Reservoir ventilation system and renovation method of pumped storage power station based on underground tunnel group

Abstract

The present invention discloses a pumped-storage power station reservoir ventilation system and modification method based on an underground tunnel group. The ventilation system includes a regulating pool, vents, and ventilation ducts. The regulating pool is arranged at the lowest point of the tunnel group, with a cylindrical cavity at the bottom and a hemispherical cavity at the top. A regulating pool vent is provided at the top of the regulating pool, and a regulating pool ventilation duct is opened from the regulating pool vent to the ground. The ventilation ducts and vents are arranged in a coordinated manner. The vents are arranged at the tops of each tunnel in the underground tunnel group, and the ventilation ducts are used to connect the vents with the bottom surface. The ventilation ducts include a return air duct in the coal test mining area, a combined machine and rail duct in the coal test mining area, a No. 1 connecting tunnel ventilation duct, a passenger yard ventilation duct, a return air duct, a parking lot ventilation duct, a No. 2 connecting tunnel ventilation duct, an extended tunnel ventilation duct, and a regulating pool ventilation duct. The present invention can achieve timely exhaust and air replenishment functions, stabilize the hydraulic flow state of the underground tunnel group, and improve air quality and ventilation conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of ventilation systems, in particular to a ventilation system for a pumped storage power station reservoir based on an underground tunnel group and a modification method thereof. Background Art

[0002] The construction of a pumped-storage power station using a closed coal mine is an exploration of a new form of pumped storage. This involves renovating, expanding, and supporting the mine's tunnels to serve as the lower reservoir for the pumped-storage power station. Because the highest point of the completed underground tunnels remains below the normal water level, aerodynamic challenges within the complex tunnels are crucial for this project.

[0003] The existing mine tunnel ventilation system uses various power sources to provide sufficient fresh air to various locations underground in the most economical manner, diluting and exhausting various harmful substances. After the underground tunnels were converted into the lower reservoir of a pumped-storage power station, the tunnels filled with water, and the water and gas conditions became complex. The existing ventilation ducts in the underground coal mine tunnels were insufficient to meet the operating conditions of the pumped-storage power station. Therefore, it was necessary to re-arrange the ventilation system after the underground mine tunnels were withdrawn, while at the same time maximizing the use of the existing ventilation ducts to save engineering work and reduce subsequent maintenance costs. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned existing technologies and provide a pumped storage power station reservoir ventilation system and modification method based on an underground tunnel group. The present invention can achieve timely exhaust and air replenishment functions, stabilize the hydraulic flow state of the underground tunnel group, and improve air quality and ventilation conditions.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A pumped storage power station reservoir ventilation system based on an underground tunnel group, the underground tunnel group includes a return air tunnel in the coal test mining area, a combined machine and rail tunnel in the coal test mining area, a No. 1 connecting tunnel, a passenger car yard, a return air tunnel, a parking lot, a No. 2 connecting tunnel and an extension tunnel.

[0007] The ventilation system includes a regulating tank, a vent, and a ventilation duct.

[0008] The regulating pool is arranged at the lowest point of the tunnel group. The shape of the regulating pool consists of two parts, the bottom of which is a cylindrical cavity and the top is a hemispherical cavity. A regulating pool vent is provided on the top of the regulating pool, and a through regulating pool ventilation duct is opened from the regulating pool vent to the ground, which is used for natural air intake and exhaust during the rising or falling of the water level in the regulating pool.

[0009] The ventilation duct is matched with the ventilation opening, the ventilation opening is arranged on the top of each tunnel of the underground tunnel group, and the ventilation duct is used to connect the ventilation opening with the bottom surface.

[0010] The ventilation ducts include the return air duct of the coal test mining area, the machine-rail integrated duct of the coal test mining area, the No. 1 connecting duct, the passenger yard ventilation duct, the return air duct, the parking lot ventilation duct, the No. 2 connecting duct, the extended duct and the regulating pool ventilation duct.

[0011] As a further preferred embodiment of the present invention, three regulating tanks are arranged in parallel, and the horizontal distance between the three regulating tanks is 40m.

[0012] As a further preferred embodiment of the present invention, the three regulating pools are respectively equipped with three regulating pool ventilation ducts, the middle regulating pool ventilation duct is arranged vertically, and the regulating pool ventilation ducts on both sides are inclined toward the middle regulating pool ventilation duct with an inclination angle of 45°. The three regulating pool ventilation ducts are merged into one and pass through to the ground.

[0013] As a further preferred embodiment of the present invention, the ventilation duct is arranged vertically, penetrating and connecting the underground tunnel group and the ground; the diameter of the ventilation duct is 1 m.

[0014] As a further preferred embodiment of the present invention, the regulating pond ventilation duct can be used as a drainage hole and a regulating pond construction channel; when used as a drainage hole, it can realize the drainage function during the maintenance of the lower reservoir of the power station; when used as a regulating pond construction channel, it can enable the reverse well drilling to directly lead to the ground during construction; and it can also serve as a maintenance channel during operation to ensure the stable operation of the system.

[0015] A construction method for a pumped storage power station reservoir ventilation system based on an underground tunnel group comprises the following steps:

[0016] Step 1. Construction of regulating pond:

[0017] Step 1-1. Select the location of the regulating pond and use a raise borer to drill a pilot well from the ground to the location of the underground regulating pond;

[0018] Step 1-2. Replace the reverse drill bit in the underground tunnel, raise the drill bit from underground to the surface, and drill through the pilot shaft;

[0019] Step 1-3. After the pilot shaft is penetrated, the regulating pond is excavated from the ground to the underground. The excavation is carried out by drilling and blasting with a hand drill. The slag is slid from the pilot shaft to the coal mine roadway and transported out.

[0020] Steps 1-4. Utilizing the existing ventilation duct, a hoisting derrick is set up on the ground. A bucket or hoisting platform is pulled by a steel wire rope, and a manual rock drill is used to excavate layer by layer. The slag is then hoisted to the coal mine tunnel and hoisted out.

[0021] Steps 1-5. Transport concrete from the surface to the underground, use steel and wood formwork and concrete to pour the regulating tank;

[0022] Step 2. Reconstruct the existing ventilation ducts: Utilize the existing ventilation ducts in the underground tunnel group. The air entering the ventilation tunnel is delivered to each cavern through the air inlet room, eliminating the need for additional vertical ventilation ducts.

[0023] Step 3. Create a new ventilation duct: For underground tunnel groups that originally had no ventilation duct, select the ventilation opening location on the bottom surface, and drill from the ground into the underground to drill out the ventilation duct.

[0024] The present invention has the following beneficial effects:

[0025] 1. The present invention aims to utilize underground coal mine tunnels as the lower reservoir of a pumped-storage power station and provides a layout plan for its ventilation system, thereby fully utilizing existing buildings, saving excavation work, and reducing subsequent maintenance costs. At the same time, it improves the air quality inside the engineering buildings and stabilizes the water-gas two-phase dynamic characteristics within the complex tunnel group.

[0026] 2. The present invention utilizes the existing ventilation ducts in underground tunnels and, based on the project's characteristics, deploys ventilation ducts at multiple points. Since underground tunnels exiting coal mines are generally located several hundred meters below the ground, the surface temperature has little effect on the internal temperature of the tunnels, making the internal temperature relatively stable. For individual deep-buried integrated tunnels with large overburden, the surface temperature has little effect on the internal temperature of the tunnels, making the internal temperature even more stable. The present invention only requires the rational planning of ventilation ducts and regulating tanks to achieve timely air intake and exhaust, offering inherent advantages over traditional underground ventilation systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a top view of the overall layout of the underground tunnel group of the present invention.

[0028] Figure 2 It is a partial top view schematic diagram of the return air lane ventilation duct in the coal test mining area, the machine and track combined lane ventilation duct in the coal test mining area, and the No. 1 connecting lane ventilation duct of the present invention.

[0029] Figure 3 It is a partial top view schematic diagram of the passenger parking lot ventilation duct of the present invention.

[0030] Figure 4 It is a partial top view schematic diagram of the return air lane ventilation duct of the present invention.

[0031] Figure 5 It is a partial top view schematic diagram of the parking lot ventilation duct of the present invention.

[0032] Figure 6 It is a partial top view schematic diagram of the No. 2 connecting lane ventilation duct and the extended lane ventilation duct of the present invention.

[0033] Figure 7 It is a front view of the regulating tank of the present invention.

[0034] Figure 8 It is a partial top view schematic diagram of the regulating tank ventilation duct of the present invention.

[0035] These include: 11. Return air lane in the coal test mining area; 12. Integrated track and machine lane in the coal test mining area; 13. No. 1 connecting lane; 14. Passenger parking lot; 15. Return air lane; 16. Parking lot; 17. No. 2 connecting lane; 18. Extension lane;

[0036] 20. Equalization tank; 21. Equalization tank vent;

[0037] 40. Ventilation duct; 41. Ventilation duct of the return air lane in the coal test mining area; 42. Ventilation duct of the integrated machine-rail lane in the coal test mining area; 43. Ventilation duct of the No. 1 connecting lane; 44. Ventilation duct of the passenger parking lot; 45. Ventilation duct of the return air lane; 46. Ventilation duct of the parking lot; 47. Ventilation duct of the No. 2 connecting lane; 48. Ventilation duct of the extended lane; 49. Ventilation duct of the regulating tank. DETAILED DESCRIPTION

[0038] The lower reservoir of the pumped-storage power station was rebuilt from a former coal mine tunnel complex. Located 280 meters below ground, it boasts approximately 22 kilometers of usable tunnels and 256,000 cubic meters of usable space. To prevent air stagnation and poor air supply at higher locations, such as tunnel ends, during water storage, ventilation systems were installed at necessary locations within the existing tunnel complex to maintain effective reservoir capacity, ensure water level stability within the tunnel complex, and ensure system safety.

[0039] Therefore, the present invention proposes a pumped storage power station reservoir ventilation system based on an underground tunnel group. Under the existing ventilation duct layout, the air intake and exhaust processes of the regulating tank and the tunnel group system are guaranteed to be smooth. During the water level rise, there is an inconspicuous air stagnation phenomenon at the top of some parallel and circular tunnels, and the dynamic characteristics of the gas phase also change smoothly, which does not affect the safe and stable operation of the system. The underground tunnel group can normally intake and exhaust air under all working conditions. Considering the gentle slope layout and low flow rate of the tunnel group, the ventilation channels in some relatively short branch tunnels can be optimized and cancelled, which can ensure the safe and stable operation of the system.

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific preferred embodiments.

[0041] like Figure 1 As shown, the underground tunnel group includes the return air tunnel 11 of the coal test mining area, the machine-rail integrated tunnel 12 of the coal test mining area, the No. 1 connecting tunnel 13, the passenger car yard 14, the return air tunnel 15, the parking lot 16, the No. 2 connecting tunnel 17 and the extension tunnel 18.

[0042] The ventilation system includes a regulating tank 20 , a vent, and a ventilation duct 40 .

[0043] The ventilation duct 40 is provided in conjunction with the ventilation openings, which are arranged at the top of each tunnel in the underground tunnel group. The ventilation duct 40 is used to connect the ventilation openings with the bottom surface. The ventilation duct 40 is arranged vertically and has a diameter of 1m.

[0044] like Figure 2 As shown in Figure 6, ventilation ducts 40 include a return air lane ventilation duct 41 for the pilot coal mining area, a combined machine and rail lane ventilation duct 42 for the pilot coal mining area, a No. 1 connecting lane ventilation duct 43, a passenger yard ventilation duct 44, a return air lane ventilation duct 45, a parking lot ventilation duct 46, a No. 2 connecting lane ventilation duct 47, an extension lane ventilation duct 48, and a regulating pond ventilation duct 49. These ventilation ducts correspond to the pilot coal mining area return air lane 11, the pilot coal mining area combined machine and rail lane 12, the No. 1 connecting lane 13, the passenger yard 14, the return air lane 15, the parking lot 16, the No. 2 connecting lane 17, the extension lane 18, and the regulating pond 20, respectively, and serve to connect the underground roadway cluster with the surface. Ventilation ducts are provided at the ends of the underground roadway cluster, particularly at the top of the tunnels, to ensure normal air supply and smooth exhaust during rising or falling water levels in the underground roadway cluster, ensuring smooth changes in the roadway cluster water level and full-flow section pressure, facilitating safe and stable operation of the system.

[0045] like Figure 7 and Figure 8 As shown, the regulating tank 20 is located at the lowest point of the underground tunnel complex and can meet the ventilation, water storage, water supply, and pressure regulation requirements of the underground tunnel complex under various operating conditions. The regulating tank 20 consists of two parts: a cylindrical cavity at the bottom and a hemispherical cavity at the top. The top of the regulating tank 20 is provided with a regulating tank vent 21. A regulating tank ventilation duct 49 extends from the regulating tank vent 21 to the ground surface, allowing natural air intake and exhaust during the rising and falling water level of the regulating tank 20.

[0046] In this embodiment, the bottom diameter of the regulating pool cylinder is preferably 10m, the height of the cylinder is 15m, and the diameter of the top hemisphere is 10m.

[0047] Three regulating pools 20 are arranged in parallel, with a horizontal spacing of 40m between them. Each of the three regulating pools 20 is equipped with three regulating pool ventilation ducts 49. In order to reduce the amount of engineering work, the middle regulating pool ventilation duct 49 is arranged vertically, and the regulating pool ventilation ducts 49 on both sides are arranged inclined toward the middle regulating pool ventilation duct 49 at an inclination angle of 45°. The three regulating pool ventilation ducts 49 are combined into one through-hole that reaches the ground.

[0048] The regulating pond ventilation duct 49 can be used as a drainage hole and a construction passage for the regulating pond. Using it as a drainage hole ensures the proper arrangement of drainage pumps and facilitates drainage during maintenance of the lower reservoir of the power station. Using it as a construction passage for the regulating pond allows the reverse borehole to directly reach the surface during construction, and also serves as a maintenance passage during operation to ensure stable operation of the system.

[0049] Based on the above ventilation system, there is a construction method for a pumped storage power station reservoir ventilation system based on an underground tunnel group, comprising the following steps:

[0050] Step 1. Construction of regulating pond:

[0051] Step 1-1. Select the location of the regulating pond and use a raise borer to drill a pilot well from the ground to the location of the underground regulating pond;

[0052] Step 1-2. Replace the reverse drill bit in the underground tunnel, raise the drill bit from underground to the surface, and drill through the pilot shaft;

[0053] Step 1-3. After the pilot shaft is penetrated, the regulating pond is excavated from the ground to the underground. The excavation is carried out by drilling and blasting with a hand drill. The slag is slid from the pilot shaft to the coal mine roadway and transported out.

[0054] Steps 1-4. Utilizing the existing ventilation duct, a hoisting derrick is set up on the ground. A bucket or hoisting platform is pulled by a steel wire rope, and a manual rock drill is used to excavate layer by layer. The slag is then hoisted to the coal mine tunnel and hoisted out.

[0055] Steps 1-5. Transport concrete from the surface to the underground, use steel and wood formwork and concrete to pour the regulating tank;

[0056] Step 2. Reconstruct the existing ventilation ducts: Utilize the existing ventilation ducts in the underground tunnel group. The air entering the ventilation tunnel is delivered to each cavern through the air inlet room, so there is no need to set up additional vertical ventilation ducts.

[0057] Step 3. Build a new ventilation duct: For underground tunnel groups that originally had no ventilation duct, select the ventilation opening location on the bottom surface, and drill from the ground into the underground to drill out the ventilation duct.

[0058] The construction of the regulating pond in step 1 can be carried out in the following manner:

[0059] The regulating pond is located near the lowest point of the underground tunnel system, with the vent at the top of the regulating pond connected to the ground. Excavation of the upper portion of the coal mine tunnel is carried out from the ground using the raise-well method. The pilot shaft is excavated using an LM400 raise-well drilling rig. The drill is positioned above the ground and a 250mm diameter pilot hole is drilled from top to bottom. A reverse drill bit is then installed at the bottom of the well and the hole is expanded upwards to a diameter of 2400mm, reaching the top of the well.

[0060] After the pilot shaft is penetrated, the regulating pool is expanded from top to bottom. The expansion is done by drilling and blasting with a hand drill. The slag slides from the pilot shaft to the coal mine tunnel, and an LK4.1 scraper is used to load the slag onto a 10t mining truck.

[0061] The lower part of the tunnel is excavated using the existing ventilation duct. A hoisting derrick is set up on the ground. The bucket or hoisting plate is pulled by a steel wire rope and a manual YT-28 rock drill is used to excavate layer by layer. The slag is then hoisted to the coal mine tunnel and transported to the hoisting system via a 10t mining truck for discharge.

[0062] Steel and wood formwork is used for concrete pouring. The concrete is transported from the ground to underground, transported to the working face by 10t mining trucks, pumped into the warehouse and poured into the regulating pool.

[0063] In the description of the present invention, it should be understood that the terms "left side," "right side," "upper," "lower," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Terms such as "first" and "second" do not indicate the importance of components and therefore should not be construed as limitations on the present invention. The specific dimensions used in this embodiment are intended only to illustrate the technical solution and do not limit the scope of protection of the present invention.

[0064] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the scope of protection of the present invention.

Claims

1. A pumped storage power station reservoir ventilation system based on an underground tunnel group, the underground tunnel group comprising a return air tunnel (11) in a coal test mining area, a machine-rail integrated tunnel (12) in a coal test mining area, a No. 1 connecting tunnel (13), a passenger parking lot (14), a return air tunnel (15), a parking lot (16), a No. 2 connecting tunnel (17), and an extension tunnel (18); The ventilation system is characterized by comprising a regulating tank (20), a vent, and a ventilation duct (40); The regulating pool (20) is arranged at the lowest point of the underground tunnel group. The regulating pool (20) consists of two parts, the bottom of which is a cylindrical cavity and the top of which is a hemispherical cavity. The top of the regulating pool (20) is provided with a regulating pool vent (21), and a through regulating pool ventilation duct (49) is opened from the regulating pool vent (21) to the ground, which is used for natural air intake and exhaust during the rising or falling process of the water level of the regulating pool (20). The regulating pools (20) are arranged in parallel. The horizontal spacing between the three regulating pools (20) is 40m. The three regulating pools (20) are respectively equipped with three regulating pool ventilation ducts (49). The middle regulating pool ventilation duct (49) is arranged vertically. The regulating pool ventilation ducts (49) on both sides are inclined to the middle regulating pool ventilation duct (49) at an inclination angle of 45°. The three regulating pool ventilation ducts (49) are combined into one through-going to the ground. The ventilation duct (40) is provided in conjunction with the ventilation opening, and the ventilation opening is arranged at the top of each tunnel of the underground tunnel group. The ventilation duct (40) is used to connect the ventilation opening with the bottom surface. The ventilation duct (40) is arranged vertically and connects the underground tunnel group and the ground. The diameter of the ventilation duct (40) is 1m. The ventilation duct (40) includes a return air lane ventilation duct (41) in the coal test mining area, a machine-rail combined lane ventilation duct (42) in the coal test mining area, a No. 1 connecting lane ventilation duct (43), a passenger yard ventilation duct (44), a return air lane ventilation duct (45), a parking lot ventilation duct (46), a No. 2 connecting lane ventilation duct (47), an extension lane ventilation duct (48) and a regulating pond ventilation duct (49). The regulating pond ventilation duct (49) can be used as a drainage hole and a regulating pond construction channel; when used as a drainage hole, it can realize the drainage function during the maintenance of the lower reservoir of the power station; when used as a regulating pond construction channel, it can enable the reverse well drilling to directly reach the ground during construction; and it can also serve as a maintenance channel during operation to ensure the stable operation of the system.

2. The construction method of the pumped storage power station reservoir ventilation system based on the underground tunnel group according to claim 1 is characterized in that: The following steps are involved: Step 1. Construction of regulating pond: Step 1-1. Select the location of the regulating pond and use a raise borer to drill a pilot well from the ground to the location of the underground regulating pond; Step 1-2. Replace the reverse drill bit in the underground tunnel, raise the drill bit from underground to the surface, and drill through the pilot shaft; Step 1-3. After the pilot shaft is penetrated, the regulating pond is excavated from the ground to the underground. The excavation is carried out by drilling and blasting with a hand drill. The slag is slid from the pilot shaft to the coal mine roadway and transported out. Steps 1-4. Utilizing the existing ventilation duct, a hoisting derrick is set up on the ground. A bucket or hoisting platform is pulled by a steel wire rope, and a manual rock drill is used to excavate layer by layer. The slag is then hoisted to the coal mine tunnel and hoisted out. Steps 1-5. Transport concrete from the surface to the underground, use steel and wood formwork and concrete to pour the regulating tank; Step 2. Reconstruct the existing ventilation ducts: Utilize the existing ventilation ducts in the underground tunnel group. The air entering the ventilation tunnel is delivered to each cavern through the air inlet room, so there is no need to set up additional vertical ventilation ducts. Step 3. Build a new ventilation duct: For underground tunnel groups that originally had no ventilation duct, select the ventilation opening location on the bottom surface, and drill from the ground into the underground to drill out the ventilation duct.

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