Method for relieving pneumatic effect of tunnel

Abstract

The invention discloses a method for relieving the pneumatic effect of a tunnel. The method comprises the following steps that (1) a first draught fan is arranged in the tunnel; (2) arranging a buffer chamber in the tunnel; (3) roughening the inner surface of the tunnel and the upper surface of a ballast bed in the tunnel; and (4) arranging a sound absorption structure in the tunnel. The first draught fan is arranged in the tunnel, the first draught fan can disturb airflow in the tunnel, and therefore micro-air-pressure waves generated when a train passes through the tunnel are weakened; the buffer chamber is arranged in the tunnel, the head wave gradient of pressure waves can be slowed down, the pressure waves caused when a train enters the tunnel are disturbed, then micro-air-pressure waves and sonic boom are relieved, and the pressure relief and buffer effects are achieved; the inner surface of the tunnel and the upper surface of the ballast bed are roughened, and micro-pressure waves in the tunnel can be relieved and interfered through the design; the sound absorption structure can absorb sound, reduce noise and relieve micro air pressure waves and sonic boom.

Description

Technical Field

[0001] The present invention relates to the field of railway tunnels, and more specifically to a method for alleviating the aerodynamic effect of tunnels. Background Art

[0002] When a train enters a tunnel, when the train speed is high enough, a sonic boom phenomenon will be triggered in a long tunnel. Similar to when a person blows a flute or other tubular objects, when the flow velocity (train speed) is constant, the thicker the tube (the larger the cross-sectional area of the tunnel), the less likely it is to make a sound, and when the tube is long enough (the tunnel is long enough to reach the corresponding critical tunnel length), a sound will be emitted. The faster the air flow velocity (the faster the train speed), the easier it is to make a sound.

[0003] The conventional tunnel pressure relief and buffering method is to set a buffering structure at the entrance of the tunnel or set a special buffering chamber in the tunnel. The above structure has a certain degree of buffering effect. However, as the running speed of the train increases, for existing tunnels without the above buffering structure, or for tunnels with the above buffering structure, as the train speed increases, the buffering effect decreases. Adding a buffering structure to existing tunnels is relatively complex in construction and limited in structural layout, and the result is that the improvement of the buffering effect is not so significant.

[0004] Therefore, how to provide a method for alleviating the aerodynamic effect of tunnels to overcome the above problems is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a method for alleviating the aerodynamic effect of tunnels.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for alleviating the aerodynamic effect of tunnels includes the following steps:

[0008] (1) Install a first fan in the tunnel;

[0009] (2) Set a buffering chamber in the tunnel;

[0010] (3) Roughen the inner surface of the tunnel and the upper surface of the roadbed in the tunnel;

[0011] (4) Install a sound-absorbing structure in the tunnel.

[0012] As can be seen from the above technical solutions, compared with the prior art, the present invention discloses a method for alleviating the aerodynamic effect of a tunnel. By arranging a first fan in the tunnel, the first fan can disturb the air flow in the tunnel, thereby weakening the micro-pressure wave generated when a train passes through the tunnel; a buffer chamber is arranged in the tunnel, which can slow down the first wave gradient of the pressure wave and interfere with the pressure wave caused by the train entering the tunnel, thereby alleviating the micro-pressure wave and sonic boom, achieving the effect of pressure relief and buffering; the inner surface of the tunnel and the upper surface of the roadbed are both roughened, and this design can alleviate and interfere with the micro-pressure wave in the tunnel; the sound-absorbing structure can absorb sound and reduce noise, alleviating the micro-pressure wave and sonic boom.

[0013] Preferably, there are multiple first fans and they are fixed on the inner side wall of the tunnel. The multiple first fans are arranged at equal intervals in sequence along the extension direction of the tunnel. The first fans disturb the air flow in the tunnel.

[0014] Preferably, there are multiple buffer chambers, and the multiple buffer chambers are arranged in sequence along the extension direction of the tunnel. The multiple buffer chambers can improve the pressure relief and buffering effect of the tunnel.

[0015] Preferably, one end of the buffer chamber penetrates the inner side wall of the tunnel, and the other end of the buffer chamber can communicate with the atmosphere outside the tunnel. The buffer chamber can slow down the first wave gradient of the pressure wave and interfere with the pressure wave caused by the train entering the tunnel.

[0016] Preferably, an auxiliary adit, inclined shaft or auxiliary pilot tunnel communicating with the atmosphere outside the tunnel is also opened in the tunnel. In addition to the buffer chamber, the setting of the auxiliary adit, inclined shaft or auxiliary pilot tunnel in the tunnel can also play the role of pressure relief and buffering.

[0017] Preferably, a second fan is installed in the buffer chamber. The second fan can further alleviate the aerodynamic effect in the tunnel.

[0018] Preferably, the air inlet end of the second fan communicates with the inside of the tunnel, and the air outlet end of the second fan can communicate with the atmosphere outside the tunnel. When the second fan operates, it can alleviate the micro-pressure wave in the tunnel.

[0019] Preferably, in step (4), the sound-absorbing structure is a tunnel sound-absorbing board, and the sound-absorbing structure is arranged on both sides of the track in the tunnel, and the sound-absorbing structure is fixed on the inner side wall of the tunnel. While having a sound-absorbing effect, the microporous structure on the sound-absorbing structure can also play a role in buffering the air pressure in the tunnel.

[0020] Preferably, in step (4), the sound-absorbing structure is a sound-absorbing material coating, and the inner surface of the tunnel and the upper surface of the roadbed in the tunnel are both covered with the sound-absorbing material coating. While having the effects of sound absorption and pressure relief and buffering, this form of sound-absorbing structure is simple in construction.

[0021] Preferably, in step (3), the inner surface of the tunnel and the upper surface of the roadbed in the tunnel are roughened. This design can further alleviate the aerodynamic effect when the train enters the tunnel. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the provided drawings.

[0023] Figure 1 It is a schematic diagram of the layout of the first fan, the second fan, the sound-absorbing structure, and the first form of the buffer chamber in the tunnel in a method for alleviating the aerodynamic effect of the tunnel;

[0024] Figure 2 It is a schematic diagram of the layout of the second form of the buffer chamber in the tunnel in a method for alleviating the aerodynamic effect of the tunnel;

[0025] Figure 3 It is a schematic diagram of the layout of the third form of the buffer chamber in the tunnel in a method for alleviating the aerodynamic effect of the tunnel;

[0026] Figure 4 It is a flow chart of a method for alleviating the aerodynamic effect of the tunnel;

[0027] Figure 5 It is the initial compression wave pressure P and the pressure-time t gradient change curves at 200 m from the tunnel entrance with and without the buffer chamber in the tunnel;

[0028] Figure 6 It is a comparison chart of the initial compression wave pressure-time gradients with and without the buffer chamber.

[0029] In the figure:

[0030] 1 is the tunnel, 2 is the first fan, 3 is the second fan, 4 is the sound-absorbing structure, 5 is the track, 6 is the air duct, and 7 is the buffer chamber. Detailed Embodiments

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0032] The present invention discloses a method for alleviating the aerodynamic effect of a tunnel. By arranging a first fan 2 in the tunnel 1, the first fan 2 can disturb the air flow in the tunnel 1, thereby weakening the micro-pressure wave generated when the train passes through the tunnel 1; a buffer chamber 7 is arranged in the tunnel 1, which can slow down the first wave gradient of the pressure wave and interfere with the pressure wave caused by the train entering the tunnel 1, thereby alleviating the micro-pressure wave and sonic boom and achieving the effect of pressure relief and buffering; the inner surface of the tunnel 1 and the upper surface of the roadbed are both roughened, and this design can alleviate and interfere with the micro-pressure wave in the tunnel 1; the sound-absorbing structure 4 can absorb sound and reduce noise, and alleviate the micro-pressure wave and sonic boom. Before the train enters the tunnel 1, the external railway control system can control the start of the first fan 2 and the second fan 3. The first fan 2 and the second fan 3 can disturb the air flow in the tunnel 1, thereby weakening the micro-pressure wave generated when the train passes through the tunnel 1; the inner surface of the tunnel 1 and the upper surface of the roadbed are both roughened to increase their surface roughness, and this design can weaken the air flow in the tunnel 1 and also play a certain buffering effect; the sound-absorbing structure 4 can be a sound-absorbing panel with micropores or a coating of sound-absorbing material. When the train runs in the tunnel 1, the sound-absorbing structure 4 can play the role of sound absorption and noise reduction and buffering the micro-pressure wave; the combined design of the first fan 2, the second fan 3, the buffer chamber 7, the roughening treatment and the sound-absorbing structure 4 greatly enhances the buffering effect of the tunnel 1, and is applicable to both newly built tunnels 1 and the renovation of existing tunnels 1. The above design is simple in construction and small in engineering quantity.

[0033] Embodiment

[0034] See Appendix Figure 1-6 It is a schematic diagram of the overall and partial structures of an embodiment of the present invention. Figure 1 The arrow in it indicates the air flow direction. The present invention specifically discloses a method for alleviating the aerodynamic effect of a tunnel, including the following steps:

[0035] (1) Arrange a first fan 2 in the tunnel 1. The first fan 2 is electrically connected to the external railway control system. The first fan 2 is an axial flow fan. The external railway control system can control the opening and closing of the first fan 2 and the adjustment of the wind speed. When the train is about to enter the tunnel 1, the external railway control system can control the first fan 2 to start. Similarly, when the train exits the tunnel 1, the external railway control system can control the first fan 2 to close.

[0036] (2) Set a buffer chamber 7 in the tunnel 1. Arrange a second fan 3 in the buffer chamber 7. The second fan 3 is electrically connected to the external railway control system. The second fan 3 is an axial flow fan or a centrifugal fan. The rated power of the second fan 3 is greater than the rated power of the first fan 2. The external railway control system can control the opening and closing of the second fan 3 and the adjustment of the wind speed. When the train is about to enter the tunnel 1, the external railway control system can control the second fan 3 to start. Similarly, when the train exits the tunnel 1, the external railway control system can control the second fan 3 to close.

[0037] (3) Roughen the inner surface of Tunnel 1 and the upper surface of the roadbed inside Tunnel 1. In this embodiment, the inner surface of Tunnel 1 and the upper surface of the roadbed inside Tunnel 1 can be roughened by chiseling. The inner wall of Tunnel 1 and the roadbed are both made of concrete. After chiseling the inner wall of Tunnel 1 and the roadbed, the surface roughness increases and the air flow velocity slows down, which is beneficial to improving the buffering effect. Or, the inner surface of Tunnel 1 can be set as a corrugated shape or other special-shaped structures, which can also achieve the roughening of the inner surface of Tunnel 1.

[0038] (4) Arrange sound-absorbing structures 4 on both sides of the track 5 inside Tunnel 1. The sound-absorbing structures 4 can play a role in sound absorption and noise reduction, and the air pressure fluctuations generated when the train enters and exits Tunnel 1 can be buffered.

[0039] In step (1), there are multiple first blowers 2, and the multiple first blowers 2 are arranged at equal intervals in sequence along the extension direction of Tunnel 1; the first blowers 2 are fixed on the inner side wall of Tunnel 1, and the blowing direction of the first blowers 2 is the same as the extension direction of Tunnel 1; the first blowers 2 are located beside the track 5, that is, the first blowers 2 are not located above the track 5. The purpose is to ensure the safety of train operation in Tunnel 1. When the train travels in Tunnel 1, if the first blower 2 drops, it will not hit the train.

[0040] In step (2), multiple buffer chambers 7 are arranged at equal intervals in sequence along the extension direction of the tunnel. Buffer chambers 7 are arranged on both sides of the track 5 inside the tunnel. The length direction of the buffer chambers 7 is perpendicular to the extension direction of Tunnel 1. The air inlet end of the second blower 3 is communicated with the inside of Tunnel 1, and the air outlet end of the second blower 3 can be communicated with the atmosphere outside Tunnel 1 or not. When the second blower 3 is communicated with the atmosphere outside Tunnel 1, an air duct 6 is fixedly installed on Tunnel 1. One end of the air duct 6 is located outside Tunnel 1, and the other end of the air duct 6 is closed. The air outlet ends of the multiple second blowers 3 are all communicated with the air duct 6; in this embodiment, the air outlet ends of the multiple second blowers 3 are all communicated with the atmosphere outside Tunnel 1.

[0041] In step (4), the sound-absorbing structure 4 is a sound-absorbing board for tunnels. Sound-absorbing structures 4 are arranged on both sides of the track 5 inside Tunnel 1. The sound-absorbing structures 4 are fixed on the inner side wall of Tunnel 1 through connectors. There is a certain gap between the sound-absorbing structures 4 and the inner side wall of Tunnel 1. The sound-absorbing structures 4 and their fixation to Tunnel 1 are all prior arts.

[0042] In step (4), the sound-absorbing structure 4 can also be a sound-absorbing material coating, that is, a sound-absorbing material coating can be sprayed on the inner surface of Tunnel 1 and the upper surface of the roadbed inside Tunnel 1.

[0043] Arrange the first blower 2 and the second blower 3 inside Tunnel 1. When the train enters Tunnel 1, the first blower 2 and the second blower 3 are started. The first blower 2 and the second blower 3 can disturb the air flow inside Tunnel 1, reduce the first wave pressure gradient, and thus relieve the micro-pressure wave at the entrance of Tunnel 1.

[0044] An auxiliary adit, inclined shaft or auxiliary pilot tunnel communicating with the atmosphere outside Tunnel 1 is also provided in Tunnel 1. The auxiliary adit, inclined shaft or auxiliary pilot tunnel are all prior arts, and the auxiliary adit, inclined shaft or auxiliary pilot tunnel can also play the role of pressure relief and buffering.

[0045] Regarding the effect of setting the buffer chamber 7 in Tunnel 1 on alleviating the micro-pressure wave in Tunnel 1:

[0046] Figure 5 It is the initial compression wave pressure P and the pressure-time t gradient change curves at a distance of 200 m from the entrance of Tunnel 1 with and without the buffer chamber 7 in Tunnel 1. Figure 6 It is a comparison diagram of the initial compression wave pressure-time gradients with and without the buffer chamber 7; adding the buffer chamber 7 changes the variation law of the initial compression wave. The buffer chamber 7 will have a shunting effect on the initial compression wave, dividing part of the energy of the initial compression wave into a compression wave propagating towards the outlet of the buffer chamber 7 and an expansion wave propagating towards the outlet of Tunnel 1.

[0047] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0048] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for alleviating aerodynamic effect in a tunnel, characterized in that: The steps include: (1) Install a fan in the tunnel; (2) Setting up a buffer chamber in the tunnel; (3) Roughening the inner surface of the tunnel and the upper surface of the tunnel ballast; (4) Install sound-absorbing structures in the tunnel.

2. A method for alleviating aerodynamic effect in a tunnel according to claim 1, characterized in that: A plurality of fans are provided and fixed on the inner wall of the tunnel, and the plurality of fans are arranged in sequence and at equal intervals along the extension direction of the tunnel.

3. The method for alleviating aerodynamic effect of a tunnel according to claim 1, characterized in that: A plurality of buffer chambers are provided, and the plurality of buffer chambers are arranged in sequence along the extension direction of the tunnel.

4. The method for alleviating aerodynamic effect of a tunnel according to claim 1, characterized in that: One end of the buffer chamber passes through the inner wall of the tunnel, and the other end of the buffer chamber can be communicated with the atmosphere outside the tunnel.

5. The method for alleviating aerodynamic effect of a tunnel according to claim 1, characterized in that: Auxiliary tunnels, inclined shafts or auxiliary guide tunnels connected to the atmosphere outside the tunnel are also provided in the tunnel.

6. The method for alleviating aerodynamic effect of a tunnel according to claim 1, characterized in that: A second fan is installed in the buffer chamber.

7. The method for alleviating aerodynamic effect of a tunnel according to claim 7, characterized in that: The air inlet end of the second fan is connected with the inside of the tunnel, and the air outlet end of the second fan can be connected with the atmosphere outside the tunnel.

8. The method for alleviating aerodynamic effect of a tunnel according to claim 1, characterized in that: In step (4), the sound absorbing structure is a tunnel sound absorbing panel, and the sound absorbing structure is arranged on both sides of the track in the tunnel, and the sound absorbing structure is fixed on the inner wall of the tunnel.

9. The method for alleviating aerodynamic effect of a tunnel according to claim 1, characterized in that: In step (4), the sound absorbing structure is a sound absorbing material coating, and the inner surface of the tunnel and the upper surface of the roadbed in the tunnel are both covered with the sound absorbing material coating.

10. The method for alleviating aerodynamic effect of a tunnel according to claim 1, characterized in that: In step (3), the inner surface of the tunnel and the upper surface of the ballast in the tunnel are roughened.

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