A device and method for eliminating air columns from underground reservoirs used in abandoned mines

Abstract

The present invention relates to the technical field of abandoned mine transformation, and provides an air column elimination device for underground water reservoirs used in abandoned mines, including a three-way pipe fitting, a float device is provided directly below the lower port of the three-way pipe fitting, the float will block the port when receiving buoyancy, and fall off the port after the buoyancy is eliminated, and the other two ports of the three-way pipe fitting are respectively connected to ventilation pipes. A method for eliminating air columns in underground water reservoirs used in abandoned mines is also disclosed, and the steps are as follows: one side of the ventilation pipe leads to the top plate position at the highest point of the tunnel, and the other side of the ventilation pipe leads to the return air connection lane of the abandoned mine mining area, and the three-way pipe fitting is located at the lowest point of the ventilation pipe. The beneficial effects are: low cost, can effectively solve the problem of offsetting the air column of the reservoir, and ensure the storage capacity of the underground water reservoir of the abandoned mine.

Description

Technical Field

[0001] The invention relates to the technical field of abandoned mine reconstruction, in particular to a device for eliminating air columns in underground water reservoirs used in abandoned mines, and also to a method for eliminating air columns in underground water reservoirs used in abandoned mines. Background Art

[0002] Coal is a non-renewable resource that is mainly stored underground. Coal is mainly mined through mines. After the coal in the mine is mined out, it will be abandoned to form abandoned mines. Abandoned mines cause a large number of underground goafs. It is estimated that by 2030, the underground space of goafs in China alone will reach 23.4 billion cubic meters. Therefore, how to utilize the underground space of abandoned mines will be an urgent problem to be solved.

[0003] At present, a mature solution for utilizing the underground space of abandoned mines is to use it for physical energy storage, mainly by transforming abandoned mines into underground reservoirs of damless pumped-storage power stations. Due to the complex structure of abandoned mine tunnels and the height difference of the terrain, the internal level of some tunnels is greater than the entrance level. During the water filling process, as the water level rises, the air in the area with a relatively high internal level is sealed by water and cannot escape, and finally a compressed air column is formed in the area, which greatly reduces the water storage capacity of the underground reservoir, thereby reducing the efficiency of pumped-storage power generation.

[0004] The problem of air column in underground mines is now mainly solved by Figure 1 There are two technical solutions shown. The first is to drill an air hole 200 on the ground to guide the air out to the compressed air column in the tunnel 100. Although this solution is effective, it has problems such as a long construction period, a high budget, house demolition and noise nuisance. The second is to lay an air pipe 300 through the return air connection tunnel 400 in the mining area of ​​the mine to guide the air out to the compressed air column in the tunnel 100. In this solution, there is no compressed air column when filling with water for the first time, but the air pipe 300 will also be filled with water when it is filled with water. After that, after the water in the mine is pumped out to the ground reservoir, water will be retained in the air pipe. During the second filling with water, the accumulated water retained in the air pipe will form a water seal, and the compressed air column will be re-formed.

[0005] Therefore, both existing technical means cannot solve the air column problem of abandoned mine underground reservoirs in a low-cost, long-term and stable manner, and cannot maximize the utilization of underground reservoir capacity, thereby reducing the utilization efficiency of abandoned mine resources. Summary of the invention

[0006] The object of the present invention is to provide an air column eliminating device for underground water reservoirs used in abandoned mines to solve the problems raised in the above-mentioned background technology.

[0007] The purpose of the present invention is to provide a method for eliminating air columns in underground water reservoirs used in abandoned mines to solve the problems raised in the above-mentioned background technology.

[0008] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an air column elimination device for underground water reservoirs used in abandoned mines, comprising a three-way pipe fitting with three ports a, b, and c, wherein port a is a vertically downward port of the three-way pipe fitting, and a hollow annular frustum-shaped shell is provided directly below port a, the small end of the shell is sealed with port a, and the large end of the shell is sealed by a mesh tray, a float is provided in the shell, the outer diameter of the float is larger than the inner diameter of port a, and the float will form a linear sealing structure with the inner wall of the shell or port a under the buoyancy; ports b and c of the three-way pipe fitting are respectively connected to ventilation pipes.

[0009] Preferably, the small end of the housing is sealed and connected to port a through threaded fitting.

[0010] Preferably, the float is a hollow float, and the inner surface of the shell is provided with a silicone coating.

[0011] Preferably, a silicone sealing ring is provided on the inner surface of the housing or the sealing fit between the port a and the float.

[0012] Preferably, the float, three-way pipe fitting, shell, mesh tray, and ventilation pipe are all made of stainless steel, and the surface of the float is chrome-plated.

[0013] A method for eliminating air columns in underground water reservoirs for abandoned mines includes the above-mentioned device for eliminating air columns in underground water reservoirs for abandoned mines, and the specific steps are as follows: a ventilation pipe connected to one end of a three-way pipe fitting leads to the highest roof position of a tunnel where an air column will be formed, and a ventilation pipe connected to the other end leads to a return air connection tunnel in a mining area of ​​the abandoned mine, and the ventilation pipe has no bends; the three-way pipe fitting is located at the lowest point of the ventilation pipe, and the port where the three-way pipe fitting is connected to the outer shell is the lowest port and is located in the vertical direction, and the outer shell, the float, and the mesh tray are located directly below the port.

[0014] Beneficial effects: 1. By combining the filling and discharging process of the underground reservoir in the abandoned mine, with the help of the buoyancy of the hollow float, the water path is blocked during filling to ensure the air out of the ventilation pipe, so that the air column in the underground reservoir is effectively eliminated, solving the problem of the reduction of water storage volume caused by the air column in the underground reservoir.

[0015] 2. The float falls into the tray under the action of gravity of the water in the pipe, and the water in the pipe is automatically drained, which solves the problem of water accumulation in some ventilation pipes laid in low-lying areas and cannot be drained, ensuring that the air column is smoothly eliminated when filling with water again.

[0016] 3. It can greatly reduce the construction of ventilation holes and save engineering expenses; it has the advantages of simple design, convenient production and fast installation; at the same time, it greatly improves the ventilation conditions of abandoned mine underground reservoirs, improves the controllability of the underground reservoir filling and discharging process and the utilization efficiency of abandoned mine resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the prior art.

[0018] Figure 2 This is a schematic structural diagram of an underground water reservoir air column elimination device for abandoned mines according to the present application.

[0019] Figure 3 Schematic diagram of the float structure.

[0020] Figure 4 This is a schematic diagram of the structure of the underground water reservoir air column elimination device for abandoned mines in the present application. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below through descriptions of embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention and facilitating its implementation.

[0022] Example 1

[0023] See also Figure 2 Figure 3 As shown, an air column elimination device for underground water reservoirs used in abandoned mines comprises a three-way pipe fitting having three ports a, b and c, wherein port a 1 is a port of the three-way pipe fitting pointing vertically downward, a hollow annular truncated cone-shaped shell 2 is arranged directly below port a, the small end of the shell is sealedly connected to port a, and the large end of the shell is sealed by a mesh tray 3, a floating ball 4 is arranged inside the shell, the outer diameter of the floating ball is larger than the inner diameter of port a, and the floating ball will form a line sealing structure with the inner wall of the shell or port a under buoyancy; ports b and c (5, 6) of the three-way pipe fitting are respectively connected to ventilation pipes 7. In practical applications, a curved pipe structure connector 8 can also be used at the bend.

[0024] As a preferred solution, in order to facilitate disassembly and installation, the small end of the shell is sealed and connected to the a port through threaded fitting.

[0025] As a preferred solution, in order to improve the sealing effect and meet the buoyancy requirements, the float is a hollow float, and the inner surface of the shell is provided with a silicone coating.

[0026] As a preferred solution, in order to improve the sealing effect, Figure 3 As shown, a silicone sealing ring 9 is provided at the sealing fitting position between the inner surface of the housing or the port a and the float.

[0027] As a preferred solution, in order to improve the corrosion resistance of the components, the float, three-way pipe, shell, mesh tray, and ventilation pipe are all made of stainless steel, and the surface of the float is chrome-plated.

[0028] Example 2

[0029] A method for eliminating air columns in underground reservoirs used in abandoned mines, such as Figure 4 As shown, it includes the underground water reservoir air column elimination device 10 for abandoned mines disclosed in Example 1, and the method is as follows: the ventilation pipe 7 connected to one end of the three-way pipe fitting leads to the highest top plate position of the tunnel 100 where the air column will be formed, and the ventilation pipe connected to the other end leads to the return air connection tunnel 400 of the abandoned mine mining area, and the ventilation pipe 7 has no bend; the three-way pipe fitting is located at the lowest point of the ventilation pipe, and the port where the three-way pipe fitting is connected to the outer shell is the lowest port and is located in the vertical direction, and the outer shell, the float, and the mesh tray are located directly below the port.

[0030] The specific steps are as follows:

[0031] (1) First, determine the relevant physical parameters such as the diameter of the ventilation pipe and the flow rate of the fluid in the pipe. According to the head loss formula of the circular pipe fluid flow, the corresponding along-the-line loss and local loss can be calculated. Combined with the maximum energy consumption requirements in the pumped storage power generation process, the total head loss should not be greater than the critical value A. The specific calculation formula is as follows:

[0032]

[0033] In formula (1), h f ——head loss along the way, m;

[0034] h j ——local head loss, m;

[0035] h——total head loss, m;

[0036] l——flow section length, m;

[0037] d——ventilation pipe diameter, m;

[0038] v——average flow velocity of the section, m / s;

[0039] λ——along-the-way resistance coefficient;

[0040] ζ——local resistance coefficient;

[0041] A——Maximum value of total head loss, m. Determined according to specific project requirements.

[0042] According to the relationship between flow rate, flow velocity and cross-sectional area, another set of relationships can be determined:

[0043]

[0044] In formula (2), Q is the flow rate of fluid in the ventilation pipe, m 3 / h.

[0045] The fluid flow rate in the ventilation pipe can be determined according to the engineering design. The corresponding ventilation pipe diameter and cross-sectional average flow velocity can be obtained by combining two sets of equations. The ventilation pipe should be combined with the cross-sectional size of the tunnel, and the pipe diameter should be increased as much as possible to reduce wind resistance and energy loss.

[0046] (2) Secondly, according to the determined diameter of the preset ventilation pipe, select the appropriate three-way pipe fitting, and the diameter of the three-way pipe fitting should match the diameter of the ventilation pipe; the diameter of the three-way branch pipe should be based on the project requirements and reasonably selected under the premise of considering factors such as the cross-sectional size of the tunnel and the difficulty of installation.

[0047] (3) Then, determine the inner and outer diameters of the hollow float and the shell angle based on the buoyancy of the float, air column pressure, float gravity, branch pipe cross-sectional area and other parameters. The shell angle is recommended to be controlled at about 30°. Ensure that the hollow float can be quickly and effectively blocked during the water filling process and can effectively fall into the tray after pumping out water. After the float floats up, perform a force analysis on the float, which should meet the following conditions:

[0048] ρgV≥mg+p0S+f (3)

[0049] In formula (3), ρ is the density of water, 1g / cm 3 ;

[0050] g——acceleration due to gravity, take 9.8m / s 2 ;

[0051] V——The volume of the hollow floating ball submerged in water, m 3 ;

[0052] m——mass of the float, kg;

[0053] p0——air column pressure, take 0.1Mpa;

[0054] S——Cross-sectional area of ​​the branch pipe at the lower end of the tee pipe fitting, m 2 ;

[0055] f——Downward component of friction between the outer shell and the hollow float, N.

[0056] (4) After the components are assembled, high-pressure water flow can be used to test the sealing of the joints of the components to ensure good sealing. Only after the test is passed can it be put into use. When in use, one end of the ventilation pipe is connected to the return air connection tunnel of the abandoned mine mining area, and the other end is deep into the highest roof of the tunnel where an air column will be formed during the water filling process.

[0057] (5) When the underground reservoir is filled with water and the water level reaches a certain elevation, the hollow float floats up with the buoyancy provided by the water pressure to block the waterway and ensure that the air column is discharged through the preset vent pipe until the pipe is full of water and the air column in the water storage space is completely eliminated.

[0058] (6) After the underground reservoir is drained, the accumulated water in the vent pipe will accumulate in the low-lying part of the pipe to form a water resistance. When the water level of the underground reservoir is lower than the inlet elevation of the vent pipe, the water in the pipe causes the hollow float to fall into the tray under the action of gravity, and the accumulated water in the part of the vent pipe laid in the low-lying part is automatically drained to solve the problem of the water resistance formed by the accumulated water in the low-lying part of the vent pipe on the impact of refilling, ensuring that the air column can be eliminated smoothly again when the underground reservoir is refilled with water.

[0059] The present invention is described above by way of example in conjunction with the accompanying drawings. Any non-substantial improvements made by using the method concept and technical solution of the present invention, or any direct application of the above concept and technical solution of the present invention to other occasions without improvement, are all within the protection scope of the present invention.

Claims

1. A method for eliminating air columns in underground reservoirs used in abandoned mines, characterized in that: An air column elimination device for underground water reservoirs used in abandoned mines is used. The air column elimination device for underground water reservoirs used in abandoned mines includes a three-way pipe fitting with three ports a, b, and c, wherein port a is a vertically downward port of the three-way pipe fitting, and a hollow annular truncated cone-shaped shell is provided directly below port a, the small end of the shell is sealed with port a, and the large end of the shell is sealed by a mesh tray, and a floating ball is provided in the shell, the outer diameter of the floating ball is larger than the inner diameter of port a, and the floating ball will form a linear sealing structure with the inner wall of the shell or port a under the buoyancy; ports b and c of the three-way pipe fitting are respectively connected to ventilation pipes; The diameter of the vent pipe is: According to the head loss formula of circular pipe fluid flow, the corresponding along-the-line loss and local loss are calculated. Combined with the maximum energy consumption requirements in the pumped storage power generation process, the total head loss should not be greater than the critical value A; the calculation formula is as follows: In formula (1), h f ——head loss along the way, unit: m; h j ——local head loss, unit: m; h——total head loss, unit: m; l——flow section length, in m; d——ventilation pipe diameter, in m; v——average flow velocity of the cross section, in m / s; λ——along-the-way resistance coefficient; ζ——local resistance coefficient; A——maximum value of total head loss, unit: m; According to the relationship between flow rate, flow velocity and cross-sectional area, another set of relationships can be determined: In formula (2), Q is the flow rate of fluid in the ventilation pipe, in m 3 / h; Among them, the fluid flow rate in the ventilation pipe can be determined according to the engineering design, and the diameter of the ventilation pipe can be obtained by combining equations (1) and (2); The buoyancy requirement of the float is: ρgV≥mg+p0S+f (3) In formula (3), ρ is the density of water, which is 1 g / cm 3 ; g——acceleration due to gravity, take 9.8m / s 2 ; V——The volume of the float submerged in water, in m 3 ; m——mass of the float, in kg; p0——air column pressure, take 0.1Mpa; S——Cross-sectional area of ​​the branch pipe at the lower end of the tee pipe fitting, unit: m 2 ; f——the downward component of the friction between the outer shell and the float, in N; The steps of the method for eliminating air columns from underground water reservoirs in abandoned mines are as follows: a ventilation pipe connected to one end of a three-way pipe fitting leads to the highest roof position of a tunnel where an air column will be formed, and a ventilation pipe connected to the other end leads to a return air connection tunnel in a mining area of ​​the abandoned mine, and the ventilation pipe has no bends; the three-way pipe fitting is located at the lowest point of the ventilation pipe, and the port where the three-way pipe fitting is connected to the outer shell is the lowest port and is located in the vertical direction, and the outer shell, the float, and the mesh tray are located directly below the port.

2. The method for eliminating air columns in underground reservoirs for abandoned mines according to claim 1, characterized in that: The small end of the shell is sealed and connected to port a through threaded fitting, and the opening angle of the shell is 30°.

3. The method for eliminating air columns in underground reservoirs for abandoned mines according to claim 2, characterized in that: The float is a hollow float, and the inner surface of the shell is provided with a silicone coating.

4. A method for eliminating air columns in underground reservoirs for abandoned mines according to claim 2 or 3, characterized in that: A silicone sealing ring is provided at the sealing fitting position between the inner surface of the shell or the port a and the float.

5. The method for eliminating air columns in underground reservoirs for abandoned mines according to claim 4, characterized in that: The float, three-way pipe fitting, shell, mesh tray and vent pipe are all made of stainless steel, and the surface of the float is chrome-plated.

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