A transverse-driving longitudinal double-tunnel ventilation system with some air flow holes taking a shortcut

Abstract

The present invention relates to a transverse-driving longitudinal double-tunnel ventilation system with some air flow openings taking a short cut and short-circuiting. The double-tunnel includes two tunnels separated by a middle partition wall. A number of transverse fan modules for conducting the air paths of the two tunnels of the double-tunnel are arranged along the length direction on the middle partition wall. One tunnel facing the suction port of the fan module is the intake tunnel, and the other tunnel facing the exhaust port of the fan module is the exhaust tunnel. During ventilation operation, the fan module sucks the intake tunnel into negative pressure, establishing a pressure difference between the two openings of the intake tunnel and the suction inlet of the fan module, so that fresh air flows continuously into the intake tunnel from the two openings at both ends of the intake tunnel, boosts the exhaust tunnel to positive pressure, and establishes a pressure difference between the exhaust port of the fan module and the two openings of the exhaust tunnel, so that the polluted air is discharged from the two openings at both ends of the exhaust tunnel along the exhaust tunnel.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel ventilation, and particularly relates to a transverse-driven longitudinal double-tunnel ventilation system with a short-cut for part of the air flow at the tunnel openings. Background Art

[0002] With the modernization of China's transportation system, there are more and more highway and railway tunnels passing through mountains, underwater railway and highway tunnels crossing large rivers, and low-level subway (light rail) tunnels in urban underground spaces, etc. This has fundamentally changed people's ways of transportation and logistics models, and has also fundamentally changed people's spatial concepts regarding cities and the distances between cities.

[0003] Currently, there are more and more tunnel projects, and the importance of the tunnel ventilation system as a life support system has become more prominent as the designed length of the tunnel gets longer. The ventilation methods for highway tunnels can be divided into three basic modes: longitudinal, semi-transverse, and fully transverse, each with its own advantages and disadvantages. From the perspective of the fire prevention and smoke exhaust effects and the hygiene conditions inside the tunnel, the semi-transverse and fully transverse ventilation system solutions are more suitable. However, such solutions require the construction of a pilot tunnel parallel to the tunnel or the installation of air ducts on the tunnel dome as dedicated channels for supplying and / or exhausting air to the tunnel, resulting in higher costs in the construction, ventilation equipment, and operation management aspects. The longitudinal ventilation solution, although having lower costs in the construction and operation aspects, has a relatively poor fire prevention and smoke exhaust effect as the length of the fire section in the tunnel is the same as the length of the tunnel.

[0004] In the past twenty years, the fully transverse and semi-transverse ventilation methods have gradually declined in highway tunnel construction, and the longitudinal ventilation system has become the mainstream mode of highway tunnel ventilation in China.

[0005] Reference Figure 1 , the jet fans 20 are installed in groups on the ceiling of the highway tunnel 10 in a distributed manner, one after another, for relay transportation, pushing the air inside the tunnel 10 to flow in the forward direction.

[0006] The following is an actual case of a highway tunnel ventilation system.

[0007] According to the February 2006 issue of "Central South Highway Engineering", a certain extra-long tunnel is located on the Lianyungang - Khorgos National Highway. The total length of the left line of the tunnel is 12,205 m, with a one-way slope of -1.64%, a maximum buried depth of about 489 m, and a maximum fresh air demand of 651 m 3 / s. Two vertical shafts are set up, and three-stage ventilation is adopted. The two vertical shaft fan rooms are equipped with 4 axial fans with a total of 380 kw. At the same time, 32 jet fans with a total of 960 kw are configured at intervals along the tunnel direction. For every 1 m of the left line of the tunnel 3 / s of fresh air requires a power load consumption of 2 kw; the total length of the right line of the tunnel is 12,260 m, with a one-way slope of +1.62%, a maximum buried depth of 477 m, and a fresh air demand of 962 m3 / s, the 3 - shaft vertical shafts adopt four - stage ventilation. The fan rooms of the 3 vertical shafts are equipped with 6 axial - flow fans with a total of 2490 kw, and 30 jet fans with a total of 900 kw are configured at intervals along the tunnel direction. The average fresh air volume of 1 m 3 / s of fresh air requires a power load of 3.5 kw.

[0008] Under the technical condition that a total of 5 ventilation vertical shafts are set on the left and right lines of this tunnel, the length of each independent ventilation section of the tunnel has been reduced to less than 4 km, and the tunnel cross - section wind speed has been reduced to about 4 m / s (secondary wind). The average fresh air volume of 1 m 3 / s of fresh air still requires power loads as high as 2.5 kw and 3.5 kw respectively. The average fresh air volume of 1 m 3 / s of fresh air has an electricity load of around 3.0 kw, and the total load of the ventilation system is as high as 4730 kw. The load configuration seriously exceeds the normal range;

[0009] According to the tunnel air - flow resistance formula ⊿P=(1 + ξ+λL / D)·ρ / 2·ν 2 , in the formula, "1" and "ξ" in the brackets are the local resistance coefficients of the tunnel outlet and inlet openings respectively. ξ generally takes 0.5; "λ" is the friction coefficient between the tunnel air - flow and the tunnel wall surface, usually between 0.022 - 0.025, dimensionless; "L" and "D" are the length of the tunnel between the openings and the equivalent diameter of the tunnel cross - section. For a two - lane tunnel, the D value is taken as 8; "ρ" and "ν" are the density and velocity of the air - flow in the tunnel. The air - flow resistance of the 4 independent ventilation sections separated by 3 ventilation vertical shafts on the right line of this tunnel=(1 + 0.5+0.025×3000 / 8)×1.2 / 2×4 2 =104.4 pa, and the air volume Q = 962 m3 / s / 4 = 240.5 m 3 / s. The effective power of the fan group to overcome the air - flow tunnel resistance of a single independent ventilation section on the right line is ⊿P×Q = 104.4 pa×240.5 m 3 / s = 25.1 kw; for the 7 independent ventilation sections of the 5 vertical shafts on the left and right lines of this tunnel, taking the upper limit calculation, the total effective power is 7×25.1 = 175.8 kw; assuming that 50% of the above - mentioned total fan load is used as the standby load and only half is actually in operation, the ventilation energy efficiency η of this tunnel = total effective power / total load = 175.8 / 4730 / 2 = 7.4%. The energy efficiency is too low, and the tunnel operation cost remains high. The ventilation system plan of this tunnel needs to be re - examined and studied from a new perspective.

[0010] During the process of research, promotion and application of the longitudinal ventilation mode in highway tunnels in the past two decades, many major theoretical and practical problems have been encountered, mainly:

[0011] ① How to reduce wind resistance and improve tunnel ventilation energy efficiency

[0012] During the operation of the longitudinal tunnel ventilation system, how to improve the overall ventilation efficiency; how to reduce the local resistance caused by the reduction of the suction port and the expansion of the outlet of the jet fan, how to reduce the friction between the jet and the tunnel dome, and how to measure and prevent the air flow short - circuit between the positive - pressure outlet and the negative - pressure suction port;

[0013] According to the tunnel air flow resistance formula ⊿P=(1 + ξ+λL / D)·ρ / 2·ν 2 , ν is generally 6m / s (level - 3 wind), which is equivalent to the air volume at the tunnel entrance of about 400m 3 / s; calculated in this way, the maximum total resistance of the ventilation section with a length of 4000m between two groups of openings (vertical and inclined shafts are also openings) is around 300pa; the total effective power of the fan N to overcome this total resistance is N = ⊿P×Q, where Q is the ventilation volume. As mentioned above, the fresh air volume Q of the independent ventilation section of the 4000m - long tunnel is about 400m 3 / s. Based on this, the value of the total effective power of single - tunnel ventilation N(=⊿P×Q) is around 120kw, and for double - tunnels it is around 240kw. These are the calculated values under the condition of very large traffic flow and ventilation volume, and they are about 1 / 6 of the ventilation power actually configured in current tunnel projects.

[0014] ② How to unify and combine the four openings of the double - tunnels

[0015] In a one - way double - tunnel highway tunnel, how to re - position the functional roles of the four openings of the double - tunnels in tunnel ventilation. Set up multiple transverse fan modules on the partition wall in the double - tunnel. Set one tunnel as an intake tunnel with air entering from both ends, and the other tunnel as an exhaust tunnel with air exhausting from both ends. The fan modules create a "dam - type" air pressure difference between their own outlets and inlets to drive the air flow along the tunnel, implementing a ventilation mode that combines vertical and horizontal ventilation with horizontal ventilation driving vertical ventilation; combine the double - tunnels to achieve "1 + 1>2"; and so on.

[0016] The ventilation system of highway tunnels, especially extra - long buried - depth highway tunnels, is a life - support system for reducing the concentration of pollutants discharged by vehicles in the tunnel and for implementing rescue in case of fire, accounting for more than 1 / 3 of the investment in extra - long tunnels; in the past thirty years, technical problems and technological problems in tunnel boring construction and rock surface anchoring construction have been successfully solved, and the tunnel ventilation system problem has become a technical focus and difficulty in the design of the highway system.

[0017] China is a mountainous country. The construction of highway tunnels, especially extra - long buried - depth tunnels, has just started and has a long way to go; theoretical research and technical development on the ventilation system of highway tunnels, creating new ventilation modes, reducing ventilation resistance and improving ventilation efficiency, will provide basic technical support for the construction of China's high - speed transportation system. Summary of the Invention

[0018] In order to solve the above problems, the present invention provides a ventilation system for a longitudinal double-tunnel with a horizontal drive and a partial airflow opening. The double-tunnel comprises two tunnels separated by a middle partition wall. A plurality of transverse fan modules are arranged along the length direction of the middle partition wall for connecting the two tunnel air paths of the double-tunnel. The tunnel to which the air intake of the fan module faces is an air intake tunnel, and the other tunnel to which the air outlet of the fan module faces is an air exhaust tunnel.

[0019] During ventilation operation, the transversely arranged fan module draws the air inlet tunnel into negative pressure, establishes a pressure difference between the two ends of the air inlet tunnel and the suction port of the fan module, so that the fresh air flows from the two ends of the air inlet tunnel continuously along the air inlet tunnel, boosts the pressure of the exhaust tunnel to become positive pressure, establishes a pressure difference between the exhaust port of the fan module and the two ends of the exhaust tunnel, and causes the polluted air to be discharged from the two ends of the exhaust tunnel along the exhaust tunnel, thereby realizing "horizontal driving vertical".

[0020] Preferably, a plurality of the fan modules are sequentially spaced apart from the middle of the double-hole tunnel to the middle partition wall between the two end openings, and driven by a plurality of parallel fan modules, a stepped air pressure difference distribution with a large pressure difference in the middle and a small pressure difference at both ends is established in the two tunnels.

[0021] Preferably, during ventilation operation, the fresh air flow, under the action of the pressure difference between the two openings at the two ends of the air inlet tunnel and the suction port of the fan module in the middle of the air inlet tunnel, flows from the two openings of the air inlet tunnel to the middle, and passes through the suction ports of the multiple fan modules arranged in parallel in the air inlet tunnel in sequence, and is sucked in and pressurized before being sent into the exhaust tunnel; under the action of the pressure difference between the middle and the two openings of the exhaust tunnel, the ventilation air flow starts to move from the middle of the exhaust tunnel to the two openings at the two ends, and along the way, the airflow sent into the air inlet tunnel by each fan module is gathered to reduce the pollutant concentration of the front-end airflow, and finally is discharged from the two openings of the exhaust tunnel as polluted air.

[0022] Preferably, during ventilation operation, part of the fresh air flow near the openings at both ends of the air inlet tunnel is pressurized by a fan module near the openings of the air inlet tunnel, and is input into the exhaust tunnel nearby to dilute the concentration of harmful components in the air at the end of the exhaust tunnel; and the discharge position of this part of the fresh air flow in the exhaust tunnel is also close to the openings at both ends of the exhaust tunnel, thereby realizing "ultra-close short-circuiting of part of the air flow openings".

[0023] Preferably, a first fan module is provided in the middle of the middle partition wall, and a second fan module, ..., an Nth fan module are sequentially and spaced apart on the middle partition wall from the first fan module to the two end openings of the double-hole tunnel, where N is an integer greater than 2.

[0024] Preferably, the first fan module is located in the very middle of the middle partition wall, and the fan modules on both sides of the first fan module are distributed in a one-to-one correspondence.

[0025] Preferably, each of the first fan module to the Nth fan module includes at least one fan.

[0026] Preferably, the number of fans in the second fan module to the Nth fan module on both sides of the first fan module is the same.

[0027] Preferably, the first fan module includes at least two first fans that rotate in one direction and at least one standby fan that can rotate forward and backward.

[0028] Preferably, a transverse-driving and longitudinal double-tunnel ventilation system with a short-cut for some air flow openings is applied to a double-tunnel with a length not exceeding 6 km and a fresh air demand of less than 600 m 3 / s or less.

[0029] Compared with the existing longitudinal tunnel ventilation technology, the present invention has the following technical effects:

[0030] ① The ventilation resistance is reduced, and the tunnel operation energy consumption is greatly reduced.

[0031] In the traditional longitudinal tunnel ventilation system, only the mutual friction and diffusion of the high-speed gas jet generated by the jet fan on the tunnel dome and the low-speed air flow in the main tunnel body can be used to drive the low-speed air flow in the main tunnel to accelerate forward, resulting in local resistance at the suction inlet and the expansion of the outlet of the jet fan in the tunnel air flow, generating a periodic longitudinal and transverse alternating velocity gradient field in the tunnel, resulting in an increase in the Reynolds number of the tunnel air flow, a serious local turbulent state, and a high-intensity noise above 80 dB, leading to resistance, friction, vortices, and mutual diffusion between air flow layers with different speeds. These phenomena are the fundamental reasons for the low air flow transportation efficiency and should be avoided as much as possible during the fluid transportation process;

[0032] Due to the combined setting of multiple transverse fan modules in the present invention, a part of the ventilation air flow near the two openings of the intake tunnel is boosted by the transverse fan modules near the openings of the intake tunnel and then input into the exhaust tunnel nearby, diluting the concentration of harmful components in the air at the end of the exhaust tunnel and improving the air quality at the end of the exhaust tunnel. Moreover, the position where this part of the ventilation air flow is discharged into the exhaust tunnel is also close to the two discharge openings at both ends of the exhaust tunnel, significantly reducing the path length of this part of the air flow, thereby further reducing the air flow rate, operating resistance, and ventilation energy consumption in the middle of the intake and exhaust tunnels, and realizing a cross-driven longitudinal tunnel ventilation mode with part of the air flow taking a short cut. This not only saves a large amount of air flow transportation power compared with the traditional longitudinal tunnel ventilation system, and saves more than 2 / 3 of the ventilation operation energy consumption of the traditional tunnel jet fan group; even compared with the cross-driven longitudinal highway tunnel fresh air system with a single transverse fan module, due to the short cut of part of the air flow at the tunnel opening and the reduction of the air pressure difference in the middle of the double-tunnel, it still saves more than 1 / 3 of the ventilation operation energy consumption.

[0033] ② Substantially reduce the infrastructure investment in the tunnel ventilation system

[0034] The present invention relates to a cross-driven longitudinal double-tunnel ventilation system with part of the air flow taking a short cut at the tunnel opening. The tunnel is the air duct, and the tunnel opening is the air inlet and outlet, realizing the integration of the air duct and the tunnel. The present invention has better compatibility with future wide-section tunnels with more than three one-way lanes.

[0035] The present invention relates to a cross-driven longitudinal double-tunnel ventilation system with part of the air flow taking a short cut at the tunnel opening, which is applied to double-tunnel with a length not exceeding 6 km, a traffic volume near 24,000 Pcu / d (equivalent number of vehicles per day), and a fresh air demand of less than 600 m 3 / s. It does not require ventilation facilities such as vertical shafts, inclined shafts, parallel adits, air supply ducts, and exhaust ducts, saving more than 2 / 3 of the infrastructure investment in the tunnel ventilation system.

[0036] For ultra-long tunnels with a length of more than 6 km, the cross-driven longitudinal double-tunnel ventilation system with part of the air flow taking a short cut in the present invention, combined with vertical shafts and inclined shafts, can operate in a segmented air supply and exhaust mode, reducing the number of vertical (inclined) shafts, and still having obvious competitive advantages in terms of investment amount, operating economy and other indicators.

[0037] ③ Stable throttling, flat interface pushing, and power dispersion

[0038] The present invention provides a ventilation system for a longitudinal double-hole tunnel with a horizontal drive, in which a part of the airflow openings are short-circuited. The transverse fan module establishes a "dam-type" air pressure difference between its own outlet and inlet, and between its own inlet and outlet and the tunnel opening to drive the airflow to move along the tunnel. A plurality of parallel transverse fan modules jointly drive the air flow in the longitudinal slender tunnel to form a long snake array airflow pattern. Due to the space constraints and resistance constraints of the huge wall of the longitudinal slender tunnel, the long snake array airflow is continuously throttled and stabilized. At any vertical section of the tunnel other than the singular points such as the air intake and exhaust ports of the transverse fan modules and dynamic vehicles, the airflow velocity at the front, rear, upper and lower positions of the section is uniform, without significant airflow vortices and significant mixed friction between multiple strands and multiple layers of airflows with different speeds, presenting an airflow pattern of expansion-type parallel propulsion of the air interface in the tunnel.

[0039] The invention discloses a ventilation system for a longitudinal double-hole tunnel with a horizontal drive and a short-circuit of some air flow openings. The system utilizes a middle partition wall to establish a "dam-type" air pressure difference to drive the airflow to perform interface expansion parallel propulsion motion along the tunnel. The airflow resistance and friction loss are greatly reduced, and the system has a strong anti-interference ability to the alternating pressure of the ambient atmosphere that may exist outside the tunnel opening: the airflow in the air inlet tunnel is pushed horizontally from the openings at both ends to the middle of the air inlet tunnel to perform full-section expansion propulsion under the combined action of the atmospheric pressure at the openings at both ends and the negative pressure difference at the air intake ports of a plurality of parallel transverse fan modules; the airflow in the exhaust tunnel is pushed horizontally from the middle of the tunnel to the openings at both ends to perform full-section expansion propulsion under the combined action of the positive pressure at the outlets of a plurality of parallel transverse fan modules and the atmospheric pressure difference at the openings at both ends. The invention also greatly reduces the deafening noise of more than 80dB of the jet fan in the longitudinal ventilation tunnel, and fundamentally improves the acoustic environment in the tunnel.

[0040] The invention discloses a transversely driven longitudinal double-tunnel ventilation system with a partial airflow opening being short-circuited. Since a plurality of transverse fan modules are used between the air inlet tunnel and the air exhaust tunnel, the system is reduced in size and is also conducive to arranging the fan modules and the fan air inlets and outlets in a narrow tunnel space, thereby achieving a decentralized ventilation power layout.

[0041] ④The length of the tunnel fire section is shortened by half

[0042] The present invention relates to a ventilation system for a double - hole tunnel with a combined horizontal - driving and vertical - wind tunnel, in which some air - flow openings take a short - cut to drive the longitudinal wind. On the "tunnel section" between the two ends of the openings (including the vertical - shaft and inclined - shaft openings), a plurality of transverse - fan modules are arranged. The intake tunnels with air intake at both ends are divided into two sections with air - flow moving relatively to form a parallel relationship of the intake air paths. The exhaust tunnels with air exhaust at both ends are divided into two sections with air - flow moving in opposite directions to form a parallel relationship of the exhaust air paths. If a fire occurs at any position in the exhaust tunnel, the smoke can be discharged through a path less than half of the "tunnel section between the two ends of the openings". If a fire occurs at any position in the intake tunnel, the fire - control system immediately shuts down all unidirectional fans and closes the air ducts, and all forward - and - reverse fan modules (including the vertical - shaft and inclined - shaft fan modules) operate in reverse to swap the functions of the intake tunnel and the exhaust tunnel. Still, the smoke can be discharged through a path less than half of the "tunnel section", thereby shortening the length of the "fire section" of the tunnel by half and reducing the smoke - diffusion length by half when a fire occurs, which is very beneficial for disaster control and rescue.

[0043] The present invention relates to a double - hole tunnel ventilation system with a combined horizontal - driving and vertical - wind tunnel, in which some air - flow openings take a short - cut, and it is compatible with the existing tunnel ventilation design specifications, construction specifications, and detection specifications.

[0044] Of course, when implementing any product of the present invention, it is not necessarily required to achieve all the above - mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following - described drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings. In the drawings:

[0046] Figure 1 It is a schematic structural diagram of a unidirectional tunnel with longitudinal ventilation using jet fans in the prior art;

[0047] Figure 2 It is a schematic diagram of the air - flow resistance of a streamlined vehicle body;

[0048] Figure 3 It is a curve graph of the air - pressure change when a vehicle passes through a tunnel section equipped with a pressure sensor;

[0049] Figure 4 It is a schematic diagram of the longitudinal air - flow in a tunnel driven by a jet - fan group;

[0050] Figure 5 It is a schematic diagram of a high - speed jet of about 35 m / s, accounting for about 1 / 10, ejected by a jet fan in the tunnel driving a main - body low - speed air - flow of 6 m / s, accounting for 9 / 10, through friction and diffusion;

[0051] Figure 6 Schematic diagram of the structure and operating pressure of a transverse-driving longitudinal double-tunnel ventilation system with some air flow openings taking a shortcut

[0052] Figure 7 Schematic diagram of the structure of a transverse-driving longitudinal double-tunnel ventilation system with some air flow openings taking a shortcut provided for Preferred Embodiment 2 of the present invention

[0053] Figure 8 Schematic diagram of the air flow operation of a transverse-driving longitudinal double-tunnel ventilation system with some air flow openings taking a shortcut provided for Preferred Embodiment 2 of the present invention

[0054] Figure 9 Distribution map of the pollutant concentration inside the tunnel of a transverse-driving longitudinal double-tunnel ventilation system with some air flow openings taking a shortcut provided for Preferred Embodiment 2 of the present invention Detailed implementation manners

[0055] For a transverse-driving longitudinal double-tunnel ventilation system with some air flow openings taking a shortcut of the present invention, its technical premise is that, under the current highway tunnel design specifications, the traffic wind generated by vehicle driving in ultra-long buried tunnels is actually very weak and difficult to utilize; the tunnel jet fan group cannot establish a "dike-type" air pressure difference between its own outlet and inlet, and between the outlet and the tunnel opening to drive the air flow forward. Instead, it can only drive the main low-speed air flow to accelerate forward by the mutual friction and diffusion penetration between the high-speed gas jet accounting for about 1 / 10 produced by the fan and the main low-speed air flow accounting for 9 / 10 in the tunnel, which greatly reduces the energy efficiency of the air flow relay transportation inside the tunnel.

[0056] The double - hole tunnel consists of two tunnels separated by a middle partition wall. The technical core of a double - hole tunnel ventilation system with a partial air - flow short - cut at the tunnel openings, which drives the longitudinal airflow horizontally, is to set several transverse fan modules on the middle partition wall of the double - hole tunnel. (In engineering, generally, the longer direction is the longitudinal direction and the shorter direction is the transverse direction. Therefore, in the present invention, the length direction of the double - hole tunnel is longer and is the longitudinal direction; the width direction of the middle partition wall is shorter and is the transverse direction. Thus, the setting direction of the fan modules is transverse. The setting direction of the fan modules is perpendicular to the length direction of the double - hole tunnel.) The fan modules are used to connect the two tunnel air paths of the double - hole tunnel. The present invention utilizes the "dam" function of the middle partition wall and the pumping effect of the fan modules to create a negative pressure in one tunnel opposite to the suction port of the fan module, establishing a pressure difference between the two openings of this tunnel and the suction inlet of the fan, so that the fresh air at the two openings of the negative - pressure tunnel continuously replenishes longitudinally along this negative - pressure tunnel. (Since the negative - pressure tunnel is used to replenish fresh air, it is also called the intake tunnel.) The other tunnel opposite to the exhaust port of the fan module is pressurized to become a positive - pressure tunnel, establishing a pressure difference between the exhaust port of the fan module and the two openings of this positive - pressure tunnel, so that the polluted air is discharged longitudinally from the two openings along this positive - pressure tunnel. (Since the polluted air is discharged from the positive - pressure tunnel, it is also called the exhaust tunnel.) Implement a ventilation mode of "driving the longitudinal tunnel airflow horizontally" by the transverse fan modules; on the basis of creating a "dam - type" air pressure difference between the exhaust port and the suction port of the transverse fan modules themselves in the "driving the longitudinal airflow horizontally" ventilation mode and driving the airflow to move longitudinally along the tunnel by this pressure difference, directly inject the fresh - air airflow near the two openings of the negative - pressure tunnel into the positions near the two openings of the positive - pressure tunnel through the corresponding fan modules in a short - cut manner to dilute the high - pollutant - concentration exhaust air at this position, implementing "partial air - flow short - cut at the tunnel openings". This not only shortens the path length of this part of the airflow in the tunnel and reduces the frictional resistance, but also reduces the air volume and velocity of the airflow flowing from the middle section of the tunnel to the two openings, thereby reducing the airflow resistance in the middle section of the tunnel and the pressure difference between the middle section of the tunnel and the two openings at the ends of the tunnel, achieving the goal of significantly reducing ventilation energy consumption.

[0057] One of the technical prerequisites of the present invention is that under the current highway tunnel design specifications, the traffic wind generated by vehicle driving in deep - long tunnels is very weak and difficult to utilize, so the tunnel ventilation direction can be decoupled from the traffic flow direction. The algorithm formula for the traffic - wind force in deep - long tunnels under the current highway tunnel design specifications:

[0058] △P t =A m / A r ·ρ / 2·n c ·(ν t -ν r ) 2

[0059] In the formula, A m —Vehicle equivalent impedance area, A r—Tunnel cross-sectional area, ρ—Air density, n c —Number of vehicles in the tunnel, ν t —Vehicle running speed, ν r —Airflow speed in the tunnel.

[0060] On the surface, this formula synthesizes various aerodynamic factors of traffic wind in the tunnel, where: A m / A r reflects the driving coefficient of running vehicles on the air in the tunnel, ρ reflects the inertia of the air, n c reflects the frequency of the vehicle flow in the tunnel driving the air flow, (ν t -ν r ) 2 reflects the tangential force of the vehicle on the air flow. However, there are many problems with this formula. Some problems are technical, and some are fundamental: ① This formula does not involve the air viscosity coefficient, which is an expression of the frictional characteristics of the air; ② This formula does not consider the absorption of the positive pressure air flow in front of the vehicle by the negative pressure vortex behind the running vehicle; ③ Most importantly, as Figure 2 shown, this formula does not consider the factors that the streamlined design of the vehicle and the new achievements of the vehicle body material have greatly reduced the air resistance of vehicle operation, and the reaction force of this air resistance is the so-called vehicle traffic wind force; for the vast majority of vehicles, the front of the vehicle is not a flat plate with an area of A m but a wedge that penetrates into the air. The wedge moves forward and squeezes the air, and the negative pressure vortex behind the vehicle absorbs the air squeezed out by the wedge and pushed around. The above three points show that the concepts, models, and algorithms of "traffic wind" are not rigorous, and its role in the ventilation operation of current highway tunnel design specifications is obviously overestimated; coupled with the strict speed limits in tunnels by the traffic management department, all below 80 km / h, the role of vehicle traffic wind in tunnels has become very weak. As Figure 3 shown, the air pressure changes when the vehicle passes through a tunnel section equipped with a pressure sensor: the pressure suddenly rises when the front of the vehicle passes through the section, and the pressure drops rapidly and then rebounds quickly when the rear of the vehicle passes through the section, which proves the existence of the negative pressure vortex behind the vehicle and the absorption of the positive pressure air flow in front of the vehicle by the negative pressure vortex.

[0061] In short highway tunnels, due to the small cross-sectional area and small resistance in the tunnel, and the two ends of the tunnel are open to the atmosphere, the vehicle traffic wind effect is good and easy to observe; however, long tunnels and extra-long tunnels are not the arithmetic sum of short tunnels. Long tunnels and extra-long tunnels are still the same as short tunnels, with only two openings open to the atmospheric environment, the tunnel interior is closed, the cross-sectional area is large, the air flow resistance is large, and the vehicle body, whose cross-sectional area is only about 1 / 20 of the tunnel section, is still streamlined. The traffic wind power generated by several dynamic isolated points where the vehicles are running in the tunnel is easily absorbed by the negative pressure vortex behind the vehicle and the tunnel and cannot develop into a continuous overall movement.

[0062] The second technical premise of the present invention is that the jet fan group of the tunnel longitudinal ventilation system can only drive the main body of the low-speed air flow to accelerate forward by the mutual friction and diffusion and penetration of the high-speed gas jet and the low-speed air flow in the tunnel main body, which greatly reduces the energy efficiency of the relay transportation of the air flow inside the tunnel.

[0063] The interval between the jet fans in the tunnel is mostly more than 100 m, and the diameter of the impeller of the jet fan is mostly about 1000 mm. The cross-sectional area of the fan itself is only about 1 / 100 of the cross-sectional area of the tunnel (the cross-sectional area of a single-tunnel with two lanes is about 65 ㎡). Even if two jet fans are set in a group, it is only about 1 / 50; in actual operation, about 1 / 10 of the flow rate in the cross-section of about 65 ㎡ in the tunnel is the low-speed air flow inhaled and pressurized by the jet fan group to become a high-speed jet of about 35 m / s. After the high-speed jet is ejected, it mutually rubs and diffuses and penetrates with the main body of the low-speed air flow in the tunnel accounting for about 9 / 10 to exchange energy, driving the main body of the low-speed air flow to accelerate forward until the speed of the high-speed jet decreases to close to the speed of the main body of the low-speed air flow and the driving force fails; then, about 1 / 10 of the low-speed air flow is inhaled, boosted, and accelerated by the next jet fan group to start the next driving and accelerating cycle of the main body of the low-speed air flow in the tunnel.

[0064] Since it is necessary to ensure that the main body space of the tunnel under the jet fan group is completely unobstructed and no cross-section for realizing the tunnel closure can be set, the jet fan group cannot establish a "dam-type" air pressure difference between its own inlet and outlet or between the outlet and the tunnel entrance to drive the air flow forward. It can only drive the main body of the low-speed air flow to accelerate forward by the mutual friction, diffusion, and penetration of the high-speed gas jet produced by the fan and the low-speed air flow in the tunnel main body, resulting in local resistance to the contraction of the air flow at the suction inlet and the expansion at the outlet of the jet fan in the tunnel, generating a periodic longitudinal and transverse alternating velocity gradient field in the tunnel, generating a deafening noise above 80 dB, and causing friction, vortices, and mutual diffusion between air flow layers with different speeds; these effects are superimposed, and the jet fan increases the pressure of the air flow in the tunnel little but consumes a large amount of mechanical energy of the high-speed gas jet, greatly reducing the energy efficiency of the relay transportation of the air flow inside the tunnel. Please refer to Figure 4 and Figure 5 .

[0065] The main model of the jet fan for highway tunnels is SDS-№10, usually two in a group, and its main parameters are diameter φ1000 mm, outlet air speed 33.8 m / s, air volume 26.5 m 3 / s, axial thrust 924 N, power 30 kw, and shaft power 18.19 kw.

[0066] If the total length of a single-tunnel is 4000 m, the cross-sectional area is 65 ㎡, and the required fresh air volume is 400 m 3 / s, the tunnel air velocity is 6.1 m / s, and the total resistance is ΔP r =(1 + ξ + λL / D)·1 / 2·ρ·ν 2 = 312.6 pa; If a jet fan group composed of 2 jet fans of the above model SDS-№10 in each group is used for longitudinal propulsion, the propulsion air pressure generated by this jet fan group is calculated by the following formula:

[0067] ΔP j = ρ·V j 2 ·A j / A r ·(1 - V r / V j )·η

[0068] Where: ρ—the air density, 1.2 kg / m 3 ; V j —the outlet air velocity of the jet fan, 33.8 m / s;

[0069] Vr—the designed tunnel air velocity, 6.1 m / s;

[0070] Aj—the outlet area of the jet fan, 0.78 m 2 ; 2 in a group, a total of 1.56 ㎡;

[0071] Ar—the tunnel cross-sectional area, 66.0 ㎡; η—the reduction coefficient of frictional resistance loss at the jet fan position, 0.9.

[0072] Substitute the above data related to the tunnel and air flow, and calculate ΔP j = 24 pa.

[0073] It can be concluded that for a 4000 m long tunnel using longitudinal ventilation, the fresh air volume is 400 m / s, the air velocity is 6.1 m / s, and the number of jet fan groups required for the whole process n = ΔP r / ΔP j = 312.6 / 24 = 13 groups, and the total power of all jet fan groups in the tunnel is as high as 13×2×30 = 780 kw.

[0074] If the power module of the tunnel ventilation is reformed, instead of relying on the friction and diffusion of the high-speed jet of about 35 m / s accounting for 1 / 10 to drive the low-speed main air flow of 6 m / s accounting for 9 / 10, but setting up a transverse fan module on the partition wall in the double-hole tunnel, and using the partition wall to establish a "dam-type" air pressure difference between the double-hole tunnels to drive the longitudinal movement of the air in the tunnel, then a transverse fan power module with the same power consumption as the above SDS-№10 jet fan group is used to provide the static pressure head and dynamic pressure head of all fresh air volume of 400 m 3 / s, the outlet air velocity is 6.1 m / s, and the static pressure generated to push the air flow is calculated by the following formula:

[0075] ⊿P=static pressure energy N / total air volume Q

[0076] = (shaft power equivalent to the jet fan unit - airflow kinetic energy) / total air volume

[0077] =(2×18.19×1000-1 / 2×1.2×400×6.1 2 )w / 400m 3 / s

[0078] =68.6pa

[0079] The two ventilation methods are compared, that is, the tunnel longitudinal ventilation system adopts the ventilation mode that the friction and diffusion between the 35m / s high-speed jet accounting for about 1 / 10 and the main low-speed airflow accounting for about 6m / s accounting for about 9 / 10 to drive the low-speed airflow, and the mode in which a transverse fan module is set on the middle partition wall of the double-hole tunnel and the middle partition wall is used to establish a "dam-like" air pressure difference between the double-hole tunnels to drive the longitudinal movement of the air in the tunnel. For the fan unit with the same shaft power, the latter establishes a "dam-like" air pressure difference between its own outlet and inlet, and between the inlet and the tunnel entrance to drive the tunnel airflow forward. The driving force ⊿P is ΔP of the jet fan unit in the former longitudinal ventilation system. j 2.86 times of that of the former; and, in addition to the driving force ⊿P provided, the latter also provides a dynamic pressure head of 6.1m / s to the entire fresh air flow, while the high-speed jet dynamic pressure head of the former is converted into a low-speed airflow driving force ΔP j Then return to zero.

[0080] Based on the analysis of the above two technical premises, i.e., the wind force formula of vehicle traffic wind in the tunnel does not involve the air viscosity coefficient, does not consider the absorption of the positive pressure airflow in front of the vehicle by the negative pressure vortex behind the running vehicle, does not consider the streamlined design of the vehicle and the new achievements of the body material that greatly reduce the air resistance factor of vehicle operation, and the analysis of the low-energy-efficiency ventilation mode of the existing tunnel longitudinal ventilation system that can only drive the main low-speed airflow to accelerate forward through the mutual friction and penetration of a small part of the high-speed jet and the low-speed airflow of the tunnel main body, the present invention is a horizontally driven longitudinal double-hole tunnel ventilation system with a short circuit of some airflow openings, which no longer takes the consistency of the ventilation airflow in the tunnel with the vehicle traffic wind as a design principle, and the tunnel ventilation airflow can be in the same direction as the vehicle flow or in the opposite direction to the vehicle flow; the present invention arranges a plurality of parallel horizontal fan modules on the middle partition wall of the double-hole highway tunnel as the distributed parallel power for the ventilation airflow in and out of the double-hole tunnel, drives the air in the double-hole tunnel to flow into from the two openings of one tunnel, discharge into another tunnel at multiple points, and then discharge from the two openings of the tunnel, implementing the "horizontally driving longitudinal" ventilation mode;

[0081] The present invention relates to a transverse-driving longitudinal double-tunnel ventilation system with some air flow holes taking a short cut. Using the middle partition wall of the double-tunnel as a "dam" to block the reflux of ventilation air flow, under the drive of multiple parallel transverse fan modules, a stepped air pressure difference distribution is established in the two tunnels, with a large pressure difference in the middle and small pressure differences at both ends. Relative to the ambient atmospheric pressure, a negative-pressure tunnel for introducing fresh air and a positive-pressure tunnel for discharging polluted air are constructed. Fresh air is inhaled from the two end holes of the negative-pressure tunnel and flows towards the middle of the tunnel. The negative-pressure tunnel serves as the intake tunnel of the double-tunnel ventilation system. Under the action of the pressure difference between the two end holes of the negative-pressure tunnel and the suction inlet of the middle fan module in the negative-pressure tunnel, during the process of flowing from the two end holes of the negative-pressure intake tunnel towards the middle, the fresh air flow sequentially passes through the suction inlets of multiple parallel transverse fan modules in the intake tunnel, is inhaled and pressurized, and then sent to the positive-pressure tunnel on the other side of the middle partition wall. The positive-pressure tunnel is the exhaust tunnel of the double-tunnel ventilation system. In the exhaust tunnel, under the action of the pressure difference between the middle of the exhaust tunnel and the two end holes of the exhaust tunnel, the ventilation air flow starts to move from the middle section of the exhaust tunnel towards the two end holes of the exhaust tunnel, collecting the air flow sent from each fan module from the negative-pressure intake tunnel along the way to reduce the pollutant concentration of the front-end air flow, and finally discharging the polluted air from the two end holes of the exhaust tunnel.

[0082] In a transverse-driving longitudinal double-tunnel ventilation system with some air flow holes taking a short cut according to the present invention, some fresh air flow near the two end holes of the intake tunnel is pressurized by the transverse fan module near the end holes of the intake tunnel, and is input into the exhaust tunnel nearby to dilute the concentration of harmful components in the air at the end of the exhaust tunnel, improve the air quality at the end of the exhaust tunnel, and the discharge position of this part of the fresh air flow in the exhaust tunnel is also close to the two end holes of the exhaust tunnel, greatly reducing the path length of this part of the ventilation air flow, thereby reducing the air velocity, air flow rate and operating resistance of the middle and outer tunnel sections of the intake tunnel and the exhaust tunnel, and realizing the "partial air flow taking a short cut and transverse-driving longitudinal tunnel ventilation mode".

[0083] The following will describe in detail a transverse-driving longitudinal double-tunnel ventilation system with some air flow holes taking a short cut provided by the present invention. This embodiment is implemented on the premise of the technical solution of the present invention, and gives the detailed implementation method and specific operation process. However, the protection scope of the present invention is not limited to the following embodiments. Those skilled in the art can modify and polish it without changing the spirit and content of the present invention.

[0084] Embodiment 1

[0085] In this embodiment, a transverse-to-longitudinal double-tunnel ventilation system with some air flow taking a short cut at the tunnel openings is presented. The technical premise is that under the current highway tunnel design specifications, the traffic wind generated by vehicles driving in long and deep tunnels is very weak and difficult to utilize. The tunnel ventilation air flow can be in the same direction as or opposite to the vehicle traffic wind. Also, the jet fan group of the longitudinal ventilation system cannot establish a "dam-type" air pressure difference between the fan outlet and inlet, or between the outlet and the tunnel opening to drive the air flow movement. Instead, it can only drive the main low-speed air flow in the tunnel to accelerate forward by the mutual friction and diffusion penetration between the high-speed gas jet accounting for about 1 / 10 produced by the fan and the 9 / 10 main low-speed air flow in the tunnel, which greatly reduces the energy efficiency of the air flow relay transportation inside the tunnel.

[0086] The technical core of a transverse-to-longitudinal double-tunnel ventilation system with some air flow taking a short cut at the tunnel openings in this embodiment is to set up a transverse fan module on the middle partition wall of the double-tunnel. By using the "dam" function of the middle partition wall and the pumping function of the fan module, the tunnel opposite to the suction port of the fan module is pumped into a negative pressure, so that the fresh air at both ends of the negative pressure tunnel continuously replenishes along this longitudinal tunnel. The tunnel opposite to the exhaust port of the fan module is pressurized to become a positive pressure tunnel, and the polluted air is longitudinally discharged from both ends of the tunnel along this positive pressure tunnel, implementing the "transverse-to-longitudinal" ventilation mode of driving the longitudinal tunnel air flow by the transverse fan module. On the basis of establishing a "dam-type" air pressure difference between the exhaust port and the suction port of the transverse fan module itself created by the "transverse-to-longitudinal" ventilation mode, and between the exhaust port and the suction port and the tunnel openings respectively, and driving the air flow to move longitudinally along the tunnel by this pressure difference, the fresh air flow at both ends of the negative pressure tunnel close to the tunnel openings is directly injected into the positions close to the tunnel openings at both ends of the positive pressure tunnel through the corresponding fan module in a short cut to dilute the high-pollutant-concentration exhaust air at this position, implementing "some air flow taking a short cut at the tunnel openings". This not only shortens the path length of this part of the air flow and reduces the frictional resistance along the way, but also reduces the air volume and wind speed flowing from the middle section of the tunnel to both ends of the tunnel, thereby reducing the air flow resistance in the middle section of the tunnel and the pressure difference between the middle section of the tunnel and both ends of the tunnel, achieving the goal of greatly reducing the ventilation energy consumption.

[0087] In this embodiment, several of the said fan modules are sequentially and spacedly arranged on the partition wall between the two ends of the double-hole tunnel starting from the middle of the double-hole tunnel. Specifically, several ventilation ducts for connecting the tunnel air paths on both sides of the partition wall are arranged on the partition wall, and the fan modules are installed in the ventilation ducts. The fan module includes at least one fan. The fan is arranged in the ventilation duct. One of the tunnels facing the air suction port of the fan is the incoming air tunnel, and the other tunnel facing the air discharge port of the fan is the exhaust air tunnel. In this embodiment, the number of fan modules on the partition wall is not specifically limited and can be set according to the actual length of the tunnel. The number of fan modules can be an even number or an odd number; for the fan modules on the partition wall from the middle to both sides, the number can be equal or unequal, and they can be symmetrically arranged or asymmetrically arranged. This embodiment does not specifically limit this and can be set according to the traffic volume and fresh air demand in the tunnel. For example, a first fan module is provided in the middle of the said partition wall, and second fan modules, …, Nth fan modules are also sequentially and spacedly arranged on the partition wall from the first fan module to the two ends of the double-hole tunnel. The first fan module can be in the very middle of the partition wall, and second fan modules, …, Nth fan modules are sequentially and spacedly arranged between the first fan module and the two ends of the partition wall respectively; or the first fan module is not in the very middle of the partition wall but on both sides of the very middle of the partition wall, that is, the first fan modules are spacedly arranged on both sides of the very middle of the partition wall, that is, two first fan modules are arranged in the middle of the partition wall, and second fan modules, …, Nth fan modules are sequentially and spacedly arranged between the first fan module and the opening of the partition wall on this side. In this embodiment, N is an integer greater than 2. The first fan module to the Nth fan module all include at least one fan.

[0088] As an embodiment, please refer to Figure 6 , taking the partition wall 12 of the double-hole tunnel 1 as a "dam" to block the reflux of ventilation air flow, 5 transverse fan modules are arranged on the partition wall 12, namely the first fan module 2 located in the middle of the partition wall 12, and the second fan module 3 and the third fan module 4 are sequentially arranged from the first fan module 2 to both ends of the partition wall 12. The air volumes of the four fan modules (two second fan modules 3 and two third fan modules 4) on the left and right sides of the partition wall 12 are equal, and the air volume of the first fan module 2 is twice that of the second fan module 3. Driven by the 5 parallel transverse fan modules in this embodiment, a partial air flow short circuit near the opening is implemented on the basis of transverse driving in the longitudinal direction, and a stepped air pressure difference distribution is established in the two tunnels (the two single-hole tunnels on both sides of the partition wall 12, one is the exhaust air tunnel 11 and the other is the incoming air tunnel 13). The pressure difference is large in the middle and small at both ends, and a negative pressure tunnel for introducing fresh air and a positive pressure tunnel for discharging dirty air are constructed relative to the ambient atmospheric pressure.

[0089] In this embodiment, fresh air is inhaled from the two ends of the negative-pressure tunnel and flows towards the middle of the tunnel. This negative-pressure tunnel serves as the intake tunnel 13 of the double-tunnel ventilation system. During the process of the air flow flowing from the two ends of the intake tunnel 13 towards the middle, it sequentially passes through the suction ports of 5 juxtaposed transverse fan modules in the intake tunnel 13. After the inhaled air flow is pressurized, it is then sent to the positive-pressure tunnel on the other side of the middle partition wall 12. This positive-pressure tunnel is the exhaust tunnel 11 of the double-tunnel ventilation system. In the exhaust tunnel 11, the ventilation air flow moves towards the two ends of the tunnel, and along the way, it gathers the air flows sent from each transverse fan module from the negative-pressure intake tunnel 13 to reduce the pollutant concentration of the front-end air flow. Finally, it is discharged as foul air from the two ends of the exhaust tunnel 11.

[0090] As Figure 6 shown, the middle part of the figure is a schematic layout structure of 5 transverse fan modules on the middle partition wall 12 of the double-tunnel 1. In this embodiment, the 5 fan modules equally divide the intake tunnel 13 and the exhaust tunnel 11 into 6 ventilation segments, and these 6 ventilation segments are symmetrically distributed on both sides with the fan module 3 as the midpoint.

[0091] Figure 6 The lower part is the air pressure distribution of the intake tunnel 13. The 2 low-slope lines composed of square dots represent the situation where all the transverse fan modules are concentrated at the midpoint of the tunnel. The left and right sections of the intake tunnel 13 intake air symmetrically, and the air velocity and air volume of each cross-section are equal. The air pressure drops of the 6 ventilation segments are also the same. The air pressure lines of the 6 ventilation segments are connected into two straight line segments. Taking the atmospheric pressure outside the tunnel entrance as zero, each point in the intake tunnel 13 is under negative pressure, and the pressure at the position of the midpoint fan module is the lowest; the broken line symmetrically distributed about the midpoint of the tunnel composed of round dots represents the situation where the 5 transverse fan modules are evenly distributed on the middle partition wall 12 of the tunnel, dividing the tunnel into 6 ventilation segments. The left and right two entrances of the intake tunnel 13 intake air symmetrically. The intake air is partially inhaled by the 5 transverse fan modules during the movement in the tunnel, implementing "partial air flow short-circuit near the entrance". The air velocity and air volume of the cross-sections of the 3 symmetric ventilation segments on both sides gradually decrease. Because the tunnel ventilation resistance is proportional to the square of the air velocity, the air pressure drops of the 3 ventilation segments symmetrically distributed about the midpoint of the tunnel also decrease correspondingly and accelerate. From the two ends of the tunnel towards the midpoint, they are ΔP, 4 / 9ΔP, and 1 / 9ΔP respectively. The air pressure lines of the 6 ventilation segments in the intake tunnel 13 are connected into a symmetric and gentle broken line segment.

[0092] Figure 6The upper part is the air pressure distribution of the exhaust tunnel 11. The two high-slope lines composed of square dots represent the situation where all the transverse fan modules are concentrated at the midpoint of the tunnel. The left and right sections of the exhaust tunnel 11 exhaust symmetrically, with the air velocity and air volume equal at each cross-section, and the air pressure drops of the airflows in the 6 ventilation sections are also the same. The air pressure lines of the airflows in the 6 ventilation sections are connected into two straight line segments. Taking the atmospheric pressure outside the tunnel entrance as zero, the pressure at each point in the exhaust tunnel 11 is positive pressure, and the pressure at the position of the midpoint fan module is the highest. The broken line symmetrically distributed about the midpoint of the tunnel and composed of dots represents the situation where 5 transverse fan modules are evenly distributed in the tunnel partition wall 12, dividing the tunnel into 6 ventilation sections. The left and right entrances of the exhaust tunnel 11 exhaust symmetrically, and the exhaust air converges into the airflows discharged by the 5 transverse fan modules during the progress of the tunnel. The air velocity and air volume of the cross-sections of the 3 symmetric ventilation sections on both sides gradually increase from the inside to the outside, implementing "partial airflow short-circuiting near the entrance". Since the ventilation resistance of the tunnel is proportional to the square of the air velocity, the air pressure drops of the 3 ventilation sections symmetrically distributed on both sides of the tunnel midpoint also increase correspondingly and accelerate. From the midpoint to the two tunnel entrances, they are 1 / 9⊿P, 4 / 9⊿P, and ⊿P respectively. The air pressure lines of the 6 ventilation sections in the exhaust tunnel 11 are connected into a symmetric and gentle broken line segment.

[0093] In this embodiment, a transverse-driving-longitudinal double-tunnel ventilation system with partial airflow short-circuiting near the entrance. The partial fresh airflows near the two entrances of the intake tunnel 13 are boosted by the transverse fan modules near the entrances of the intake tunnel 13 and are input into the exhaust tunnel 11 nearby to dilute the concentration of harmful components in the air at the end of the exhaust tunnel 11 and improve the air quality at the end of the exhaust tunnel 11. Moreover, the injection positions of this part of the fresh airflows in the exhaust tunnel 11 are also near the two entrances of the exhaust tunnel 11, greatly reducing the path length of this part of the ventilation airflows, thereby reducing the air velocity, air volume, and operating resistance of the middle and middle-outer tunnel sections of the intake tunnel 13 and the exhaust tunnel 11.

[0094] Embodiment 2

[0095] This embodiment and Embodiment 1 are both tunnel ventilation systems that implement the concepts of "transverse-driving-longitudinal", "interface flat-pushing", and "partial airflow short-circuiting near the entrance", and this embodiment has all the advantages of Embodiment 1.

[0096] The difference between this embodiment and Embodiment 1 is that there are more transverse fan modules, reaching 9. They are the first fan module 2, the second fan module 3, the third fan module 4, the fourth fan module 5, and the fifth fan module 6 sequentially arranged at intervals from the middle to both sides of the partition wall 12. The first fan module 2 is located in the middle of the partition wall 12. These 9 fan modules divide the tunnel into 10 ventilation sections, as Figure 7As shown in the figure; the first fan module 2 in the middle position is composed of 3 fans, that is, it includes a standby fan 22 arranged in the middle and the first fans 21 on both sides of the standby fan. The standby fan 22 can run in both forward and reverse directions to solve the smoke exhaust problem when a fire occurs in two tunnels; the two first fans 21 that operate normally in the first fan module 2 rotate in one direction only. The second fan module 3 to the fifth fan module 6 each include one second fan. The total air volume of the two first fans 21 is 1.5 times the total air volume of the 8 second fans on the outside. That is, the air volume of the first fan module 2 accounts for 60% of the total tunnel ventilation air volume, while the air volume of each of the 8 fan modules from the second fan module 3 to the fifth fan module 6 is the same, and the air volume of each fan module accounts for 5% of the total tunnel air volume.

[0097] In this embodiment, the air flow path in the longitudinal tunnel is divided into more detailed paragraphs, and the ventilation operation is smoother. As Figure 8 shown, and because the air volume of the first fan module 2 at the midpoint accounts for 60% of the total tunnel ventilation air volume, the control of the pollutant concentration in the whole tunnel is more reliable, especially suitable for tunnel ventilation projects where the total air volume is controlled near the critical level of the pollutant concentration.

[0098] Under the condition of stable traffic flow and continuous and balanced pollutant emissions in the left and right line tunnels, the change of the pollutant concentration in the tunnel of this embodiment is as Figure 9 shown.

[0099] Due to the implementation of ultra-short circuits for some air flow at the openings, the ventilation air volume of the intake tunnel 13 of this embodiment gradually decreases section by section from both ends of the opening to the midpoint, with a 5% decrease in the air volume of each small section, and the pollutant concentration gradually increases section by section. When it reaches the suction opening of the first fan module 2 at the midpoint, the air volume decreases to 60%, and the pollutant concentration reaches the highest value; after that, the air flow with a pollutant concentration reaching the highest value in the intake tunnel 13, which accounts for 60%, enters the exhaust tunnel 11 and runs from the midpoint to the two outer openings, gradually connecting and absorbing 5% of the air flow of the ultra-short circuit at the opening of this section, with the air volume increasing by 5% section by section until the air volume at the outermost opening reaches 100%; in the exhaust tunnel 11, the exhaust pollutant concentration continuously rises in each ventilation small section, and is diluted by the air flow of the ultra-short circuit at the opening of this section when reaching the connection of two adjacent ventilation small sections, and the concentration decreases, and then enters the next ventilation small section to absorb pollutants until finally discharged from the two outermost openings.

Claims

1. A transverse-driving longitudinal double-tunnel ventilation system with a short-cut for partial air flow openings. The double-tunnel includes two tunnels separated by a middle partition wall, and is characterized in that A number of transverse fan modules for conducting the air paths of the two tunnels of the double - hole tunnel are arranged along the length direction on the middle partition wall. One tunnel facing the suction port of the fan module is the intake tunnel, and the other tunnel facing the exhaust port of the fan module is the exhaust tunnel; During ventilation operation, the fan module sucks the intake tunnel into negative pressure, establishing a pressure difference between the two ends of the intake tunnel and the suction port of the fan module, so that the fresh air flow at the two ends of the intake tunnel continuously replenishes along the intake tunnel, pressurizes the exhaust tunnel to positive pressure, and establishes a pressure difference between the exhaust port of the fan module and the two ends of the exhaust tunnel, so that the polluted air is discharged from the two ends of the exhaust tunnel along the exhaust tunnel; A number of the above - mentioned fan modules are sequentially and spaced apart from the middle of the double - hole tunnel to the middle partition wall between the two ends of the tunnel. Driven by multiple parallel fan modules, a stepped air pressure difference distribution with a large pressure difference in the middle and a small pressure difference at both ends is established in the two tunnels respectively; The middle of the middle partition wall is provided with a first fan module, and a second fan module, …, an Nth fan module are also sequentially and spaced apart from the first fan module to the middle partition walls at the two ends of the double - hole tunnel respectively, where N is an integer greater than 2; During ventilation operation, a part of the fresh air flow near the two ends of the intake tunnel is pressurized by the fan modules near the intake tunnel openings and is input into the exhaust tunnel nearby to dilute the concentration of harmful components in the air at the end of the exhaust tunnel; and the discharge position of this part of the fresh air flow in the exhaust tunnel is also close to the two ends of the exhaust tunnel; During ventilation operation, under the action of the pressure difference between the two ends of the intake tunnel and the suction port of the fan module in the middle of the intake tunnel, when the fresh air flow flows from the two ends of the intake tunnel to the middle, it sequentially passes through the suction ports of multiple parallel fan modules in the intake tunnel, is sucked in, pressurized and then sent into the exhaust tunnel; the ventilation air flow, under the action of the pressure difference between the middle and the two ends of the exhaust tunnel, starts to move from the middle of the exhaust tunnel to the two ends, and collects the air flows sent from the intake tunnel by each fan module along the way to reduce the concentration of pollutants in the front - end air flow, and finally is discharged as polluted air from the two ends of the exhaust tunnel.

2. The cross-driving longitudinal double-tunnel ventilation system with some air flow holes taking a shortcut, as described in claim 1, is characterized in that The first fan module is located in the very middle of the middle partition wall, and the fan modules on both sides of the first fan module are distributed in a one - to - one correspondence; 3. A transverse-driving longitudinal double-tunnel ventilation system with some air flow holes taking a short cut, as described in claim 1, characterized in that, Each of the first fan module to the Nth fan module includes at least one fan; 4. A cross-driving longitudinal double-tunnel ventilation system with some air flow holes taking a shortcut, as described in claim 3, wherein The number of fans of the second fan module to the Nth fan module on both sides of the first fan module is the same respectively; 5. The cross-driving and longitudinal double-tunnel ventilation system with partial air flow holes taking a shortcut, as described in claim 3, is characterized in that The first fan module includes at least two first fans that rotate in one direction and at least one standby fan that can rotate forward and backward; 6. The cross-driving longitudinal double-tunnel ventilation system with some air flow holes taking a shortcut, as described in claim 1, is characterized in that It is applied to double - hole tunnels with a length not exceeding 6 km and a fresh air demand of less than 600 m³ / s.

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