Tunnel thrust fan system and method of designing the same

Abstract

The present application relates to a tunnel thrust fan system and its design method. When the tunnel thrust fan system is a one-way thrust fan system, the system can only take in air from one end and blow air into the tunnel from the nozzle at the other end, so as to realize the static pressure rise in the tunnel behind the nozzle. When the tunnel thrust fan system is a two-way thrust fan system, the static pressure rise in the main tunnel can be realized in the positive or reverse ventilation by changing the air inlet and blowing direction of the fan. The two-way thrust fan system effectively reduces the power of the thrust fan system by setting a negative pressure air inlet valve in the static pressure tank. For the one-way thrust fan system and the two-way thrust fan system, the air inlet of the fan is inclined into the main tunnel through the nozzle pipe, so as to improve the static pressure of the main tunnel behind the nozzle and ensure the longitudinal ventilation air volume and speed in the tunnel under normal or accident conditions.

Description

Technical Field

[0001] This invention relates to the field of thrust fan technology, and particularly to a thrust fan system for tunnels and its design method. Background Technology

[0002] Thrust fan systems are primarily used in ventilation systems for long tunnels, working in conjunction with tunnel fans in the preceding and following shafts and jet fans within the tunnel to meet the longitudinal ventilation volume and velocity requirements under normal or emergency conditions. Previously, thrust fan system designs were not standardized or modularized, lacking fixed design patterns. The final thrust fan system was often based on the experience of designers and construction personnel, resulting in significant variations in the thrust fan systems presented on-site. Some thrust fan systems required higher fan power to meet the demands, but the current power limit for high-power fans that can be installed in tunnels is limited, causing some thrust fan systems to fail to achieve the expected pressure increase effect after installation. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art, which has limited upper limit for the power of high-power fans that can be installed in tunnels, making it impossible for the thrust fan system to achieve the expected pressure increase effect after installation. This invention provides a thrust fan system for tunnels and its design method.

[0004] In a first aspect, the present invention provides a thrust fan system for tunnels, comprising: a fan, the fan being fixed to an installation space via a fan foundation, the installation space being located outside the side or above the top surface of a main tunnel;

[0005] The tunnel thrust fan system is either a unidirectional thrust fan system or a bidirectional thrust fan system. When the tunnel thrust fan system is a unidirectional thrust fan system, one end of the fan is connected to the air inlet collector, and the other end is connected in sequence to the top-round-and-bottom, the guide pipe, the acceleration pipe and the nozzle pipe. The end of the air inlet collector connected to the fan is smaller than the other end of the air inlet collector. When the tunnel thrust fan system is a bidirectional thrust fan system, the fan is a reversible bidirectional fan. Both ends of the fan are connected outward in sequence to a round top and square bottom, a static pressure box, a guide pipe, an acceleration pipe, and a nozzle pipe. The static pressure box is fixed to the installation space through a static pressure box foundation, and the static pressure box is connected to the installation space through a negative pressure air inlet valve. Wherein, the end of the round-and-square structure connected to the fan is smaller than the end of the round-and-square structure connected to the guide pipe. The guide pipe is bent or twisted toward the main tunnel. The end of the acceleration pipe connected to the guide pipe is larger than the end of the acceleration pipe connected to the nozzle pipe. The nozzle pipe is inclined relative to the axial direction of the main tunnel. The nozzle pipe is fixed to the installation space through the nozzle pipe foundation corresponding to the fan. The nozzle pipe is connected to the main tunnel.

[0006] The tunnel thrust fan system of this invention, when the tunnel thrust fan system is a unidirectional thrust fan system, uses an air intake collector connected to one end for air intake. Since the end of the air intake collector connected to the fan is smaller than the other end of the air intake collector, the difficulty of air intake is reduced, and the power required by the fan can be reduced. The other end of the fan is connected in sequence to a top-to-bottom section, a guide pipe, an acceleration pipe, and a nozzle pipe. The guide pipe is bent or folded towards the main tunnel side, so that the nozzle pipe is inclined relative to the axial direction of the main tunnel, thereby causing the air blown into the main tunnel at an angle, achieving an increase in static pressure in the tunnel after the nozzle. The end of the acceleration pipe connected to the guide pipe is larger than the end of the acceleration pipe connected to the nozzle pipe, which can accelerate the air, thereby increasing the air velocity delivered into the main tunnel by the nozzle pipe, increasing the static pressure in the tunnel after the nozzle, ensuring the longitudinal ventilation volume and air velocity in the tunnel under normal or emergency conditions, so that the thrust fan system can achieve the expected pressure increase effect after installation.

[0007] When the tunnel thrust fan system is a bidirectional thrust fan system, the fan is a reversible bidirectional fan. One end of the fan connects to a plenum chamber, static pressure box, guide pipe, acceleration pipe, and nozzle pipe for air intake, while the other end connects to the same components for air delivery to the main tunnel, increasing the static pressure in the main tunnel after the nozzles. By changing the fan's air intake direction, the static pressure after the nozzles can be increased when the main tunnel is ventilated in either the forward or reverse direction. The functions of the plenum chamber, guide pipe, acceleration pipe, and nozzle pipe are the same as in a unidirectional thrust fan system, using a static pressure box to control the static pressure. The box is connected to the installation space via a negative pressure air inlet valve. When air intake is needed at this end, the negative pressure air inlet valve can be opened to compensate for insufficient air intake at this end of the nozzle pipe, providing sufficient air volume for the fan and reducing the power required by the fan. Moreover, when air is needed from this end of the nozzle, the negative pressure air inlet valve can be closed to prevent air leakage from the valve, thus ensuring that the air volume is not affected. Through this bidirectional thrust fan system design, the longitudinal ventilation air volume and air velocity in the tunnel under normal or emergency conditions can be guaranteed while reducing the power required by the fan, so that the thrust fan system can achieve the expected pressure increase effect after installation.

[0008] Preferably, when the tunnel thrust fan system is a unidirectional thrust fan system, the air inlet collector is a linear collector, an arc-shaped collector, or a round-and-square type.

[0009] Preferably, when the air inlet collector is an arc-shaped collector, the arc radius of the arc-shaped collector is... r With the diameter of the fan D The ratio between r / D A value of ≥0.2 can reduce the local resistance of the air intake, thereby reducing the power required by the fan.

[0010] Preferably, the round top and square bottom are connected to the fan via a flexible joint; the flexible joint serves as a vibration isolation mechanism, which can reduce the impact of fan vibration on the round top and square bottom. And / or, the end of the guide pipe near the fan is connected to a connecting short pipe. The fan is fixed by the fan foundation, the nozzle pipe is fixed by the nozzle pipe foundation, and the guide pipe is specially designed. Through the characteristics determined by the connecting short pipe, it can avoid the guide pipe and the fan from being unable to communicate due to design and installation problems, and the connecting short pipe has the function of facilitating connection.

[0011] Preferably, the axial tilt angle θ of the nozzle pipe relative to the main tunnel is generally 5° to 45°. θ The smaller the diameter, the longer the installation space along the axial length of the main tunnel, increasing the cost. However, the greater the lift pressure generated by the tunnel thrust fan system, with θ ranging from 5° to 45°, can balance the cost and the lift pressure requirements of the tunnel thrust fan system.

[0012] Preferably, it also includes a silencer. When the tunnel thrust fan system is a unidirectional thrust fan system, the silencer is provided at the end of the air inlet collector and / or the end of the circular-to-square structure away from the fan. When the tunnel thrust fan system is a bidirectional thrust fan system, at least one of the two ends of the fan (the top and bottom surfaces) is provided with the silencer at the end furthest from the fan.

[0013] Preferably, the installation space is an enlarged section of the main tunnel protruding from the side of the main tunnel or an excavated space above the main tunnel; When the tunnel thrust fan system is a unidirectional thrust fan system, the fan is installed horizontally in the enlarged section of the tunnel, or the fan is installed vertically or horizontally in the excavated space above the main tunnel. When the fan is installed vertically in the excavated space above the main tunnel, the air intake collector is connected to the outside of the tunnel. When the tunnel thrust fan system is a bidirectional thrust fan system, the fan is installed horizontally in the enlarged section of the tunnel or in the excavated space above the main tunnel.

[0014] In a second aspect, the present invention provides a design method for a tunnel thrust fan system, comprising the following steps: S1: Determine the average wind speed requirement v in the main tunnel, the pressure rise requirement ΔP of the tunnel thrust fan system, and the area F of the main tunnel. Calculate the required air volume Q of the main tunnel based on the area F and the average wind speed requirement v. Determine the structural form of the tunnel thrust fan system. S2: Based on the assumed axial tilt angle θ of the nozzle pipe relative to the main tunnel, the area ratio m of the nozzle pipe and the main tunnel, the air volume ratio n of the nozzle pipe and the main tunnel, and the structural form of the tunnel thrust fan system, the boost pressure ΔP' of the tunnel thrust fan system is calculated using the momentum theorem. Then, it is determined whether ΔP' meets the boost pressure requirement ΔP of the tunnel thrust fan system. If ΔP' < ΔP or ΔP' > 1.1ΔP, step S2 is repeated; if ΔP ≤ ΔP' ≤ 1.1ΔP, step S3 is performed. S3: Output ΔP≤ΔP'≤1. Nozzle tube cross-sectional area under the condition 1ΔP. F 0 and nozzle outlet air volume Q 0; S4: Based on the cross-sectional area of ​​the nozzle tube F 0 and nozzle outlet air volume Q 0. Initial selection of the fan is carried out, and then the results of the initial fan selection, the structural form of the tunnel thrust fan system, and the cross-sectional area of ​​the nozzle pipe are considered. F 0 and nozzle outlet air volume Q 0. Design the component parameters of the thrust fan system for tunnels; S5: Calculate the resistance of the tunnel thrust fan system based on the design results of the component parameters of the tunnel thrust fan system; S6: Select the fan model based on the resistance of the tunnel thrust fan system. If the fan model cannot meet the resistance requirements of the tunnel thrust fan system, then re-assume at least one of the following parameters: the axial tilt angle θ of the nozzle pipe relative to the main tunnel, the area ratio m of the nozzle pipe and the main tunnel, and the air volume ratio n of the nozzle pipe and the main tunnel. Repeat steps S2-S6 until the fan selection is successful and the design is completed.

[0015] By adopting the above-mentioned design method for tunnel thrust fan systems, the structural form and parameters of each component of the tunnel thrust fan system can be designed systematically, and the successful selection of the fan can be guaranteed.

[0016] Preferably, in step S1, determining the form of the tunnel thrust fan system includes: determining the airflow organization direction of the main tunnel according to the organization principle of tunnel ventilation; if the airflow in the main tunnel is only organized in the same direction, then the tunnel thrust fan system is a unidirectional thrust fan system; if the airflow in the main tunnel needs to move in one direction along the tunnel axis under different working conditions, then the tunnel thrust fan system is a bidirectional thrust fan system; and determining whether to install a silencer, silencer foundation, connecting short pipe, and flexible connection according to requirements; when the tunnel thrust fan system is a unidirectional thrust fan system, determining that the air inlet collector is a straight collector, an arc collector, or a round-and-square type. Nozzle outlet air velocity v The value of 0 is generally between 10 and 40. m / s , v 0= Q 0 / F 0; In step S2, the area ratio m of the nozzle pipe and the main tunnel, and the air volume ratio n of the nozzle pipe and the main tunnel can be assumed to calculate the outlet air velocity of the nozzle pipe. v 0, making v 0 is within the above-mentioned numerical range; the axial tilt angle of the nozzle pipe relative to the main tunnel. θ The angle ranges from 5° to 45°. In step S4, the design of component parameters for the tunnel thrust fan system includes: based on the cross-sectional area of ​​the nozzle pipe F 0 and nozzle outlet air volume Q 0. Perform initial selection of the blower, and solve the parameters of each component of the thrust blower system for tunnels in sequence, including the nozzle pipe, silencer, top-to-bottom shape, acceleration pipe and guide pipe. Then solve the parameters of each component of the silencer foundation, blower foundation and nozzle pipe foundation in sequence. Finally, solve the parameters of the tunnel wall line of the enlarged section and the relevant parameters of the enlarged section tunnel.

[0017] Preferably, when the nozzle pipe is tilted at an axial angle relative to the main tunnel... θ When the angle is ≥30°, the guide tube is angled. At this time, the two angle-dividing components of the guide tube are identical, and the included angle of the two angle-dividing components is ≥30°. θ / 2; Based on the axial tilt angle θ of the nozzle pipe relative to the main tunnel, and the pipeline space l between the tunnel thrust fan system and the tunnel wall of the enlarged section... min Given the parameters of the nozzle and accelerator tubes, solve for the cross-sectional enlargement angle Φ of the enlarged tunnel section.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides a tunnel thrust fan system. When the tunnel thrust fan system is a unidirectional thrust fan system, the fan uses an air intake collector connected to one end for air intake. Since the end of the air intake collector connected to the fan is smaller than the other end of the air intake collector, the difficulty of air intake is reduced, thus reducing the power required by the fan. For both unidirectional and bidirectional thrust fan systems, the guide pipe is bent or folded towards the main tunnel side, and its placement causes the nozzle pipe to be axially inclined relative to the main tunnel, thereby causing the air blown into the main tunnel at an angle, increasing the static pressure in the tunnel after the nozzle. The round-top, square-bottom structure and placement can slow down the wind speed and increase the static pressure, thus reducing the power required by the fan. The shape and placement of the acceleration pipe accelerate the air, thereby increasing the wind speed delivered into the main tunnel by the nozzle pipe, increasing the static pressure in the tunnel after the nozzle, and meeting the requirements of the tunnel... The longitudinal ventilation volume and velocity under normal or emergency conditions are measured. When the tunnel thrust fan system is a bidirectional thrust fan system, the static pressure after the nozzle can be increased when the main tunnel axial ventilation is in the forward or reverse direction by changing the fan's air intake direction. By setting up a static pressure box and connecting it to the installation space through a negative pressure air intake valve, the negative pressure air intake valve can be opened when air intake is needed at that end, using the negative pressure air intake valve to compensate for the insufficient air intake of the nozzle pipe at that end, providing sufficient air volume for the fan and reducing the power required by the fan. Moreover, when air is needed from the nozzle at that end, the negative pressure air intake valve can be closed to prevent air leakage from the negative pressure air intake valve, thus ensuring that the blowing volume is not affected. Both the unidirectional and bidirectional thrust fan systems can ensure the longitudinal ventilation volume and velocity under normal or emergency conditions in the tunnel while reducing the power required by the fan, so that the thrust fan system can achieve the expected pressure increase effect after installation.

[0019] 2. This invention provides a design method for a tunnel thrust fan system, which can systematically design the structural form and parameters of each component of the tunnel thrust fan system, and ensure successful fan selection. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the planar layout of the unidirectional thrust fan system described in this invention; Figure 2 This is a schematic diagram of the side arrangement of the unidirectional thrust fan system described in this invention; Figure 3 This is a schematic diagram of the plan layout of the bidirectional thrust fan system described in this invention; Figure 4 Flowchart for thrust fan system design; Figure 5 Schematic diagram of the nozzle tube design; Figure 6 A schematic diagram of the angle division of the guide tube; Figure 7 A schematic diagram of the design and implementation of a unidirectional thrust fan system; Figure 8 The thrust fan system is placed inside the second tunnel for air intake; Figure 9 Schematic diagram of the nozzle tube design; Figure 10 This is a schematic diagram of a nozzle tube node. Figure 11 This is a schematic diagram of the accelerator tube node. Figure 12 This is a schematic diagram of the flow guide pipe node. Figure 13 This is a schematic diagram of the large-scale node of the celestial circle and the square earth. Figure 14 This is a schematic diagram of a collector node.

[0021] Marked in the diagram: 1. Fan foundation; 2. Fan; 3. Flexible connector; 4. Round top and square bottom; 5. Silencer; 6. Silencer foundation; 7. Connecting short pipe; 8. Guide pipe; 9. Accelerator pipe; 10. Nozzle pipe; 11. Nozzle pipe foundation; 12. Enlarged section tunnel wall line; 13. Enlarged section tunnel; 14. Main tunnel; 15. Static pressure box; 16. Static pressure box foundation; 17. Negative pressure air inlet valve; 18. Second tunnel. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0023] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0024] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0025] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0026] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0027] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0028] Example 1 like Figure 1 and Figure 2 As shown, a tunnel thrust fan system is a unidirectional thrust fan system, comprising: a fan 2, two flexible connectors 3, two round-and-square connectors 4, two silencers 5, a connecting short pipe 7, a guide pipe 8, an acceleration pipe 9, and a nozzle pipe 10.

[0029] The tunnel thrust ventilation system is fixed in an installation space, which is located inside a second tunnel 18 that communicates with the side of the main tunnel 14, or outside or above the top surface of the main tunnel 14; the installation space is the enlarged section tunnel 13 protruding from the side of the main tunnel 14 or the excavated space above the main tunnel 14; such as Figure 1As shown, the tunnel thrust fan system is installed in the enlarged section tunnel 13 excavated on one side of the main tunnel 14. The wall line 12 of the enlarged section tunnel is an isosceles trapezoidal structure. This arrangement allows the fan 2 to be fixed in the longitudinal middle of the enlarged section tunnel 13 via the fan foundation 1, which is beneficial for the excavation of the enlarged section tunnel 13 and reduces the construction cost of the enlarged section tunnel 13. The tunnel thrust fan system can also be installed vertically or horizontally in the excavated space above the main tunnel 14. When the tunnel thrust fan system is installed horizontally in the excavated space above the main tunnel 14, that is, the fan 2 is installed horizontally in the excavated space above the main tunnel 14, its installation method is the same as... Figure 1 Similarly, when the tunnel thrust fan system is vertically installed in the excavated space above the main tunnel 14, that is, when the fan 2 is vertically installed in the excavated space above the main tunnel 14, the upper part of the fan 2 (round top and square bottom) needs to be vertically connected to the outside of the tunnel. For example... Figures 1-2 As shown, the fan 2 is fixed to the middle of the enlarged section tunnel 13 via the fan foundation 1. The left end of the fan 2 is connected to the flexible joint 3, the square-shaped top and bottom joint 4, and the silencer 5 in sequence. The right end of the fan 2 is connected to the flexible joint 3, the square-shaped top and bottom joint 4, the silencer 5, the connecting short pipe 7, the guide pipe 8, the acceleration pipe 9, and the nozzle pipe 10 in sequence. The silencer 5 is fixed to the enlarged section tunnel 13 via the silencer foundation 6, and the nozzle pipe 10 is fixed to the enlarged section tunnel 13 via the nozzle pipe foundation 11. The fan foundation 1, the silencer foundation 6, and the nozzle pipe foundation 11 are all made of concrete. The guide pipe 8 is bent or folded toward the main tunnel 14, so that the nozzle pipe 10 is inclined relative to the axial direction of the main tunnel 14. In use, the air passes through the silencer 5, the top-bottom joint 4 and the flexible joint 3 at the left end and is drawn into the fan 2. Then, from the right end, it passes through the flexible joint 3, the top-bottom joint 4, the silencer 5, the connecting short pipe 7, the guide pipe 8, the acceleration pipe 9 and the nozzle pipe 10 in sequence, and is then inclined into the main tunnel 14 by the nozzle pipe 10, thereby increasing the wind speed delivered into the main tunnel by the nozzle pipe 10. The end of the circular-to-square 4 connected to the right end of the fan 2 is smaller than the end of the circular-to-square 4 connected to the guide pipe 8, which can reduce the wind speed from the fan 2 to the guide pipe 8, and balance the total pressure of the entire system, thereby increasing the static pressure of the guide pipe 8. When the wind passes through the curved or bent guide pipe, it is beneficial to further reduce the power required by the fan 2. The end of the acceleration pipe 9 connected to the guide pipe 8 is larger than the end of the acceleration pipe 9 connected to the nozzle pipe 10, which can accelerate the wind, thereby increasing the wind speed delivered into the main tunnel by the nozzle pipe 10, and meeting the longitudinal ventilation volume and wind speed in the tunnel under normal or emergency conditions.

[0030] In this embodiment, the silencer 5 at the left end reduces noise. Furthermore, the left-end concentric circle 4 (round top and square bottom) is larger on the left and smaller on the right, reducing the difficulty of air intake and thus decreasing the power required by the fan 2. The left-end concentric circle 4 connects to the air inlet of the fan 2. This concentric circle 4 can be replaced with various other air inlet collectors, such as a straight-line collector or an arc-shaped collector. When the air inlet collector is an arc-shaped collector, the arc radius of the arc-shaped collector... r With the diameter of fan 2 D The ratio between r / D A value ≥0.2 can reduce local resistance, thereby reducing the power required by the fan 2. When the inlet of the fan 2 is connected to the top-bottom junction box 4 by a straight-line collector or an arc-shaped collector, the connection between the straight-line collector or the arc-shaped collector and the fan 2 does not need to be made by a flexible connection 3.

[0031] In this embodiment, the silencer 5, silencer foundation 6, flexible connector 3, and connecting short pipe 7 are all selected and designed according to actual conditions. These components may not be required in the tunnel thrust fan system. The circular-to-square 4 is connected to the fan 2 via the flexible connector 3; the flexible connector 3 serves as vibration isolation, reducing the impact of fan 2 vibration on the circular-to-square 4; since the fan 2 is fixed via the fan foundation 1, and the nozzle pipe 10 is fixed via the nozzle pipe foundation 11, while the guide pipe 8 is specially designed, its characteristics, determined by the connecting short pipe 7, can prevent the guide pipe 8 from being unable to connect with the fan 2 due to design and installation problems. The connecting short pipe 7 also facilitates connection, especially when a silencer 5 is included, making it easier to connect the silencer 5 to the guide pipe 8. In a unidirectional thrust fan system, the silencer 5 can be installed at the air inlet collector and / or at the end of the circular-to-square 4 furthest from the fan 2. In an optional embodiment, the axial tilt angle θ of the nozzle pipe 10 relative to the main tunnel 14 is generally 5° to 45°. θ The smaller the size, the longer the installation space is along the axis of the main tunnel 14, increasing the cost. However, the greater the lift pressure generated by the tunnel thrust fan system, with θ ranging from 5° to 45°, can balance the cost and the lift pressure capacity of the tunnel thrust fan system.

[0032] In an optional implementation, when the nozzle tube 10 is tilted at an axial angle relative to the main tunnel 14 θ When the angle is ≥30°, the guide tube 8 is divided into two segments. At this time, the two segmented components of the guide tube 8 are identical, and the included angle between the two segmented components is 1. θ / 2, that is, the guide tube 8 adopts a bent shape, such as Figures 5-6As shown, this design facilitates the processing of the guide tube 8, avoiding the problem of the guide tube 8 having too large an arc and being impossible to process; moreover, this design can reduce local resistance and further reduce the power required by the fan 2.

[0033] In the above design, such as Figures 1-2 As shown, the left-hand circular-square structure 4 enhances the air intake effect of the fan 2 and reduces the power required by the fan 2; the right-hand circular-square structure 4 reduces the wind speed and increases the static pressure, allowing it to pass better through the curved guide pipe 8 and reducing the loss at the curved guide pipe 8, thereby further reducing the power required by the fan 2; then, the decelerated wind is accelerated through the acceleration pipe 9, increasing the wind speed delivered into the main tunnel by the nozzle pipe 10, satisfying the longitudinal ventilation air volume and wind speed in the tunnel under normal or emergency conditions. Under the premise of reducing the power required by the fan 2, it ensures the longitudinal ventilation air volume and wind speed in the tunnel under normal or emergency conditions, so that the thrust fan system can achieve the expected pressure increase effect after installation.

[0034] like Figure 8 As shown, the thrust fan system is located inside the second tunnel 18 to draw air, that is, the thrust fan system's air intake silencer 5 draws air from the second tunnel 18.

[0035] Example 2 This embodiment provides a thrust fan system for tunnels, such as Figure 3 As shown, this is a bidirectional thrust fan system, including a fan 2, a flexible connector 3, a top-to-bottom joint 4, a static pressure box 15, a connecting short pipe 7, a guide pipe 8, an acceleration pipe 9, and a nozzle pipe 10. The fan 2 is a reversible bidirectional fan. Both ends of the fan 2 are sequentially connected to the flexible connector 3, the top-to-bottom joint 4, the static pressure box 15, the connecting short pipe 7, the guide pipe 8, the acceleration pipe 9, and the nozzle pipe 10. The bidirectional thrust fan system is fixed in an installation space located outside the side or above the top surface of the main tunnel 14. The installation space is either the enlarged section tunnel 13 protruding from the side of the main tunnel 14 or the excavated space above the main tunnel 14.

[0036] like Figure 3 As shown, the bidirectional thrust fan system is installed within the enlarged section tunnel 13 excavated on one side of the main tunnel 14. The wall line 12 of the enlarged section tunnel is an isosceles trapezoidal structure. This arrangement allows the fan 2 to be fixed to the longitudinal center of the enlarged section tunnel 13 via the fan foundation 1, which is beneficial for the excavation of the enlarged section tunnel 13 and reduces the construction cost of the enlarged section tunnel 13. The bidirectional thrust fan system can also be installed horizontally in the excavated space above the main tunnel 14, and its installation method is the same as... Figure 3 similar.

[0037] The fan 2 is fixed in the middle of the enlarged tunnel 13 via the fan foundation 1, the nozzle pipe 10 is fixed in the enlarged tunnel 13 via the nozzle pipe foundation 11, and the static pressure box 15 is fixed in the enlarged tunnel 13 via the static pressure box foundation 16. The fan foundation 1, the static pressure box foundation 16 and the nozzle pipe foundation 11 are all made of concrete.

[0038] like Figure 3 As shown, the static pressure box 15 is connected to the installation space through the negative pressure air inlet valve 17. When the negative pressure air inlet valve 17 is opened, the air in the installation space can enter the static pressure box 15 through the negative pressure air inlet valve 17.

[0039] Wherein, the end of the round top and square bottom 4 that connects to the fan 2 is smaller than the end of the round top and square bottom 4 that connects to the guide pipe 8, which reduces the difficulty of air intake and can reduce the power required by the fan 2.

[0040] In this embodiment, the silencer 5, silencer foundation 6, flexible connector 3, and connecting short pipe 7 are all selected and designed according to actual conditions. These components may not be required in the tunnel thrust fan system. The circular-to-square 4 is connected to the fan 2 via the flexible connector 3; the flexible connector 3 serves as vibration isolation, reducing the impact of fan 2 vibration on the circular-to-square 4; since the fan 2 is fixed via the fan foundation 1, and the nozzle pipe 10 is fixed via the nozzle pipe foundation 11, while the guide pipe 8 is specially designed, its characteristics, determined by the connecting short pipe 7, can prevent the guide pipe 8 from being unable to connect with the fan 2 due to design and installation problems. The connecting short pipe 7 also facilitates connection, allowing the static pressure box 15 to connect with the guide pipe 8. In an optional embodiment of the bidirectional thrust fan system, at least one of the circular-to-square 4 at both ends of the fan 2 is provided with the silencer 5 at the end furthest from the fan 2, such as... Figure 3 In the middle, a silencer 5 can be installed between the round-and-square box 4 and the static pressure box 15.

[0041] In an optional embodiment, the axial tilt angle θ of the nozzle pipe 10 relative to the main tunnel 14 is generally 5° to 45°. θ The smaller the size, the longer the installation space is along the axis of the main tunnel 14, increasing the cost. However, the greater the lift pressure generated by the tunnel thrust fan system, with θ ranging from 5° to 45°, can balance the cost and the lift pressure capacity of the tunnel thrust fan system.

[0042] In an optional implementation, when the nozzle tube 10 is tilted at an axial angle relative to the main tunnel 14 θ When the angle is ≥30°, the guide tube 8 is divided into two segments. At this time, the two segmented components of the guide tube 8 are identical, and the included angle between the two segmented components is 1. θ / 2, that is, the guide tube 8 adopts a bent shape, such as Figures 5-6As shown, this design facilitates the processing of the guide tube 8, avoiding the problem of the guide tube 8 having too large an arc and being impossible to process; moreover, this design can reduce local resistance and further reduce the power required by the fan 2.

[0043] In the above design, such as Figure 3 As shown, when air is supplied to the right, the fan 2 has two air intake paths through the left side. Specifically, the left negative pressure air intake valve 17 is opened and the right negative pressure air intake valve 17 is closed. The first air intake path: air enters through the left nozzle pipe 10, passes through the left acceleration pipe 9, guide pipe 8, connecting short pipe 7, static pressure box 15, top-bottom joint 4, and flexible joint 3 before entering the fan 2. The second air intake path: air enters the static pressure box 15 through the left negative pressure air intake valve 17 from the installation space, then passes through the top-bottom joint 4 and flexible joint 3 before entering the fan 2. Research shows that the air intake resistance of the first air intake path is relatively large, resulting in a larger power requirement for the fan 2, which may lead to the inability to meet the power requirements of the fan 2. The second air intake path has a stronger air intake capacity, which can significantly reduce the power required by the fan 2. By using both the first and second air intake paths, the power required by the fan 2 can be further reduced without affecting the bidirectional air supply function. When air is supplied to the right, after the fan 2 enters through the left side, it sequentially passes through the right side flexible joint 3, the top-bottom joint 4, the static pressure box 15, the connecting short pipe 7, the guide pipe 8, the acceleration pipe 9, and the nozzle pipe 10 before being inclinedly delivered into the main tunnel 14. This ensures the longitudinal ventilation volume and velocity in the tunnel under normal or emergency conditions, so that the thrust fan system can achieve the expected pressure increase effect after installation. Its air supply principle is similar to that of Example 1.

[0044] When air is supplied to the left, the fan 2 takes in air through the right side. At this time, the negative pressure air inlet valve 17 on the right side needs to be opened and the negative pressure air inlet valve 17 on the left side needs to be closed. Then, two air inlet paths are formed on the right side, which are similar in principle to the air inlet path on the left side.

[0045] like Figure 3As shown, by setting up a static pressure box 15 and connecting it to the installation space via a negative pressure air inlet valve 17, the negative pressure air inlet valve 17 can be opened when air intake is needed at this end, using the negative pressure air inlet valve 17 to compensate for the insufficient air intake of the nozzle pipe 10 at this end, providing sufficient air volume for the fan 2 and reducing the power required by the fan 2; and when air blowing is needed from the nozzle at this end, the negative pressure air inlet valve 17 at this end can be closed to prevent air leakage from the negative pressure air inlet valve 17 at this end, thereby ensuring that the blowing volume is not affected; the round top and square bottom 4 at the air inlet end enhances the air intake effect of the fan 2 and reduces the power required by the fan 2; the round top and square bottom 4 at the air outlet end reduces the wind speed. The increased static pressure allows for better flow through the curved guide pipe 8, reducing losses at the curved guide pipe 8 and further reducing the power required by the fan 2. Then, the accelerated air is accelerated through the acceleration pipe 9 at the outlet end, increasing the air velocity delivered into the main tunnel by the nozzle pipe 10 at the inlet end. This satisfies the longitudinal ventilation volume and velocity requirements in the tunnel under normal or emergency conditions. Through this bidirectional thrust fan system design, the longitudinal ventilation volume and velocity in the tunnel under normal or emergency conditions can be guaranteed while reducing the power required by the fan 2, so that the thrust fan system can achieve the expected pressure increase effect after installation.

[0046] Example 3 like Figures 1-7 As shown, this embodiment provides a design method for a tunnel thrust fan system, used to design a tunnel thrust fan system as described in Embodiment 1 or Embodiment 2, including the following steps: S1: Determine the average wind speed requirement v in the main tunnel 14, the pressure rise requirement ΔP of the tunnel thrust fan system, and the area F of the main tunnel 14. Calculate the required air volume Q of the main tunnel based on the area F and the average wind speed requirement v in the main tunnel 14, where Q = F * v; determine the structural form of the tunnel thrust fan system. In step S1, determining the form of the tunnel thrust fan system includes: determining the airflow organization direction of the main tunnel 14 according to the organization principle of tunnel ventilation; if the airflow in the main tunnel 14 is only organized in the same direction, then the tunnel thrust fan system is a unidirectional thrust fan system; if the airflow in the main tunnel 14 needs to move in one direction along the tunnel axis under different working conditions, then the tunnel thrust fan system is a bidirectional thrust fan system; and determining whether to install silencers 5, silencer foundations 6, connecting short pipes 7, and flexible connections 3 according to requirements. The installation of these components will affect the space length occupied by the tunnel thrust fan system, and thus affect the construction length of the installation space; when the tunnel thrust fan system is a unidirectional thrust fan system, the air inlet collector is determined to be a straight collector, an arc collector, or a round-and-square type 4. S2: Based on the assumed axial tilt angle θ of the nozzle pipe 10 relative to the main tunnel 14, the area ratio m of the nozzle pipe 10 and the main tunnel 14, the air volume ratio n of the nozzle pipe 10 and the main tunnel 14, and the structural form of the tunnel thrust fan system, the boost pressure ΔP' of the tunnel thrust fan system is obtained by solving the momentum theorem. An optional implementation method is to solve the following equations (1.3-2, 1.3-12, 1.3-14, 1.3-15, 1.3-19) and (1.2-3). , , , , , , , Then, according to equations (1.2-1 to 2 or 4), the boost pressure ΔP' of the tunnel thrust fan system can be obtained; Then, it is determined whether ΔP' meets the pressure increase requirement ΔP of the tunnel thrust fan system. If ΔP' < ΔP or ΔP' > 1.1ΔP, step S2 is repeated; if ΔP ≤ ΔP' ≤ 1.1ΔP, step S3 is performed. The design considers ΔP' = ΔP as a critical condition. If ΔP' is significantly higher than ΔP, the design capacity will be excessive, leading to waste. The area ratio m between the nozzle pipe 10 and the main tunnel 14 is... F 0 / F, F 0 represents the cross-sectional area of ​​the nozzle pipe, and F represents the area of ​​the main tunnel 14; the airflow ratio n between the nozzle pipe 10 and the main tunnel 14 is... Q 0 / Q , Q 0 represents the air volume output from the nozzle pipe, and Q represents the air volume required for the main tunnel.

[0047] In step S2, the air velocity at the nozzle outlet is... v The size of 0 is 10 to 40. m / s , v 0= Q 0 / F 0; Nozzle outlet air velocity v The larger the value of 0, the greater the boost pressure that the tunnel thrust fan system can generate, but the greater the resistance loss of the tunnel thrust fan system, thus affecting the range of selectable fans. In step S2, v0 can be calculated by assuming the area ratio m of the nozzle pipe and the main tunnel 14, and the air volume ratio n of the nozzle pipe 10 and the main tunnel 14, such that v0 is within the above-mentioned numerical range; the axial tilt angle of the nozzle pipe 10 relative to the main tunnel 14. θ The angle ranges from 5° to 45°. θThe smaller the value, the longer the enlarged section of tunnel 13 becomes, and the higher the cost of the enlarged section of tunnel 13 becomes. However, the greater the lift pressure generated by the tunnel thrust fan system at this time.

[0048] In step S2, the pressure boosting requirement ΔP' of the tunnel thrust fan system can be calculated using equation (1.2-1):

[0049] In the formula: —Pressure coefficient; —Air density, kg / m 3 ; — Nozzle pipe cross-sectional wind speed m / s ; When the tunnel thrust fan system is placed inside the main tunnel 14 for ventilation, the pressure rise coefficient It can be calculated using the following formula (1.2-2):

[0050] In the formula: — Nozzle tube outlet front edge The cross-sectional area of ​​the ventilation section within the tunnel. m 2 ; —Rear edge of nozzle tube outlet The cross-sectional area of ​​the tunnel under ventilation is within the specified range. m 2 ; —Air passage area of ​​the nozzle tube cross section m 2 ; —Cross-sectional area of ​​the main tunnel m 2 ; —The main tunnel requires ventilation. m 3 / h ; —The angle between the nozzle pipe and the axis of the main tunnel is recommended to be 15° to 30°; — The distance between the silencer and the tunnel wall of the widened section, in mm, is generally taken as 600 mm; —Width of the silencer behind the fan. mm ; The minimum distance from the lower edge of the accelerator tube to the wall of the main tunnel, in mm, is generally taken as 400 mm; —Width of the rear end of the accelerator tube mm ; —Top-down view of the accelerator tube ° ; —Height of the main tunnel mm ; —Wind speed at the silencer section m / s; —The area ratio of the nozzle pipe to the main tunnel; —The air volume ratio between the nozzle pipe and the main tunnel; Figure 9 The diagram shows the design of the nozzle pipe when the thrust fan system is placed inside the main tunnel body for air intake. Various parameters are shown in the diagram.

[0051] In equation (1-2) , It can be calculated using equation (1.2-3):

[0052] In the formula: —Angle between the long side of the nozzle pipe and the tunnel wall of the enlarged section, °; —Height of the rear end of the accelerator tube mm ; —Silencer base height mm ; —Accelerator tube viewed from the front, waist length mm ; —Direct view of the accelerator tube ° ; When the tunnel thrust fan system is placed inside the second tunnel 18 for ventilation, the pressure rise coefficient It can be calculated using the following formula (1.2-4):

[0053] In the formula: —Area of ​​the tunnel section before the nozzle pipe m 2 When the cross-sectional areas of the main tunnel before and after the nozzle pipe are equal, i =1.

[0054] S3: Nozzle tube cross-sectional area when the output ΔP'≥ΔP condition F 0 and nozzle outlet air volume Q 0; S4: Based on the cross-sectional area of ​​the nozzle tube F 0 and nozzle outlet air volume Q 0. Initial selection of fan 2 is carried out, and then the results of the initial selection of fan 2, the structural form of the tunnel thrust fan system, and the cross-sectional area of ​​the nozzle pipe are combined. F 0 and nozzle outlet air volume Q 0. Design the component parameters of the thrust fan system for tunnels; In step S4, the design of component parameters for the tunnel thrust fan system includes: based on the cross-sectional area of ​​the nozzle pipe F 0 and nozzle outlet air volume Q 0. Perform the initial selection of fan 2, and solve the parameters of each component of the tunnel thrust fan system, namely nozzle pipe 10, silencer 5, round and square 4, acceleration pipe 9 and guide pipe 8. Then solve the parameters of each component of silencer foundation 6, fan foundation 1 and nozzle pipe foundation 11. Finally, solve the relevant parameters of the tunnel wall line 12 and the tunnel 13 of the enlarged section.

[0055] When the nozzle pipe 10 is tilted relative to the axial angle of the main tunnel 14 θ When ≥30°, such as Figure 5 and Figure 6 As shown, the guide tube 8 is divided into two segments. The two segments of the guide tube 8 are identical, and the included angle between the two segments is [missing information]. θ / 2; This design can reduce the difficulty of processing, avoid the inability to process the guide pipe 8 due to excessive angle, and at the same time, it can reduce wind resistance and reduce the power required by the fan 2.

[0056] like Figure 7 As shown, based on the axial tilt angle θ of the nozzle pipe 10 relative to the main tunnel 14, and the pipeline space l between the tunnel thrust fan system and the tunnel wall line 12 of the enlarged section, min Given the parameters of nozzle tube 10 and acceleration tube 9, solve for the cross-sectional enlargement angle Φ of the enlarged section tunnel 13.

[0057] Figure 10 The figure shows the detailed design of nozzle pipe 10. The design parameters of nozzle pipe (10) are calculated using formulas (1.3-1 to 1.3-8):

[0058] In the formula: —Air volume from the nozzle tube m 3 / s ; —Air velocity inside the nozzle tube m / s ; —Cross-sectional area of ​​the nozzle tube m 2; —Nose tube cross-sectional width, mm ; — Nozzle tube cross-sectional height, mm ; — Nozzle tube outlet length mm ; —The angle between the nozzle pipe and the axis of the main tunnel; —Length of the short side of the nozzle tube mm ; —Minimum distance from the lower edge of the accelerator tube to the wall line of the main tunnel. mm ; —Length of the long side of the nozzle tube mm ; —Length of the pre-drilled hole in the sidewall of the nozzle tube (if any). mm ; — Height of the pre-drilled hole in the side wall of the nozzle tube (if any). mm ; — Installation length from the centerline of the nozzle tube to the end. mm; Figure 11 For the detailed design of accelerator tube 9, the design parameters of accelerator tube 9 are calculated using formulas (1.3-9 to 1.3-15):

[0059] In the formula: —Accelerate pipe length, mm ; —Height of the silencer behind the fan; —Width of the silencer behind the fan; —Angle of accelerator tube, °, ≤60°; —Accelerator tube positive angle, °, ≤60°; —The projection length of the accelerator tube centerline onto the main tunnel. mm ; —Length of the hypotenuse in the top view of the accelerator tube mm ; —Length of the hypotenuse in the front view of the accelerator tube mm ; —Maximum distance from the lower edge of the accelerator tube to the wall line of the main tunnel, in mm; —Minimum distance from the lower edge of the accelerator tube to the wall line of the main tunnel. mm ; right and It is recommended that when hour, ,when hour, ,when hour, ,when hour, ; Figure 12 For the detailed design of the 8-node guide pipe, the design parameters of the 8-node guide pipe are calculated using formulas (1.3-16 to 1.3-18):

[0060] when θ When ≥30°,

[0061] when θ When the angle is less than 30°, the guide tube does not have an angle.

[0062] In the formula: —The length of the centerline of the guide tube projected onto the horizontal plane. mm ; —Length of the hypotenuse of the accelerator tube mm; The parameters of silencer 5 or connecting short pipe 7 are calculated using formulas (1.3-19 to 1.3-21):

[0063] In the formula: —Height of the silencers or connecting short pipes before and after the fan mm ; —Width of the silencers or connecting short pipes before and after the fan. mm ; —Designed air velocity in the silencers or connecting short pipes before and after the fan. m / s ; —Height of the silencer foundations before and after the fan. mm ; —Width of the silencer foundations before and after the fan. mm ; In the subscript letters x Depending on whether the structure is located in front of or behind the wind turbine, it corresponds to... q or h When designing the silencers before and after the fan, the silencer wind speed should be ≤6. m / s Design; When only short connecting pipes are used before and after the fan, the size of the short connecting pipes can be the same as the size of the silencer, and the length of the short connecting pipes can be flexibly adjusted according to the site conditions; the width and height of the silencer or the short connecting pipes can be flexibly designed according to the actual site conditions; the length of the silencer is designed based on the fan noise spectrum diagram and the noise reduction target; Figure 13 The front and rear sections of the fan are shown in the diagram. The four parameters of the front and rear sections of the fan are calculated using formulas (1.3-22 to 1.3-24):

[0064] In the formula: —Length of the square earth in front of and behind the wind turbine mm ; —Fan diameter mm ; —View from above, ≤60°; —View of a square earth with a round heaven, °, ≤60°; The width of the exit of the square-shaped structure; The height of the exit from the square-shaped, celestial-shaped structure; The inlet velocity of the fan front collector is designed to be ≤8m / s. Figure 14 For the collector design, the parameters of the arc-shaped collector in front of the fan are calculated using formulas (1.3-25 to 1.3-26):

[0065] In the formula: —Collector radian ratio; —Length of the arc-shaped collector in front of the wind turbine mm ; —Inlet diameter of the arc-shaped collector in front of the fan mm .

[0066] S5: Calculate the resistance of the tunnel thrust fan system based on the design results of the component parameters of the tunnel thrust fan system; The resistance calculation for the tunnel thrust fan system, as in the example, involves determining the total resistance of the tunnel thrust fan system based on the solved parameters of the nozzle pipe, silencer, top-to-bottom configuration, acceleration pipe, and guide pipe. The resistance of system components can be calculated using the local resistance coefficient table in the "Practical Heating and Air Conditioning Design Manual." After calculating the component resistances, the total resistance of the thrust fan system can be obtained. S6: Select the model of fan 2 based on the resistance of the tunnel thrust fan system. If the model of fan 2 cannot meet the resistance requirements of the tunnel thrust fan system, then re-assume at least one of the following parameters: the axial tilt angle θ of the nozzle pipe 10 relative to the main tunnel 14, the area ratio m of the nozzle pipe 10 and the main tunnel 14, and the air volume ratio n of the nozzle pipe 10 and the main tunnel 14. Repeat steps S2-S6 until the fan 2 is successfully selected and the design is completed.

[0067] Optionally, the selection of the blower for the tunnel thrust fan system is based on the air volume output from the nozzle pipe. Q 0. Total resistance of the tunnel thrust fan system: Verify the system's parameters. If the pressure head provided by the fan does not meet the total resistance requirements of the tunnel thrust fan system, the nozzle outlet air velocity needs to be re-assumed. v 0. Axial tilt angle of nozzle pipe 10 relative to the main tunnel 14 θ The area ratio of the nozzle pipe and the main tunnel 14 m The air volume ratio between the nozzle pipe 10 and the main tunnel 14 n At least one parameter is used to repeatedly solve the parameters of each component of the tunnel thrust fan system until a tunnel thrust fan system that meets the requirements is found.

[0068] The following describes the design of the above embodiments in conjunction with specific parameters: For example, a tunnel that organizes airflow in a single direction, such as Figure 7 As shown, the cross-sectional area of ​​the main tunnel 14 is F = 20.38 m². 2 The main tunnel 14 has a tunnel height H=4.75m. Through airflow organization design, the wind speed requirement of its main tunnel is... v =5m / s, tunnel pressure rise demand Δ P =40Pa, and the inlet and outlet of fan 2 are designed with noise reduction in mind. Based on the above conditions, a thrust fan system that meets the pressure increase requirements of the tunnel is designed.

[0069] Based on the aforementioned unidirectional airflow organization, the required thrust fan system is determined to be a side-mounted unidirectional thrust fan system, such as... Figure 1As shown, the thrust fan system consists of a fan 2, a fan foundation 1, front and rear flexible connections for the fan 3, front and rear circular and square connections for the fan 4, front and rear silencers for the fan 5, front and rear silencer foundations for the fan 6, connecting short pipes 7, guide pipes 8, acceleration pipes 9, nozzle pipes 10, nozzle pipe foundations 11, enlarged section tunnel wall line 12, enlarged section tunnel 13, and main tunnel 14.

[0070] Based on the cross-sectional area of ​​the main tunnel 14 F =20.38m 2 Main tunnel wind speed requirements v =5m / s, so the air volume of the main tunnel can be calculated as Q = 101.9m. 3 / s. Assuming the axial tilt angle θ of the nozzle pipe 10 relative to the main tunnel 14 is 30°, the area ratio of the nozzle pipe to the main tunnel 14 is... m =0.05, the air volume ratio between nozzle pipe 10 and the main tunnel 14 n = Q 0 / Q =0.32, at which point the cross-sectional area of ​​the nozzle tube can be calculated. F 0 = F * m = 20.38 m 2 *0.05=1.02m 2 Air volume from nozzle pipe Q 0= Q *n=101.9m 3 / s * 0.32 = 32.61m 3 / s, based on the cross-sectional area of ​​the nozzle tube F 0 and nozzle outlet air volume Q 0. Calculate the wind speed at the nozzle cross-section. v 0= Q 0 / F 0 = 32 m / s. When the high-velocity airflow is ejected from the nozzle, the momentum component of the nozzle along the tunnel direction exchanges momentum with the low-velocity airflow in the tunnel in front of the nozzle, causing the static pressure of the air in the tunnel to increase before and after the nozzle. According to equations (1.2-1~2), the pressure rise Δ at this time can be obtained. P’ =29.34Pa<Δ P =40Pa.

[0071] Therefore, it is re-assumed that the axial tilt angle θ of the nozzle pipe 10 relative to the main tunnel 14 is 30°, and the area ratio of the nozzle pipe to the main tunnel 14 is... m =0.05, the air volume ratio between nozzle pipe 10 and the main tunnel 14 n =0.3633, at which point the cross-sectional area of ​​the nozzle tube can be calculated. F 0 = 1.02m 2 Air volume from nozzle pipe Q 0 = 37.02 m³ / s, nozzle cross-sectional wind speed v0 = 36.33 m / s. Solving for the pressure rise Δ, we obtain the pressure rise at this point. P’ =40Pa=Δ P .

[0072] To make the results clearer, this embodiment adjusts the axial tilt angle θ of the nozzle pipe 10 relative to the main tunnel 14 and the area ratio of the nozzle pipe to the main tunnel 14. m The air volume ratio between the nozzle pipe 10 and the main tunnel 14 n To obtain the satisfaction Δ P Different nozzle cross-sectional areas at 40 Pa F 0. Nozzle pipe air volume Q 0 and nozzle cross-sectional wind speed v 0, the results are shown in Table 1 below: Table 1, satisfying Δ P Different nozzle cross-sectional areas at 40 Pa F 0. Nozzle pipe air volume Q 0 and nozzle cross-sectional wind speed v 0 Indication Table

[0073] Further, based on result 1 in Table 1, a preliminary selection of the fan was made, and the fan number 16# was initially selected, with a diameter of 1610mm and a length of 1150mm.

[0074] Furthermore, the space between the thrust fan system and the tunnel wall for pipelines... min =0.6m (meeting minimum equipment installation and pipeline space requirements), based on the obtained nozzle pipe and acceleration pipe parameters, solve for the enlargement angle Φ of the enlarged cross-section. = 139.9°, combined with the parameters of each component of the thrust fan, the enlarged cross-sectional dimensions of the enlarged section tunnel 13 can be calculated.

[0075] Furthermore, the parameters of each component—the nozzle pipe, silencer, front and rear circular and square sections of the fan, acceleration pipe, and guide pipe—are solved sequentially. The air velocity across the silencer section is designed to be 5.5 m / s. The local resistance and friction loss of the thrust fan system components are shown in Table 2 below, with the total pressure of the thrust fan selected at 658 Pa. When the air velocity at the nozzle pipe section... v 0 is relatively large (e.g.) v When the speed is 0=50m / s, the total pressure of the fan will exceed 1500Pa. At this time, it is difficult to select the fan type. It is necessary to adjust the axial tilt angle θ of the nozzle pipe 10 relative to the main tunnel 14 and the area ratio of the nozzle pipe to the main tunnel 14. m The air volume ratio between the nozzle pipe 10 and the main tunnel 14 n To ensure that the wind turbine theme is selectable, therefore v 0 is recommended, with a value of 10-40. m / s。

[0076] Table 2. Local resistance and frictional resistance of components in the thrust fan system, Result 1.

[0077] Furthermore, since the larger the angle of the guide tube, the greater its local resistance coefficient, this invention requires... θ When the angle is ≥30°, the guide tube is divided into angles. In the calculation of result 1, the guide tube has already been divided into angles.

[0078] By adopting the above-mentioned design method for tunnel thrust fan system, the structural form and parameters of each component of tunnel thrust fan system can be designed systematically, and the selection of fan 2 can be guaranteed.

[0079] To ensure the design and application effectiveness of the thrust fan system, this invention proposes a thrust fan system for tunnels and its design method, which standardizes and modularizes the design of the thrust fan system and its components, fundamentally improving the design theory of the thrust fan system.

[0080] 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 design method for a thrust fan system for tunnels, characterized in that, For designing a tunnel thrust fan system, the tunnel thrust fan system includes a fan (2), the fan (2) being fixed to an installation space by a fan foundation (1), the installation space being located in a second tunnel (18) connected to the side of the main tunnel (14) or located outside the side or above the top surface of the main tunnel (14); The tunnel thrust fan system is either a unidirectional thrust fan system or a bidirectional thrust fan system. When the tunnel thrust fan system is a unidirectional thrust fan system, one end of the fan (2) is connected to the air inlet collector, and the other end is connected in sequence to the round and square (4), the guide pipe (8), the acceleration pipe (9) and the nozzle pipe (10). The end of the air inlet collector connected to the fan (2) is smaller than the other end of the air inlet collector. When the tunnel thrust fan system is a bidirectional thrust fan system, the fan (2) is a reversible bidirectional fan. Both ends of the fan (2) are connected outward in sequence to the top and bottom (4), static pressure box (15), guide pipe (8), acceleration pipe (9) and nozzle pipe (10). The static pressure box (15) is fixed to the installation space through the static pressure box foundation (16). The static pressure box (15) is connected to the installation space through the negative pressure air inlet valve (17). Wherein, the end of the round-and-square (4) connected to the fan (2) is smaller than the end of the round-and-square (4) connected to the guide pipe (8), the guide pipe (8) is bent or bent toward the main tunnel (14), the end of the acceleration pipe (9) connected to the guide pipe (8) is larger than the end of the acceleration pipe (9) connected to the nozzle pipe (10), the nozzle pipe (10) is inclined relative to the axial direction of the main tunnel (14), the nozzle pipe (10) is fixed to the installation space through the nozzle pipe foundation (11) corresponding to the fan (2), and the nozzle pipe (10) is connected to the main tunnel (14). Includes the following steps: S1: Determine the average wind speed requirement v in the main tunnel (14), the pressure rise requirement ΔP of the tunnel thrust fan system, and the area F of the main tunnel (14). Calculate the required air volume Q of the main tunnel based on the area F of the main tunnel (14) and the average wind speed requirement v in the main tunnel (14). Determine the structural form of the tunnel thrust fan system. S2: Based on the assumed axial tilt angle θ of the nozzle pipe (10) relative to the main tunnel (14), the area ratio m of the nozzle pipe (10) and the main tunnel (14), the air volume ratio n of the nozzle pipe (10) and the main tunnel (14), and the structural form of the tunnel thrust fan system, the boost pressure ΔP' of the tunnel thrust fan system is obtained according to the momentum theorem. Then, it is determined whether ΔP' meets the boost pressure requirement ΔP of the tunnel thrust fan system. If ΔP' < ΔP or ΔP' > 1.1ΔP, then step S2 is repeated; if ΔP ≤ ΔP' ≤ 1.1ΔP, then step S3 is entered. S3: Nozzle tube cross-sectional area when output ΔP≤ΔP'≤1.1ΔP condition F 0 and nozzle outlet air volume Q 0; S4: Based on the cross-sectional area of ​​the nozzle tube F 0 and nozzle outlet air volume Q 0. Conduct preliminary selection of fan (2), and then combine the preliminary selection results of fan (2), the structural form of the tunnel thrust fan system, and the cross-sectional area of ​​the nozzle pipe. F 0 and nozzle outlet air volume Q 0. Design the component parameters of the thrust fan system for tunnels; S5: Calculate the resistance of the tunnel thrust fan system based on the design results of the component parameters of the tunnel thrust fan system; S6: Select the model of the blower (2) according to the resistance of the tunnel thrust blower system. If the model of the blower (2) cannot meet the resistance requirements of the tunnel thrust blower system, then assume at least one of the following parameters: the axial tilt angle θ of the nozzle pipe (10) relative to the main tunnel (14), the area ratio m of the nozzle pipe (10) and the main tunnel (14), and the air volume ratio n of the nozzle pipe (10) and the main tunnel (14). Repeat steps S2-S6 until the blower (2) is successfully selected and the design is completed. Nozzle outlet air velocity v The size of 0 is 10 to 40. m / s , v 0= Q 0 / F 0; In step S2, v0 can be calculated by assuming the area ratio m of the nozzle pipe and the main tunnel (14) and the air volume ratio n of the nozzle pipe (10) and the main tunnel (14), such that v0 is within the above-mentioned numerical range; the axial tilt angle of the nozzle pipe (10) relative to the main tunnel (14) θ The angle ranges from 5° to 45°. In step S2, the pressure boosting requirement ΔP' of the tunnel thrust fan system can be calculated using equation (1.2-1): In the formula: —Up pressure coefficient; —Air density; —Wind speed at the nozzle cross section.

2. The design method of a tunnel thrust fan system according to claim 1, characterized in that, In step S1, determining the form of the tunnel thrust fan system includes: determining the airflow organization direction of the main tunnel (14) according to the organization principle of tunnel ventilation; if the airflow in the main tunnel (14) is only organized in the same direction, then the tunnel thrust fan system is a unidirectional thrust fan system; if the airflow in the main tunnel (14) needs to move in one direction along the tunnel axis under different working conditions, then the tunnel thrust fan system is a bidirectional thrust fan system; when the tunnel thrust fan system is a unidirectional thrust fan system, the air inlet collector is determined to be a straight collector, an arc collector, or a round-and-square type (4); and whether to install a silencer (5), a silencer foundation (6), a connecting short pipe (7), and a flexible connection (3) according to the requirements. When the tunnel thrust fan system is placed inside the main tunnel (14) for air intake, the pressure rise coefficient It can be calculated using the following formula (1.2-2): In the formula: — Nozzle tube outlet front edge The cross-sectional area of ​​the ventilation section within the tunnel; —Rear edge of nozzle tube outlet The cross-sectional area of ​​the ventilation section within the tunnel; —Air passage area of ​​the nozzle tube cross section; —Cross-sectional area of ​​the main tunnel; —The main tunnel requires a certain amount of ventilation; —The angle between the nozzle pipe and the axis of the main tunnel; —Distance between the silencer and the wall of the widened tunnel section; —Width of the silencer behind the fan; —Minimum distance between the lower edge of the accelerator tube and the wall of the main tunnel; —Width of the rear end of the accelerator tube; —The top-down view of the accelerator tube; —Height of the main tunnel; —Wind speed at the silencer section; —The area ratio of the nozzle pipe to the main tunnel; —The air volume ratio between the nozzle pipe and the main tunnel; In equation (1-2) , It can be calculated using equation (1.2-3): In the formula: —The angle between the long side of the nozzle pipe and the tunnel wall of the enlarged section; —Height of the rear end of the accelerator tube; —Silencer foundation height; —Accelerator tube viewed from the front, waist length; —Direct viewing angle of the accelerator tube; When the tunnel thrust fan system is placed in the second tunnel (18) for air intake, the pressure coefficient is increased. It can be calculated using the following formula (1.2-4): In the formula: —The area of ​​the tunnel section before the nozzle pipe, when the cross-sectional areas of the main tunnel before and after the nozzle pipe are equal. i =1; In step S4, the design of component parameters for the tunnel thrust fan system includes: based on the cross-sectional area of ​​the nozzle pipe F 0 and nozzle outlet air volume Q 0. Perform initial selection of the fan (2), and solve the parameters of each component of the thrust fan system for tunnels in sequence, including nozzle pipe (10), silencer (5), round and square (4), acceleration pipe (9) and guide pipe (8). Then solve the parameters of each component of silencer foundation (6), fan foundation (1) and nozzle pipe foundation (11) in sequence. Finally, solve the relevant parameters of the tunnel wall line (12) and the tunnel (13) of the enlarged section. The design parameters of the nozzle tube (10) are calculated using formulas (1.3-1 to 1.3-5 and 1.3-8): In the formula: —Air volume output from the nozzle tube; —Air velocity inside the nozzle tube; —Cross-sectional area of ​​the nozzle tube; —Nose tube cross-sectional width; — Nozzle tube cross-sectional height; — Nozzle tube outlet length; —The angle between the nozzle pipe and the axis of the main tunnel; —Length of the short side of the nozzle tube; —Minimum distance between the lower edge of the accelerator tube and the wall of the main tunnel; —Length of the long side of the nozzle tube; — Installation length from the centerline of the nozzle tube to its end ； The design parameters of the accelerator tube (9) are calculated using formulas (1.3-9 to 1.3-15): In the formula: —Accelerate pipe length; —Height of the silencer behind the fan; —Width of the silencer behind the fan; —Accelerator tube top view ≤60°; —Accelerating the positive angle of view ≤60°; —The projection length of the centerline of the accelerator tube onto the main tunnel; —Length of the hypotenuse in the top view of the accelerator tube; —Length of the hypotenuse in the front view of the accelerator tube; —The maximum distance between the lower edge of the accelerator tube and the wall line of the main tunnel; —Minimum distance between the lower edge of the accelerator tube and the wall of the main tunnel; for and ,when hour, ,when hour, ,when hour, ,when hour, ; The design parameters of the guide pipe (8) are calculated using formulas (1.3-16 to 1.3-18): when θ When ≥30°, when θ When the angle is less than 30°, the guide tube does not have an angle. In the formula: —The length of the centerline of the guide tube projected onto the horizontal plane; —Length of the hypotenuse of the accelerator tube ； The parameters of the silencer (5) or connecting short pipe (7) are calculated using formulas (1.3-19 to 1.3-21): In the formula: —Height of the silencers or connecting short pipes before and after the fan; —Width of the silencers or connecting short pipes before and after the fan; —Designed wind speed in the silencers or connecting short pipes before and after the fan; —Height of the silencer foundations at the front and rear of the fan; —Width of the silencer foundations in front of and behind the fan; The parameters of the front and rear of the fan (4) are calculated using formulas (1.3-22 to 1.3-24): In the formula: —Length of the square area in front of and behind the wind turbine; —Fan diameter; —A bird's-eye view of a round heaven and a square earth ≤60°; —A true perspective of the concept of a round heaven and a square earth. ≤60°; The width of the exit of the square-shaped structure; The height of the exit from the square-shaped, celestial-shaped structure; The inlet velocity of the fan front collector is designed to be ≤8m / s. The parameters of the arc-shaped collector in front of the wind turbine are calculated using formulas (1.3-25 to 1.3-26): In the formula: —Collector radian ratio; —Length of the arc-shaped collector in front of the fan; —Inlet diameter of the arc-shaped collector in front of the fan.

3. The design method of a tunnel thrust fan system according to claim 2, characterized in that, When the nozzle pipe (10) is tilted at an axial angle relative to the main tunnel (14) θ When the angle is ≥30°, the guide tube (8) is divided into angles. At this time, the two angle-dividing components of the guide tube (8) are the same, and the included angle of the two angle-dividing components is ≥30°. θ / 2; Based on the axial tilt angle θ of the nozzle pipe (10) relative to the main tunnel (14), and the pipeline space l between the tunnel thrust fan system and the tunnel wall line (12) of the enlarged section, min Given the parameters of the nozzle tube (10) and the acceleration tube (9), solve for the cross-sectional enlargement angle Φ of the enlarged section tunnel (13).

4. The design method of a tunnel thrust fan system according to claim 1, characterized in that, When the tunnel thrust fan system is a unidirectional thrust fan system, the air inlet collector is a straight collector, an arc collector, or a round-and-square type (4).

5. The design method of a tunnel thrust fan system according to claim 4, characterized in that, When the air inlet collector is an arc-shaped collector, the radius of the arc of the arc-shaped collector is... r The diameter of the fan (2) D The ratio between r / D ≥0.

2.

6. The design method of a tunnel thrust fan system according to claim 1, characterized in that, The round-and-square structure (4) is connected to the fan (2) via a flexible connector (3); And / or, the guide pipe (8) is connected to a connecting short pipe (7) at one end near the fan (2).

7. The design method of a tunnel thrust fan system according to claim 1, characterized in that, It also includes a silencer (5). When the tunnel thrust fan system is a unidirectional thrust fan system, the silencer (5) is installed at the end of the air inlet collector and / or the round-and-square (4) away from the fan (2). When the tunnel thrust fan system is a bidirectional thrust fan system, at least one of the round top and square bottom (4) at both ends of the fan (2) is provided with the silencer (5) at the end away from the fan (2).

8. The design method of a tunnel thrust fan system according to claim 1, characterized in that, The installation space is the enlarged section tunnel (13) protruding from the side of the main tunnel (14) or the excavated space above the main tunnel (14); When the tunnel thrust fan system is a unidirectional thrust fan system, the fan (2) is installed horizontally in the enlarged section tunnel (13), or the fan (2) is installed vertically or horizontally in the excavated space above the main tunnel (14). When the fan (2) is installed vertically in the excavated space above the main tunnel (14), the air intake collector is connected to the outside of the tunnel. When the tunnel thrust fan system is a bidirectional thrust fan system, the fan (2) is installed horizontally in the enlarged section tunnel (13) or in the excavated space above the main tunnel (14).

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