A gas tunnel lining trolley roof gas accumulation elimination wind deflector

Abstract

The application discloses a gas tunnel lining trolley top gas accumulation eliminating wind deflector, and relates to the technical field of tunnel construction ventilation. The lining trolley has an arched top extending along the longitudinal direction of the tunnel; the wind deflector comprises an arc-shaped flow guide plate and a mounting mechanism for mounting the arc-shaped flow guide plate on the windward side of the trolley top; the windward surface of the arc-shaped flow guide plate and the outer surface of the trolley vault top form a tapered air duct with an air inlet larger than an air outlet; the windward surface deflects part of the tunnel ventilation airflow upward; the deflected airflow accelerates in the tapered air duct and forms an attached airflow on the leeward side of the trolley vault top; the accumulated gas on the trolley top is carried into the main ventilation airflow; the mounting mechanism comprises a hinged seat and a locking part, so that the pitch angle of the flow guide plate can be adjusted and locked. The application utilizes the existing main ventilation airflow, does not increase power, has no electrical components and no electrical spark hidden danger, and can eliminate the ventilation dead zone of the arched interlayer on the trolley top and the gas accumulation.

Description

Technical Field

[0001] This invention relates to the field of ventilation technology in tunnel construction, specifically to a guide plate on the top of a gas tunnel lining trolley to eliminate gas accumulation. Background Technology

[0002] Gas tunnels refer to highway, railway, and hydraulic tunnels that pass through gas-bearing strata. During their construction, gas from the surrounding rock continuously seeps into the tunnel space. The main component of gas is methane, which, if it accumulates locally to an explosive concentration and encounters an ignition source, will cause a gas combustion or explosion accident. Therefore, gas tunnel construction requires the installation of an independent forced ventilation system, where fresh air is forced through ventilation ducts from external fans to the tunnel face and various work areas inside the tunnel to dilute and carry away the gas. During the secondary lining construction stage, a lining trolley needs to be placed inside the tunnel for pouring concrete lining. This lining trolley is an arched steel mold adapted to the tunnel cross-section, large in size, occupying most of the space in the upper section of the tunnel, and requiring a long placement period.

[0003] The existing practices for ensuring ventilation safety in the lining trolley section mainly rely on controlling the average wind speed and return air gas concentration in the tunnel cross section according to the specifications. This is achieved by increasing the total air volume of the forced ventilation and increasing the cross section wind speed to dilute the gas. In some projects, local ventilation fans or flexible air ducts are added near the trolley to supplement the airflow to the trolley working face.

[0004] However, between the outer surface of the arched top of the lining trolley and the inner wall of the tunnel's initial support or already poured lining, there exists a long, narrow, arc-shaped interlayer space extending longitudinally along the tunnel. When the main ventilation airflow in the tunnel flows along the cross-section, it encounters this massive obstacle of the trolley. The airflow mainly passes through the vehicle and pedestrian spaces on both sides and at the bottom of the trolley, and the aforementioned arched interlayer is precisely within the low-speed flow shadow zone formed by the surrounding airflow, where the airflow speed is very low and almost stagnant. At the same time, methane, being less dense than air, naturally rises and accumulates at the top of the space under the influence of gravity. The combination of these two factors makes the arc-shaped interlayer at the top of the lining trolley a double-layered area where ventilation is difficult to reach and methane easily accumulates. The methane concentration can easily rise silently here, even exceeding the safety limit. Furthermore, fixed methane monitoring probes are often not placed within this interlayer, making this hidden danger difficult to detect in a timely manner. Simply increasing the total air volume mainly increases the wind speed in the main channel, which has limited improvement on the dead zone in the arch formed by the geometric flow around the tunnel, and significantly increases energy consumption. Adding local fans and ducts requires additional power, electricity, and wiring. The trolley moves frequently with the construction cycle, and the ducts cannot easily follow the trolley. In addition, the gas environment inside the tunnel has high requirements for the explosion-proof of electrical equipment, resulting in a heavy maintenance burden.

[0005] Current ventilation designs mostly focus on whether the overall air volume and average wind speed of the tunnel cross-section meet the specifications, but neglect the airflow accessibility of the local space in the arched interlayer at the top of the lining trolley. Meeting the overall ventilation standards of the tunnel cross-section does not mean that every local space is effectively swept by airflow; the interlayer at the top of the trolley is precisely a geometric blind spot bypassed by the main ventilation airflow. In fluid mechanics, it is a known phenomenon that when airflow bypasses a blunt body, a low-speed backflow zone is formed on its leeward side and within its concave cavity. However, in the field of ventilation design for lining trolley sections, this local dead zone is generally not actively eliminated as an independent treatment target.

[0006] Therefore, how to proactively eliminate the ventilation dead zone and remove the accumulated gas in the arc-shaped interlayer at the top of the lining trolley without adding an extra power source, without relying on simply increasing the total air volume, and while being able to adapt to the frequent movement of the lining trolley, has become a technical problem to be solved in the ventilation safety of gas tunnel lining construction. Summary of the Invention

[0007] The technical problem to be solved by this invention is: in the secondary lining construction of gas tunnels, the arc-shaped interlayer between the outer surface of the arched top of the lining trolley and the inner wall of the tunnel is located in the low-speed zone of the main ventilation airflow, where gas easily accumulates and is difficult to remove effectively. This invention provides a guide plate on the top of the lining trolley of a gas tunnel to eliminate gas accumulation, so as to actively remove the gas accumulated in the arc-shaped interlayer by utilizing the existing main ventilation airflow of the tunnel without adding an additional power source or relying on simply increasing the total air volume.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0009] This invention provides a guide plate for eliminating gas accumulation on the top of a gas tunnel lining trolley. The lining trolley has an arched top extending longitudinally along the tunnel. The guide plate includes an arc-shaped guide plate and an installation mechanism for mounting the arc-shaped guide plate on the windward side of the top of the lining trolley. The arc-shaped guide plate extends longitudinally along the lining trolley, with its windward surface facing the direction of the tunnel ventilation airflow. The windward surface of the arc-shaped guide plate and the outer surface of the arched top of the lining trolley form a gradually narrowing air duct. The inlet cross-section of the gradually narrowing air duct along the direction of the incoming airflow is larger than the outlet cross-section. The windward side of the deflector plate deflects a portion of the tunnel ventilation airflow upwards. The deflected airflow is accelerated within the narrowing duct and forms a wall-adhering airflow that flows along the outer surface of the arched top of the lining trolley towards the leeward side. This wall-adhering airflow carries the gas accumulated on the top of the lining trolley and merges it into the main tunnel ventilation airflow. The mounting mechanism includes a hinge seat and a locking element. The arc-shaped deflector plate is hinged to the arched top of the lining trolley via the hinge seat and can pitch and rotate about the axis of the hinge axis along the longitudinal direction of the lining trolley. The locking element locks the arc-shaped deflector plate at a selected pitch angle.

[0010] Optionally, the windward surface of the arc-shaped guide plate is a smooth, outwardly convex arc surface, the concave surface of the arc surface faces the outer surface of the arched top of the lining trolley, and the cross-sectional line of the windward surface along the direction of the incoming flow is a circular arc or a parabola.

[0011] Optionally, the cross-sectional area of ​​the outlet of the tapering duct is one-third to two-thirds of the cross-sectional area of ​​the inlet, and the gap between the edge of the outlet of the arc-shaped guide plate and the outer surface of the arched top of the lining trolley is 20 mm to 80 mm.

[0012] Optionally, the air outlet edge of the arc-shaped guide plate is provided with a plurality of turbulence teeth arranged at intervals along the longitudinal direction of the lining trolley, and a turbulence gap is formed between two adjacent turbulence teeth; further, the turbulence teeth are triangular teeth that are inclined toward the leeward side, and the tooth tips of adjacent turbulence teeth are alternately deflected toward the two sides of the top of the lining trolley.

[0013] Optionally, the hinge seat includes a support fixed to the arched top of the lining trolley and a hinge shaft, and the locking member includes an arc-shaped guide groove fixedly connected to the arc-shaped guide plate and a locking bolt passing through the arc-shaped guide groove, wherein the center of the arc-shaped guide groove is located on the axis of the hinge shaft.

[0014] Optionally, the arc-shaped guide plate is composed of multiple plate units sequentially spliced ​​along the longitudinal direction of the lining trolley. Each plate unit is connected to the arched top of the lining trolley via its respective installation mechanism, and the pitch angle of each plate unit can be adjusted independently.

[0015] Optionally, the concave surface of the arc-shaped guide plate is provided with multiple guide ribs extending along the incoming flow direction, and the multiple guide ribs divide the gradually narrowing air duct into multiple sub-air ducts arranged laterally along the lining trolley.

[0016] Optionally, the arc-shaped guide plate is made of anti-static and flame-retardant material, and the arc-shaped guide plate has flexible sealing skirts on the longitudinal edges of both sides near the top of the lining trolley.

[0017] The present invention also provides a gas tunnel lining trolley, including a trolley body having an arched top extending longitudinally along the tunnel, and further including a wind guide plate as described in any of the above claims, wherein the wind guide plate is mounted on the windward side of the arched top of the trolley body.

[0018] The beneficial effects of this invention are as follows: The air guide plate works by utilizing the existing forced main ventilation airflow within the tunnel, without consuming any power or containing any electrical components. This eliminates the need for power supply and wiring for local fans and ducts, as well as the explosion-proof hazards of electrical equipment in a gas environment, and eliminates the risk of electrical sparks. The arc-shaped air guide plate and the outer surface of the arched top of the lining trolley form a gradually narrowing air duct with a large inlet and a small outlet, which introduces and accelerates the airflow that originally flowed around the sides of the trolley, forming a high-speed wall-attached airflow that adheres to the top surface of the trolley. The airflow actively sweeps away the arc-shaped interlayer that has long been in a dead zone and is prone to gas accumulation; the turbulence teeth at the air outlet further create disturbance at the corners of the arch and lining joint, compensating for the insufficient cleaning of corner dead zones by the wall-mounted airflow; the pitch angle of the guide plate can be adjusted around the hinge seat and mechanically locked by the locking device, which makes it easy to adjust the upward and acceleration degree of the airflow for different tunnel cross sections and different main airflow velocities; the entire guide plate has a simple structure and can be moved with the lining trolley without repeated deployment, with little interference to the existing construction process. Attached Figure Description

[0019] Figure 1 is a schematic diagram of a tunnel cross section with the air guide plate installed on the top of the lining trolley according to an embodiment of the present invention; Figure 2 is a cross-sectional schematic diagram of the working principle of the air guide plate provided in the embodiment of the present invention along the longitudinal direction of the tunnel; Figure 3 is a partially enlarged schematic diagram of the arc-shaped guide plate and its installation mechanism provided in an embodiment of the present invention; Figure 4 is a partially enlarged schematic diagram of the turbulence teeth at the air outlet end of the arc-shaped guide plate provided in an embodiment of the present invention; Figure 5 is a cross-sectional view of the arc-shaped guide vane in Figure 2 along the AA direction.

[0020] Reference numerals: 1—lining trolley; 2—initial tunnel support; 3—arc-shaped interlayer; 10—arc-shaped guide plate; 11—windward face; 12—concave face; 13—guide rib; 14—sub-ventilation duct; 20—installation mechanism; 21—hinged seat; 211—support; 212—hinged shaft; 22—locking element; 221—arc-shaped guide groove; 222—locking bolt; 30—gradually narrowing ventilation duct; 31—air inlet; 32—air outlet; 40—turbulence teeth; 41—turbulence notch; 50—flexible sealing skirt. Detailed Implementation

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In the absence of conflict, the technical features of the various embodiments of the present invention can be combined with each other. It should be noted that the angles, dimensions, flow velocities, and other values ​​given herein, unless otherwise specified, are exemplary values ​​listed to facilitate understanding of the present invention, and those skilled in the art can make corresponding adjustments according to the tunnel cross-section, gas outburst situation, and ventilation conditions. In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the windward side, leeward side, upper, lower, longitudinal, etc., is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, and does not indicate that the structure referred to must have a specific orientation, and therefore should not be construed as a limitation of the present invention. The upward flow of airflow referred to herein means that the airflow is guided to deviate from the original mainstream direction and flow towards the side of the trolley arch; the sweeping refers to the process of the airflow flowing along the outer surface of the trolley arch and carrying away the gas trapped above it.

[0022] To facilitate understanding, several terms used in this article will be explained first. The "incoming flow direction" refers to the overall flow direction of the main ventilation airflow supplied by the tunnel forced ventilation system along the longitudinal direction of the tunnel towards the tunnel face or return air side; the side facing the incoming flow direction is called the windward side, and the side away from the incoming flow direction is called the leeward side. For tunnels with forced ventilation, the main ventilation airflow is forced from the tunnel entrance through the ventilation duct towards the tunnel face, and then returns to the tunnel entrance along the tunnel; the incoming flow direction in the trolley section is the direction of this return airflow. For tunnels with exhaust ventilation, fresh air flows along the tunnel towards the tunnel face; the incoming flow direction in the trolley section is the direction of this fresh airflow. The "flow shadow zone" refers to the low-speed return flow area formed in the arc-shaped interlayer between the arched top of the trolley and the inner wall of the tunnel when the main ventilation airflow bypasses the large obstacle of the lining trolley. The airflow velocity in this area is much lower than the average wind speed of the tunnel cross-section, approaching stagnation, and is a place where gas easily accumulates; therefore, this article also refers to it as the ventilation dead zone. The term "converging air duct" refers to the flow channel formed by the windward side of the arc-shaped guide plate and the outer surface of the arched top of the lining trolley, where the cross-section gradually decreases along the direction of the incoming flow. The upstream end facing the incoming flow is the air inlet, and the downstream end near the top surface of the trolley is the air outlet. The cross-section of the air inlet is larger than that of the air outlet. Due to fluid continuity, the velocity of the same airflow increases as the cross-section decreases when passing through the converging air duct, thus accelerating the airflow. The term "wall-adhering airflow" refers to the high-speed airflow that, after being accelerated by the converging air duct, adheres to the outer surface of the arched top of the lining trolley. Because the airflow tends to adhere to the convex arc surface, this wall-adhering airflow can continuously flow towards the leeward side along the arc-shaped contour of the trolley's top, thereby sweeping across the arc-shaped interlayer at the top of the trolley. The pitch angle refers to the angle between the chord line of the cross-sectional profile of the arc-shaped guide plate (i.e., the line segment connecting its inlet and outlet edges in the plane) and the tangent line of the cross-section of the outer surface of the arched top of the lining trolley in the plane, within a vertical plane perpendicular to the longitudinal direction of the lining trolley. A larger pitch angle results in a stronger interception and upward lifting effect of the arc-shaped guide plate on the incoming airflow. Those skilled in the art will understand that the definition of the "chord line" is based on a cross-section perpendicular to the longitudinal direction, and the corresponding geometric relationship of the overall arc-shaped plate in three-dimensional space can be deduced accordingly. The arc-shaped guide plate extends longitudinally with a uniform cross-section, and the pitch angle is the same at each cross-section. The turbulence teeth refer to the tooth-like structures located at the outlet edge of the arc-shaped guide plate, used to create localized disturbances in the airflow; the gap between two adjacent turbulence teeth is called a turbulence gap. The guide ribs refer to the strip-shaped protrusions that are located on the concave surface of the arc-shaped guide plate and extend along the direction of the incoming flow. Multiple guide ribs divide the gradually narrowing air duct into multiple parallel air ducts along the trolley, which are called sub-air ducts.

[0023] Referring to Figure 1, Figure 1 shows the tunnel cross-section when the air guide plate of an embodiment of the present invention is installed on the top of the lining trolley. A lining trolley 1 for pouring secondary lining is placed inside the gas tunnel. The lining trolley 1 has an arched top that adapts to the tunnel cross-section and extends longitudinally along the tunnel. Between the outer surface of its arched top and the inner wall of the initial support 2 of the tunnel, there is an arc-shaped interlayer 3 extending longitudinally along the tunnel with a crescent-shaped cross-section. The lining trolley 1 occupies most of the space in the upper section of the tunnel. The main ventilation airflow of the tunnel mainly passes through the space between the sides and bottom of the lining trolley 1 and the inner wall of the tunnel. The arc-shaped interlayer 3 is located in the flow shadow area formed by the surrounding flow, where the airflow is almost stagnant. In addition, methane rises upwards, and gas easily accumulates in the arc-shaped interlayer 3. The air guide plate of this embodiment includes an arc-shaped guide plate 10 and an installation mechanism 20. The arc-shaped guide plate 10 is installed on the windward side of the arched top of the lining trolley 1 via the installation mechanism 20. The arc-shaped guide vane 10 extends along the transverse width of the tunnel trolley arch, covering the section in the center of the arch surface where gas is most likely to accumulate, and can also extend to cover the areas on both sides of the arch surface where it meets the tunnel inner wall. For tunnels with different cross-sectional shapes such as three-centered circles and horseshoe shapes, the transverse profile of the arc-shaped guide vane 10 can be adapted to the corresponding arc surface shape of the tunnel trolley arch. The number of arc-shaped guide vanes 10 can be one, laid out transversely along the windward side of the tunnel trolley arch, or multiple vanes can be arranged side by side along the transverse side of the arch surface, each covering a different transverse section of the arch surface.

[0024] Referring to Figure 2, which illustrates the working principle of the air guide plate when cut along the longitudinal direction of the tunnel, i.e., along the direction of the incoming flow. The arc-shaped air guide plate 10 extends longitudinally along the lining trolley 1, and its longitudinal length can be equivalent to the longitudinal length of the lining trolley 1, or it can only cover a section on the windward side of the lining trolley 1. When the arc-shaped air guide plate 10 only covers a section on the windward side of the lining trolley 1, the wall-adhering airflow ejected from its outlet 32 ​​can continue to flow along the top surface of the trolley through the section not covered by the air guide plate under the action of inertia, thereby sweeping a longer interlayer with a smaller air guide plate size; when the uniformity of sweeping the entire length of the interlayer is required to be high, the longitudinal length of the arc-shaped air guide plate 10 can be close to the longitudinal length of the lining trolley 1, or multiple plate units can be arranged longitudinally to sweep in relay. The longitudinal length of the arc-shaped air guide plate 10 can generally be one-third to the full length of the longitudinal length of the lining trolley 1. The arc-shaped guide vane 10 has a windward surface 11 facing the direction of the incoming flow and a concave surface 12 facing away from the direction of the incoming flow and towards the outer surface of the arched top of the lining trolley 1. The edge of the air inlet of the arc-shaped guide vane 10 is raised away from the top surface of the trolley, leaving a large opening between it and the top surface of the trolley, while the edge of the air outlet is close to the top surface of the trolley, leaving only a small gap between it and the top surface of the trolley. This allows the windward surface 11 to both deflect and intercept a portion of the incoming flow upwards and form a gradually narrowing air duct 30 with a large inlet and a small outlet between it and the outer surface of the top surface of the trolley. As shown by the arrows in Figure 2, the incoming flow comes from the windward side. A portion of the flow near the top of the trolley is lifted by the windward surface 11 and enters the air inlet 31. After being accelerated along the narrowing air duct 30, it is ejected from the air outlet 32, forming a wall-adhering airflow that flows along the outer surface of the trolley's arch towards the leeward side. Meanwhile, most of the incoming flow near the bottom of the tunnel still passes through the sides and bottom of the trolley, and the two flows re-converge on the leeward side of the trolley.

[0025] There are several ways to implement the profile of the arc-shaped guide vane 10. In one implementation, the windward surface 11 is a smooth, convex arc surface, and its cross-sectional line along the direction of the incoming flow is a circular arc. The radius of the circular arc can be 0.5 to 2 times the radius of curvature of the outer surface of the arched top of the lining trolley 1 at the installation point, so that the curvature of the arc-shaped guide vane 10 is coordinated with the top surface of the trolley. In another implementation, the cross-sectional line is a parabola, with the opening of the parabola facing the leeward side, making the arc-shaped guide vane 10 steeper at the air inlet end and gentler at the air outlet end. The airflow tends to be ejected parallel to the top surface of the trolley at the air outlet end, thereby reducing airflow separation at the air outlet. In yet another implementation, the cross-sectional line is a combination of a circular arc and a straight line segment, that is, the windward end of the arc-shaped guide vane 10 is a circular arc segment, and the air outlet end is a straight line segment that tends to be parallel to the top surface of the trolley. All of the above-mentioned profiles can deflect the incoming airflow upwards on the windward surface 11 and form a gradually narrowing airflow channel 30 with the top surface of the trolley. Among them, the arc profile is easy to process, while the parabolic profile is beneficial for maintaining the smoothness of the airflow at the outlet under higher main wind speeds. The surface of the arc-shaped guide plate 10 can be a smooth plate surface, or several shallow guide grooves can be set on the windward surface 11 in the direction of the incoming flow to guide the airflow smoothly upwards along the windward surface 11. The windward edge of the arc-shaped guide plate 10 can also be turned up to form a collecting leading edge, which is slightly opened in the direction of the incoming flow to increase the windward receiving area and guide more airflow smoothly into the air inlet 31. The arc-shaped guide plate 10 should have sufficient rigidity to resist the scouring of the airflow and deformation due to its own weight. For this purpose, a reinforcing rib extending along the direction of the incoming flow or along the longitudinal direction of the lining trolley 1 can be provided on one side of its concave surface 12. This reinforcing rib can also be combined with the guide rib 13 described later. When the arc-shaped guide plate 10 is made of steel plate, its plate thickness can be 2 mm to 6 mm. When fiber reinforced composite material is used, the plate thickness can be appropriately increased to ensure rigidity.

[0026] Referring to Figure 2, the windward surface 11 of the arc-shaped guide plate 10 and the outer surface of the arched top of the lining trolley 1 form a narrowing air duct 30. The upstream end of the narrowing air duct 30 along the incoming flow direction is the air inlet 31, and the downstream end is the air outlet 32. The flow cross-section of the air inlet 31 is larger than that of the air outlet 32. In one implementation, the flow cross-sectional area of ​​the air outlet 32 ​​is one-third to two-thirds of the flow cross-sectional area of ​​the air inlet 31. When this ratio is small, the airflow acceleration ratio is large, and the velocity of the airflow adhering to the wall is high, but the flow resistance increases accordingly, and the airflow rate introduced into the narrowing air duct 30 decreases. Conversely, when this ratio is large, the opposite occurs. Therefore, it can be selected within the above range according to the main wind speed of the tunnel to ensure that the airflow adhering to the wall has both sufficient velocity and sufficient flow rate. In one implementation, the gap between the outlet edge of the arc-shaped guide plate 10 and the outer surface of the arched top of the lining trolley 1 is 20 mm to 80 mm. If the gap is too small, the outlet 32 ​​is easily affected by local unevenness or attachments on the top surface of the trolley, reducing the effective flow area. If the gap is too large, the adhesion effect of the wall-mounted airflow is weakened, and the flow velocity increase is limited. The height of the inlet 31 is usually 1.5 to 4 times the gap of the outlet 32. The inlet 31 opens towards the direction of the incoming flow, and its orientation can be roughly consistent with the longitudinal direction of the tunnel to face the main ventilation airflow. When the direction of the main ventilation airflow in the tunnel is slightly deflected due to the position of the air duct outlet, the installation position of the arc-shaped guide plate 10 on the arch of the trolley can be adjusted to make the inlet 31 face the incoming flow as directly as possible to improve the efficiency of receiving the incoming flow. The edge of the arc-shaped guide vane 10 at the air outlet 32 ​​can be roughly parallel to the top surface of the trolley, so that the direction of the ejected airflow adhering to the wall is as close as possible to the top surface of the trolley. The edge of the air outlet can also be set to be finely adjustable so that the gap size of the air outlet 32 ​​can be adjusted on site according to the actual adhesion of the airflow adhering to the wall. The tapering effect of the tapering air duct 30 can be formed by the curvature of the arc-shaped guide vane 10 itself, as described above, or by the arc-shaped guide vane 10 being placed at an angle relative to the top surface of the trolley. That is, the arc-shaped guide vane 10 is in an inclined posture with the air inlet end higher and the air outlet end lower, and the distance between its windward surface 11 and the top surface of the trolley gradually decreases along the direction of the incoming flow. Under the premise of roughly maintaining the flow rate, the velocity of the wall-adhering airflow at the air outlet 32 ​​is approximately proportional to the ratio of the cross-sectional area of ​​the air inlet 31 to that of the air outlet 32. Therefore, reducing the gap of the air outlet 32 ​​or increasing the height of the air inlet 31 can increase the velocity of the wall-adhering airflow. The height of the air inlet 31 is mainly determined by the pitch angle of the arc-shaped guide plate 10. The larger the pitch angle, the higher the windward surface 11 is raised, the larger the air inlet 31 is, and the more airflow is intercepted and lifted. In actual selection, a balance should be achieved between the velocity and flow rate of the wall-adhering airflow, so that the wind speed in the interlayer reaches the value required to prevent gas accumulation, without significantly increasing the obstruction of the main ventilation airflow due to an excessively large pitch angle.The accelerating effect of the gradually narrowing air duct 30 on the airflow is similar to that of the contraction section of a Venturi tube. However, this invention does not aim to generate a high negative pressure at the throat, but rather focuses on obtaining a directional airflow with a certain velocity and flow rate close to the top surface of the trolley at the air outlet 32. Since the arc-shaped guide plate 10 only intercepts a small portion of the main ventilation airflow near the top of the trolley, and most of the remaining main ventilation airflow still passes normally from the sides and bottom of the trolley, this invention has a very small increase in the overall ventilation resistance of the tunnel and will not significantly affect the total air volume of the tunnel cross section.

[0027] Referring to Figure 3, the mounting mechanism 20 is used to mount the arc-shaped guide plate 10 onto the arched top of the lining trolley 1 and to make the pitch angle of the arc-shaped guide plate 10 adjustable. The mounting mechanism 20 includes a hinge seat 21 and a locking member 22. The hinge seat 21 includes a support 211 fixed to the arched top of the lining trolley 1 and a hinge shaft 212. The air outlet end of the arc-shaped guide plate 10 is hinged to the support 211 via the hinge shaft 212, thereby enabling pitch rotation about the axis of the hinge shaft 212 along the longitudinal direction of the lining trolley 1. The locking member 22 includes an arc-shaped guide groove 221 fixedly connected to the arc-shaped guide plate 10 and a locking bolt 222 passing through the arc-shaped guide groove 221 and screwed into the support 211. The center of the arc-shaped guide groove 221 is located on the axis of the hinge shaft 212. When the locking bolt 222 is loosened, the arc-shaped guide plate 10 can rotate around the hinge axis 212 to change the pitch angle, and the locking bolt 222 slides along the arc-shaped guide groove 221; after rotating to the selected pitch angle, the locking bolt 222 is tightened, that is, the arc-shaped guide plate 10 is locked at that pitch angle. The adjustable range of the pitch angle can be from 15 degrees to 60 degrees. In order to facilitate quick reading and reproduction of the pitch angle on site, an angle scale can be set on the support 211, and a matching indicator mark can be set on the arc-shaped guide plate 10; the two ends of the arc-shaped guide groove 221 can be provided with limiting structures to limit the upper and lower limits of the adjustable pitch angle, so as to avoid the adjustment exceeding the reasonable range. The mounting mechanism 20 can also employ other purely mechanical structures capable of angle adjustment and locking, such as replacing the arc-shaped guide groove 221 and locking bolt 222 with a ratchet and pawl mechanism, or setting multiple positioning holes distributed circumferentially on the support 211 and using pins to position the arc-shaped guide plate 10 at a selected pitch angle; these structures do not contain any electrical components. In cases where frequent pitch angle adjustments are required, a manual worm gear mechanism can also be installed on the mounting mechanism 20, which drives the arc-shaped guide plate 10 to slowly pitch and lock by rotating the handwheel, facilitating precise adjustment and automatically maintaining the angle after adjustment. The mounting mechanism 20 and the arched top of the lining trolley 1 can be connected by welding, bolts, or clamps, allowing the guide plate to be detachably installed on different lining trolleys and move with the trolley when it moves, eliminating the need for repeated installation within the tunnel. Multiple sets of installation mechanisms 20 can be arranged at intervals along the longitudinal direction of the lining trolley 1 to jointly support the same arc-shaped guide plate 10. The supports 211 of each set of installation mechanisms 20 are fixed to the outer surface of the arch of the lining trolley 1 along the same longitudinal straight line to ensure the installation stability of the arc-shaped guide plate 10 over a large longitudinal length. Spring washers or double nuts can be installed between the locking bolts 222 and the supports 211 to prevent loosening due to vibration.When the air guide plate needs to be used between different models of lining trolleys 1, the support 211 can be designed as a clamp type, which is clamped onto the longitudinal steel beam of the trolley arch and fastened with bolts, so that welding is not required on the trolley, making it easy to disassemble and fine-tune the position.

[0028] Referring to Figure 4, the edge of the air outlet of the arc-shaped guide plate 10 is provided with multiple turbulence teeth 40 arranged longitudinally along the lining trolley 1, with turbulence gaps 41 formed between adjacent turbulence teeth 40. After the wall-attached airflow ejected from the air outlet 32 ​​is alternately divided by the turbulence teeth 40 and the turbulence gaps 41, it forms an alternating strong and weak airflow in the downstream direction. Adjacent strong and weak airflows mutually attract each other, generating lateral disturbance, thereby stirring up the dead corners at the corners of the arch and lining joints where the wall-attached airflow is not easily swept directly. In one implementation, the turbulence teeth 40 are triangular teeth tilted towards the leeward side, with the tilt direction consistent with the direction of the wall-attached airflow to reduce resistance; the tooth height of the turbulence teeth 40 is 5 mm to 30 mm, and the ratio of the tooth width of the turbulence teeth 40 to the width of the turbulence gaps 41 is 1:1 to 3:1. In one implementation, the tips of adjacent turbulence teeth 40 alternately veer to both sides along the transverse direction of the lining trolley 1 (i.e., alternately veer to the left and right sides towards the trolley arch, see [reference]). Figure 4 The airflow from adjacent turbulence teeth 40 is deflected to both sides, enhancing lateral mixing and corner coverage. The turbulence teeth 40 can be rectangular, trapezoidal, or wavy; when corner disturbance is not critical, the turbulence teeth 40 can be omitted, and only the wall-mounted airflow ejected from the outlet 32 ​​sweeps across the interlayer. It should be noted that the corners of the joint between the arch and the tunnel wall or the cast-in-place lining are often where the wall-mounted airflow velocity is lowest and methane is most likely to remain. The turbulence teeth 40 divide the continuous wall-mounted airflow into alternating jets of varying strength along the longitudinal direction, creating a lateral velocity difference between adjacent jets and mutual entrainment, forming small-scale vortices near the corners, thereby drawing in the methane trapped at the corners and carrying it away with the main flow. The smaller the tooth pitch and the more numerous the turbulence teeth 40, the finer the turbulence, but the flow resistance also increases accordingly. The appropriate tooth pitch can be selected according to the gas residue in the corner. Generally, the tooth pitch between adjacent turbulence teeth 40 is 30 mm to 100 mm.

[0029] Referring to Figure 5, which is a cross-sectional view of the arc-shaped guide plate 10 in Figure 2 along the AA direction, the concave surface 12 of the arc-shaped guide plate 10 is provided with multiple guide ribs 13 extending along the incoming flow direction (i.e., the longitudinal direction of the lining trolley 1). The multiple guide ribs 13 are arranged at intervals along the transverse direction of the lining trolley 1 (i.e., the width direction of the trolley arch), dividing the gradually narrowing air duct 30 into multiple parallel sub-air ducts 14. That is to say, each sub-air duct 14 is arranged transversely along the lining trolley, and each sub-air duct 14 extends longitudinally (in the incoming flow direction). The guide ribs 13 serve two purposes: firstly, they constrain the airflow along the incoming direction and suppress longitudinal crossflow and diffusion within the converging duct 30, ensuring that the airflow along the wall of each sub-duct 14 more evenly covers different longitudinal positions on the top surface of the trolley; secondly, the edges of the guide ribs 13 away from the concave surface 12 can abut or approach the top surface of the trolley, providing support and maintaining the gap for the arc-shaped guide plate 10. The number of guide ribs 13 can be 2 to 10, and the spacing between adjacent guide ribs 13 can be 100 mm to 400 mm. When the arc-shaped guide plate 10 is composed of multiple plate units, guide ribs 13 can be installed on the concave surface 12 of each plate unit; the guide ribs 13 located at the joints of plate units can be appropriately heightened and thickened, also serving as longitudinal baffles between plate units to reduce crossflow between adjacent plate units in the converging duct 30. The cross-section of the guide rib 13 can be rectangular, triangular or trapezoidal, and its edge facing the top surface of the trolley can be made of flexible material such as rubber so that it can conform to the undulation of the top surface of the trolley when it is against it, thus reducing wear.

[0030] The curved guide plate 10 may have flexible sealing skirts 50 on its longitudinal edges near the top of the lining trolley 1. These flexible sealing skirts 50 seal the lateral gap between the curved guide plate 10 and the outer surface of the arched top of the lining trolley 1, reducing airflow leakage from both sides into the converging air duct 30 and converting more airflow into wall-attached airflow that sweeps across the interlayer. The flexible sealing skirts 50 may be made of rubber strips, silicone strips, or brush strips and conform to the contours of the trolley's top surface. The curved guide plate 10 may be made of steel plate, aluminum alloy plate, or fiber-reinforced composite material; considering the safety requirements of a gas environment, the curved guide plate 10 is preferably made of antistatic and flame-retardant materials, or has an antistatic and flame-retardant coating on its surface to avoid static electricity accumulation and spark generation. The arc-shaped guide plate 10 and the installation mechanism 20 are constantly exposed to the humid tunnel environment, and their metal surfaces can be hot-dip galvanized or sprayed with anti-corrosion coating. The concave surface 12 of the arc-shaped guide plate 10 and the narrowing air duct 30 may accumulate concrete splashes or dust after long-term use; these can be cleaned periodically to maintain the flow cross-section of the narrowing air duct 30. Furthermore, the guide plate of this invention is not only applicable to lining trolleys for secondary lining, but also to other large construction equipment in tunnel construction that also has an arched top and a similar arc-shaped interlayer between its top and the tunnel wall, such as waterproofing trolleys and the top shielding structure of inverted arch trestle bridges. The arc-shaped guide plate and installation mechanism can be installed on the windward side of its top to eliminate gas accumulation at the top. The air guide plate of the present invention is applicable to both forced ventilation tunnels and exhaust ventilation tunnels. In exhaust ventilation, the incoming flow direction is the direction of airflow from the tunnel cross section to the return air inlet, and the windward side of the arc-shaped air guide plate 10 is arranged accordingly facing the incoming flow direction.

[0031] To accommodate uneven interlayer heights or prevailing wind speeds along the tunnel's longitudinal direction, the arc-shaped guide plate 10 can be constructed by sequentially splicing multiple plate units along the longitudinal direction of the lining trolley 1. Each plate unit is connected to the arched top of the lining trolley 1 via its own installation mechanism 20, and the pitch angle of each plate unit can be adjusted independently. Thus, when the height of the arc-shaped interlayer 3 differs at different longitudinal positions of the lining trolley 1, each plate unit can be adjusted to a pitch angle appropriate for that location. Similarly, when gas outbursts are strong in a certain longitudinal section, the corresponding plate unit can be adjusted to a larger pitch angle to enhance the wall-adhering airflow at that location. Small longitudinal gaps can be left between the plate units, or they can be overlapped with flexible connectors to allow for independent rotation.

[0032] The following describes the working process of the air guide plate of the present invention in eliminating gas accumulation on the top of the lining trolley. Referring to Figure 2, the main ventilation airflow supplied by the tunnel forced ventilation system flows in the direction of incoming flow. When the air guide plate is not installed, the main ventilation airflow mainly passes through the sides and bottom of the lining trolley 1 after encountering it. The arc-shaped interlayer 3 at the top of the trolley is in the flow shadow area, and the airflow is almost stagnant. At the same time, methane, which is less dense than air, rises and accumulates in the arc-shaped interlayer 3, causing the gas concentration at this location to gradually increase. Since the probe is usually not placed in this interlayer, the increase in concentration is not easily detected in time.

[0033] After the air guide plate of this invention is installed, when the main ventilation airflow reaches the windward side of the lining trolley 1, a portion of the airflow near the trolley's arch is intercepted and deflected upward by the windward surface 11 of the arc-shaped guide plate 10, entering the inlet 31 of the gradually narrowing air duct 30 formed by the windward surface 11 and the outer surface of the trolley's arch. Since the cross-sectional area of ​​the gradually narrowing air duct 30 gradually decreases along the incoming flow direction, according to the principle of fluid continuity, under the premise of a constant flow rate, the flow velocity is inversely proportional to the cross-sectional area. Therefore, this portion of the airflow is continuously accelerated during its flow through the gradually narrowing air duct 30, reaching a flow velocity at the outlet 32 ​​that is significantly higher than that at the inlet. After the airflow is ejected from the outlet 32, it adheres to the convex arc surface of the trolley's arch, forming a wall-adhering airflow that flows along the outer surface of the trolley's arch towards the leeward side. The tendency of the airflow to adhere to the convex arc surface without immediately detaching allows the high-speed airflow ejected from the outlet 32 ​​to extend continuously along the arc-shaped contour of the trolley's arch, preventing it from diffusing and being lifted off the trolley's top surface immediately upon exiting the outlet. It is precisely through this adhesion characteristic that the high-speed airflow generated by the converging duct 30 can be effectively constrained near the trolley's top surface, continuously sweeping across the arc-shaped interlayer 3. This wall-adhering airflow continuously sweeps across the arc-shaped interlayer 3 at a speed higher than the average wind speed of the tunnel cross-section, entraining and carrying away the gas that was originally accumulated there and rising upwards. As it flows towards the leeward side, it is carried out of the arc-shaped interlayer 3, merges into the main ventilation airflow of the tunnel, and is then discharged, thereby eliminating gas accumulation and ventilation dead zones within the arc-shaped interlayer 3. After leaving the interlayer on the leeward side of the trolley, the gas-laden airflow merges and mixes with the main ventilation airflow passing through the sides and bottom of the trolley. The gas is diluted to below a safe concentration and discharged from the tunnel with the main ventilation airflow. Due to the continuous sweeping of the wall-laden airflow, the gas in the arc-shaped interlayer 3 does not have time to accumulate, thus fundamentally eliminating the potential for gas accumulation in this area. Therefore, this invention does not inject additional airflow or power into the system. Instead, it reorganizes the portion of airflow that originally flowed around the trolley from the side and below, having no effect on the dead zone of the arch, into a high-speed wall-laden airflow that sweeps directionally through the interlayer, effectively reusing the existing airflow. From a fluid dynamics perspective, when the main ventilation airflow bypasses the blunt body of the lining trolley 1, boundary layer separation occurs within the concave cavity of the trolley's arch, forming a low-speed recirculation zone, i.e., the flow shadow zone at the arc-shaped interlayer 3. This area is separated from the mainstream by a shear layer, making it difficult for the momentum of the mainstream to be transferred to the depths of the interlayer. Therefore, simply increasing the mainstream airflow mainly increases the wind speed in the main channels on both sides of the trolley, with limited improvement to the interior of the interlayer. The arc-shaped guide plate 10 of this invention is equivalent to setting an active flow collection and guiding structure at the entrance of the interlayer, confining the airflow that would otherwise flow away from the side of the trolley between the windward surface 11 and the top surface of the trolley, accelerating it within the converging air duct 30, and then sending it along the top surface of the trolley into the depths of the dead zone, thereby achieving a significant increase in the wind speed within the interlayer with minimal structural cost.It should also be noted that methane, due to its lower density than air, forms a gas stratification at the top of the arc-shaped interlayer 3, with the concentration increasing closer to the arch. The wall-mounted airflow of the present invention flows precisely along the outer surface of the arch, and its position of action coincides with the enrichment location of the gas stratification, which can directly flush and destroy the gas stratification. This is one of the reasons why the present invention is particularly effective against gas accumulation at the top of the trolley.

[0034] As the airflow along the top surface of the tunnel trolley flows, it sweeps most thoroughly over the central area of ​​the arch, while the sweeping is relatively weaker at the corners where the arch meets the tunnel wall or the lining. Therefore, the airflow ejected from the outlet 32 ​​is first divided by the turbulence teeth 40 at the outlet end of the arc-shaped guide plate 10, forming a longitudinally alternating, mutually entraining airflow downstream. This disturbs the aforementioned corners and dead zones, further suppressing gas stagnation at these corners. The airflow disturbed by the turbulence teeth 40 gradually merges with the main ventilation airflow on the leeward side of the tunnel trolley. Throughout this process, the gas within the arc-shaped interlayer 3 is continuously carried, diluted, and discharged, preventing long-term stagnation in any one area. When the arc-shaped guide plate 10 is equipped with guide ribs 13, the airflow from each sub-duct 14 covers different longitudinal strips on the top surface of the tunnel trolley, ensuring that the entire arc-shaped interlayer 3 is swept relatively evenly along the longitudinal direction. If the transverse span of the arch of the lining trolley 1 is large, arc-shaped guide plates 10 can be set in the middle and on both sides of the transverse arch to allow the airflow along the wall to cover different sections of the transverse arch and avoid sweeping blind spots in areas other than the middle of the transverse arch.

[0035] When the tunnel cross-sectional dimensions and main airflow velocity change, the locking bolt 222 can be loosened, and the arc-shaped guide plate 10 can be rotated around the hinge shaft 212 to adjust its pitch angle. This changes the interception amount and upward lift of the incoming airflow on the windward side 11, thereby adjusting the airflow flow and acceleration entering the gradually narrowing air duct 30, so that the airflow against the wall matches the current working conditions. Then, the locking bolt 222 is tightened to lock it. For example, when the interlayer height is large or the main airflow velocity is low, the pitch angle can be appropriately increased to intercept and lift more airflow; when the interlayer height is small or the main airflow velocity is high, the pitch angle can be appropriately decreased to avoid excessive resistance. The entire adjustment process is a purely mechanical operation. Since the guide plate of this invention works by utilizing the existing main ventilation airflow of the tunnel, it does not have its own power source such as a fan, nor does it contain electrical components. It does not increase the burden of power supply and wiring, nor does it have the explosion-proof problem of electrical equipment in a gas environment. Compared with the solution of adding local fans and ducts to the trolley, this invention has no electrical spark hazard, is convenient to move with the trolley, and has low maintenance costs. For example, under conditions where the main wind speed is approximately 1.0 m / s and the interlayer height is approximately 0.5 m, the pitch angle can be adjusted to approximately 40 degrees to intercept and lift more airflow. However, when the main wind speed increases to approximately 1.8 m / s and the interlayer height is approximately 0.3 m, the pitch angle can be reduced to approximately 20 degrees to avoid excessive resistance while still creating sufficient wall-hugging airflow within the interlayer. The pitch angle adjustment of the air guide plate can be stepless or multi-stage stepped, facilitating repeated fine-tuning on-site based on the measured interlayer wind speed.

[0036] Example Taking the secondary lining construction of a high-gas highway tunnel as an example, a specific application of the air guide plate of this invention will be fully described. The tunnel is a one-way, two-lane tunnel with an excavation cross-section span of approximately 12 meters and a height of approximately 9 meters. Forced ventilation is used, and the average wind speed at the tunnel cross-section where the lining trolley 1 is parked is approximately 1.2 meters per second. The radial height of the arc-shaped interlayer 3 between the outer surface of the arched top of the lining trolley 1 and the inner wall of the initial support 2 is approximately 0.4 meters at the center of the arch. Without the air guide plate, the measured wind speed at the center of the arch of the arc-shaped interlayer 3 is less than 0.2 meters per second. Before the work team moved the trolley, a gas concentration of 0.8% by volume was detected at this location, close to the alarm value.

[0037] The wind guide plate of this invention is installed on the windward side of the arched top of the lining trolley 1. The arc-shaped guide plate 10 is arranged longitudinally along the tunnel, with a longitudinal length of 4 meters. The windward surface 11 adopts an arc shape with a cross-sectional arc radius of 0.6 meters. The initial pitch angle of the arc-shaped guide plate 10 is adjusted to 35 degrees by the installation mechanism 20 and locked with locking bolt 222. At this time, the windward surface 11 of the arc-shaped guide plate 10 and the outer surface of the trolley arch form a gradually narrowing air duct 30. The radial height of the air inlet 31 is about 0.18 meters, the gap between the air outlet 32 ​​and the top surface of the trolley is 0.05 meters, and the flow cross-sectional area of ​​the air outlet 32 ​​is about half of the flow cross-sectional area of ​​the air inlet 31. The outlet end of the arc-shaped guide plate 10 is provided with triangular turbulence teeth 40 with a tooth height of 15 mm, and the concave surface 12 is provided with 4 guide ribs 13 extending along the incoming flow direction, with a spacing of about 0.2 meters between adjacent guide ribs 13. During installation, first fix the supports 211 of each installation mechanism 20 along the longitudinal straight line on the windward side of the arch of the lining trolley 1, and then install the arc-shaped guide plate 10 on the supports 211 via the hinge shaft 212. After initially adjusting the pitch angle, tighten the locking bolts 222. After the ventilation is turned on, use an anemometer to measure the wind speed at the arch of the arc-shaped interlayer 3, and adjust the pitch angle accordingly until the wind speed at that location stabilizes at more than 1.0 m / s.

[0038] During ventilation, a portion of the main ventilation airflow near the trolley's arch is lifted by the windward surface 11 and introduced into the converging air duct 30. Within the converging section, the airflow is accelerated from approximately 1.2 m / s at the inlet to approximately 2.4 m / s at the outlet, and then ejected from the outlet 32, forming a wall-adhering airflow that flows along the trolley's top surface. This wall-adhering airflow sweeps across the arc-shaped interlayer 3, and the measured wind speed at the center of the arch increases from less than 0.2 m / s to approximately 1.5 m / s, exceeding the 1.0 m / s usually required to prevent gas accumulation. The gas concentration at the arch of the arc-shaped interlayer 3 decreases from 0.8% by volume to below 0.2% by volume. After being disturbed by the turbulence teeth 40 at the corners of the arch and lining joints, no significant gas retention is observed. When the tunnel transitioned to the lining construction of the smaller emergency stopping zone, the pitch angle of the arc-shaped guide vane 10 was reduced from 35 degrees to 25 degrees to accommodate the reduced interlayer height, while still maintaining an air velocity of no less than 1.0 m / s within the interlayer. In contrast, under the same tunnel and main ventilation conditions, if the guide vane was not installed and the total forced ventilation volume was increased by approximately 20%, the air velocity at the arch of the arc-shaped interlayer 3 was still less than 0.5 m / s, resulting in limited improvement in gas concentration and a significant increase in ventilation energy consumption. This demonstrates that for the geometrically dead zone of the trolley arch, the localized airflow diversion method of this invention is more effective and economical than simply increasing the total air volume.

[0039] In another application scenario, for a high-gas railway tunnel with a larger cross-section, the longitudinal length of the lining trolley 1 is relatively long, and the height of the arc-shaped interlayer 3 varies at different longitudinal positions. This railway tunnel is a single-track tunnel, with the lining trolley 1 having a longitudinal length of approximately 12 meters, and the height of the arch interlayer 3 varying between 0.3 and 0.5 meters. The average wind speed at the trolley's parking location is approximately 1.0 meter per second. The arc-shaped guide plate 10 is divided into three plate units along the tunnel's longitudinal direction, each plate unit having a longitudinal length of approximately 4 meters. These units are installed on the windward side of the arch of the lining trolley 1 via their respective installation mechanisms 20. The plate unit with stronger gas outburst and higher interlayer near the working face is adjusted to a 40-degree pitch angle, the middle plate unit to 30 degrees, and the plate unit further away from the working face with a lower interlayer to 22 degrees. This ensures that the wall-following airflow from the three gradually narrowing air ducts 30 is adapted to the interlayer height of their respective sections, thereby achieving a relatively uniform sweeping wind speed of not less than 1.0 m / s along the entire arc-shaped interlayer 3. A longitudinal gap of approximately 20 mm is left between each plate unit to allow for independent rotation. The wall-following airflow from adjacent plate units connects at the gaps, preventing the formation of new stagnation zones.

[0040] In another application scenario, the arc-shaped guide plate 10 does not use a curved profile, but is instead a flat plate placed at an angle relative to the top surface of the trolley to form a gradually narrowing air duct 30. In this case, the arc-shaped guide plate 10 is a flat plate with its inlet end raised and its outlet end lowered. The distance between the windward surface 11 and the outer surface of the trolley arch gradually decreases from approximately 0.2 meters to approximately 0.05 meters along the direction of the incoming flow, similarly forming a gradually narrowing air duct 30 with a large inlet and a small outlet. Those skilled in the art will understand that this flat plate solution can essentially be considered an extreme case of the aforementioned arc-shaped guide plate (radius of curvature tending to infinity). Its windward surface and the top surface of the trolley also form a gradually narrowing air duct and generate wall-mounted airflow, thus also falling under the implementation of the inventive concept. This method has the simplest structure, is easy to process on-site, and is suitable for tunnels with relatively regular cross-sections and where the requirements for airflow smoothness are not high; the installation mechanism 20, the turbulence teeth 40, etc., are set up in the same way as in the aforementioned embodiments.

[0041] Field monitoring of the aforementioned high-gas highway tunnel embodiment showed that, before and after installing the air guide plate of the present invention, the wind speed at the arch of the arc-shaped interlayer 3 increased from less than 0.2 meters per second to about 1.5 meters per second, and the gas concentration decreased from about 0.8% by volume to below 0.2% by volume. Furthermore, the air guide plate moves together with the lining trolley 1, requiring no additional power supply or separate maintenance. Compared with the active solution of adding local fans and ducts to the trolley, the present invention eliminates the dead zone at the arch while avoiding the introduction of electrical equipment and its explosion-proof and wiring problems in the gas environment, resulting in superior safety and economy. The values ​​in the above embodiments are merely examples and do not constitute a limitation of the present invention.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ventilation deflector on the top of a gas tunnel lining trolley for eliminating gas accumulation, the lining trolley having an arched top extending longitudinally along the tunnel, characterized in that, The air guide plate includes an arc-shaped air guide plate and an installation mechanism for mounting the arc-shaped air guide plate on the windward side of the top of the lining trolley; The arc-shaped guide plate extends longitudinally along the lining trolley, with its windward surface facing the direction of the tunnel ventilation airflow. The windward surface of the arc-shaped guide plate and the outer surface of the arched top of the lining trolley form a gradually narrowing air duct. The cross-section of the air inlet of the gradually narrowing air duct along the direction of the incoming flow is larger than the cross-section of the air outlet. The windward side of the arc-shaped guide plate deflects a portion of the tunnel ventilation airflow upward. The deflected airflow is accelerated in the narrowing air duct and forms a wall-adhering airflow that flows along the outer surface of the arched top of the lining trolley towards the leeward side. The wall-adhering airflow carries the gas accumulated on the top of the lining trolley and merges it into the main ventilation airflow of the tunnel. The installation mechanism includes a hinge seat and a locking element. The arc-shaped guide plate is hinged to the arched top of the lining trolley via the hinge seat and can pitch and rotate about the axis of the hinge axis along the longitudinal direction of the lining trolley. The locking element locks the arc-shaped guide plate at a selected pitch angle.

2. The air guide plate according to claim 1, characterized in that, The windward surface of the arc-shaped guide plate is a smooth, outwardly convex arc surface, and the concave surface of the arc surface faces the outer surface of the arched top of the lining trolley. The cross-sectional line of the windward surface along the direction of the incoming flow is a circular arc or a parabola.

3. The air guide plate according to claim 1, characterized in that, The cross-sectional area of ​​the outlet of the tapered air duct is one-third to two-thirds of the cross-sectional area of ​​the inlet. The gap between the air outlet edge of the arc-shaped guide plate and the outer surface of the arched top of the lining trolley is 20 mm to 80 mm.

4. The air guide plate according to claim 1, characterized in that, The air outlet edge of the arc-shaped guide plate is provided with a plurality of turbulence teeth arranged at intervals along the longitudinal direction of the lining trolley, and a turbulence gap is formed between two adjacent turbulence teeth.

5. The air guide plate according to claim 4, characterized in that, The turbulence teeth are triangular teeth that are inclined toward the leeward side, and the tips of adjacent turbulence teeth are alternately bent toward the two sides of the top of the lining trolley.

6. The air guide plate according to claim 1, characterized in that, The hinge seat includes a support fixed to the arched top of the lining trolley and a hinge shaft. The locking element includes an arc-shaped guide groove fixedly connected to the arc-shaped guide plate and a locking bolt passing through the arc-shaped guide groove. The center of the arc-shaped guide groove is located on the axis of the hinge shaft.

7. The air guide plate according to claim 1, characterized in that, The arc-shaped guide plate is composed of multiple plate units sequentially spliced ​​along the longitudinal direction of the lining trolley. Each plate unit is connected to the arched top of the lining trolley via its respective installation mechanism, and the pitch angle of each plate unit can be adjusted independently.

8. The air guide plate according to claim 1, characterized in that, The concave surface of the arc-shaped guide plate is provided with multiple guide ribs extending along the incoming flow direction. These multiple guide ribs divide the gradually narrowing air duct into multiple sub-air ducts arranged laterally along the lining trolley.

9. The air guide plate according to claim 1, characterized in that, The arc-shaped guide plate is made of anti-static and flame-retardant materials; The arc-shaped guide plate has flexible sealing skirts on its longitudinal edges near the top of the lining trolley. The flexible sealing skirts provide contact sealing for the lateral gap between the arc-shaped guide plate and the outer surface of the arched top of the lining trolley.

10. A gas tunnel lining trolley, comprising a trolley body having an arched top extending longitudinally along the tunnel, characterized in that, It also includes a wind deflector as described in any one of claims 1 to 9, wherein the wind deflector is mounted on the windward side of the arched top of the trolley body by a mounting mechanism.

Images