A ventilation design method for tunnels without intermediate inclined shafts

Abstract

The present invention relates to a ventilation design method for a tunnel without an intermediate inclined shaft, comprising the following steps: calculating the required air volume for diluting smoke in the tunnel and determining it as the air intake required for tunnel ventilation; selecting a dust collector, arranging the dust collector in the tunnel and designing the number of dust collectors and the arrangement scheme; determining the key points of the tunnel and calculating the smoke concentration ratio of the key points of the tunnel, then simulating the smoke concentration ratio of the key points of the tunnel by a computer and adjusting the tunnel air intake so that the smoke concentration ratio at the tunnel exit is approximately 1; designing the number of jet fans required for tunnel ventilation according to the adjusted tunnel air intake; establishing an integrated control system for feedback regulation. The beneficial effects of the present invention are: starting from reducing the smoke concentration in the tunnel, combining the relationship between the dust collector and the jet fan and the required air volume of the tunnel, reducing equipment and energy consumption, so as to achieve a more economical and efficient ventilation scheme.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel ventilation, and in particular to a ventilation design method for a tunnel without an intermediate inclined vertical shaft. Background Art

[0002] With the improvement of tunnel construction technology in my country, the construction length of tunnels has gradually increased. Underwater tunnels are affected by water protection and the difficulty of constructing vertical shafts in the water section. The vertical shafts of long and large underwater tunnels are mostly set in the land section. Mountain tunnels are sometimes affected by the topography and it is difficult to set up inclined vertical shafts. These two factors lead to the tunnel ventilation length exceeding 10km, resulting in a surge in air demand and difficulties in designing ventilation plans. Therefore, it is necessary to propose a ventilation form suitable for ventilation lengths exceeding 10km.

[0003] At present, there are four main types of tunnel ventilation: longitudinal ventilation, full transverse ventilation, semi-transverse ventilation, and combined ventilation. Longitudinal ventilation is the simplest and most economical ventilation method, but it is not very economical for long tunnels because a large number of jet fans need to be installed; full transverse ventilation basically does not produce longitudinal flow of wind, only transverse flow of wind, but it needs to set up air supply and exhaust ducts, and the amount of civil engineering is relatively large; semi-transverse ventilation often uses delivery-type semi-transverse ventilation, and the pollutant concentration is basically the same along the length of the tunnel, but it is necessary to set up an air supply duct to blow fresh air directly to the height of the car exhaust port; combined ventilation can combine the actual situation of the tunnel to select the advantages of the ventilation method for combined ventilation.

[0004] For super-long highway tunnels, longitudinal ventilation is often used, but it has the following three limitations: (1) The concentration of harmful gases in the tunnel is uneven, with the highest concentration at the exit. (2) In long tunnels, jet fans are installed for induction, and the number of jet fans required is too high, which consumes a lot of energy and has high maintenance costs. (3) There are also a lot of dust particles in the gas in the tunnel. Longitudinal ventilation cannot substantially reduce the particulate matter, but instead discharges the harmful particulate matter in the tunnel into the atmosphere, which can easily cause environmental pollution and affect surrounding residents and businesses.

[0005] In addition, in the operation ventilation design of long and large tunnels, the smoke air volume is generally used as the control air volume. Whether it is a long highway tunnel or an urban tunnel, 90% of the dust particles discharged into the atmosphere have a particle size of less than PM10, and most of them are heavy metal components, which will be substituted into the atmospheric environment, causing air pollution in the area where the tunnel is located. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a ventilation design method for a tunnel without an intermediate inclined shaft. Starting from reducing the smoke concentration in the tunnel, the relationship between the dust collector and the jet fan and the required air volume of the tunnel is combined to reduce equipment and energy consumption, so as to achieve a more economical and efficient ventilation solution.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A ventilation design method for a tunnel without an intermediate inclined shaft comprises the following steps:

[0009] Calculate the required air volume for diluting smoke and dust in the tunnel under the most unfavorable working conditions, and determine the required air volume for diluting smoke and dust in the tunnel as the required air intake volume for tunnel ventilation;

[0010] Select the dust collector, install the dust collector in the tunnel and design the number and layout of the dust collector;

[0011] Determine the key points of the tunnel and calculate the smoke concentration ratio of the key points of the tunnel, then simulate the smoke concentration ratio of the key points of the tunnel through a computer, and adjust the tunnel air intake during the simulation so that the smoke concentration ratio at the tunnel exit is approximately 1;

[0012] Design the number of jet fans required for tunnel ventilation according to the tunnel air volume adjusted during simulation;

[0013] Establish an integrated control system for feedback regulation of dust collectors and jet fans.

[0014] Furthermore, the dust collector is a fan-type dust collector, and the processing air volume of the fan-type dust collector is 80m 3 / s, the dust removal efficiency of the fan-type dust collector is 80%.

[0015] Furthermore, when designing the number of dust collectors, let the design number of dust collectors be t, then the design number of dust collectors satisfies the formula Where L is the tunnel length in meters, L t is the maximum ventilation section length of the dust collector, in meters. t The t value corresponding to the time when the value is closest to 5km is determined as the number of dust collectors.

[0016] Furthermore, the dust collectors are evenly arranged longitudinally along the length of the tunnel with the maximum ventilation section length of the dust collector as the spacing.

[0017] Furthermore, the tunnel entrance, tunnel exit, 0.5m in front of the dust collector, the rear end of the dust collector, and 0.5m in front of the dust collector are taken as the key points of the tunnel.

[0018] Further, the integrated control system includes an integrated control center and a soot concentration sensor. The soot concentration sensor is disposed at the tunnel exit and 0.5 m in front of the dust collector. The soot concentration sensor, the dust collector, and the jet fan are all electrically connected to the integrated control center.

[0019] Further, the feedback regulation mechanism of the integrated control system includes:

[0020] The soot concentration sensor 0.5 m in front of the dust collector detects the soot concentration in the tunnel and transmits the detected soot concentration to the integrated control center in the form of a signal.

[0021] The soot concentration sensor at the tunnel exit detects the soot concentration at the tunnel exit and transmits the detected soot concentration to the integrated control center in the form of a signal. The integrated control center then calculates the theoretical concentration ratio of the soot concentration 0.5 m in front of the dust collector based on the soot concentration at the tunnel exit.

[0022] The integrated control center calculates and converts the soot concentration ratio detected by the soot concentration sensor 0.5 m in front of the dust collector into the actual soot concentration ratio, then compares the actual soot concentration ratio with the theoretical concentration ratio of the soot concentration 0.5 m in front of the dust collector, and then adjusts the operating parameters of the dust collector according to the comparison result.

[0023] The adjusted dust removal efficiency or dust removal air volume of the dust collector is fed back to the integrated control center in the form of a signal. The integrated control center calculates the theoretical air volume and theoretical lift pressure that the jet fan should output based on the feedback signal, and then adjusts the power and output air volume of the jet fan according to the theoretical air volume and theoretical lift pressure that the jet fan should output.

[0024] Repeat the above operations until the actual soot concentration ratio at the tunnel exit is 1, with a fluctuation of 1%.

[0025] Further, let the actual soot concentration ratio be S1, and the soot concentration ratio calculated by the integrated control center be S2. If S1 > S2, the integrated control center transmits a signal to increase the dust removal efficiency or dust removal air volume to the dust collector. If S1 < S2, the integrated control center transmits a signal to decrease the dust removal efficiency or dust removal air volume to the dust collector.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. By designing and calculating the air intake volume of the tunnel, and then designing the number of required dust collectors and jet fans, the present invention minimizes the installation quantity of equipment as much as possible, thereby reducing energy consumption and the workload of later maintenance, and solving the problem of high ventilation cost caused by the excessive length of long highway tunnels.

[0028] 2. The present invention adjusts the operation of the dust collector and the jet fan according to the real-time concentration ratio through the setting of an integrated control system, so that the operation of the dust collector and the jet fan meets the timely working conditions, avoiding the problem of further energy waste caused by the mismatch between equipment operation and working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of installing the smoke concentration sensor in front of the dust collector in the present invention;

[0030] Figure 2 It is a schematic diagram of the layout of the dust collector in the present invention;

[0031] Figure 3 It is a schematic diagram of the distribution of key points of smoke concentration in the present invention;

[0032] Figure 4 It is a schematic diagram of the layout of the dust collector in the tunnel cross section of the present invention;

[0033] Figure 5 is a concentration ratio curve diagram of the key points of the tunnel in the present invention;

[0034] Figure 6 It is a schematic diagram of the feedback mechanism principle of the integrated control system in the present invention;

[0035] Figure 7 This is a schematic diagram of existing bypass dust removal ventilation;

[0036] Figure 8 This is a curve diagram of the altitude coefficient considering smoke. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following description.

[0038] Embodiment 1

[0039] like Figure 1-7 As shown, a ventilation design method for a tunnel without an intermediate inclined shaft comprises the following steps:

[0040] S1. Calculate the required air volume for diluting smoke and dust in the tunnel under the most unfavorable working conditions, and determine the required air volume for diluting smoke and dust in the tunnel as the required air intake volume for tunnel ventilation.

[0041] Specifically, let the air volume required for tunnel ventilation be Q in The required air volume for diluting smoke in the tunnel is Q req , then Q in =Q req. The determination of the required air volume control standard needs to comply with the safety, hygiene and comfort standards, that is, to meet the ventilation volume required to dilute the dust in the tunnel. The specific calculation formula for the ventilation volume can be found in the "Highway Tunnel Ventilation Design Specifications" (JTGTD702-02-2014). Because there are many working conditions involved, it is only necessary to meet the most unfavorable working conditions. According to the "Highway Tunnel Ventilation Design Specifications" (JTG / T D70 / 2-02-2014), the baseline emissions of harmful gases from motor vehicles should be based on the year 2000 as the starting point, and the emissions obtained by the design target year should be calculated at an annual decrease rate of 2.0%. This shall be used as the baseline emissions for the tunnel ventilation design target year, and the maximum reduction period should not exceed 30 years. The baseline emissions of smoke and dust in harmful gases from motor vehicle tailpipes in 2000 should be 2.0m 2 / (veh·km), according to the "Highway Tunnel Ventilation Design Specifications" (JTG / T D70 / 2-02-2014), the calculation formula for smoke emissions is:

[0042]

[0043] Where: Q——tunnel smoke emission (m 2 / s); q——the smoke benchmark emission in the design target year [m 2 / (veh·km)];f a ——vehicle condition coefficient; f d ——vehicle density coefficient; f h ——Altitude coefficient; f iv ——longitudinal slope-vehicle speed coefficient; f m ——Vehicle type coefficient; L——Tunnel length (m); n——Vehicle type number; N m ——Traffic volume of corresponding vehicle type (veh / h).

[0044] f a Take values ​​according to the following table:

[0045]

[0046]

[0047] f d Obtain values ​​according to the following table:

[0048] Operating speed (km / h) 100 80 70 60 50 40 30 20 10 <![CDATA[f d ]]> 0.6 0.75 0.85 1 1.2 1.5 2 3 6

[0049] f h according to Figure 8 Take the value.

[0050] f iv Take values ​​according to the following table:

[0051]

[0052] f m Obtain values ​​according to the following table:

[0053] Passenger cars, light trucks Medium truck Heavy trucks, large buses Trailer, container truck 0.4 1.0 1.5 3.0

[0054] The calculation formula for the required air volume to dilute the smoke is as follows:

[0055]

[0056] Where: Q req(VI) ——Required air volume for diluting smoke in tunnel (m 3 / s); Q VI ——Tunnel smoke emission (m 2 / s); K——smoke design concentration (m -1 ).

[0057] K is taken according to the following table:

[0058]

[0059] S2. Select the dust collector, install the dust collector in the tunnel and design the number and layout of the dust collector.

[0060] Specifically, by reducing the amount of smoke in the tunnel, the required air volume for diluting the smoke in the tunnel can be reduced, thereby reducing the number of jet fans and energy consumption, and reducing ventilation costs. Therefore, a dust collector can be installed in the tunnel for dust removal, and then through coupling, the air intake required for tunnel ventilation and the air volume required for diluting the smoke in the tunnel after dust removal by the dust collector can be made as close as possible, thereby making it easier for the jet fan to meet the air intake demand for diluting the smoke with the smallest possible power.

[0061] like Figure 4 As shown, the main types of dust collectors are bypass dust removal stations, ceiling dust removal stations and fan dust collectors. The advantage of fan dust collectors is that they occupy less tunnel space and are basically not limited by the cross-sectional area of ​​the tunnel. Therefore, the dust collector is preferably a fan dust collector and is installed in the tunnel cross section. The "Highway Tunnel Ventilation Regulations" stipulate that the dust removal rate of the dust collection device can be 70%-80%. For this reason, the preferred embodiment is to use a dust collection device with a processing air volume of 80m 3 / s, a fan-type dust collector with a dust removal efficiency of up to 80%.

[0062] Assume that the design number of dust collectors is t, then the design number of dust collectors satisfies the formula Where L is the tunnel length in meters, L tThe maximum ventilation section length of the dust collector, in meters. According to the "Highway Tunnel Ventilation Design Regulations", when longitudinal ventilation is adopted, tunnels with one-way traffic and a length of L ≤ 5000m can adopt a full jet longitudinal ventilation scheme. Since the ventilation method of the longitudinal dust collector is similar to the role played by the inclined shaft in the segmented longitudinal ventilation, the installation position of the dust collector is also preferably evenly arranged close to the 5km division point, that is, the maximum ventilation section length of the dust collector is L t It is preferred to take a value close to 5 km, and then t The value of t corresponding to the value closest to 5 km is determined as the number of dust collectors, and the maximum ventilation section length L t The dust collectors are evenly arranged longitudinally along the length of the tunnel for spacing.

[0063] S3. Determine the key points of the tunnel and calculate the smoke concentration ratio of the key points of the tunnel, then simulate the smoke concentration ratio of the key points of the tunnel through a computer, and adjust the air intake during the simulation so that the smoke concentration ratio at the tunnel exit reaches approximately 1.

[0064] Specifically, Figure 3 As shown, the tunnel entrance, tunnel exit, 0.5m in front of the dust collector, the rear end of the dust collector, and 0.5m in the rear end of the dust collector are taken as the tunnel key points. The key points of each tunnel are sorted from the tunnel entrance to the tunnel exit in order, which are: Figure 3 From point 1 to point 11 in the figure, the smoke concentration ratio of each key point is calculated and then the corresponding concentration ratio curve can be obtained through simulation.

[0065] Since the fan-type dust collector has a similar principle to the bypass-type dust collector, the selection of tunnel key points is mainly based on the bypass-type dust collector. Figure 7 As shown, first select point A at the entrance as the key point, which can detect the tunnel air intake and the smoke concentration in the air intake. Then select 0.5m in front of the dust collector, which corresponds to point B in the figure. The smoke concentration at this time has not been processed by the dust collector, and after calculation, the smoke concentration will not change significantly at a smaller distance. Therefore, it can be approximately equal to the smoke concentration of the dust collector air intake. The smoke concentration can be detected by the smoke concentration sensor. There is a 0.5m space before and after, so that the smoke concentration sensor will not be touched when replacing the equipment later. 0.5m behind the dust collector corresponds to point D in the figure. The smoke concentration at this time has been processed by the dust collector. Point E is the tunnel exit. The smoke concentration at the tunnel exit is detected to ensure that the smoke concentration ratio at the exit is 1. This means that the air intake is just enough to dilute the smoke in the tunnel, and it will not increase consumption too much, nor will it be too little to affect the effect.

[0066] The smoke concentration ratio at point A at the tunnel entrance is 0; let the smoke concentration ratio at point B be C2, then Where Q req1is the required air volume for diluting the smoke at point B; let the smoke concentration ratio at point C be C3, point C is the rear end of the dust collector, specifically the process point between the dust collector and point D close to the dust collector, then Where Q req2 is the air volume required to dilute the smoke at point C, Q c is the air volume of the dust collector. Although the values ​​of C3 and C2 are not much different, it is still necessary to calculate the smoke concentration at point C. If the smoke concentration at point D is C4, then Where C2×Q c (1-η V1 ) is the required air volume for dilution of untreated smoke in the dust collector’s treated air volume, η V1 is the dust removal efficiency of the dust collector, C3×(Q in -Q c ) is the required air volume for diluting the smoke in the air flowing through the dust collector without being processed by the dust collector; assuming that the smoke concentration ratio at point E is C5, then Where Q req3 The required air volume to dilute the smoke at point E.

[0067] S4. Design the number of jet fans required for tunnel ventilation based on the adjusted air intake volume during simulation.

[0068] Specifically, the design requires the required air volume for smoke dilution, that is, the air intake volume after simulation adjustment, and the lift pressure of a single jet fan. In addition, the traffic ventilation force, tunnel resistance, and natural ventilation force of the tunnel need to be calculated. Finally, the parameters of the jet fan and the number of units to be set are obtained through calculation.

[0069] According to the "Highway Tunnel Ventilation Design Specifications" (JTG / T D70 / 2-02-2014), the calculation formula for tunnel resistance is as follows:

[0070] Δp r =Δp λ +Δp ζi

[0071]

[0072]

[0073] Where: Δp λ ——Friction resistance along the tunnel (N / m 2 );λ——tunnel resistance coefficient;ρ——air density (kg / m 3 );v r ——tunnel design wind speed (m / s); L——tunnel length (m); D r ——Equivalent diameter of tunnel section (m); Δp ξi ——Local resistance in the tunnel (N / m2 );ξ i ——Tunnel local resistance coefficient.

[0074] The calculation formula for the natural ventilation force in the tunnel is as follows:

[0075]

[0076] Where: Δp m —Natural ventilation force in the tunnel (N / m 2 );ξ e —local resistance coefficient at the tunnel entrance, taken as 0.5; r ——Tunnel resistance coefficient along the way, take 0.02; D r ——Equivalent diameter of the tunnel, m, S7 underwater shield tunnel clear cross-sectional area A r 91.4m 2 , tunnel section perimeter C r is 40.3m, and the equivalent diameter is 9.07m; v n ——Natural wind speed is 2~3m / s, take 3m / s.

[0077] In the case of one-way traffic, traffic ventilation force is considered as a driving force. However, when the vehicle speed is less than the design wind speed, traffic ventilation force is considered as resistance. The calculation formula of traffic ventilation force is as follows:

[0078]

[0079] Where: ΔP t ——Traffic ventilation force (N / m 2 );n c ——Number of vehicles in the tunnel, v t ——Vehicle speed in each working condition (m / s); v r ——Tunnel design wind speed, m / s; A m ——Equivalent impedance area of ​​the vehicle (m 2 ), can be calculated according to the following formula:

[0080] A m =(1-r l )·A cs ·ξ c1 +r l ·A cl ·ξ c2

[0081] Where: r l ——Proportion of large vehicles; A cs ——Front projection area of ​​small car (m 2 ), 2.13m is acceptable2 ; A cl ——Large vehicle frontal projection area (m 2 ), 5.37m is acceptable 2 ξ ci ——The air resistance coefficient of a small or large vehicle in a tunnel can be calculated according to the following formula:

[0082] ξ ci =0.0768x i +0.35

[0083] Where: x i ——The occupation ratio of the ith vehicle type in the tunnel driving space (%).

[0084] The formula for calculating the pressure rise of a single jet fan is as follows:

[0085]

[0086] Where: ΔP j ——The pressure rise of a single jet fan (N / m 2 );v j ——Exit wind speed of jet fan (m / s); A j ——Exit area of ​​jet fan (m 2 );η——jet fan position friction loss reduction coefficient.

[0087] Under the condition of meeting the tunnel design wind speed vr, the calculation formula for the number of jet fans is as follows:

[0088]

[0089] In the formula: i is the number of jet fans required.

[0090] S5. Establish an integrated control system for feedback regulation of dust collectors and jet fans.

[0091] Specifically, since the tunnel ventilation condition cannot always be in the most unfavorable working condition scenario, if the ventilation intensity of the most unfavorable scenario is still used in a relatively favorable scenario, it will cause a lot of energy consumption and mechanical consumption. Therefore, an integrated control system is established to feedback and adjust the dust collector and jet fan so that the operation of the dust collector and jet fan can meet the timely working conditions. Figure 1 , 2 As shown in Figure 5, the integrated control system includes an integrated control center and a smoke concentration sensor. The smoke concentration sensor is installed at the tunnel exit and 0.5m in front of the dust collector. The smoke concentration sensor, dust collector and jet fan are all electrically connected to the integrated control center.

[0092] like Figure 5As shown in the figure, the feedback regulation mechanism of the integrated control system includes:

[0093] A1. The smoke concentration sensor at 0.5 m in front of the dust collector detects the smoke concentration in the tunnel and transmits the detected smoke concentration to the integrated control center in the form of a signal.

[0094] A2. The smoke concentration sensor at the tunnel exit detects the smoke concentration at the tunnel exit and transmits the detected smoke concentration to the integrated control center. The integrated control center then calculates the theoretical concentration ratio of the smoke concentration at 0.5 m in front of the dust collector based on the smoke concentration at the tunnel exit.

[0095] A3. The integrated control center converts the smoke concentration ratio detected by the smoke concentration sensor at 0.5 m in front of the dust collector into the actual smoke concentration ratio, then compares the actual smoke concentration ratio with the theoretical concentration ratio of the smoke concentration at 0.5 m in front of the dust collector, and then adjusts the operating parameters of the dust collector according to the comparison result.

[0096] Specifically, let the actual smoke concentration ratio be S1 and the smoke concentration ratio calculated by the integrated control center be S2. If S1 > S2, the integrated control center transmits a signal to increase the dust removal efficiency or the dust removal air volume to the dust collector. If S1 < S2, the integrated control center transmits a signal to decrease the dust removal efficiency or the dust removal air volume to the dust collector.

[0097] A4. The adjusted dust removal efficiency or dust removal air volume of the dust collector is fed back to the integrated control center in the form of a signal. The integrated control center calculates the theoretical air volume and theoretical lift pressure that the jet fan should output based on the feedback signal, and then adjusts the power and output air volume of the jet fan according to the theoretical air volume and theoretical lift pressure that the jet fan should output.

[0098] A5. Repeat the above operations until the actual smoke concentration ratio at the tunnel exit is 1, with a floating range of 1%.

[0099] Embodiment 2

[0100] Based on the design method in Embodiment 1, this embodiment takes the S7 Shanghai-Chongming West Channel Tunnel as an example for ventilation design. The Shanghai-Chongming West Channel is an underwater shield ultra-long highway tunnel, designed according to the standard of a double-hole two-way six-lane expressway, with a designed speed of 100 km / h.

[0101] According to the calculation formula in the "Code for Highway Tunnel Ventilation Design" (JTGT D702-02-2014), the required air volume for diluting the smoke in the tunnel under the most unfavorable working conditions is calculated as shown in the following table:

[0102]

[0103] From the table, we can see that the required air volume for diluting smoke is 604.74m 3 / s, and the air volume required to dilute the smoke is used as the control air volume.

[0104] According to the total length of S7 Shanghai-Chongqing West Channel tunnel of 17,910m, through calculation and comparison, three dust collectors are set and evenly arranged along the longitudinal direction of the tunnel. In this way, the maximum ventilation section length of the dust collector is 4,477.5m, which is the value closest to 5km.

[0105] The key points of each tunnel are sorted in sequence from the tunnel entrance to the tunnel exit, and then the smoke concentration ratio of each key point of the tunnel is obtained through calculation and adjustment as shown in the following table:

[0106]

[0107]

[0108] Then we can get Figure 5 The concentration ratio graph is shown.

[0109] The parameters and number of jet fans can be calculated based on the adjusted tunnel air intake volume as shown in the following table:

[0110]

[0111] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A ventilation design method for a tunnel without an intermediate inclined shaft, characterized in that: It includes the following steps: Calculate the required air volume for diluting the soot in the tunnel under the most unfavorable working conditions, and determine the required air volume for diluting the soot in the tunnel as the incoming air volume required for tunnel ventilation; Select the type of dust collector, arrange the dust collector in the tunnel, and design the number and arrangement plan of the dust collectors; Determine the key points of the tunnel and calculate the soot concentration ratio at the key points of the tunnel. Then, use a computer to simulate the soot concentration ratio at the key points of the tunnel, and adjust the incoming air volume of the tunnel during the simulation to make the soot concentration ratio at the tunnel exit approximately 1; The tunnel entrance, tunnel exit, 0.5m from the front of the dust collector, the rear of the dust collector, and 0.5m from the rear of the dust collector are taken as the key points of the tunnel; if the tunnel entrance is point A, the smoke concentration ratio at point A is 0; if 0.5m from the front of the dust collector is point B, the smoke concentration ratio at point B is Where Q req1 is the air volume required to dilute the smoke at point B, Q in is the air volume required for tunnel ventilation; assuming the rear end of the dust collector is point C, the smoke concentration at point C is Where Q req2 is the air volume required to dilute the smoke at point C, Q c is the air volume of the dust collector; if the dust collector is 0.5m behind the rear end as point D, then the smoke concentration at point D is Where C2×Q c (1-η V1 ) is the required air volume for dilution of untreated smoke in the dust collector’s treated air volume, η V1 is the dust removal efficiency of the dust collector, C3×(Q in -Q c ) is the required air volume for diluting the smoke that has not been processed by the dust collector in the air flowing through the dust collector; assuming that the tunnel exit is point E, the smoke concentration at point E is Where Q req3 is the air volume required to dilute the smoke at point E; Design the number of jet fans required for tunnel ventilation according to the adjusted incoming air volume of the tunnel during the simulation; Establish an integrated control system for feedback adjustment of the dust collector and the jet fan.

2. The ventilation design method for a tunnel without an intermediate inclined shaft according to claim 1 is characterized in that: The dust collector is a fan-type dust collector, and the air volume of the fan-type dust collector is 80m 3 / s, the dust removal efficiency of the fan-type dust collector is 80%.

3. The ventilation design method for a tunnel without an intermediate inclined shaft according to claim 1 is characterized in that: When designing the number of dust collectors, let the number of dust collectors be t, then the number of dust collectors meets the formula Where L is the tunnel length in meters, L t is the maximum ventilation section length of the dust collector, in meters. t The t value corresponding to the time when the value is closest to 5km is determined as the number of dust collectors.

4. The ventilation design method for a tunnel without an intermediate inclined shaft according to claim 3 is characterized in that: Arrange the dust collectors longitudinally and evenly along the tunnel length at intervals of the maximum ventilation section length of the dust collector.

5. The ventilation design method for a tunnel without an intermediate inclined shaft according to claim 1 is characterized in that: The integrated control system includes an integrated control center and a soot concentration sensor. The soot concentration sensor is arranged at the tunnel exit and 0.5 m in front of the dust collector. The soot concentration sensor, the dust collector, and the jet fan are all electrically connected to the integrated control center.

6. The ventilation design method for a tunnel without an intermediate inclined shaft according to claim 5 is characterized in that: The feedback adjustment mechanism of the integrated control system includes: The soot concentration sensor 0.5 m in front of the dust collector detects the soot concentration in the tunnel and transmits the detected soot concentration to the integrated control center in the form of a signal; The soot concentration sensor at the tunnel exit detects the soot concentration at the tunnel exit and transmits the detected soot concentration to the integrated control center in the form of a signal. The integrated control center then calculates the theoretical concentration ratio of the soot concentration 0.5 m in front of the dust collector based on the soot concentration at the tunnel exit; The integrated control center calculates and converts the soot concentration ratio detected by the soot concentration sensor 0.5 m in front of the dust collector into the actual soot concentration ratio, then compares the actual soot concentration ratio with the theoretical concentration ratio of the soot concentration 0.5 m in front of the dust collector, and adjusts the operating parameters of the dust collector according to the comparison result; The adjusted dust removal efficiency or air volume of the dust collector is fed back to the integrated control center in the form of a signal. The integrated control center calculates the theoretical air volume and theoretical lift pressure that the jet fan should output based on the fed-back signal, and then adjusts the power and output air volume of the jet fan according to the theoretical air volume and theoretical lift pressure that the jet fan should output; Repeat the above operations until the actual soot concentration ratio at the tunnel exit is 1, with a fluctuation of ±1%.

7. The ventilation design method for a tunnel without an intermediate inclined shaft according to claim 6 is characterized in that: Let the actual soot concentration ratio be S1, and the soot concentration ratio calculated by the integrated control center be S2. If S1 > S2, the integrated control center transmits a signal to increase the dust removal efficiency or air volume of the dust collector. If S1 < S2, the integrated control center transmits a signal to decrease the dust removal efficiency or air volume of the dust collector.

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