A numerical simulation method for ventilation characteristics of complex underground space combined with tunnel construction

Abstract

The application provides a tunneling and complex underground space combined ventilation characteristic numerical simulation method, a tunneling and complex underground space combined ventilation physical model is set, a ventilation characteristic numerical simulation model is established, and the flow velocity, pressure and wall shear stress distribution of the tunneling and complex underground space combined space, the pressure boosting reduction coefficient of the jet fan and the ventilation resistance are solved to realize the analysis of the jet fan arrangement and the flow field characteristics of the tunneling and complex underground space combined space, solve the pain points of the ventilation setting of the tunneling and complex underground engineering, provide the ventilation condition analysis for the tunneling and complex underground engineering, and optimize the fan layout setting.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engineering numerical modeling, in particular to a method for numerical simulation of ventilation characteristics of a complex underground space combined with a tunnel. BACKGROUND

[0002] A tunnel is a semi-closed building, and both accident communication and rescue are greatly limited. Once a fire occurs in a tunnel, it can cause serious structural damage, casualties and property losses. Personnel and vehicles can only escape through the tunnel entrance. Therefore, the tunnel entrance and exit are extremely important locations. In recent years, China's infrastructure has been growing, and the structure has become increasingly diverse. Tunnel entrances and exits have begun to directly access commercial building underground spaces. For example, an underground traffic ring tunnel connects multiple underground parking lots or commercial district entrances together, and an underground interlinked tunnel is an "underground overpass" for underground pedestrian and vehicle traffic.

[0003] The present application relates to a complex underground project combined with a tunnel. A municipal tunnel is connected to a commercial exhibition building. Due to the influence of the upper cover structure plate of the commercial building, the U-shaped groove part of the municipal tunnel entrance and exit is covered by the upper cover structure plate. Therefore, after the municipal tunnel passes under the city's rivers, lakes, and lakes, the municipal tunnel entrance and exit will be connected to the auxiliary road of the commercial exhibition building underground highway tunnel entrance and exit, forming a complex underground project combined with a tunnel.

[0004] Such projects face many ventilation technical difficulties. The main contents are as follows: (1) The project needs to set up a fan at the complex structure combined with a tunnel to ensure smooth ventilation in the complex underground space combined with a tunnel. (2) Since the distance between the highway auxiliary road and the structure plate cannot hang a jet fan, the jet fan can only be set on the structure plate above the municipal tunnel entrance and exit. (3) The tunnel vault of the complex underground project combined with a tunnel under the building section has a dense beam grid structure. The beam grid will affect the airflow organization and flow field distribution in the tunnel, and thus affect the layout position and technical parameters of the jet fan in the tunnel. It also leads to the need to set up a niche fan in the commercial exhibition underpass tunnel area. (4) The fan setting at the complex structure combined with a tunnel and the commercial exhibition underpass tunnel area has a bias, so the fan deflection parameters at the complex structure combined with a tunnel have a great influence on the ventilation characteristics of the complex underground space combined with a tunnel. SUMMARY

[0005] To solve the above engineering problems existing in the prior art, constructing a complex underground space model is a key technical means for studying the ventilation characteristics and ventilation setting parameters of the complex underground space combined with building and tunneling, and is also the basis for realizing engineering refinement. The present application provides a numerical simulation method for ventilation characteristics of a complex underground space combined with building and tunneling, which improves the ventilation efficiency of the complex underground space combined with building and tunneling, solves the pain points of ventilation setting of the complex underground engineering combined with building and tunneling, provides ventilation condition analysis for the complex underground engineering combined with building and tunneling, and optimizes the layout and setting of the fan.

[0006] According to a first aspect of the present application, a numerical simulation method for ventilation characteristics of a complex underground space combined with building and tunneling is provided, characterized in that it comprises:

[0007] Step 10: determining the model parameters of the physical model of the complex underground space combined with building and tunneling, including the geometric dimensions of the tunnel, the geometric dimensions of the building, the model of the jet fan, and the arrangement range of the jet fan.

[0008] Step 20: dividing the unstructured space grid of the physical model of the complex underground space combined with building and tunneling, and establishing a numerical model for ventilation of the complex underground space combined with building and tunneling.

[0009] Step 30: determining the control equation of the turbulent k-ε model for fluid domain calculation in the numerical model for ventilation of the complex underground space combined with building and tunneling.

[0010] Step 40: determining the boundary conditions of the control equation, including the inlet and outlet pressure, wind speed, and hydraulic parameters.

[0011] Step 50: determining the initial conditions of the control equation, including the ambient temperature, atmospheric pressure, gage pressure, initial velocity, turbulent kinetic energy, turbulent dissipation rate, fluid density, and fluid viscosity.

[0012] Step 60: using the SIMPLE algorithm of pressure-velocity coupling to solve the numerical model for ventilation characteristics of the complex underground space combined with building and tunneling by iterative calculation of pressure and velocity.

[0013] Step 70: obtaining the flow velocity, pressure, and wall shear stress distribution of the complex underground space combined with building and tunneling according to the solution results of the numerical model for ventilation characteristics of the complex underground space combined with building and tunneling.

[0014] Step 80: obtaining the pressure boosting reduction coefficient and ventilation resistance of the jet fan according to the flow velocity, pressure, and wall shear stress distribution of the complex underground space combined with building and tunneling.

[0015] Step 90: obtaining the optimal layout scheme of the jet fan of the complex underground space combined with building and tunneling according to the flow velocity, pressure, and wall shear stress distribution of the complex underground space combined with building and tunneling and the pressure boosting reduction coefficient and ventilation resistance of the jet fan.

[0016] Further, the tunnel-building combined complex underground space ventilation characteristic numerical simulation method provided by the application is characterized in that the jet flow fan arrangement range includes a jet flow induction section length l y According to the jet flow development reduction model of the tunnel-building combined complex underground space, the following is obtained:

[0017] l y = λ (7.16 + 62.93T - 108.2mU) d ε ,

[0018]

[0019] wherein, l y is the jet flow induction section length, T is a dimensionless velocity ratio, U is a dimensionless area ratio, m is the number of parallel fans in a section, d ε is the equivalent diameter of the tunnel, λ is the ventilation reduction coefficient of the tunnel-building combination, l b is the distance between the dense girders on the cover of the tunnel-building combination.

[0020] Further, the tunnel-building combined complex underground space ventilation characteristic numerical simulation method provided by the application is characterized in that the turbulent flow k-ε model is an RNG k-ε model:

[0021]

[0022]

[0023] wherein, ε is the turbulent dissipation rate, k is the turbulent kinetic energy, u is the wind speed, x i , x j , x k are space coordinates, "-" represents taking an average, ρ is the fluid density, μ t is the turbulent viscosity, C μ is the first empirical constant. The transport equation corresponding to k and ε is:

[0024]

[0025]

[0026] wherein, G k is the turbulent kinetic energy generation term caused by the average velocity gradient, α k is the second empirical constant, is the coefficient reflecting the time-averaged strain rate of the main flow, μ eff is the diffusion coefficient.

[0027] Further, the tunnel construction combined with complex underground space ventilation characteristic numerical simulation method provided by the application has the characteristics that the wind speed, pressure and wall shear stress distribution of the tunnel construction combined with complex underground space include: tunnel wind speed distribution graph when the fan is arranged at different deflection angles, ceiling fan axis height wind speed distribution graph when the fan is arranged at different deflection angles, tunnel cross section wind speed distribution graph when the fan is arranged at different deflection angles, and fan pressure rise graph.

[0028] Further, the tunnel construction combined with complex underground space ventilation characteristic numerical simulation method provided by the application has the characteristics that the wind speed, pressure and wall shear stress distribution of the tunnel construction combined with complex underground space include: tunnel wind speed distribution graph when the fan is arranged at different deflection angles, ceiling fan axis height wind speed distribution graph when the fan is arranged at different deflection angles, tunnel cross section wind speed distribution graph when the fan is arranged at different deflection angles, and fan pressure rise graph.

[0029] Further, the tunnel construction combined with complex underground space ventilation characteristic numerical simulation method provided by the application has the characteristics that the wind speed, pressure and wall shear stress distribution of the tunnel construction combined with complex underground space include: tunnel wind speed distribution graph when the fan is arranged at different deflection angles, ceiling fan axis height wind speed distribution graph when the fan is arranged at different deflection angles, tunnel cross section wind speed distribution graph when the fan is arranged at different deflection angles, and fan pressure rise graph.

[0030] The pressure reduction coefficient of the jet fan is:

[0031]

[0032] Wherein, η is the pressure reduction coefficient of the jet fan group; Δp aj is the actual pressure rise of the jet fan group, which is measured by experiment; Δp jt is the theoretical pressure rise of the jet fan group, and the theoretical pressure rise of a single jet fan is:

[0033]

[0034] Wherein, v j is the outlet wind speed of the jet fan, v r is the design wind speed in the tunnel, A j is the outlet area of the jet fan; A r is the cross-sectional area of the tunnel; and N is the number of jet fans in the cross section.

[0035] ∑Δp j = Δp c + Δp n1 + Δp n2 = Δp aj + ∑p r ,

[0036] Wherein, Δp c is the theoretical pressure rise of the ceiling fan, Δp n1 is the theoretical pressure rise of the first group of wall niche fans, Δp n2 is the theoretical pressure rise of the second group of wall niche fans, and ∑p r is the total resistance loss in the tunnel.

[0037] Further, the tunnel construction combined with complex underground space ventilation characteristic numerical simulation method provided by the application is characterized in that the actual pressure rise Δp of the jet fan group aj The maximum pressure rise Δp of the fan obtained by numerical simulation j-max .

[0038] According to the second aspect of the application, a computer device comprises:

[0039] The memory is configured to store instructions, and the processor is configured to invoke the instructions stored in the memory to execute the tunnel construction combined with complex underground space ventilation characteristic numerical simulation method according to any one of claims 1-7.

[0040] According to the third aspect of the application, a computer readable storage medium stores instructions, and the instructions are executed by a processor to execute the tunnel construction combined with complex underground space ventilation characteristic numerical simulation method according to the first aspect.

[0041] Compared with the prior art, the technical scheme has at least the following beneficial effects:

[0042] 1. The application can realize the analysis of the jet fan arrangement and flow field characteristics of the tunnel construction combined with complex underground space, improve the numerical simulation capability of urban underground space operation ventilation, and promote the process of engineering refinement.

[0043] 2. The application realizes the analysis of the operation ventilation efficiency and resistance loss of the tunnel construction combined with complex underground space, promotes the design of underground space operation ventilation resistance reduction, and optimizes the underground space operation ventilation scheme.

[0044] 3. The application realizes the precise control and dynamic regulation of the operation ventilation design parameters of the tunnel construction combined with complex underground space, and improves the timeliness of the selection of the operation ventilation parameters of the tunnel construction combined with complex underground space.

[0045] 4. The application uses the numerical simulation method to analyze the ventilation characteristics of the tunnel construction combined with complex underground space, analyzes the flow field distribution characteristics and pressure distribution characteristics of the underground space, obtains the best fan arrangement scheme, improves the ventilation efficiency, and reduces the ventilation energy consumption.

[0046] 5. The application realizes the rapid research and design of the operation ventilation of the tunnel construction combined with complex underground space, and provides technical support for the research and design of the operation ventilation of the tunnel construction combined with complex underground space.

[0047] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the application. BRIEF DESCRIPTION OF DRAWINGS

[0048] The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate embodiments consistent with the application and, together with the description, further serve to explain the principles of the application.

[0049] Figure 1 is a flow chart of a numerical simulation method of ventilation characteristics of a complex underground space combined with a tunnel according to an example embodiment.

[0050] Figure 2 is a three-dimensional schematic diagram of a numerical model of ventilation characteristics of a complex underground space combined with a tunnel according to an example embodiment.

[0051] Figure 3 is a tunnel velocity distribution graph when two fans are set at different deflection angles according to an example embodiment.

[0052] Figure 4 is a ceiling fan axis height velocity distribution graph when two fans are arranged at different deflection angles according to an example embodiment.

[0053] Figure 5 is a tunnel cross-sectional velocity distribution graph when two fans are set at different deflection angles according to an example embodiment.

[0054] Figure 6 is a fan boost pressure graph according to an example embodiment.

[0055] Figure 7 is a fan boost coefficient graph according to an example embodiment.

[0056] Figure 8 is a tunnel ventilation system resistance graph according to an example embodiment. DETAILED DESCRIPTION

[0057] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0058] The embodiment of the present application provides a numerical simulation method of ventilation characteristics of a complex underground space combined with a tunnel, and a flow chart thereof is shown as Figure 1 , and the method comprises the following steps.

[0059] Step 10: determining the model parameters of the tunnel combined complex underground space ventilation physical model, including the tunnel geometric size, the building geometric size, the jet fan model, and the jet fan arrangement range.

[0060] Step 20: Divide the unstructured space grid of the combined tunnel and complex underground space physical model to establish a combined tunnel and complex underground space ventilation numerical model.

[0061] Step 30: Determine the control equation of the turbulent flow k-ε model for fluid domain calculation in the combined tunnel and complex underground space ventilation numerical model.

[0062] Step 40: Determine the boundary conditions of the control equation, including the inlet and outlet pressure, wind speed, and hydraulic parameters.

[0063] Step 50: Determine the initial conditions of the control equation, including the ambient temperature, atmospheric pressure, gage pressure, initial velocity, turbulent kinetic energy, turbulent dissipation rate, fluid density, and fluid viscosity.

[0064] Step 60: Use the SIMPLE algorithm of pressure-velocity coupling to solve the combined tunnel and complex underground space ventilation characteristic numerical model by iterative calculation of pressure and velocity.

[0065] Step 70: Obtain the flow velocity, pressure, and wall shear stress distribution of the combined tunnel and complex underground space based on the solution results of the combined tunnel and complex underground space ventilation characteristic numerical model.

[0066] Step 80: Obtain the pressure boosting reduction coefficient of the jet fan and the ventilation resistance based on the flow velocity, pressure, and wall shear stress distribution of the combined tunnel and complex underground space.

[0067] Step 90: Obtain the optimal layout scheme of the jet fan of the combined tunnel and complex underground space based on the flow velocity, pressure, and wall shear stress distribution of the combined tunnel and complex underground space and the pressure boosting reduction coefficient of the jet fan and the ventilation resistance.

[0068] In some embodiments, the jet fan arrangement range includes the jet-induced segment length l y According to the jet development reduction model of the combined tunnel and complex underground space, we have:

[0069] l y = λ (7.16 + 62.93T - 108.2mU) d ε ,

[0070]

[0071] wherein l y is the jet-induced segment length, T is the dimensionless velocity ratio, U is the dimensionless area ratio, m is the number of parallel fans in the cross section, d ε is the equivalent diameter of the tunnel, λ is the ventilation reduction coefficient of the combined tunnel, and l b is the spacing between the dense girders on the cover of the combined tunnel.

[0072] In some embodiments, the turbulent flow k-ε model is the RNG k-ε model:

[0073]

[0074]

[0075] wherein ε is the turbulent dissipation rate, k is the turbulent kinetic energy, u is the wind speed, x i , x j , x k is the spatial coordinate, "-" represents taking the average, p is the fluid density, μ t is the turbulent viscosity, C μ is the first empirical constant (generally taken as 0.09). The corresponding transport equations for k and ε are:

[0076]

[0077]

[0078] wherein G k is the turbulent kinetic energy generation term due to the average velocity gradient, a k is the second empirical constant (generally taken as 1.39), is the coefficient reflecting the time-averaged strain rate of the main flow, μ eff is the diffusion coefficient.

[0079] In some embodiments, the wind speed, pressure, and wall shear stress distribution of the tunnel combined with the complex underground space includes: a tunnel wind speed distribution graph when the fan is set at different deflection angles, a suspended ceiling type fan axis height wind speed distribution graph when the fan is deflected, a tunnel cross-sectional wind speed distribution graph when the fan is set at different deflection angles, and a fan pressure rise graph.

[0080] In some embodiments, the pressure rise reduction coefficient and ventilation resistance of the jet fan include: a fan pressure rise coefficient graph and a tunnel ventilation system resistance graph.

[0081] In some embodiments, the jet fan includes a suspended ceiling type fan and a niche type fan, and step 80 further includes:

[0082] The pressure rise reduction coefficient of the jet fan is:

[0083]

[0084] wherein η is the pressure rise reduction coefficient of the jet fan group; Δp aj is the actual pressure rise of the jet fan group, which is measured by experiment; Δp jt is the theoretical pressure rise of the jet fan group, and the theoretical pressure rise of a single jet fan is:

[0085]

[0086] Among them, v j v is the outlet velocity of the jet fan. r A is the design wind speed inside the tunnel. j A is the outlet area of ​​the jet fan; r Where is the tunnel cross-sectional area; N is the number of jet fans within the cross-section. Ventilation resistance is:

[0087] ∑Δp j =Δp c +Δp n1 +Δp n2 =Δp aj +∑p r ,

[0088] Where, Δp c Δp is the theoretical pressure rise of the ceiling-mounted fan. n1 The theoretical pressure rise of niche-type fan group 1, Δp n2 For the theoretical pressure rise of two sets of niche-type fans, ∑p r This represents the total resistance loss within the tunnel.

[0089] In some embodiments, the actual pressure rise Δp of the jet fan unit aj The maximum boost pressure Δp of the wind turbine was obtained through numerical simulation. j-max .

[0090] This invention provides a numerical simulation method for the ventilation characteristics of a complex underground space combining tunnel and building, taking a certain actual project as an example.

[0091] In step 10, the parameters of the tunnel construction combined with the ventilation physical model of the complex underground space are as follows (e.g.) Figure 2 (As shown): The model is 327m long, 15m wide, and has a maximum height of 11.2m. It is equipped with 3 ceiling-mounted fans and 2 niche-type fans, with a longitudinal spacing of 110m between the fans. The crossbeams are 1m × 1.2m in size and 0.4m wide; the longitudinal beams are 1.8m × 1.2m in size and 0.4m wide.

[0092] In step 40, the jet fan inlet and outlet are set as velocity inlet with a velocity of 32.5 m / s, and the tunnel outlet boundary condition is set as pressure outlet.

[0093] In step 70, the tunnel velocity contour map is shown when the two wind turbines are set with different deflection angles. Figure 3 ,Depend on Figure 3(a) can be known: with the increase of the deflection angle of the fan, the wind speed on the side of the tunnel where the fan is installed decreases, and the wind speed on the side where the fan is not installed increases; when the deflection angle of the two fans is 10°, the deflection angle of the fan is too large, and the wind speed in the tunnel 100m-150m range decreases. By Figure 3 (b) can be known: when the two fans are deflected, the wind speed on the side of the tunnel where the fan is not installed can be increased, and the wind speed in the tunnel is more continuous and stable; this is because the two deflected jet fans can provide greater ventilation force, can overcome the resistance generated by the dense girder, and maintain the wind speed in the tunnel. Considering the wind speed on both sides of the tunnel, when the deflection angle of the two fans is 5°-8°, a higher wind speed can be formed on both sides of the tunnel, which is beneficial to improve the overall operation and ventilation of the tunnel.

[0094] When the two fans are deflected, the speed distribution of the ceiling fan axis at the tunnel 100m is shown in Figure 4 The figure shows that: compared with the deflection of one fan, the deflection of two fans can provide greater ventilation on the side where the fan is not installed, and the wind speed on the side where the fan is not installed increases with the increase of the deflection angle of the fan; on the contrary, on the side where the fan is installed, the wind speed decreases due to the decrease of the ventilation. When the fan has no deflection and the deflection angle is 2°, the wind speed distribution in the tunnel is high on the left and low on the right, and the wind speed on the side where the fan is not installed is improved little; when the deflection angle of the fan is 8°-10°, the deflection angle of the fan is too large, and the wind speed in the tunnel presents a distribution of "both sides large and middle small"; when the deflection angle of the fan is 5°, the wind speed distribution on both sides of the tunnel is relatively uniform, and the ventilation effect is good.

[0095] The wind speed distribution cloud diagram of the tunnel at different distances when the two fans are set at different deflection angles is shown in Figure 5 It can be known from Figure 5 that: with the increase of the deflection angle of the fan, the average wind speed in the tunnel increases. When the deflection angle of the fan is 5°-8°, the jet flow generated by the three ceiling fans can still mix at the tunnel 100m, and the wind speed on the tunnel section at the tunnel 150m can be ensured to be relatively uniform; when the deflection angle of the fan is 10°, the deflection angle of the fan is large, and two independent jet flows are formed in the tunnel, which causes the wind speed at the middle position of the tunnel section to decrease slightly; when the two fans are deflected, the ventilation of the fan increases, and the wind speed on the tunnel section can still be improved after the tunnel 200m, which is better than the case of one fan deflection.

[0096] The average pressure rise of the tunnel when the two fans are set at different deflection angles is shown in Figure 6 It can be known from Figure 6It can be seen that the boost of two fans deflection is similar to the boost of one fan deflection, when the deflection angle of the fan is 2°-5°, the overall boost in the tunnel is higher; when the deflection angle of the fan is 8°-10°, the deflected jet impact the side wall, and the subsequent ventilation is insufficient, resulting in the boost of the subsequent two alcove fans being lower, which is not conducive to the overall ventilation of the tunnel; when the two fans are deflected by 5°, the boost in the tunnel is larger, and the fan boost effect is better.

[0097] In step 80, Figure 7 The ceiling fan boost coefficient of two fans with different deflection angles can be found that when the two fans are deflected by 5°, the fan boost coefficient is increased by about 5%, and the fan boost efficiency is higher; when the fan is deflected by 8°-10°, the fan boost efficiency is slightly reduced.

[0098] When the two fans are deflected by different angles, the resistance of the tunnel ventilation system is Figure 8 It can be found that when the two fans are deflected, when the fan is deflected by 2°-5°, the tunnel ventilation resistance is slightly reduced; when the deflection angle continues to increase, the tunnel resistance loss will also increase.

[0099] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice in the art to which the application pertains. It is intended that the specification and examples be considered exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0100] It is to be understood that the application is not limited to the precise construction here described and as shown in the drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is limited only by the claims that follow.

Claims

1. A method for numerical simulation of ventilation characteristics of complex underground space combined with tunnel construction, characterized in that, The method comprises the following steps: Step 10: determining the model parameters of the tunnel-constructed combined complex underground space ventilation physical model, including the tunnel geometric size, the building geometric size, the jet fan model, and the jet fan arrangement range; The tunnel-constructed combined complex underground engineering comprises a municipal tunnel connected with a commercial exhibition building, an U-shaped groove part of an entrance and exit of the municipal tunnel covered by an upper cover structure plate, and the entrance and exit of the municipal tunnel communicated with an entrance and exit auxiliary road of a lower road tunnel of the commercial exhibition building, wherein a dense beam grid structure exists in a tunnel vault of a tunnel-constructed combined complex underground engineering section, and the jet fan arrangement of the tunnel-constructed combined complex structure and the commercial exhibition lower tunnel region has a deflection characteristic; The jet fan arrangement range includes a jet induction section length l y According to the tunnel construction and the jet development reduction model of complex underground space, the following is obtained: l y = λ(7.16 + 62.93T - 108.2mU)d ε , 0≤l b ≤7.5， Wherein, l y is the length of the jet flow induction section, T is the dimensionless speed ratio, U is the dimensionless area ratio, m is the number of parallel fans in the cross section, d ε is the equivalent diameter of the tunnel, λ is the reduction coefficient of the tunnel junction ventilation, l b is the distance between the dense girders on the cover of the tunnel junction Step 20: dividing the unstructured space grid of the tunnel-constructed combined complex underground space physical model, and establishing a tunnel-constructed combined complex underground space ventilation numerical model; Step 30: determining the control equation of the turbulent flow k-ε model used for fluid domain calculation in the tunnel-constructed combined complex underground space ventilation numerical model; Step 40: determining the boundary condition of the control equation, including the entrance and exit pressure, the wind speed, and the hydraulic parameter; Step 50: determining the initial condition of the control equation, including the environmental temperature, the atmospheric pressure, the gage pressure, the initial velocity, the turbulent flow kinetic energy, the turbulent flow dissipation rate, the fluid density, and the fluid viscosity; Step 60: adopting the SIMPLE algorithm of pressure and velocity coupling to solve the tunnel-constructed combined complex underground space ventilation characteristic numerical model through iterative calculation of pressure and velocity; Step 70: obtaining the flow velocity, pressure and wall shear stress distribution of the tunnel-constructed combined complex underground space according to the solving result of the tunnel-constructed combined complex underground space ventilation characteristic numerical model; The flow velocity, pressure and wall shear stress distribution of the tunnel-constructed combined complex underground space comprises the tunnel velocity distribution graph when the jet fan arrangement has different deflection angles, the ceiling type jet fan axis height velocity distribution graph when the jet fan deflection arrangement, the tunnel cross section velocity distribution graph when the jet fan arrangement has different deflection angles, and the jet fan pressure boosting graph; Step 80: obtaining the jet fan pressure boosting reduction coefficient and the ventilation resistance condition according to the flow velocity, pressure and wall shear stress distribution of the tunnel-constructed combined complex underground space; Step 90: obtaining the jet fan optimal arrangement scheme of the tunnel-constructed combined complex underground space according to the flow velocity, pressure and wall shear stress distribution of the tunnel-constructed combined complex underground space and the jet fan pressure boosting reduction coefficient and the ventilation resistance condition.

2. The method according to claim 1, wherein, The turbulent flow k-ε model is an RNG k-ε model: wherein ε is the turbulent dissipation rate, k is the turbulent kinetic energy, u is the wind speed, xi, xj, xk are the spatial coordinates, "----" means taking the average, ρ is the fluid density, μ t is the turbulent viscosity, C μ is the first preset empirical constant; The transport equations corresponding to k and ε are: where G k is a turbulent kinetic energy production term due to the mean velocity gradient, a k is a second predetermined empirical constant, is a coefficient reflecting the time-averaged strain rate of the main flow, μ eff is a diffusion coefficient.

3. The method according to claim 1, wherein, The jet fan pressure boosting reduction coefficient and the ventilation resistance condition comprise a jet fan pressure boosting coefficient graph and a tunnel ventilation system resistance graph.

4. The method according to claim 1, wherein, The jet fan comprises a ceiling type jet fan and a niche type jet fan, and the step 80 further comprises: The jet fan pressure boosting reduction coefficient is: Wherein, η is the boost reduction factor of the jet fan unit; Δp aj is the actual boost pressure of the jet fan unit, which is measured by test; Δp jt is the theoretical boost pressure of the jet fan unit, and the theoretical boost pressure of a single jet fan is: Wherein, v j is the outlet air speed of the jet fan, v r is the design air speed in the tunnel, A j is the outlet area of the jet fan; A r is the cross-sectional area of the tunnel; N is the number of jet fans in the cross section; The ventilation resistance is: ∑Δp j = Δp c + Δp n1 + Δp n2 = Δp aj + ∑p r , where Δp c is the theoretical pressure rise of the ceiling fan, Δp n1 is the theoretical pressure rise of the alcove fan group 1, Δp n2 is the theoretical pressure rise of the alcove fan group 2, and ∑p r is the total resistance loss in the tunnel.

5. The method according to claim 4, wherein, Actual pressure rise Δp of the fan unit aj Maximum pressure rise Δp of the fan obtained by numerical simulation j-max .

6. A computer device, comprising: The method comprises the following steps: The memory is configured to store instructions; The processor is configured to invoke the instructions stored in the memory to execute the tunnel-constructed combined complex underground space ventilation characteristic numerical simulation method. ​ 7. A computer-readable storage medium, characterized in that, The storage has instructions, when the instructions are executed by the processor, the method for building a tunnel combined with the numerical simulation of the ventilation characteristics of complex underground space is executed as claimed in any one of claims 1-5.

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