A method and system for simulating the ventilation of a diffusion chamber with a wave absorber

Abstract

The application discloses a kind of diffusion chamber ventilation wave-damping simulation methods, comprising: establishing diffusion chamber ventilation pipeline model;Collect ventilation pipeline information, the actual wind resistance of ventilation pipeline is calculated;The actual wind resistance is compared with calibration wind resistance;The minimum cross-sectional area of ventilation passage is calculated;Wave-damping material is installed to the inner wall of ventilation pipeline.According to the minimum cross-sectional area of ventilation passage and the thickness of foamed aluminum calculated by diffusion chamber ventilation pipeline model, and foamed aluminum of different density can be selected according to the thickness of foamed aluminum, reduce the power of shock wave propagation along ventilation pipeline, reduce the damage to equipment on ventilation pipeline, play a protective role, while fully considering the influence of friction resistance coefficient of foamed aluminum material on wind resistance, so as to ensure that the wind resistance inside ventilation pipeline is less than calibration wind resistance, meet the ventilation requirement, reduce the power consumption of auxiliary ventilation fan.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of diffuser ventilation wave absorption, and particularly relates to a diffuser ventilation wave absorption simulation method and system. BACKGROUND

[0002] The diffuser is an important part of the underground protective engineering. In order to ensure the air environment quality inside the diffuser and give full play to the efficiency of the diffuser, corresponding ventilation and air conditioning measures must be taken inside the diffuser, which aims to ensure the ventilation and air exchange between the inside and outside of the engineering. In order to ensure the normal survival of personnel in the underground engineering, fresh air should be transported into the underground engineering to dilute and remove harmful gases in the engineering.

[0003] At present, due to the winding and tortuous underground ventilation pipeline, various devices such as fans and filters are arranged on the ventilation pipeline, and the fan is used for auxiliary ventilation in ordinary times to enhance the ventilation effect. The larger the cross section of the ventilation pipeline is, the stronger the ventilation capacity is, but the wave absorption capacity is poor. Once attacked by explosion, the shock wave will propagate along the ventilation pipeline, which will cause damage to the devices on the ventilation pipeline. In order to reduce the propagation of the shock wave along the ventilation pipeline, the cross section area of the ventilation pipeline is often reduced, which will affect the ventilation capacity of the ventilation pipeline, and it is difficult to simultaneously consider both. SUMMARY

[0004] The technical problem solved by the present application is that in order to reduce the propagation of the shock wave along the ventilation pipeline, the cross section area of the ventilation pipeline is currently reduced, which will affect the ventilation capacity of the ventilation pipeline, and it is difficult to simultaneously consider both.

[0005] To solve the above technical problems, the present application provides the following technical scheme: a diffuser ventilation wave absorption simulation method, comprising: establishing a diffuser ventilation pipeline model; collecting ventilation pipeline information, calculating the actual wind resistance of the ventilation pipeline; comparing the actual wind resistance with the calibrated wind resistance; calculating the minimum cross section area of the ventilation channel; and installing wave absorption material on the inner wall of the ventilation pipeline.

[0006] As a preferred scheme of the diffuser ventilation wave absorption simulation method, the diffuser ventilation pipeline model comprises a ventilation pipe and a diffuser, and wave absorption material is arranged on the inner wall of the ventilation pipe.

[0007] As a preferred scheme of the diffuser ventilation wave absorption simulation method, collecting ventilation pipeline information comprises: calibrating a measurement base point, an initial measurement point and a final measurement point; measuring the air pressure of the measurement base point, the initial measurement point and the final measurement point, and obtaining corresponding readings; and calculating the cross section area of the ventilation pipeline.

[0008] As a preferred scheme of the diffusion chamber ventilation wave cancellation simulation method, the calculation expression of the actual wind resistance of the ventilation duct is:

[0009]

[0010] wherein, represents the wind resistance, represents the cross-sectional area of the ventilation duct, respectively represent the static pressure difference readings of the initial measuring point and the final measuring point, in Pa, respectively represent the static pressure difference readings of the initial measuring point and the final measuring point, in Pa.

[0011] As a preferred scheme of the diffusion chamber ventilation wave cancellation simulation method, the value of the calibration wind resistance is obtained, and the calibration wind resistance is compared with the value of the actual wind resistance. If the calibration wind resistance is smaller than the actual wind resistance, the ventilation duct needs to be modified to reduce the wind resistance.

[0012] If the calibration wind resistance is greater than the actual wind resistance, it indicates that the ventilation duct is qualified.

[0013] As a preferred scheme of the diffusion chamber ventilation wave cancellation simulation method, the friction resistance coefficient of the wave cancellation material is obtained, and the calculation expression of the minimum cross-sectional area of the ventilation passage is:

[0014] S f

[0015] wherein, S f represents the minimum cross-sectional area of the ventilation passage, represents the friction resistance coefficient of the wave cancellation material, the thickness of the wave cancellation material is calculated by the minimum cross-sectional area of the ventilation passage and the cross-sectional area of the ventilation duct, and the wave cancellation material is installed on the inner wall of the ventilation duct.

[0016] A diffusion chamber ventilation wave cancellation simulation system comprises a computer module for establishing a diffusion chamber ventilation duct model, an information acquisition module for acquiring ventilation duct information, the ventilation duct information including air pressure of measuring points, initial measuring points and final measuring points, and cross-sectional area of the ventilation duct, and a storage module for storing diffusion chamber ventilation duct model data information and ventilation duct information, and the storage module is connected with the computer module.

[0017] ​As a preferred scheme of the diffusion chamber ventilation wave-absorption simulation system, the computer module comprises a DM software unit for establishing a diffusion chamber ventilation duct model and connected with the storage module; an input unit for inputting geometric parameters for establishing the diffusion chamber ventilation duct model and establishing diffusion chamber ventilation duct models under different working conditions; and a calculation unit internally provided with calculation expressions, and the calculation results can be obtained by inputting calculation parameters.

[0018] As a preferred scheme of the diffusion chamber ventilation wave-absorption simulation system, the information acquisition module comprises a barometer and a control unit, the barometer is connected with the control unit, the control unit is connected with the input unit, and the control unit is used for controlling the barometer to acquire air pressure information of the measurement base point, the initial measurement point and the final measurement point and inputting the air pressure information into the computer module.

[0019] The present application has the following advantages: the foam aluminum material installed on the inner wall of the ventilation duct is beneficial to strengthen the wave-absorption capacity of the ventilation duct, the minimum cross-sectional area of the ventilation channel and the thickness of the foam aluminum are calculated according to the diffusion chamber ventilation duct model, and the foam aluminum with different densities can be selected according to the thickness of the foam aluminum, the power of the shock wave propagating along the ventilation duct is reduced, the damage to the equipment on the ventilation duct is reduced, the protection effect is achieved, the influence of the friction resistance coefficient of the foam aluminum material on the wind resistance is fully considered, so that the wind resistance inside the ventilation duct is less than the calibrated wind resistance, the ventilation requirement is met, and the power consumption of the fan for auxiliary ventilation is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A basic flowchart of a diffusion chamber ventilation wave-absorption simulation method provided for an embodiment of the present application is shown.

[0021] Figure 2 A structure diagram of a diffusion chamber ventilation wave-absorption simulation system provided for an embodiment of the present application is shown.

[0022] Figure 3 A connection diagram of a horizontal diffusion chamber and a ventilation duct of a diffusion chamber ventilation wave-absorption simulation method provided for an embodiment of the present application is shown.

[0023] Figure 4 A connection diagram of a vertical diffusion chamber and a ventilation duct of a diffusion chamber ventilation wave-absorption simulation method provided for an embodiment of the present application is shown.

[0024] Figure 5 A foam aluminum structure diagram of a diffusion chamber ventilation wave-absorption simulation method and system provided for an embodiment of the present application is shown. DETAILED DESCRIPTION

[0025] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.

[0026] Embodiment 1

[0027] With reference to Figure 1 and Figures 3 to 5 For an embodiment of the present application, a diffusion chamber ventilation wave suppression simulation method is provided, comprising:

[0028] S1: Establishing a diffusion chamber ventilation duct model.

[0029] The diffusion chamber ventilation duct model comprises a ventilation duct and a diffusion chamber, and a wave suppression material arranged on the inner wall of the ventilation duct.

[0030] Since the bending path and length of each ventilation duct of the diffusion chamber are different, the ventilation duct cannot be simply regarded as a long straight pipe, which will lead to too large errors in the existing method of calculating the duct wind resistance according to the duct length and cross-sectional area, resulting in lack of accuracy.

[0031] According to the shape, position and structure of the ventilation duct and the diffusion chamber of the actual protective engineering, a geometric model of the ventilation duct and the diffusion chamber is established in the modeling software, and the DM software is preferably used.

[0032] S2: Collecting ventilation duct information and calculating the actual wind resistance of the ventilation duct.

[0033] Collecting ventilation duct information comprises:

[0034] Calibrating the measurement base point, the initial measurement point and the final measurement point;

[0035] Measuring the air pressure of the measurement base point, the initial measurement point and the final measurement point and obtaining the corresponding readings. Preferably, an air pressure gauge is used to measure the air pressure of the measurement base point, the initial measurement point and the final measurement point.

[0036] The cross-sectional area of the ventilation duct is calculated. The radial size of the ventilation duct is a known parameter, which can be obtained by checking the design standard or measuring on site.

[0037] The calculation expression of the actual wind resistance of the ventilation duct is:

[0038]

[0039] wherein, represents the wind resistance, represents the cross-sectional area of the ventilation duct, respectively represent the initial measurement point and the final measurement point static pressure difference readings, units: Pa, respectively represent reading The static pressure difference reading of the measuring base point is measured, and the unit is Pa.

[0040] After the actual wind resistance of the ventilation duct is calculated, the value of the calibration wind resistance is obtained, and the calibration wind resistance and the value of the actual wind resistance are compared: the value of the calibration wind resistance can be obtained by querying the wind resistance information of the relevant ventilation index, and the preferred ventilation index in the embodiment has a wind resistance of ≤200 Pa.

[0041] S3: comparing the actual wind resistance with the calibration wind resistance

[0042] If the calibration wind resistance is less than the actual wind resistance, the ventilation duct needs to be reconstructed to reduce its wind resistance.

[0043] If the calibration wind resistance is greater than the actual wind resistance, it indicates that the ventilation duct is qualified.

[0044] In the underground protective engineering that has been put into use, the installation of filtering equipment or explosion-proof gate on the ventilation duct will cause poor ventilation, resulting in a wind resistance greater than the original designed wind resistance during use. By reconstructing the factors affecting the ventilation duct, the wind resistance inside the ventilation duct is reduced until it is less than the calibration wind resistance, which can optimize the ventilation duct in the underground protective engineering that has been put into use.

[0045] In the design stage of the underground protective engineering, the ventilation duct can be pre-assembled in the experimental site according to the ventilation duct, and the air pressure of the measuring base point, the initial measuring point and the final measuring point is measured by the barometer. The wind resistance of the ventilation duct can be calculated in advance to obtain accurate data. In the case of excessive wind resistance, it is convenient to improve in time and avoid rework in the later stage.

[0046] S4: calculating the minimum cross-sectional area of the ventilation passage.

[0047] The friction resistance coefficient of the wave absorbing material is obtained, and the calculation expression for calculating the minimum cross-sectional area of the ventilation passage is:

[0048] S f

[0049] Wherein, Sf represents the minimum cross-sectional area of the ventilation passage, The friction resistance coefficient of the wave-absorbing material, the minimum cross-sectional area of the ventilation passage, and the cross-sectional area of the ventilation duct, such as a circular ventilation duct, can be calculated by the area formula of a circle. The radius of the ventilation passage is then subtracted from the radius of the ventilation duct to obtain the thickness of the wave-absorbing material. The main protrusions and grooves of the wave-absorbing material can absorb the shock wave generated by the explosion. The friction resistance coefficient of the aluminum foam material has a great influence on wind resistance, and the friction resistance coefficient of the aluminum foam material needs to be considered.

[0050] The base material of the aluminum foam wave-absorbing structure is preferably a ductile pure aluminum material. The density of industrial pure aluminum is 2.70 g / cm 3 , and the density of the prepared aluminum foam should be less than 1.0 g / cm 3 . Different densities of aluminum foam can be selected in the range of less than 1.0 g / cm 3 , and the friction resistance coefficient is measured.

[0051] The wave-absorbing material is preferably aluminum foam material. Aluminum foam is not only widely used as packaging and cushioning materials in industrial and civilian fields, but also used as protective materials in high-speed impact conditions in the fields of national defense and military, such as composite armor. Aluminum foam has higher strength and energy absorption than commonly used polymer foam, so it can be used as a more effective impact protection material under high-energy impact conditions such as explosion load. However, the strength of aluminum foam is relatively low, so the foam metal material is generally used as an inner lining material to attenuate air shock waves. The main characteristics of aluminum foam material include: light weight, high energy absorption, high specific strength and stiffness, high efficiency of heat dissipation and insulation, noise reduction, and multifunctional integration.

[0052] Aluminum foam can be used as an energy-absorbing material and is widely used as a protective material. The essence of protection is to absorb the energy of external impact and make the force acting on the protected object less than a certain permitted value. The energy absorbed by aluminum foam during compression is mainly in the platform stage. Low-density aluminum foam enters a long stress platform after a small elastic deformation during compression. The longer the platform, the more energy the material can absorb under a smaller stress. As the density of the material increases, the platform stress increases, so the energy absorption capacity of aluminum foam is closely related to the density, but not a simple linear relationship. If the density of the selected aluminum foam is too low, the energy has not been completely absorbed when it is compacted, and the final force is significantly increased due to the compaction of the material until it exceeds the permitted value. If the density is too high, the platform stress may exceed the stress permitted value of the protected object, causing the aluminum foam to be torn apart by the shock wave. Different densities of aluminum foam can be selected according to the thickness of the aluminum foam.

[0053] The foamed aluminum material installed on the inner wall of the ventilation duct is beneficial to strengthening the wave absorbing capacity of the ventilation duct, the minimum cross-sectional area of the ventilation passage and the thickness of the foamed aluminum are calculated according to the diffusion chamber ventilation duct model, and the foamed aluminum with different densities can be selected according to the thickness of the foamed aluminum, the power of the shock wave propagating along the ventilation duct is reduced, the damage to the equipment on the ventilation duct is reduced, the protection effect is achieved, the influence of the friction resistance coefficient of the foamed aluminum material on the wind resistance is fully considered, so that the wind resistance in the ventilation duct is less than the calibrated wind resistance, the ventilation requirement is met, and the power consumption of the fan for auxiliary ventilation is reduced.

[0054] Through experimental verification of different working conditions, the technical effects adopted in the method are verified and illustrated, the traditional technical scheme is compared with the method of the embodiment, the test results are compared by scientific demonstration means, and the real effect of the method is verified.

[0055] According to the wave absorbing structure and arrangement style of the foamed aluminum, six working conditions are designed to study the ventilation performance of the diffusion chamber. The first group is the control group, four variables, namely the ventilation pipe size, the ventilation volume, the foamed aluminum ventilation hole diameter and the diffusion chamber arrangement style, are changed respectively. The outlet wind speed of the diffusion chamber, the wind speed distribution in the diffusion chamber, the pressure distribution in the diffusion chamber and the ventilation resistance of the diffusion chamber under different working conditions are compared and analyzed by the control variable method. The optimal working condition meeting the ventilation index is selected. The initial measuring point and the final measuring point can be respectively arranged at the air inlet and the air outlet of the ventilation duct, and the conditions of different working conditions are as shown in the following table.99.82

[0056] Table 1: Pressure measurement table of different working conditions.

[0057] Operating condition Diffuser form Vent pipe size (mm) Ventilation quantity (m 3 / h) Initial measuring point pressure (kPa) Final measuring point pressure (kPa) Measuring base point pressure (kPa) 1 Vertical 600 3600 104.1 99.68 98.63 2 The method 600 3600 103.8 99.84 99.82 3 Vertical 400 3600 107.7 97.79 99.34 4 Horizontal 600 3600 103.6 99.56 99.79 5 Vertical 600 8000 109.6 99.34 98.76

[0058] The pressure difference between the initial measuring point and the final measuring point is of the order of kPa, and the measured pressure difference is static pressure. The density increases due to the input air volume of the air inlet, and the pressure increases. The velocity difference is represented by dynamic pressure, which can be calculated by 0.5p v 2 . It can be seen that when the ventilation pipe size is the same, the smaller the outlet pressure is, the more resistance loss the wind pressure in the ventilation duct has, that is, the wind resistance is larger. As can be seen from working condition 1 and working condition 2, the final measuring point pressure, that is, the pressure of the outlet part of the ventilation duct, is smaller than that of the traditional method. The wind resistance of the ventilation duct is calculated and optimized in advance in the method, the factors affecting the wind resistance are removed, a layer of foamed aluminum is installed on the inner wall of the ventilation duct, the ventilation capacity is still close to that of the traditional method, the power of the shock wave propagating along the ventilation duct is reduced, the damage to the equipment on the ventilation duct is reduced, the protection effect is achieved, and the ventilation capacity and wave absorbing capacity can be considered at the same time.

[0059] Table 2: Wind speed measurement table of different working conditions.

[0060] Operating condition Diffuser form Vent pipe size (mm) Ventilation volume (m 3 / h) Inlet air velocity (m / s) Outlet air velocity (m / s) 1 Vertical 600 3600 3.54 0.0903 2 The method 600 3600 3.54 0.0989 3 Vertical 400 3600 3.54 0.0530 4 Horizontal 600 3600 3.54 0.1003 5 Vertical 600 8000 7.86 0.1024

[0061] The ventilation performance of the air outlet can be compared by analyzing the air speed of the air outlet at this time. According to the ventilation volume, the air speed at the air outlet should increase with the increase of the air inlet volume, and reach a stable state when the ventilation distribution of the entire diffusion chamber is uniform. However, it takes at least tens of seconds for the entire diffusion chamber to reach a stable state, and the air speed in the ventilation pipe decreases, but this effect is not obvious. What is more obvious is that the diameter of the ventilation pipe is changed, and the air speed of the air outlet increases by 45.6%. Due to the change of the air pipe area, the final air outlet volume decreases. When the diffusion chamber and the wave suppression structure are arranged in a horizontal manner, the air outlet volume and air speed increase, but the wave suppression performance decreases in the following text. When the ventilation volume is set to 8000 m 3 / h, the air speed and air volume also increase, but the effect is still not obvious. From the working conditions 1 and 2, it can be concluded that the outlet air speed of the present method is close to the traditional method, and is slightly larger than the traditional method.

[0062] Embodiment 2

[0063] Referring to Figure 2 , another embodiment of the present application is different from the first embodiment in that a diffusion chamber ventilation wave suppression simulation system is provided.

[0064] The computer module 100 is used to establish a diffusion chamber ventilation pipe model; the computer module 100 preferably uses an existing computer installed with modeling software.

[0065] The information acquisition module 200 is used to acquire ventilation pipe information, including the air pressure of the measurement base point, the initial measurement point and the final measurement point, and the cross-sectional area of the ventilation pipe; the measurement base point, the initial measurement point and the final measurement point can be calibrated first; the air pressure of the measurement base point, the initial measurement point and the final measurement point is measured by using an air pressure gauge, and the corresponding readings are obtained.

[0066] The storage module 300 is used to store diffusion chamber ventilation pipe model data information and ventilation pipe information, and the storage module 300 is connected with the computer module 100.

[0067] The computer module 100 includes a DM software unit 101 for establishing a diffusion chamber ventilation duct model, and is connected with the storage module 300, and can store the diffusion chamber ventilation duct model data into the storage module 300, and also can call the diffusion chamber ventilation duct model data information and ventilation duct information in the storage module 300. An input unit 102 is used for inputting geometric parameters for establishing the diffusion chamber ventilation duct model, and establishing diffusion chamber ventilation duct models under different working conditions; a calculation unit 103 has a calculation expression preset in the inside, and a calculation parameter is inputted to obtain a calculation result. The diffusion chamber ventilation duct model includes various working conditions, such as a diffusion chamber with a bedroom and a vertical type, and the position of the ventilation duct connected with the diffusion chamber, and the arrangement shape of the ventilation duct will cause an influence on the wind resistance. The calculation parameters include air pressure values of a measurement base point, an initial measurement point and a final measurement point, and a diameter of the ventilation duct,

[0068] The information collection module 200 includes an air pressure gauge 201 and a control unit 202, the air pressure gauge 201 is connected with the control unit 202, the control unit 202 is connected with the input unit 102, and the control unit 202 is used for controlling the air pressure gauge 201 to collect air pressure information of the measurement base point, the initial measurement point and the final measurement point, and inputting the air pressure information into the computer module 100. After the air pressure gauge 201 is installed at the measurement base point, the initial measurement point and the final measurement point, the control unit 202 sends a measurement instruction to each air pressure machine at the same time, and measurement records are obtained, so that more accurate wind resistance calculation results are obtained. The control unit 202 can adopt an existing controller, and is directly connected with the computer module 100.

[0069] It should be appreciated that embodiments of the present application can be realized or implemented by computer hardware, a combination of hardware and software, or through computer instructions stored in a non-transitory computer readable storage medium. The method can be implemented in a computer program using standard programming techniques, including a non-transitory computer readable storage medium configured with a computer program, wherein the storage medium thus configured causes a computer to operate in a specific and predefined manner according to the methods described in the specific embodiments and the accompanying drawings. Each program can be implemented in a high-level procedural or object-oriented programming language to communicate with a computer system. However, if necessary, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language. In addition, the program can be run on a programmed special integrated circuit for this purpose.

[0070] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced, without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A method for simulating wave attenuation during ventilation in a diffusion chamber, characterized in that, include: Establish a model of the ventilation duct of the diffusion chamber; Collect ventilation duct information and calculate the actual air resistance of the ventilation duct; Compare the actual wind resistance with the calibrated wind resistance; Calculate the minimum cross-sectional area of ​​the ventilation duct; Install wave-damping material on the inner wall of the ventilation duct; The diffusion chamber ventilation duct model includes a ventilation duct and a diffusion chamber, as well as wave-damping material disposed on the inner wall of the ventilation duct; Information collected on ventilation ducts includes: Calibrate the measurement baseline, initial measuring point, and final measuring point; The air pressure at the measurement base point, initial measurement point, and final measurement point is measured, and the corresponding readings are obtained; Calculate the cross-sectional area of ​​the ventilation duct; The formula for calculating the actual air resistance of the ventilation duct is: ; in, Indicates wind resistance, This indicates the cross-sectional area of ​​the ventilation duct. These represent the static pressure difference readings at the initial and final measuring points, respectively, in Pa. These are respectively represented as reading The static pressure difference reading at the reference point is measured in Pa.

2. The diffusion chamber ventilation and wave attenuation simulation method as described in claim 1, characterized in that: Obtain the value of the calibrated wind resistance, and compare the calibrated wind resistance with the value of the actual wind resistance: If the calibrated air resistance is less than the actual air resistance, the ventilation duct needs to be modified to reduce its air resistance. If the calibrated air resistance is greater than the actual air resistance, it indicates that the ventilation duct is qualified.

3. The diffusion chamber ventilation and wave attenuation simulation method as described in claim 2, characterized in that: The frictional resistance coefficient of the wave-damping material is obtained, and the calculation expression for the minimum cross-sectional area of ​​the ventilation duct is as follows: S f ; Among them, S f This represents the minimum cross-sectional area of ​​the ventilation duct. The friction resistance coefficient of the wave-damping material is represented by the thickness of the wave-damping material calculated using the minimum cross-sectional area of ​​the ventilation channel and the cross-sectional area of ​​the ventilation duct, and the wave-damping material is then installed on the inner wall of the ventilation duct.

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