Method, device and system for monitoring performance of air duct in tunnel construction

Abstract

The application provides a tunnel construction air pipe ventilation performance monitoring method, device and system, the method comprises the following steps: obtaining the fan operation frequency and the monitoring point pressure at the current time; according to the adjacent two monitoring point pressures at the current time and the fan operation frequency at the current time, calculating the comprehensive evaluation index of the target section air pipe at the current time; calculating the change value of the comprehensive evaluation index of the target section air pipe; if the change value of the comprehensive evaluation index of the target section air pipe is greater than the preset air leakage threshold, it is determined that the target section air pipe leaks air. The embodiment of the application can realize real-time monitoring of air pipe air leakage, consider the influence of air volume and air leakage on the ventilation resistance of the air pipe in the monitoring process, introduce the comprehensive evaluation index, more accurately reflect the working state of the air pipe, timely find the air leakage interval of the air pipe, and improve the efficiency of air pipe air leakage monitoring.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel ventilation, in particular to a method, device and system for monitoring ventilation performance of a tunnel construction air pipe. BACKGROUND

[0002] During the construction of underground projects, fresh air needs to be delivered to the construction site to ensure the oxygen needs of personnel and vehicles, and to discharge harmful exhaust gas and dust. Fresh air delivery usually uses an air pipe, which is hung on the top of the tunnel and arranged continuously along the entire tunnel. One end of the air pipe is located outside the tunnel and connected to the air outlet of an axial flow fan, and the other end is located at the construction site inside the tunnel. Fresh air is pressurized by the axial flow fan and delivered from outside the tunnel to the underground construction site through the air pipe.

[0003] During use, the air pipe is easily damaged by construction machinery or human damage, causing local air leakage, and a large amount of high-pressure air gushing out from the damaged part, thereby reducing the air volume delivered to the construction site and reducing the efficiency of fresh air delivery. Supervision and management of the air pipe may be lacking at the construction site, resulting in a lack of timely detection of local damage to the air pipe. When the air pipe damage affects the air quality at the construction site, the fan power is usually manually increased to increase the air supply, which increases the energy consumption of the fan. The fan at the construction site usually operates 24 hours a day for several years, and the increase in fan energy consumption significantly increases the construction cost.

[0004] Currently, most construction units lack management of the air pipe, and a few construction organization units mainly rely on manual inspection to detect air pipe damage. For thousands of kilometers of air pipe, the inspection process requires a lot of manual labor costs, and the damage is not detected in a timely manner. At the same time, inspection can only detect damage on the side facing the walkway and cannot detect damage on the back, resulting in missed detection. SUMMARY

[0005] To solve the above problems, the embodiment of the present application provides a method for monitoring the ventilation performance of a wind pipe in tunnel construction, which is applied to a wind pipe intelligent monitoring system, the wind pipe intelligent monitoring system comprises a plurality of intelligent monitoring devices, each of the intelligent monitoring devices is arranged along a wind pipe installation path at intervals, and is used for collecting the pressure of a monitoring point in the wind pipe, and the method comprises the following steps: acquiring the fan operation frequency at a current time and the pressure of the monitoring point; calculating the comprehensive evaluation index of a target section of the wind pipe at the current time according to the pressure of two adjacent monitoring points at the current time and the fan operation frequency at the current time; the target section of the wind pipe is the wind pipe between the two adjacent monitoring points; calculating the change value of the comprehensive evaluation index of the target section of the wind pipe; the change value of the comprehensive evaluation index is the difference between the comprehensive evaluation index of the target section of the wind pipe at the current time and the comprehensive evaluation index of the target section of the wind pipe at an initial time; the fan operation frequency at the current time is equal to the fan operation frequency at the initial time; and if the change value of the comprehensive evaluation index of the target section of the wind pipe is greater than a preset air leakage threshold, it is determined that the target section of the wind pipe leaks air.

[0006] Optionally, the wind pipe comprises a plurality of target sections of the wind pipe connected end to end; the preset air leakage threshold is a multiple of the standard deviation of the change values of the comprehensive evaluation indexes of all the target sections of the wind pipe, and the multiple is greater than one.

[0007] Optionally, the step of calculating the comprehensive evaluation index of the target section of the wind pipe at the current time according to the pressure of two adjacent monitoring points at the current time and the fan operation frequency at the current time comprises the following steps: calculating the difference value of the pressure of the two adjacent monitoring points at the current time; calculating the comprehensive evaluation index of the target section of the wind pipe at the current time according to the difference value and the fan operation frequency at the current time; the comprehensive evaluation index of the target section of the wind pipe at the current time is positively correlated with the difference value, and the comprehensive evaluation index of the target section of the wind pipe at the current time is negatively correlated with the fan operation frequency at the current time.

[0008] Optionally, the method further comprises the following steps: calculating the difference value of the pressure of two adjacent monitoring points at an initial time; calculating the comprehensive evaluation index of the target section of the wind pipe at the initial time according to the difference value and the fan operation frequency at the initial time; the comprehensive evaluation index of the target section of the wind pipe at the initial time is positively correlated with the difference value, and the comprehensive evaluation index of the target section of the wind pipe at the initial time is negatively correlated with the fan operation frequency at the initial time.

[0009] Optionally, the calculation formula of the comprehensive evaluation index is as follows:

[0010]

[0011] wherein, P i-1 is the pressure of a previous monitoring point, Pi Pn+1 is the pressure of the next monitoring point adjacent to the previous monitoring point, f is the fan operating frequency at the time corresponding to the monitoring pressure, and γ is the air density. i Pn+1 is the pressure of the next monitoring point adjacent to the previous monitoring point, f is the fan operating frequency at the time corresponding to the monitoring pressure, and γ is the air density.

[0012] Optionally, the method further comprises: if it is determined that the target section of the air pipe leaks air, sending air leakage reminding information to a designated terminal; the air leakage reminding information comprises location information and / or number information of the target section.

[0013] The embodiment of the application provides a device for monitoring the ventilation performance of a tunnel construction air pipe, which is applied to an intelligent air pipe monitoring system. The intelligent air pipe monitoring system comprises a plurality of intelligent monitoring devices. The intelligent monitoring devices are arranged at intervals along an air pipe installation path and are used to collect the pressures of monitoring points in the air pipe. The device comprises: an acquisition module, which is used to acquire the fan operating frequency at a current time and the pressures of the monitoring points; a monitoring module, which is used to calculate the comprehensive evaluation index of a target section of the air pipe at the current time according to the pressures of two adjacent monitoring points at the current time and the fan operating frequency at the current time; the target section of the air pipe is the air pipe between the two adjacent monitoring points; a change value calculation module, which is used to calculate the change value of the comprehensive evaluation index of the target section of the air pipe; the change value of the comprehensive evaluation index is the difference between the comprehensive evaluation index of the target section of the air pipe at the current time and the comprehensive evaluation index of the target section of the air pipe at an initial time; the fan operating frequency at the current time is equal to the fan operating frequency at the initial time; and an air leakage determination module, which is used to determine that the target section of the air pipe leaks air if the change value of the comprehensive evaluation index of the target section of the air pipe is greater than a preset air leakage threshold.

[0014] The embodiment of the application provides a tunnel construction air pipe ventilation performance monitoring system, which comprises an intelligent monitoring device, a wireless communication device and an intelligent data processor. The intelligent monitoring device comprises a plurality of pressure sensors. The pressure sensors are arranged at intervals along an air pipe installation path. The wireless communication device is in communication connection with the intelligent data processor through the intelligent monitoring device. The intelligent data processor is used to execute the tunnel construction air pipe ventilation performance monitoring method.

[0015] Optionally, the air pipe is composed of a plurality of air pipe sections. The pressure sensors are installed at the connection positions of two air pipe sections.

[0016] Optionally, the pressure sensors comprise a battery or a self-power supply module, or the pressure sensors are connected with an external power supply.

[0017] The comprehensive evaluation index change value of each section of the air pipe can be calculated in the embodiment of the application, which represents the change degree of the comprehensive evaluation index at the current moment relative to the comprehensive evaluation index at the initial moment, and if the comprehensive evaluation index change value is greater than a preset threshold, the section of the air pipe is determined to have air leakage, so that the air leakage of the air pipe can be monitored in real time, and the influence of the air volume and the air leakage on the ventilation resistance of the air pipe is considered in the monitoring process, the comprehensive evaluation index is introduced, and the working state of the air pipe is more accurately reflected, the air pipe air leakage interval is found in time, and the efficiency of the air pipe air leakage monitoring is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0019] Figure 1 It is a schematic diagram of installation of the tunnel construction air pipe ventilation performance monitoring system in the embodiment of the present application.

[0020] Figure 2 It is a simplified schematic diagram of monitoring of the ventilation pipeline in the embodiment of the present application.

[0021] Figure 3 It is a schematic diagram of influence of the hundred-meter air leakage rate on the comprehensive evaluation index in the embodiment of the present application.

[0022] Figure 4 It is a schematic flow chart of a method of tunnel construction air pipe ventilation performance monitoring in the embodiment of the present application.

[0023] Figure 5 It is a side view of the intelligent monitoring device in the embodiment of the present application.

[0024] Figure 6 It is a sectional view of the intelligent monitoring device in the embodiment of the present application.

[0025] Figure 7 It is a schematic diagram of the pressure sensor in the embodiment of the present application.

[0026] Figure 8 It is a sectional view of the intelligent monitoring device in the embodiment of the present application.

[0027] Figure 9 It is a structural schematic diagram of a device of tunnel construction air pipe ventilation performance monitoring in the embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the above objectives, characteristics and advantages of the present application more apparent, concrete embodiments of the present application will be described in detail below with reference to the drawings. It should be understood that the concrete embodiments described herein are only used to explain the present application and do not limit the present application.

[0029] During tunnel construction, the air in the deep tunnel is difficult to exchange with the outside air. However, the construction personnel and machinery need sufficient fresh air to maintain normal breathing and equipment operation, and at the same time, a large amount of dust and harmful gas generated during construction also needs to be discharged in time. During construction, an axial flow fan is usually used as a driven ventilation device to deliver fresh air to the inside of the tunnel and discharge dust and harmful gas.

[0030] The axial flow fan is located outside the tunnel, usually maintaining a distance of more than 20m from the portal, and has sufficient fresh air to use. The outlet of the axial flow fan is connected to a soft air pipe, which is hung on the top of the tunnel and arranged continuously along the tunnel to the construction site. Fresh air is pressurized by the axial flow fan, flows through the soft air pipe, and is discharged at the outlet of the air pipe in the tunnel. Thus, the construction personnel and equipment on site can obtain sufficient oxygen supply. After the fresh air is released at the construction site, the air pressure formed pushes the dirty air in the tunnel to flow outward along the tunnel, thereby bringing dust and harmful gas out of the tunnel, so that the air quality in the tunnel meets the national standard requirements.

[0031] The length of the tunnel is usually several kilometers, and the air pipe is 20-100m per section. Multiple air pipes are connected together to form a long pipe line to deliver fresh air to the farthest construction site.

[0032] In the embodiments of the present application, the Internet of Things sensor technology, network communication technology and intelligent algorithm are used to form a tunnel construction air pipe ventilation performance monitoring system. The system can continuously monitor the pressure in the air pipe and its change, judge the air pipe leakage through intelligent algorithm, identify the air pipe leakage interval, and timely issue an alarm to remind the maintenance personnel to repair the damaged air pipe.

[0033] The tunnel construction air pipe ventilation performance monitoring system comprises an intelligent monitoring device, a wireless communication device and an intelligent data processor installed on the air pipe passage.

[0034] Referring to Figure 1 The installation schematic diagram of the tunnel construction air pipe ventilation performance monitoring system is shown in the figure, which shows the fan support 1, the axial flow fan 2, the air pipe 3, the air pipe outlet 4, the intelligent data processor 5, the wireless communication device 6 and the intelligent monitoring device 7.

[0035] Along the ventilation path of the duct, IoT smart monitoring devices are installed every 100-200 meters to monitor the static pressure of the air inside the duct. The monitoring data is transmitted to a smart data processor via wireless communication. The smart data processor analyzes and processes the ventilation data to determine the ventilation performance of the duct and detect areas of air leakage.

[0036] See Figure 2 The diagram shown is a simplified illustration of a ventilation duct monitoring system, using a 7-section duct connection as an example. Where L is the length of each duct section, P0 and Q0 are the air pressure and air volume at the fan outlet; P7 and Q7 are the air pressure and air volume at the end of the flexible duct; P... i (i = 1...6) represents the wind pressure measured by the i-th intelligent monitoring device; Q i (i = 1...6) represents the air volume at the i-th intelligent monitoring device, h i (i=1...7) represents the pressure loss of the i-th duct segment.

[0037] The ventilation resistance of the i-th duct section is calculated using the following formula.

[0038]

[0039] In the formula, h i Let λ be the resistance (Pa) of the i-th duct segment, λ be the coefficient of friction, ρ be the air density, d be the duct cross-sectional diameter, and β be the duct cross-section diameter. i Let L be the air leakage rate per 100 meters of the i-th duct segment, and L be the length of the i-th duct segment. i Let be the air volume at the outlet of the i-th duct segment.

[0040] The air volume at the outlet of the i-th duct section can be calculated using the following formula:

[0041]

[0042] In the formula, f is the operating frequency of the fan (Hz), and α is the air volume coefficient.

[0043] According to equations (1) and (2), ventilation resistance is affected by the fan operating frequency, duct diameter, and air leakage rate.

[0044] In tunnel ventilation systems, once the ducts are installed, their diameter remains unchanged, while the fan operating frequency is adjusted in real time according to construction procedures and the tunnel environment. Therefore, in actual operation, changes in ventilation resistance are affected by both variations in airflow and sudden duct leaks. This embodiment considers the combined effects of airflow changes and duct leaks on ventilation resistance, which can be represented by the pressure difference between two locations within the duct. It should be noted that during duct leak detection, the effects of airflow changes (i.e., changes in fan operating frequency) must be eliminated.

[0045] In the process of monitoring the air leakage of the air duct, the influence of the air volume is introduced, so that the air leakage characteristics are more accurately reflected. Formula (2) is brought into formula (1) to obtain

[0046]

[0047] Divide the left and right sides of formula (3) by f 2 to obtain the comprehensive evaluation index γ, and obtain

[0048]

[0049] According to formula (4), the change of the air leakage rate β can be judged according to the change of γ, that is .

[0050] Referring to the schematic diagram of the influence of the comprehensive evaluation index on the air leakage rate of 100 meters shown in Figure 3 , under the condition that the length of the air duct is constant, the comprehensive evaluation index γ decreases with the increase of the air duct air leakage rate, and if the i-th air duct appears air leakage, the comprehensive evaluation index of the i-th air duct and the subsequent air ducts will decrease. On the contrary, the change of the comprehensive evaluation index of the i-th air duct and the subsequent air ducts can be monitored to speculate whether the i-th air duct has air leakage phenomenon.

[0051] For the air duct with a low nominal air leakage rate, the slight change of the air leakage rate caused by the damage of the air duct will cause a large decrease of the comprehensive evaluation index.

[0052] Figure 4 is a schematic flow chart of a method for monitoring the ventilation performance of a tunnel construction air duct in the embodiment of the present application. The method is applied to an air duct intelligent monitoring system, the air duct intelligent monitoring system comprises a plurality of intelligent monitoring devices, the intelligent monitoring devices are arranged at intervals along the installation path of the air duct, and are used for collecting the pressure of the monitoring points in the air duct. The method comprises the following steps:

[0053] S402, acquiring the fan operating frequency and the monitoring point pressure at the current time.

[0054] The intelligent monitoring devices respectively collect the monitoring point pressure at the corresponding installation positions. The air duct between two adjacent intelligent monitoring devices is taken as an independent object to be identified whether air leakage occurs.

[0055] S404, calculating the comprehensive evaluation index of the target air duct at the current time according to the adjacent two monitoring point pressures at the current time and the fan operating frequency at the current time.

[0056] The target air duct is the air duct between the adjacent two monitoring points. In the embodiment, the target air duct can be the air duct between any adjacent two monitoring points, and the change value of the comprehensive evaluation index of each air duct is calculated respectively, so that it is judged which air duct appears air leakage.

[0057] Based on the foregoing analysis of the change of the ventilation resistance, which is jointly affected by the change of the air volume and the air leakage of the air duct, the comprehensive evaluation index is used to represent whether the air duct leaks. If there is air leakage, the pressure difference between the inlet and the outlet of the target section of the air duct is larger than that in the case of no air leakage, and the larger the pressure difference, the larger the comprehensive evaluation index. The higher the frequency of the operation of the fan (corresponding to the larger air volume), the less obvious the pressure difference caused by the air leakage, that is, the higher the frequency of the operation of the fan, the smaller the comprehensive evaluation index.

[0058] Optionally, the comprehensive evaluation index of the target section of the air duct at the current time is calculated in the following manner:

[0059] First, the difference between the pressures of the adjacent two monitoring points at the current time is calculated. Second, the comprehensive evaluation index of the target section of the air duct at the current time is calculated according to the difference and the frequency of the operation of the fan at the current time. The comprehensive evaluation index of the target section of the air duct at the current time is positively correlated with the difference and negatively correlated with the frequency of the operation of the fan at the current time.

[0060] Optionally, the comprehensive evaluation index at the initial time is calculated in the following manner:

[0061] First, the difference between the pressures of the adjacent two monitoring points at the initial time is calculated. Second, the comprehensive evaluation index of the target section of the air duct at the initial time is calculated according to the difference and the frequency of the operation of the fan at the initial time. The comprehensive evaluation index of the target section of the air duct at the initial time is positively correlated with the difference and negatively correlated with the frequency of the operation of the fan at the initial time.

[0062] S406, a change value of the comprehensive evaluation index of the target section of the air duct is calculated.

[0063] The change value of the comprehensive evaluation index is the difference between the comprehensive evaluation index of the target section of the air duct at the current time and the comprehensive evaluation index of the target section of the air duct at the initial time. The change value of the comprehensive evaluation index represents the change of the comprehensive evaluation index at different times relative to the comprehensive evaluation index at the initial time. The initial time can be a time when the fan is in a normal working state, for example, a time when the air duct is arranged, the fan is normally operated, and the air duct is checked for air leakage.

[0064] Considering that the change of the ventilation resistance is jointly affected by the change of the air volume and the air leakage of the air duct, the influence caused by the change of the air volume (i.e., the change of the frequency of the operation of the fan) needs to be eliminated in the comparison of the comprehensive evaluation indexes. In this embodiment, the frequency of the operation of the fan at the current time is set to be equal to the frequency of the operation of the fan at the initial time. The frequency of the operation of the fan used to calculate the comprehensive evaluation index of the target section of the air duct at the current time is equal to the frequency of the operation of the fan used to calculate the comprehensive evaluation index of the target section of the air duct at the initial time.

[0065] S408, if the change value of the comprehensive evaluation index of the target section air duct is greater than the preset air leakage threshold, it is determined that the target section air duct leaks air.

[0066] The air duct at least includes a plurality of target section air ducts connected head to tail, the preset air leakage threshold is a multiple of the standard deviation of the change value of the comprehensive evaluation index of all target section air ducts, and the multiple is greater than one.

[0067] In the above monitoring process, the monitoring sensitivity of the system can be adjusted by changing the preset air leakage threshold as the judgment standard. For example, the preset air leakage threshold can be set to 3 times the standard deviation; if the preset air leakage threshold is set to 1 times the standard deviation, the sensitivity is improved; if the change value is increased to 6 times the variance, the sensitivity is reduced.

[0068] The method for monitoring the ventilation performance of the air duct in tunnel construction provided by the embodiment of the application can calculate the change value of the comprehensive evaluation index of each section of the air duct, which represents the change degree of the comprehensive evaluation index at the current time relative to the comprehensive evaluation index at the initial time. If the change value of the comprehensive evaluation index is greater than the preset threshold, it is determined that the section of the air duct leaks air, so that the air leakage of the air duct can be monitored in real time. In the monitoring process, the influence of air volume and air leakage on the ventilation resistance of the air duct is considered, the comprehensive evaluation index is introduced, the working state of the air duct is more accurately reflected, the air leakage interval of the air duct is found in time, and the efficiency of air leakage monitoring of the air duct is improved.

[0069] After it is determined that air leakage occurs based on the above steps, the following steps can be further performed: if it is determined that the target section air duct leaks air, air leakage reminding information is sent to a designated terminal; and the air leakage reminding information includes position information and / or number information of the target section.

[0070] For example, the calculation formula of the above comprehensive evaluation index is as follows:

[0071]

[0072] Wherein, P i-1 is the pressure of the previous monitoring point, P i is the pressure of the next monitoring point adjacent to the previous monitoring point, f is the running frequency of the fan at the time corresponding to the monitoring pressure, γ i is the comprehensive evaluation index of the target section air duct at the current time.

[0073] In the embodiment, the performance comprehensive evaluation index of the section of the air duct is calculated through the pressure difference between the adjacent two monitoring points; the change trend of the comprehensive evaluation index is analyzed, and the air leakage of the air duct is inferred. The change value of the comprehensive evaluation index of the i section of the air duct at t time is

[0074] Δγ i (t)=γ i (t)-γ i (0)

[0075] Where, Δγ i (t) represents the change in the comprehensive evaluation index of the i-th section of the duct at time t, γ i (t) represents the comprehensive evaluation index of the i-th duct segment at time t, γ i (0) is the comprehensive evaluation index of the i-th duct segment at the initial moment.

[0076] Therefore, starting from the fan outlet, we search for the section of duct with the greatest change in comprehensive evaluation indicators, based on the following criteria:

[0077] Δγ k >3σ(Δγ i )

[0078] Where, σ(Δγ) i ) represents the standard deviation of the changes in the comprehensive evaluation index of all target duct sections.

[0079] If the above formula is satisfied, it is considered that the air leakage rate of the k-th duct exceeds the standard, indicating that there is damage and air leakage, which needs to be dealt with in a timely manner.

[0080] This invention provides a tunnel construction duct ventilation performance monitoring system, including an intelligent monitoring device, a wireless communication device, and an intelligent data processor. The intelligent monitoring device includes multiple pressure sensors arranged at intervals along the duct installation path; the wireless communication device is communicatively connected to the intelligent data processor via the intelligent monitoring device; the intelligent data processor is used to execute the aforementioned method for monitoring the tunnel construction duct ventilation performance.

[0081] Optionally, the duct is composed of multiple sections, and the pressure sensor is installed at the connection between two sections.

[0082] Optionally, the pressure sensor may include a battery or a self-powered module, or the pressure sensor may be connected to an external power source.

[0083] For example, intelligent monitoring devices are arranged at intervals along the duct installation path, with a spacing of approximately 100-200 meters, and can be installed at the connection points of two duct sections. Wireless communication devices are installed on each intelligent monitoring device and also on the intelligent data processor, providing wireless data transmission functionality. The intelligent data processor is responsible for processing the collected information and determining the leakage areas in the duct.

[0084] See Figure 5 The side view of the intelligent monitoring device shown and Figure 6The cross-section view of the intelligent monitoring device shows that the basic structure of the intelligent monitoring device 7 is cylindrical, and the mounting ring 10 for connecting the flexible air pipe is arranged at the front and back. The pressure sampling points 9 are evenly distributed near the cylinder wall in the middle of the device. The pressure sampling points are connected by rubber pipes and collected to the pressure sensor 8. The pressure of the air in the air pipe is converted into a digital signal, which is transmitted to the intelligent data processor through the wireless communication device 6.

[0085] Referring to Figure 7 The schematic view of the pressure sensor shows the pressure sensor 8 and the pressure sampling point 9.

[0086] The pressure sensor can be powered by a long-acting lithium battery, or an external power supply, or a self-powered module. Referring to Figure 8 The cross-section view of the intelligent monitoring device shows that the self-powered module includes a micro wind turbine 11, and the self-powered module also includes a lithium battery and a power management module. Through the flow of gas inside the air pipe, the micro wind turbine 11 is driven to rotate, and the generated power charges the lithium battery.

[0087] The implementation of the above-mentioned air pipe ventilation performance monitoring system is divided into three main steps:

[0088] The first step is to install the intelligent monitoring device at equal intervals along the ventilation pipeline, with an interval of 100-200 meters; install the intelligent data processor and set up the wireless communication device. For example, install the intelligent monitoring device at equal intervals along the line where the air pipe is arranged; install the intelligent data processor; and configure the connection of the wireless signal.

[0089] The second step is to run the ventilation system. Under normal working conditions, the initial ventilation pressure of each section of the air pipe and the fan running frequency are monitored as a comparison reference. For example, run the fan to the normal working state, and record the initial pressure of each section of the air pipe.

[0090] The third step is to run the monitoring system in real time, calculate the change of the comprehensive evaluation index of each section of the air pipe, and if abnormal fluctuations occur, determine the number of the air pipe with air leakage and remind the personnel to handle it. For example, monitor the fan output frequency and the change of the comprehensive evaluation index of each section of the air pipe in real time; calculate the mean square deviation of the change of the comprehensive evaluation index of each section of the air pipe; find the position where the change of the comprehensive evaluation index exceeds 3σ from the fan outlet; and issue a prompt message that the above-mentioned position has air leakage.

[0091] In the above working process, the threshold value of the judgment standard can be changed to adjust the sensitivity of the system. For example, if the change value is limited to 1 times the variance, the sensitivity is improved; if the change value is increased to 6 times the variance, the sensitivity is reduced.

[0092] The embodiment of the present application provides a tunnel construction air pipe ventilation performance monitoring method, which can timely find air pipe air leakage, and reminds field workers to repair in time through sound-light alarm, short message, WeChat and the like.

[0093] In the monitoring process, the influence of air volume on air pipe ventilation resistance is considered, a comprehensive evaluation index is introduced, and the working state of the air pipe is more accurately reflected.

[0094] By reducing air pipe air leakage, the fan can realize a good tunnel working environment under reasonable power, and energy waste is reduced.

[0095] Figure 9 It is a structural schematic diagram of a tunnel construction air pipe ventilation performance monitoring device in the embodiment of the present application, the device is applied to an air pipe intelligent monitoring system, the air pipe intelligent monitoring system comprises a plurality of intelligent monitoring devices, the intelligent monitoring devices are arranged at intervals along an air pipe installation path, and are used for collecting air pipe internal monitoring point pressures, and the device comprises:

[0096] The acquisition module 901 is used for acquiring a fan operation frequency at a current moment and the monitoring point pressure;

[0097] The monitoring module 902 is used for calculating a comprehensive evaluation index of a target section air pipe at the current moment according to two adjacent monitoring point pressures at the current moment and the fan operation frequency at the current moment; the target section air pipe is an air pipe between the two adjacent monitoring points;

[0098] The change value calculation module 903 is used for calculating a comprehensive evaluation index change value of the target section air pipe; the comprehensive evaluation index change value is a difference between the comprehensive evaluation index of the target section air pipe at the current moment and the comprehensive evaluation index of the target section air pipe at an initial moment; the fan operation frequency at the current moment is equal to the fan operation frequency at the initial moment;

[0099] The air leakage determination module 904 is used for determining that the target section air pipe leaks air if the comprehensive evaluation index change value of the target section air pipe is greater than a preset air leakage threshold.

[0100] The device for monitoring the ventilation performance of the wind pipe in tunnel construction provided by the embodiment of the present application can calculate the comprehensive evaluation index change value of each section of the wind pipe, which represents the change degree of the comprehensive evaluation index at the current time relative to the comprehensive evaluation index at the initial time, and if the comprehensive evaluation index change value is greater than the preset threshold value, it is determined that the section of the wind pipe leaks air, so that the air leakage of the wind pipe can be monitored in real time, the influence of the air volume and the air leakage on the ventilation resistance of the wind pipe is considered in the monitoring process, the comprehensive evaluation index is introduced, the working state of the wind pipe is more accurately reflected, the air leakage interval of the wind pipe is found in time, and the efficiency of the air leakage monitoring of the wind pipe is improved.

[0101] Optionally, the wind pipe at least comprises a plurality of target section wind pipes connected end to end; the preset air leakage threshold value is a multiple of the standard deviation of the comprehensive evaluation index change value of all the target section wind pipes, and the multiple is greater than one.

[0102] Optionally, the monitoring module is specifically configured to: calculate the difference value of the pressures of the adjacent two monitoring points at the current time; and calculate the comprehensive evaluation index of the target section wind pipe at the current time according to the difference value and the fan operation frequency at the current time; the comprehensive evaluation index of the target section wind pipe at the current time is positively correlated with the difference value, and the comprehensive evaluation index of the target section wind pipe at the current time is negatively correlated with the fan operation frequency at the current time.

[0103] Optionally, the device further comprises a calculation module configured to: calculate the difference value of the pressures of the adjacent two monitoring points at the initial time; and calculate the comprehensive evaluation index of the target section wind pipe at the initial time according to the difference value and the fan operation frequency at the initial time; the comprehensive evaluation index of the target section wind pipe at the initial time is positively correlated with the difference value, and the comprehensive evaluation index of the target section wind pipe at the initial time is negatively correlated with the fan operation frequency at the initial time.

[0104] Optionally, the calculation formula of the comprehensive evaluation index is as follows:

[0105]

[0106] wherein, P i-1 is the pressure of the previous monitoring point, P i is the pressure of the next monitoring point adjacent to the previous monitoring point, f is the fan operation frequency at the time corresponding to the monitoring pressure, γ i is the comprehensive evaluation index of the target section wind pipe at the current time.

[0107] Optionally, the device further comprises a reminding module configured to: if it is determined that the target section wind pipe leaks air, send air leakage reminding information to a designated terminal; and the air leakage reminding information comprises the position information and / or the number information of the target section.

[0108] The embodiment of the present application further provides a computer readable storage medium, and the computer readable storage medium stores a computer program, the computer program is executed by a processor to realize each process of the yield metering method based on image segmentation and achieve the same technical effects, and details are not repeated here. The computer readable storage medium is, for example, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, an optical disk or the like.

[0109] Of course, those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer degree to instruct a control device, and the program can be stored in a computer readable storage medium. The program can include the processes of the above-mentioned method embodiments when executed, and the storage medium can be a memory, a magnetic disk, an optical disk or the like.

[0110] In this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without limitation, an element preceded by "comprises... a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0111] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same or similar parts between various embodiments can be referred to each other.

[0112] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for monitoring the ventilation performance of a wind pipe in tunnel construction, characterized in that The method is applied to a duct intelligent monitoring system, the duct intelligent monitoring system comprises a plurality of intelligent monitoring devices, each intelligent monitoring device is arranged along a duct installation path at intervals, and is used for collecting pressures of monitoring points in a duct, and the method comprises the following steps: obtaining a fan operation frequency at a current moment and the pressures of the monitoring points; calculating a comprehensive evaluation index of a target duct at the current moment according to the pressures of two adjacent monitoring points at the current moment and the fan operation frequency at the current moment; the target duct is a duct between the two adjacent monitoring points; calculating a change value of the comprehensive evaluation index of the target duct; the change value of the comprehensive evaluation index is a difference between the comprehensive evaluation index of the target duct at the current moment and a comprehensive evaluation index of the target duct at an initial moment; the fan operation frequency at the current moment is equal to a fan operation frequency at the initial moment; if the change value of the comprehensive evaluation index of the target duct is greater than a preset air leakage threshold, it is determined that the target duct leaks air; the method further comprises the following steps: calculating a difference value of the pressures of the two adjacent monitoring points at the current moment; calculating the comprehensive evaluation index of the target duct at the current moment according to the difference value and the fan operation frequency at the current moment; the comprehensive evaluation index of the target duct at the current moment is positively correlated with the difference value, and the comprehensive evaluation index of the target duct at the current moment is negatively correlated with the fan operation frequency at the current moment; the method further comprises the following steps: calculating a difference value of the pressures of the two adjacent monitoring points at the initial moment; calculating the comprehensive evaluation index of the target duct at the initial moment according to the difference value and the fan operation frequency at the initial moment; the comprehensive evaluation index of the target duct at the initial moment is positively correlated with the difference value, and the comprehensive evaluation index of the target duct at the initial moment is negatively correlated with the fan operation frequency at the initial moment.

2. The method of claim 1, wherein, the duct comprises a plurality of target ducts connected end to end; the preset air leakage threshold is a multiple of a standard deviation of the change values of the comprehensive evaluation indexes of all the target ducts, and the multiple is greater than one.

3. The method according to claim 1 or 2, characterized in that, a calculation formula of the comprehensive evaluation index is as follows: Wherein, P i-1 is the pressure of the previous monitoring point, P i is the pressure of the next monitoring point adjacent to the previous monitoring point, f is the fan operating frequency corresponding to the time of monitoring the pressure, γ i is the comprehensive evaluation index of the target section air pipe at the current time.

4. The method of claim 1, wherein, the method further comprises the following steps: if it is determined that the target duct leaks air, sending air leakage reminding information to a specified terminal; the air leakage reminding information comprises position information and / or number information of the target duct.

5. A device for monitoring the ventilation performance of a wind pipe in tunnel construction, characterized in that The device is applied to a duct intelligent monitoring system, the duct intelligent monitoring system comprises a plurality of intelligent monitoring devices, each intelligent monitoring device is arranged along a duct installation path at intervals, and is used for collecting pressures of monitoring points in a duct, and the device comprises the following steps: an obtaining module, used for obtaining a fan operation frequency at a current moment and the pressures of the monitoring points; The monitoring module is configured to calculate a comprehensive evaluation index of a target section of air pipe at the current time according to pressures of two adjacent monitoring points at the current time and a fan operation frequency at the current time, the target section of air pipe being air pipe between the two adjacent monitoring points; The change value calculation module is configured to calculate a change value of the comprehensive evaluation index of the target section of air pipe, the change value of the comprehensive evaluation index being a difference between the comprehensive evaluation index of the target section of air pipe at the current time and a comprehensive evaluation index of the target section of air pipe at an initial time, the fan operation frequency at the current time being equal to a fan operation frequency at the initial time; The air leakage determination module is configured to determine that the target section of air pipe is air-leaked if the change value of the comprehensive evaluation index of the target section of air pipe is greater than a preset air leakage threshold. The monitoring module is specifically configured to: calculate a difference between the pressures of the two adjacent monitoring points at the current time; calculate the comprehensive evaluation index of the target section of air pipe at the current time according to the difference and the fan operation frequency at the current time, the comprehensive evaluation index of the target section of air pipe at the current time being positively correlated with the difference, and the comprehensive evaluation index of the target section of air pipe at the current time being negatively correlated with the fan operation frequency at the current time. The device further comprises a calculation module configured to calculate a difference between pressures of two adjacent monitoring points at an initial time, and calculate a comprehensive evaluation index of a target section of air pipe at the initial time according to the difference and a fan operation frequency at the initial time, the comprehensive evaluation index of the target section of air pipe at the initial time being positively correlated with the difference, and the comprehensive evaluation index of the target section of air pipe at the initial time being negatively correlated with the fan operation frequency at the initial time.

6. A tunnel construction air duct ventilation performance monitoring system characterized by, The device comprises an intelligent monitoring device, a wireless communication device and an intelligent data processor. The intelligent monitoring device comprises a plurality of pressure sensors, each of the pressure sensors being arranged along an installation path of the air pipe, and the wireless communication device is in communication connection with the intelligent data processor through the intelligent monitoring device. The intelligent data processor is configured to execute the method for monitoring ventilation performance of a tunnel construction air pipe according to any one of claims 1-4.

7. The system of claim 6, wherein, The air pipe is composed of a plurality of sections of air pipe, and the pressure sensors are installed at connection positions of two sections of air pipe.

8. The system of claim 6, wherein, The pressure sensors comprise a battery or a self-power supply module, or the pressure sensors are connected with an external power supply. The pressure sensors comprise a battery or a self-power supply module, or the pressure sensors are connected with an external power supply.

Images