A induced-injection ventilation and smoke exhaust system for spiral tunnels

Abstract

The present invention discloses an ejection type ventilation and smoke exhaust system for a spiral tunnel, and belongs to the technical field of tunnel smoke exhaust systems. It comprises a spiral tunnel, and an airflow ejection ventilation and smoke exhaust device installed along the top of the spiral tunnel, wherein the airflow ejection ventilation and smoke exhaust device is composed of a plurality of groups of linear jet fan units and a plurality of groups of airflow ejection devices, and a group of airflow ejection devices is arranged between each two adjacent groups of linear jet fan units; the airflow ejection device is composed of a collector, an axial flow fan, a muffler, and a subsonic nozzle, and along the smoke exhaust direction, the collector, the axial flow fan, the muffler, and the subsonic nozzle are sequentially connected by flange sealing. By adding an airflow ejection device between two adjacent groups of linear jet fan units, the polluted air in the spiral tunnel is relayed step by step until the polluted air or smoke in the tunnel is discharged out of the tunnel, and a faster airflow can be generated, thereby overcoming the resistance of the spiral tunnel and achieving a better smoke exhaust effect.

Description

Technical Field

[0001] The invention relates to an ejection type ventilation and smoke exhaust system for a spiral tunnel, belonging to the technical field of tunnel smoke exhaust systems. Background Art

[0002] The main structure of the spiral tunnel is a plane curve with a longitudinal slope. When a vehicle is driving in a spiral tunnel, whether it is an uphill tunnel or a downhill tunnel, it always drives along the plane curve and longitudinal slope of the tunnel; for an uphill tunnel, the concentration and amount of automobile exhaust emissions gradually increase as the tunnel is extended and dispersed along the tunnel, making dilution very difficult; for a high-altitude spiral tunnel on a plateau, the atmospheric pressure in the uphill tunnel gradually decreases along the direction of vehicle travel, and the total air volume demand in the tunnel increases. The longer the tunnel, the greater the ventilation resistance of the plane curve pipe network, the greater the difficulty of ventilation and smoke exhaust, and the heavier the load of ventilation and smoke exhaust in tunnel operation. All jet fans used in straight tunnels cannot meet the ventilation and exhaust requirements of spiral tunnels.

[0003] The existing straight tunnel ventilation method is to install jet fans on the top of the straight tunnel, two in a group. The air inlet and outlet directions of the jet fans are consistent with the driving direction of the tunnel, that is, completely consistent with the direction of the tunnel line. The airflow ejected by the jet fan generates thrust. As the jet velocity decreases, its kinetic energy is transferred along the air in the tunnel, thereby causing the air to flow in the tunnel. The pressure difference in the tunnel is equal to the quotient of the fan thrust and the current cross-sectional area of ​​the tunnel. This pressure difference is used to overcome the resistance of air flow in the tunnel. The air flow direction in a straight tunnel is always straight, and the air flow resistance is low. The use of straight jet fans can fully meet the needs of straight tunnel operation ventilation.

[0004] However, the ventilation requirements of spiral tunnels are different. For spiral tunnels, the air flow in the tunnel is always changing direction. The air flow resistance in the spiral tunnel is greater than that in the straight tunnel, and the kinetic energy required for the air flow in the spiral tunnel is also greater than that in the straight tunnel. A higher fan outlet wind speed is required in the spiral tunnel to meet the ventilation and smoke exhaust requirements during tunnel operation. The thrust and outlet wind speed provided by the linear jet fan cannot fully meet the ventilation and smoke exhaust requirements of the spiral tunnel operation; after the air flow resistance in the spiral tunnel is determined, the higher the fan outlet wind speed, the greater the airflow kinetic energy provided; therefore, a induced ventilation and smoke exhaust system for spiral tunnels is designed, which is a ventilation and smoke exhaust system that combines a linear tunnel jet fan with an airflow induced ventilation device. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an ejection type ventilation and smoke exhaust system for a spiral tunnel, which solves the problem that the smoke exhaust effect of the current spiral tunnel smoke exhaust system needs to be improved.

[0006] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0007] A induced-air ventilation and smoke exhaust system for a spiral tunnel, comprising a spiral tunnel and an airflow induced-air ventilation and smoke exhaust device installed along the top of the spiral tunnel, wherein the airflow induced-air ventilation and smoke exhaust device comprises a plurality of groups of linear jet fan units and a plurality of groups of airflow induced-air exhaust devices, wherein a group of airflow induced-air exhaust devices is arranged between each two adjacent groups of linear jet fan units;

[0008] The airflow ejection device is composed of a collector, an axial flow fan, a muffler, and a subsonic nozzle. Along the smoke exhaust direction, the collector, the axial flow fan, the muffler, and the subsonic nozzle are sequentially connected through flange sealing.

[0009] As a preferred example, the linear jet fan unit is composed of at least two side-by-side axial flow fans.

[0010] As a preferred example, a protective net is provided at the air inlet end of the collector.

[0011] As a preferred example, the linear jet fan unit and the airflow ejection device are both fixed to the top of the spiral tunnel via a suspension rod.

[0012] The beneficial effects of the present invention are as follows: the linear jet fan unit and the airflow introduction device are staggered in coordination, and the linear jet fan unit blows the polluted air or smoke in the tunnel to the airflow introduction device. The airflow blown to the airflow introduction device enters the axial flow fan through the collector, is accelerated and pressurized, flows into the muffler, and after the comprehensive noise of the airflow is eliminated, enters the subsonic nozzle for acceleration, and the airflow ejected by the subsonic nozzle forms a larger airflow outlet dynamic pressure, which drives the airflow around the airflow introduction device to flow, thereby increasing the airflow speed in the introduced area, and the airflow at the subsonic nozzle outlet flows to the next group of linear jet fan units together with the introduced airflow; by adding the airflow introduction device between two adjacent groups of linear jet fan units, the polluted air in the spiral tunnel is relayed step by step until the polluted air or smoke in the tunnel is discharged out of the tunnel, and a faster airflow can be generated, thereby overcoming the resistance of the spiral tunnel and achieving a better smoke exhaust effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a side structural schematic diagram of the present invention;

[0014] Figure 2 It is a schematic diagram of the top structure of the present invention.

[0015] In the figure: spiral tunnel 1, vault 11, driving road surface 12, linear jet fan unit 2, air flow guide device 3, collector 4, axial flow fan 5, muffler 6, subsonic nozzle 7. DETAILED DESCRIPTION

[0016] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0017] like Figure 1 , Figure 2 As shown, a induced-air ventilation and smoke exhaust system for a spiral tunnel comprises a spiral tunnel 1, and an airflow induced ventilation and smoke exhaust device installed along the top of the spiral tunnel 1, the airflow induced ventilation and smoke exhaust device comprises a plurality of groups of linear jet fan units 2 and a plurality of groups of airflow induced devices 3, and a group of airflow induced devices 3 is arranged between each two adjacent groups of linear jet fan units 2; the top of the spiral tunnel 1 is a vault 11, and the bottom is a driving road surface 12;

[0018] The airflow ejection device 3 is composed of a collector 4, an axial flow fan 5, a muffler 6, and a subsonic nozzle 7. Along the smoke exhaust direction, the collector 4, the axial flow fan 5, the muffler 6, and the subsonic nozzle 7 are sequentially connected through flange seals.

[0019] The linear jet fan unit 2 is composed of at least two axial flow fans 5 arranged side by side.

[0020] A protective net (not shown) is arranged at the air inlet end of the collector 4.

[0021] The linear jet fan unit 2 and the airflow ejection device 3 are both fixed to the top of the spiral tunnel 1 through a suspension rod.

[0022] The arrows in the figure indicate the direction of smoke exhaust and driving.

[0023] Example

[0024] Collector 4: The collector 4 is arranged before the air inlet of the axial flow fan 5. A protective net is arranged at the air inlet end of the collector 4. The diameter of the air inlet of the collector 4 is taken to be more than 1.5 times the diameter of the configured axial flow fan 5. The protective net is used to prevent large debris (plastic bags, etc.) from entering the ventilation system during tunnel operation;

[0025] Axial flow fan 5: Axial flow fan 5 is one of the main components of airflow ejection device 3. High-speed airflow ejection device 3 is equipped with low-noise axial flow fan 5. The diameter of axial flow fan 5 is not more than 1000mm, the motor power is not more than 22KW, and the air volume is not less than 23m 3 / s, the fan outlet wind speed is not less than 30m / s, and the fan speed is not more than 960rpm;

[0026] Muffler 6: arranged at the air outlet of the axial flow fan 5, connected to the flange of the axial flow fan 6, the length of the muffler 6 is the same as the diameter of the axial flow fan 5, and is used to eliminate the comprehensive noise at the air outlet of the axial flow fan 5;

[0027] Subsonic nozzle 7: It is a pipe with a gradually decreasing cross-sectional area, which continuously accelerates the subsonic airflow. The speed increase of the subsonic airflow in the convergent nozzle flow channel is limited. The airflow speed on the minimum cross-sectional area (on the air outlet) can only reach the speed of sound at most. At this time, the Mach number on the outlet cross section is 1; the Mach number of the subsonic nozzle 7 configured by the high-speed airflow injection system 3 is not greater than 1, and the flow speed in the entire subsonic nozzle 7 is subsonic. The wind speed at the outlet of the subsonic nozzle 7 depends on the air volume of the selected axial flow fan 5 and the area ratio of the minimum cross-sectional area of ​​the nozzle to the cross-sectional area of ​​the air outlet of the axial flow fan 5; for the high-speed airflow injection system for the spiral tunnel, the area ratio is taken as 0.3-0.5, and for the axial flow fan 5 with an outlet wind speed of 30m / s, the outlet wind speed of the subsonic nozzle 7 is 60m / s-100m / s;

[0028] Linear jet fan unit 2: The linear jet fan unit 2 still uses two axial flow fans 5 arranged in a group.

[0029] Working principle: the linear jet fan unit 2 and the airflow ejection device 3 are staggered and matched. The linear jet fan unit 2 blows the polluted air or smoke in the tunnel to the airflow ejection device 3. The airflow blown to the airflow ejection device 3 enters the axial flow fan 5 through the collector 4, and after acceleration and pressurization, it flows into the muffler 6. After the comprehensive noise of the airflow is eliminated, it enters the subsonic nozzle 7 for acceleration. The airflow ejected by the subsonic nozzle 7 forms a larger airflow outlet dynamic pressure, which drives the airflow around the airflow ejection device 3 to flow, thereby increasing the airflow speed in the ejected area. The airflow at the outlet of the subsonic nozzle 7 flows to the next group of linear jet fan units 2 together with the ejected airflow; by adding the airflow ejection device 3 between two adjacent groups of linear jet fan units 2, the polluted air in the spiral tunnel 1 is relayed step by step until the polluted air or smoke in the tunnel is discharged out of the tunnel, which can generate an airflow with a faster flow rate, thereby overcoming the resistance of the spiral tunnel 1 and achieving a better smoke exhaust effect.

[0030] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A induced-flow ventilation and smoke exhaust system for a spiral tunnel, comprising a spiral tunnel and an airflow induced-flow ventilation and smoke exhaust device installed along the top of the spiral tunnel, characterized in that: The airflow-inducing ventilation and smoke exhaust device is composed of multiple groups of linear jet fan units and multiple groups of airflow-inducing devices, and a group of airflow-inducing devices is arranged between each two adjacent groups of linear jet fan units; the airflow-inducing device is composed of a collector, an axial flow fan, a muffler, and a subsonic nozzle, and along the smoke exhaust direction, the collector, the axial flow fan, the muffler, and the subsonic nozzle are connected in sequence through flange sealing; the linear jet fan unit is composed of at least two side-by-side axial flow fans; a protective net is arranged at the air inlet end of the collector; By adopting the staggered matching mode of linear jet fan units and airflow ejection devices, the linear jet fan units blow the polluted air or smoke in the tunnel to the airflow ejection devices. The airflow blown to the airflow ejection devices enters the axial flow fan through the collector, is accelerated and pressurized, flows into the muffler, and after the comprehensive noise of the airflow is eliminated, enters the subsonic nozzle for acceleration. The airflow ejected by the subsonic nozzle forms a larger airflow outlet dynamic pressure, which drives the airflow around the airflow ejection device, thereby increasing the airflow speed in the ejected area. The airflow at the subsonic nozzle outlet flows to the next group of linear jet fan units together with the ejected airflow. By adding an airflow ejection device between two adjacent groups of linear jet fan units, the polluted air in the spiral tunnel is relayed step by step until the polluted air or smoke in the tunnel is discharged out of the tunnel, which can generate an airflow with a faster flow rate.

2. According to claim 1, the induced ventilation and smoke exhaust system for a spiral tunnel is characterized in that: The linear jet fan unit and the airflow ejection device are both fixed to the top of the spiral tunnel through a suspension rod.

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