferably, relevant components of a resistance device are installed inside the pressure relief valve to slow down the air outlet speed during pressure relief.

[0083] In the description of this specification, the descriptions referring to terms such as "preferred embodiments", "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

[0084] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. Support method for a fire-retardant inert airbag sealing support structure in a gob-side entry retaining gob area. The sealing support structure is arranged between the floor and the roof and is used to support the roof of the gob-side entry retaining roadway. The sealing support structure is also arranged between the gob-side entry retaining roadway and the gob area and is used to isolate the gob area. It is characterized in that, The described sealed support structure includes at least one support unit capable of isolating and sealing the goaf. When there are two or more support units, the two or more support units are arranged side by side horizontally and are hermetically connected to each other. The support unit includes a first sealed airbag filled with inert gas inside, and at least a pair of magnet pairs that play a supporting role and are connected to the first sealed airbag. The two magnets of the magnet pair are respectively located on the upper and lower walls of the first sealed airbag and are arranged corresponding to each other. The first sealed airbag is made of a flexible flame-retardant material. The first sealed airbag is connected with an inflation valve and a pressure relief valve. The top and bottom of the first sealed airbag can respectively abut against and be hermetically connected to the roof and the floor. The two magnets of the magnet pair are respectively a first magnet installed on the floor and connected to the bottom of the first sealed airbag, and a second magnet connected to the top of the first sealed airbag and capable of generating a repulsive force with the first magnet. The second magnet supports the roof by the repulsive force generated with the first magnet. The first magnet and the second magnet are permanent magnets with opposite magnetic poles; or both the first magnet and the second magnet are electromagnets; or one of the first magnet and the second magnet is a permanent magnet and the other is an electromagnet. The described support method includes the following steps: S1. Assume that the coal body and the rock stratum are horizontally occurring, simplify the overlying rock stratum of the coal mining face into a multi-layer combined rock beam structure, and obtain the number, thickness, average gravity density and span of the combined rock beam, as well as the weight ratio on the top of the first sealed airbag. S2, Calculate the required supporting force S3. Set the sharing coefficient \(0.5\leqslant\sigma\leqslant1\), and use the formula to obtain the current value \(I\) flowing through the coil of the electromagnet; S4, according to obtain the pressure P of the first sealing airbag, Δ is the upper limit parameter of the supporting force, and Δ≥1; S5. Maintain the pressure P of the first sealed airbag and pass an electric current I through the electromagnet to realize the double jacking of the first sealed airbag and the magnet pair. Among them, S 气 is the area of the top of the first sealing airbag, i is the number of the rock beam, n is the number of rock beams jacked up by the first sealing airbag, m i is the thickness of the i-th rock beam, γ i is the average gravity density of the i-th rock beam, L i is the span of the i-th rock beam, C i is the weight ratio of the i-th rock beam on the top of the first sealing airbag, P is the pressure of the first sealing airbag, j is the number of the magnet pair, m is the total number of magnet pairs, μ0 is the vacuum permeability, μ is the permeability in air, and its value is μ0, N is the number of turns of the coil of an electromagnet in the magnet pair, I is the current value flowing through the coil, L is the distance between the repulsive surfaces of the two magnets in the magnet pair, S 磁 is the area of the magnet repulsive surface of the first sealing airbag.

2. The support method according to claim 1, characterized in that, The first magnet is arranged inside or outside the bottom of the first sealed airbag, and the second magnet is arranged inside or outside the top of the first sealed airbag. When the first magnet is arranged outside the bottom of the first sealed airbag, the outside of the bottom of the first sealed airbag has a downward concave pit for accommodating the first magnet. When the second magnet is arranged outside the top of the first sealed airbag, the outside of the top of the first sealed airbag has an upward concave pit for accommodating the second magnet.

3. The support method according to claim 1 or 2, characterized in that, When there are two or more support units, the two or more support units are closely arranged. The surfaces of the first sealed airbags of adjacent two support units are sprayed with polyurethane material having a sealing and flame-retardant effect, or the first sealed airbags of adjacent two support units are sealed by a flame-retardant sealant.

4. The support method according to claim 1 or 2, characterized in that, When there are two or more support units, the two or more support units are arranged at intervals, and at least one second sealed airbag for sealing the two adjacent support units is arranged between the two adjacent support units. The second sealed airbag is made of a flexible flame-retardant material. The second sealed airbag is connected with an inflation valve and a pressure relief valve.

5. The support method according to claim 4, characterized in that, The surface of the first sealed airbag in contact with the second sealed airbag is sprayed with polyurethane material having a sealing and flame-retardant effect, or the first sealed airbag and the second sealed airbag are sealed by a flame-retardant sealant. When there are two or more second sealing airbags arranged between two adjacent support units, the surfaces of the second sealing airbags in contact with each other are sprayed with polyurethane material having a sealing and flame-retardant effect, or the second sealing airbags are sealed with a flame-retardant sealant between them.

6. The support method according to claim 4, characterized in that, The support units and the second sealing airbags are arranged alternately.

7. The support method according to claim 1 or 2, characterized in that, The first sealing airbag consists of one airbag with internal communication; or the first sealing airbag includes a plurality of airbag compartments arranged side by side horizontally, the plurality of airbag compartments communicate with each other, and all or part of the airbag compartments are provided with the magnet pairs; or the first sealing airbag is composed of two sub-airbags, the two sub-airbags are respectively a first sub-airbag located below and a second sub-airbag located above the first sub-airbag, the top of the first sub-airbag abuts and is sealingly connected to the bottom of the second sub-airbag, the first magnet is connected to the first sub-airbag, the second magnet is connected to the second sub-airbag, both sub-airbags are connected with inflation valves, and at least one of the two sub-airbags is connected with a pressure relief valve.

8. The support method according to claim 1, characterized in that, When the roof pressure reaches the high pressure limit, the pressure relief valve of the first sealing airbag opens and starts to relieve pressure, and the pressure relief stops when the pressure relief reaches the safe value. The pressure relief is carried out in multiple steps during the pressure relief.

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