Special-shaped wind bin type ventilation technology for long-distance tunnel construction

Abstract

The invention relates to the field of tunnel construction ventilation, and discloses a special-shaped air bin type ventilation technology for long-distance tunnel construction. The core of the technology is an integral special-shaped air bin, an adjustable baffle structure is arranged, and the air pressure of each fan can be accurately regulated and controlled by flexibly changing the position of a baffle, so that the efficient operation of the fan is ensured. In order to solve the problem of wind robbing during cooperative operation of two fans in a main tunnel of a tunnel, the technology effectively solves the problems of energy loss and uneven ventilation caused by airflow turbulence through the design of a trapezoidal air duct and a scientific airflow guide mechanism. The inclined shaft tunnel is divided into an upper air supply channel and a lower air exhaust channel through a partition plate, a reserved air hole is formed in the upper end of the partition plate and used for guiding fresh air into the trapezoidal air bin, a negative pressure area cannot appear in the air bin, and therefore a draught fan in the air bin operates normally. The technology provides an efficient, energy-saving and stable solution for long-distance tunnel ventilation, and has remarkable practical value and wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel construction ventilation, and particularly relates to a special-shaped air bin ventilation system and method for long-distance tunnel construction. This technology is particularly applicable to the construction ventilation of large underground projects such as railway tunnels, highway tunnels, and municipal tunnels, and especially provides an innovative solution to the ventilation problem of extra-long tunnels over 5 kilometers. Through the synergistic effect of the integral special-shaped air bin structure and the intelligent control system, the high efficiency, stability, and energy conservation of long-distance tunnel construction ventilation are realized. Background Art

[0002] Traditional ventilation methods have gradually revealed many limitations when facing long-distance tunnels. For conventional forced ventilation, as the ventilation distance increases, the wind pressure loss increases sharply, resulting in a significant reduction in ventilation efficiency and being unable to effectively deliver fresh air to the working face deep in the tunnel. Moreover, the complex terrain and changing geological conditions of long-distance tunnels make it difficult to evenly control the air flow distribution. The differences in cross-sectional shapes and surrounding rock characteristics in different sections are likely to cause local ventilation dead zones, further weakening the ventilation effect. In addition, from the perspective of energy consumption, traditional ventilation often needs to be equipped with high-power fans to make up for the insufficient wind pressure caused by the long distance. The long-term high-power operation not only consumes a large amount of electric energy, increases the operation cost, but also goes against the current development concept of energy conservation and emission reduction. The air bin ventilation technology emerged precisely under such urgent needs, aiming to specifically overcome a series of problems in long-distance tunnel ventilation, achieve efficient, energy-saving, and uniform and stable ventilation effects, and ensure the smooth progress of tunnel projects.

[0003] The special-shaped air bin ventilation technology has achieved a key breakthrough on the basis of the air bin ventilation. It innovatively introduces an adjustable baffle structure, and flexibly adjusts the wind pressure size by means of the baffle to accurately adapt to the different ventilation requirements of each section of the tunnel, ensuring stable and reasonable wind pressure distribution. Particularly prominent is that the shape of this air bin effectively solves the problem of air grabbing that is extremely easy to occur when multiple fans work together. By optimizing the air duct design and the air flow guiding mechanism, each fan performs its own duties and synergistically increases efficiency, avoiding energy loss and uneven ventilation caused by air flow disorder. As an advanced optimization solution, the special-shaped air bin ventilation provides strong support for overcoming a series of problems in long-distance tunnel ventilation, aiming to achieve efficient, energy-saving, and uniform and stable ventilation results, and laying a solid foundation for the smooth implementation of tunnel projects. Summary of the Invention

[0004] The present invention aims to solve the problem of insufficient ventilation efficiency caused by uneven air flow distribution, low collaborative efficiency of multiple fans, and excessive energy consumption in long-distance tunnel construction, specifically including:

[0005] 1. How to effectively reduce the wind pressure loss during long-distance air supply;

[0006] 2. How to eliminate the air flow interference phenomenon when multiple fans operate in parallel;

[0007] 3. How to achieve precise dynamic regulation of the air volume in different sections of the tunnel;

[0008] 4. How to improve the energy utilization efficiency of the ventilation system;

[0009] 5. How to ensure the complete isolation of fresh air and polluted air.

[0010] To achieve the above objectives, the present invention patent provides the following technical solutions:

[0011] This special-shaped air chamber ventilation technology includes the optimized design of the trapezoidal air chamber structure, intelligent dynamic air pressure regulation, and double-cycle air flow separation technology.

[0012] Furthermore, the special-shaped air chamber structure adopts a centrally symmetric trapezoidal configuration, and its hypotenuse forms a certain diversion angle with the tunnel axis, replacing the traditional rectangular air chamber. The ratio of the lengths of the upper and lower bases of the trapezoidal structure is 1:1.618 (the golden ratio). Through the optimized design of fluid dynamics, a streamline-shaped diversion layer (surface roughness Ra ≤ 0.8 μm) is laid on the inner surface of the hypotenuse to effectively inhibit the air flow separation phenomenon.

[0013] Furthermore, multiple axial fans are arranged in the trapezoidal air chamber, and they are arranged in an interval staggered pattern along the longitudinal axis of the air chamber. The staggered spacing is not less than 1.2 times the diameter of the fan to ensure uniform air flow distribution and eliminate the "air robbing" phenomenon.

[0014] Furthermore, the adjustable air pressure plate adopts an aviation-grade aluminum alloy composite plate (thickness 10 - 15 mm), and realizes continuous displacement through a motor-driven slide rail device. The displacement accuracy is controlled within the range of ±5 mm; the slide rail device includes two parallel precision linear guide rails, and the surface of the guide rails is coated with a wear-resistant ceramic layer (friction coefficient ≤ 0.05) to ensure the positioning accuracy and stability of the air pressure plate.

[0015] Furthermore, the double-cycle air flow separation technology includes an upper air supply duct and a lower exhaust duct. The upper air supply duct is responsible for transporting fresh air to the tunnel working face through the trapezoidal air chamber mechanism; the lower exhaust duct is formed by being separated by an airtight partition. The partition adopts a three-layer composite structure (1.5 mm galvanized steel plate + 50 mm polyurethane foam layer + 0.2 mm nano-ceramic coating), and the airtightness reaches the EN12101-3 standard CLASS 4 level, and the air leakage rate is less than 3%. The polluted air is discharged after being treated by a cyclone dust removal device (dust removal efficiency ≥ 98%) and an activated carbon filtration module. Description of the Drawings

[0016] In order to more clearly illustrate the technical cases of the implementation of the present invention patent, the following briefly introduces the drawings required for the description of the invention patent.

[0017] Figure 1 This is a schematic plan view of the special-shaped air duct warehouse of the present invention, showing the trapezoidal air duct warehouse structure, the layout of the fans, and the connection method of the air ducts.

[0018] Figure 2 This is a cross-sectional view of the system's horizontal passage, clearly showing the structural relationship between the upper air supply duct and the lower exhaust duct.

[0019] Figure 3 This is a three-dimensional structure diagram of the special-shaped air duct warehouse, visually presenting the three-dimensional shape and spatial layout of the air duct warehouse.

[0020] Figure 4 This is a detailed drawing of the slide rail device, including the rail structure, the motor drive system, and the positioning mechanism.

[0021] In the figure: 1 - trapezoidal air duct warehouse structure, 2 - fan, 3 - air duct, 4 - adjustable air pressure plate, 401, 402, 403, 404 - air pressure plate adjustment nodes, 5 - position of the reserved air hole in the cross tunnel, 6 - partition, 7 - exhaust duct, 8 - slide rail device, 9 - motor. Detailed implementation manners

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] Refer to Figure 1 、 Figure 3 , through the synergistic effect of the bevel diversion angle and the golden ratio in the airflow optimization design of the trapezoidal air duct warehouse, the uniformity of the airflow velocity field is increased by 42%, and the turbulence intensity is reduced to below 0.12. The staggered layout of the fans combined with the diversion layer design can also increase the multi-fan synergy efficiency to over 95%, completely solving the airflow interference problem of traditional parallel fans.

[0024] Refer to Figure 3 、 Figure 4 , regarding the regulation mechanism of the dynamic wind pressure, when the ratio of the air volume required in the large mileage section (Q1) to the air volume required in the small mileage section (Q2) ≥ 1.5, the control system drives the air pressure plate to move in the direction of the small mileage by a displacement amount By adjusting the cross-sectional area ratio of the air duct, the wind pressure on the large mileage side is increased by 25% - 35%, and the power of the inclined shaft fan is reduced by 18% - 22%. During the displacement of the air pressure plate, the guide rail gap is strictly controlled within 3 - 5 mm to avoid air leakage.

[0025] Refer to Figure 2 , a gradient negative pressure field (-150 Pa ± 10 Pa) is constructed in the exhaust duct (7) to ensure complete isolation of fresh air and polluted air.

[0026] Implementation manners of the present invention:

[0027] Step 1: Installation of the air chamber and airtightness detection. Prefabricate a trapezoidal air chamber according to the design parameters. After on-site assembly, use the smoke tracing method to detect the air leakage rate (≤3%).

[0028] Step 2: Fan configuration and coordinated testing. Install an axial flow fan (2) in the trapezoidal air chamber, fix it, with an alternating spacing of 1.5 times the fan diameter, and achieve dynamic adjustment of the air volume by ±5% through a frequency conversion controller.

[0029] Step 3: Dynamic regulation of the air pressure plate. Initialize the air pressure plate (4) to the central axis of the slide rail (8), drive the air pressure plate to move according to the real-time monitoring data, and the gap after locking is ≤3mm.

[0030] Step 4: Joint debugging of the double-circulation system. Start the jet fan in the exhaust passage, adjust the negative pressure to -150Pa ± 10Pa, and verify the air flow separation effect through a CO sensor and a dust detector.

[0031] Technical effects

[0032] Compared with the prior art, the present invention has the following significant advantages:

[0033] 1. Greatly improved ventilation efficiency: The trapezoidal air chamber structure improves the uniformity of the air flow velocity field by 42%, reduces the turbulence intensity to below 0.12, and extends the effective air supply distance to 8 - 10 kilometers.

[0034] 2. Significantly reduced energy consumption: The adjustable system can reduce the overall energy consumption of the ventilation system by 25% - 30%, and the annual electricity cost savings can reach the million - yuan level.

[0035] 3. High degree of automation: The system is equipped with an intelligent monitoring platform, which can achieve remote control and adaptive adjustment, reducing manual intervention.

[0036] 4. Obvious improvement in air quality: The double - circulation system can ensure a significant reduction in the dust concentration and CO concentration during excavation.

[0037] Through the above - mentioned implementation methods, the special - shaped air chamber type ventilation system of the present invention can exert the best performance in long - distance tunnel construction, providing a safe, efficient, and energy - saving ventilation guarantee for engineering construction.

Claims

1. A special-shaped air storage type ventilation system for long-distance tunnel construction, comprising a special-shaped air storage structure, a fan assembly, a ventilation pipeline and a control device, characterized in that: The ventilation duct is partitioned by an adjustable partition (6) to form an upper air supply duct and a lower exhaust air duct (7). A reserved air outlet (5) is provided at the upper end of the partition to send fresh air from the cross tunnel into the trapezoidal air bin, so that the fan in the air bin operates. The fan assembly includes axial fans (2) symmetrically arranged in the trapezoidal air bin and forms a double-cycle ventilation network through flexible air ducts (3). The control device includes a wind pressure regulating plate (4) that can be displaced along the slide rail device (8). The slide rail device (8) is arranged in parallel in the intervals of 401 - 402 and 403 - 404 at the bottom of the air bin and is equipped with a motor drive system (9).

2. The special-shaped air storage bin type ventilation system according to claim 1, wherein: The inclined baffle of the trapezoidal air bin structure forms a certain diversion angle with the tunnel axis. The two axial fans (2) are arranged in an interval staggered pattern along the longitudinal axis of the air bin, and the staggered interval is not less than 1.2 times the diameter of the fan. A streamlined diversion layer is laid on the inner surface of the trapezoidal inclined baffle.

3. The special-shaped air storage bin type ventilation system according to claim 1, wherein: The wind pressure regulating plate (4) has a motor drive system (9) and can perform bidirectional continuous displacement along the slide rail device (8) within the intervals of 401 - 402 and 403 - 404, and the displacement accuracy is controlled within the range of ±5 mm. When the air volume required in the large mileage section of the tunnel increases, the regulating plate can be displaced to the critical point (401) on the small mileage side, so that the wind pressure of the corresponding side fan (2) is increased by 25% - 35%.

4. The special-shaped air storage bin type ventilation system according to claim 1, characterized in that: The slide rail device includes two precision linear guide rails (8) arranged in parallel. The surface of the guide rail is provided with a wear-resistant ceramic coating, and a motor (9) is configured on the guide rail to drive the movement of the regulating plate. When the two fans supply air in cooperation, the wind pressure regulating plate (4) is positioned at the central axis position of the guide rail, and the gap between the two sides of the plate body and the guide rail is controlled within the range of 3 - 5 mm.

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