Drainage pipe flow monitoring device and method

Abstract

The present invention proposes a drainage pipe flow monitoring device and method, which includes a blocking system, a pumping system, and a monitoring system. The blocking system is used to block upstream water, the pumping system is used to lift incoming water to the monitoring system, and the monitoring system is used to monitor real-time flow. The blocking system includes an annular water inlet and an inlet pipe, one end of which is connected to the water inlet, and the other end is connected to the water inlet end of the hollow balloon via a connecting flange. A hollow balloon tube runs through the middle of the hollow balloon, and a trachea interface is provided on one side of the water outlet end of the hollow balloon. The trachea interface is connected to the trachea, and the upper end of the trachea is connected to an air pump for controlling the air pressure of the hollow balloon. This system can convert the non-full flow in the drainage pipe into a pressurized flow, and then use an electromagnetic flowmeter for flow monitoring. Compared with the ultrasonic Doppler flowmeter, more accurate monitoring results can be obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of municipal drainage pipe networks and relates to a drainage pipe flow monitoring device and method. Background Art

[0002] Ultrasonic Doppler flowmeters are a type of flow monitoring device currently widely used in drainage pipe flow measurement. Their principle is to analyze the average flow velocity of the hydraulic section of the drainage pipe based on the ultrasonic frequency shift effect. They are also equipped with a liquid level sensor to calculate the hydraulic cross-sectional area through liquid level monitoring. Finally, the area-velocity method is used to measure the pipe flow online. These flowmeters are generally suitable for monitoring flow in partially filled, large-diameter drainage pipes. However, in actual projects, Doppler ultrasonic flowmeter probes are easily contaminated and affected by water flow impact in drainage pipes, resulting in significant deviations from actual monitoring data. Furthermore, ultrasonic flowmeter probes require regular maintenance and upkeep, resulting in high purchase and operating costs. Electromagnetic flowmeters, on the other hand, primarily detect pressure pipe flow based on electromagnetic induction. Their flow monitoring accuracy is generally higher, especially for rainwater and sewage containing particulate pollutants. The equipment has a simple structure and significantly lower purchase and maintenance costs. Summary of the Invention

[0003] The purpose of the present invention is to address the defects of the existing technology and provide a drainage pipe flow monitoring device and method. The present invention is mainly based on a blocking system, a pumping system and a monitoring system, which can realize temporary and accurate detection of drainage pipe flow data. At the same time, based on the drainage pipe liquid level-flow analysis, the drainage pipe flow can be deduced based on the liquid level monitoring data.

[0004] In a first aspect of the present invention, a drainage pipe flow monitoring device is provided, comprising a blocking system, a pumping system, and a monitoring system. The blocking system is used to block the upstream water in the drainage pipe. The pumping system is used to lift the water in the drainage pipe to the monitoring system so that all the upstream water enters the monitoring system through the pumping system. The monitoring system is used to monitor the real-time flow rate.

[0005] The sealing system includes an annular water inlet and a water inlet pipe. One end of the water inlet pipe is connected to the water inlet, and the other end is connected to the water inlet end of the hollow balloon through a connecting flange. A hollow tube of the airbag runs through the middle of the hollow balloon. A trachea interface is provided on one side of the water outlet end of the hollow balloon. The trachea interface is connected to the trachea, and the upper end of the trachea is connected to the air pump for controlling the air pressure of the hollow balloon.

[0006] Preferably, the pumping system includes a water inlet connecting pipe, a water pump, a cable and a water outlet connecting pipe. The two ends of the water inlet connecting pipe are respectively connected to the water outlet end of the airbag hollow tube and the water inlet end of the water pump through connecting flanges. The water pump is used to lift the water in the drainage pipe to the ground monitoring system. The cable connects the distribution box and the generator to power the water pump. The water outlet connecting pipe is used to transport the water output from the water pump to the ground monitoring system.

[0007] Preferably, the monitoring system includes a valve, a flowmeter inlet pipe, an electromagnetic flowmeter, a flowmeter outlet pipe, a drain pipe and a liquid level meter. The drain pipe is used to discharge the water after detection. The liquid level meter is installed at the center of the bottom of the straight section of the drainage pipe downstream of the drain pipe outlet inspection well to detect the pipeline liquid level. The valve is connected between the outlet connecting pipe and the flowmeter inlet pipe, the electromagnetic flowmeter is connected between the flowmeter inlet pipe and the flowmeter outlet pipe, and the drain pipe is connected to the flowmeter outlet pipe.

[0008] Preferably, the blocking system, pumping system and monitoring system are partially installed in a mobile engineering vehicle, and the air pump, distribution box, generator, valve, electromagnetic flowmeter, flowmeter inlet pipe and flowmeter outlet pipe are all fixedly installed in the engineering vehicle.

[0009] A second aspect of the present invention provides a drainage pipe flow monitoring method using any of the drainage pipe flow monitoring devices described above, comprising a temporary monitoring phase and a long-term monitoring phase, wherein the temporary monitoring phase specifically includes the following steps:

[0010] S1 point selection: Based on the flow monitoring requirements, conduct a preliminary survey of the municipal drainage pipeline where flow monitoring is planned, and select the monitoring location according to the following requirements: the maximum fullness of the pipeline at the planned monitoring location on a sunny day does not exceed 75%; the pipeline at the monitoring location is straight, and there are no branch pipes connected to the inspection well where the water pump is planned to be placed and the two consecutive inspection wells downstream; there are no hidden branch pipes or external water infiltration caused by pipeline damage in the pipeline between the two consecutive inspection wells downstream, and the hydraulic elements of the entire pipeline section between the two consecutive inspection wells downstream are consistent;

[0011] S2 system equipment selection and assembly: Obtain the pipe diameter D, slope i, burial depth h, and basic pipe material information of the monitoring section based on the drainage drawings. Calculate the flow rate when the pipe is 75% full as the maximum pump lift flow rate. Use the depth of the inspection well M1 as the required lift for the pump. Select the pump so that the upper limit of the electromagnetic flowmeter's flow monitoring is higher than the flow rate value when the pipe is 75% full.

[0012] S3 on-site installation: The required equipment should be collected by a special engineering vehicle and transported to the monitoring point in a unified manner. Before monitoring, the pipe sections of inspection well M1 and inspection well M2 should be fenced off corresponding to the municipal roads and the parking range of engineering vehicles. During on-site installation, first place all the connected accessories of the plugging system, pumping system and monitoring system on the ground, and adjust the valves, distribution box and air pump to the closed state. Then install a triangular crane above the wellhead of inspection well M1, and hoist the hollow air bag and water pump to the bottom of inspection well M1. Then use the hook to adjust the position of the hollow air bag so that it is completely placed at the bottom of the upstream pipeline of inspection well M1. Finally, place the water outlet end of the drain pipe in the downstream inspection well M2.

[0013] S4 system startup: First, turn on the mobile power supply in the engineering vehicle, start the air pump through the distribution box to inflate the hollow airbag, and stop inflating when the upstream pipeline of the inspection well M1 is completely blocked. Open the valve to the maximum opening, start the water pump, and the drain pipe begins to drain water;

[0014] S5 Data Observation: During the monitoring process, observe the flow meter inlet pipe. Adjust the valve opening to keep the inlet pipe just full to ensure accurate monitoring by the electromagnetic flowmeter. During the monitoring process, set the flow and liquid level data reading interval according to the monitoring requirements, and read the electromagnetic flowmeter readings regularly to complete temporary monitoring of the instantaneous flow in the drainage pipe.

[0015] S6 Temporary Monitoring System Dismantling: After obtaining sufficient data, the plugging system, pumping system and monitoring system can be dismantled and kept, and the level gauge can be retained for level monitoring.

[0016] Preferably, the long-term monitoring phase includes:

[0017] Step 1 Liquid level-flow relationship analysis: Input the measured drainage pipe liquid level y and flow Q data into the data analysis software Origin. Use the liquid level y as the independent variable and the flow Q as the dependent variable. Use the nonlinear curve fitting tool to enter the following two fitting formulas:

[0018]

[0019] Where: Q is the flow rate in the pipe, i is the pipe slope, D is the pipe diameter, n is the pipe roughness coefficient, is the angle between the center of the pipe and the two ends of the liquid surface line, and y is the liquid level in the pipe;

[0020] The pipe diameter D and slope i values ​​at the monitoring point are calculated iteratively to obtain the fitted yQ curve and n value, and the liquid level-flow relationship at the monitoring point can be obtained, which is expressed as follows:

[0021]

[0022] θ=2cos -1(1-6.73y) (4);

[0023] Step 2 Analysis of long-term monitoring data: During long-term monitoring, by substituting the acquired measured liquid level y monitoring data into the liquid level-flow relationship, the flow value represented by the liquid level can be obtained so as to analyze and judge the pipeline operation status.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention provides a drainage pipe flow monitoring device and method. Through this system device, the non-full flow in the drainage pipe can be converted into pressurized flow, and then an electromagnetic flowmeter is used to monitor the flow. Compared with the ultrasonic Doppler flowmeter, the electromagnetic flowmeter can obtain more accurate monitoring results in principle.

[0026] The present invention forms a low-cost long-term flow monitoring method. The use cost of the electromagnetic flowmeter is significantly lower than that of the ultrasonic Doppler flowmeter. Based on the liquid level-flow relationship analysis method of the present invention, it is possible to use liquid level meter monitoring instead of flow meter monitoring during long-term monitoring, and the flow analysis of the monitoring point can also be realized, which can greatly reduce the investment cost and subsequent operation and maintenance cost of the flow monitoring equipment.

[0027] The present invention forms a vehicle-mounted flow monitoring system device with high flexibility, simple operation and easy operation and maintenance. The main accessories of this system are commonly found on the market. All professional pipe network operation and maintenance units can simply purchase them or use existing drainage equipment and engineering vehicles for modification. In addition, the various accessories are simple to operate and do not require complex professional operation and maintenance. It has the advantages of high work efficiency and easy operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the system layout in the temporary monitoring stage of the present invention.

[0029] Figure 2 Schematic diagram of the system layout for the medium and long-term monitoring stage of the present invention.

[0030] Figure 3 The liquid level and flow rate data are monitored and obtained in one embodiment of the present invention.

[0031] Figure 4 This is a screenshot of parameter settings for an embodiment of the present invention.

[0032] Figure 5 The figure is a schematic diagram of the calculation process of an embodiment of the present invention.

[0033] Figure 6 This is a liquid level curve diagram obtained by fitting in an embodiment of the present invention.

[0034] In the figure: 1. Sealing system; 2. Pumping system; 3. Monitoring system; 101. Water inlet; 102. Water inlet pipe; 103. Connecting flange; 104. Hollow bag; 105. Air bag hollow tube; 106. Air pipe interface; 107. Air pipe; 108. Air pump; 201. Water inlet connecting pipe; 202. Water pump; 203. Cable; 204. Distribution box; 205. Generator; 206. Water outlet connecting pipe; 301. Valve; 302. Flowmeter inlet pipe; 303. Electromagnetic flowmeter; 304. Flowmeter outlet pipe; 305. Drain pipe; 306. Liquid level meter. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the preferred embodiments of the present invention are described below in conjunction with specific embodiments. However, it should be understood that the drawings are only for illustrative purposes and cannot be understood as limiting this patent; in order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted; the positional relationships described in the drawings are only for illustrative purposes and cannot be understood as limiting this patent.

[0036] As an embodiment of the present invention, see the attached Figure 1-Figure 3 This embodiment provides a drainage pipe flow monitoring device, comprising a blocking system 1, a pumping system 2, and a monitoring system 3. The blocking system 1 is used to block the upstream water in the drainage pipe, and the pumping system 2 is used to lift the water in the drainage pipe to the monitoring system 3 for flow monitoring, so that all the upstream water enters the monitoring system 3 through the pumping system 2. The monitoring system 3 is used to monitor the real-time flow; wherein,

[0037] The blocking system 1 includes an annular water inlet 101 and a water inlet pipe 102. The water inlet 101 is made of metal and has a certain counterweight to ensure that the water inlet will not float in the water during use. A filter is installed in the middle to prevent larger particles from entering the system. One end of the water inlet pipe 102 is connected to the water inlet 101, and the other end is connected to the water inlet end of the hollow balloon 104 through a connecting flange 103. The hollow balloon 104 is a conical rubber balloon with a balloon hollow tube 105 running through the middle of the balloon, which can play a role in The drainage pipe is blocked, and the upstream water is prevented from flowing to the downstream through the drainage pipe, and the water can only be drawn into the water pump 202 through the airbag hollow tube 105. The airbag hollow tube 105 should be made of PE material and tightly sealed with the outer surface of the airbag hollow tube 105 to avoid water leakage or air leakage during use. An air pipe interface 106 is provided on one side of the water outlet end of the hollow bag 104, and the air pipe interface 106 is connected to the air pipe 107. The upper end of the air pipe 107 is connected to the air pump 108, which is used to control the air pressure of the hollow bag 104.

[0038] Specifically, in the above embodiment, the pumping system 2 includes an inlet connecting pipe 201, a water pump 202, a cable 203 and an outlet connecting pipe. The inlet connecting pipe 201 is made of a hose to prevent the sealing system 1 and the pumping system 2 from being unable to dock due to the fluctuation of the bottom elevation of the well when the well is placed. The two ends of the inlet connecting pipe 201 are respectively connected to the outlet end of the airbag hollow tube 105 and the inlet end of the water pump 202 through connecting flanges. The water pump 202 is used to lift the water in the drainage pipe to the monitoring system 3 on the ground. The water pump 202 should have a head and maximum flow rate that are suitable for the use scenario of the detected drainage pipe, so that all instantaneous water upstream of the drainage pipe can be lifted to the monitoring system 3 to ensure that the flow monitoring results are accurate. The cable 203 is connected to the distribution box 204 and the generator 205 for powering the water pump 202. The outlet connecting pipe 206 is used to transport the water output of the water pump 202 to the monitoring system 3 on the ground.

[0039] Specifically, the monitoring system 3 includes a valve 301, a flow meter water inlet pipe 302, a flow meter water outlet pipe 304, a drain pipe 305 and a liquid level meter 306. The valve 301 is connected to the water outlet connecting pipe 206 and is used to adjust the flow capacity of the monitoring system or stop the system water outlet in an emergency. A butterfly valve or a ball valve can be used. The flow meter water inlet pipe 302 and the flow meter water outlet pipe 304 should be made of hard material that can be used as a pressure pipe, and the length should meet the length requirements of the two straight pipe sections before and after the electromagnetic flow meter 303 used to ensure the stability of the water flow inlet of the electromagnetic flow meter 303. To ensure the accuracy of flow monitoring, in order to facilitate the water inflow of the pipe, the flow meter inlet pipe 302 should be a transparent PVC pipe, the outlet pipe can be a PE pipe or a steel pipe, and the drain pipe 305 is used to discharge the water after detection. The liquid level meter 306 is installed at the center of the bottom of the straight section of the drainage pipe downstream of the outlet inspection well of the drain pipe 305 to detect the pipeline liquid level; the valve 301 is connected between the outlet connecting pipe 206 and the flow meter inlet pipe 302, the electromagnetic flowmeter is connected between the flow meter inlet pipe 302 and the flow meter outlet pipe 304, and the drain pipe 305 is connected to the flow meter outlet pipe 304.

[0040] In some preferred embodiments, please refer to the attached Figure 1 The plugging system 1, the pumping system 2 and the monitoring system 3 are installed in a mobile engineering vehicle. The air pump 108, the distribution box 204, the generator 205, the valve 301, the electromagnetic flowmeter 303, the flowmeter inlet pipe 302 and the flowmeter outlet pipe 304 are all fixedly installed in the engineering vehicle.

[0041] In some preferred embodiments, see the attached Figure 1 This embodiment provides a drainage pipe flow monitoring method using any of the drainage pipe flow monitoring devices described above, including a temporary monitoring phase and a long-term monitoring phase. The temporary monitoring phase specifically includes the following steps:

[0042] Selection of S1 point: Combined with the flow monitoring requirements, a preliminary survey of the municipal drainage pipeline to be monitored is conducted, and the monitoring location is selected according to the following requirements: (1) The maximum fullness of the liquid level in the pipeline at the monitoring location on a sunny day does not exceed 75%; (2) The pipeline at the monitoring location is straight, and there are no branch pipes connected to the inspection well M1 where the water pump is to be placed and the two consecutive inspection wells M2 and M3 downstream; (3) There is no hidden branch pipe connection or external water infiltration caused by pipeline damage in the pipeline between the two consecutive inspection wells M2 and M3 downstream, and the hydraulic elements of the entire pipeline section of the two consecutive inspection wells M2 and M3 downstream are consistent; (4) There must be no siltation in the pipeline and inspection wells within the range of M1 to M3. If there is siltation, it should be flushed in advance;

[0043] S2 System Equipment Selection and Assembly: Obtain the pipe diameter D, slope i, burial depth h, and basic pipe material information of the monitoring section based on the drainage drawings. Calculate the flow rate when the pipe is 75% full as the maximum flow rate of water pump 202. Use the depth of inspection well M1 as the required lift of the water pump. Select the type of water pump 202 so that the upper limit of the flow monitoring of the electromagnetic flowmeter 303 is higher than the flow rate value when the pipe is 75% full.

[0044] S3 On-site installation: The required equipment should be collected by a special engineering vehicle and transported to the monitoring point in a unified manner. Before monitoring, the pipe sections of the inspection well M1 and inspection well M2 should be fenced off corresponding to the municipal roads and the parking range of the engineering vehicle. During on-site installation, first place all the connected accessories of the plugging system 1, pumping system 2 and monitoring system 3 on the ground, among which the valve 301, distribution box 204 and air pump 108 are adjusted to the closed state. Then, install a triangular crane above the wellhead of the inspection well M1, and hoist the hollow air bag 104 and water pump 202 to the bottom of the inspection well M1. Then, use the hook to adjust the placement of the hollow air bag 104 so that it is completely placed at the bottom of the upstream pipeline of the inspection well M1. Finally, place the water outlet end of the drain pipe 305 in the downstream inspection well M2.

[0045] S4 system start-up: First, turn on the mobile power supply in the engineering vehicle, start the air pump 108 through the distribution box 204 to inflate the hollow bag 104. When the upstream pipeline of the inspection well M1 is completely blocked, stop inflating, open the valve 301 to the maximum opening, start the water pump 202, and start draining water through the drain pipe 305;

[0046] S5 Data Observation: During the monitoring process, observe the flow meter inlet pipe 302. Adjust the opening degree of the valve 301 to keep the flow meter inlet pipe 302 just full at all times to ensure accurate monitoring by the electromagnetic flowmeter 303. During the monitoring process, set the flow and liquid level data reading intervals according to monitoring requirements, and read the electromagnetic flowmeter 303 readings at regular intervals to complete temporary monitoring of the instantaneous flow in the drainage pipe.

[0047] S6 Dismantling of temporary monitoring system: After obtaining sufficient data, the plugging system 1, the pumping system 2 and the monitoring system 3 can be dismantled and kept, and the liquid level meter 306 is retained for liquid level monitoring.

[0048] In some preferred embodiments, the long-term monitoring phase includes:

[0049] Step 1 Liquid level-flow relationship analysis: Input the measured drainage pipe liquid level y and flow Q data into the data analysis software Origin. Use the liquid level y as the independent variable and the flow Q as the dependent variable. Use the nonlinear curve fitting tool to enter the following two fitting formulas:

[0050]

[0051] Where: Q is the flow rate in the pipe, i is the pipe slope, D is the pipe diameter, n is the pipe roughness coefficient, is the angle between the center of the pipe and the two ends of the liquid surface line, and y is the liquid level in the pipe;

[0052] The monitoring status during the long-term monitoring phase is as follows: Figure 2 As shown in the figure, the pipe diameter D and slope i value of the monitoring point are calculated and the fitting yQ curve and n value are obtained after iterative calculation, and the liquid level-flow relationship of the monitoring point can be obtained;

[0053] Step 2 Analysis of long-term monitoring data: During long-term monitoring, by substituting the acquired measured liquid level y monitoring data into the liquid level-flow relationship, the flow value represented by the liquid level can be obtained so as to analyze and judge the pipeline operation status.

[0054] The determination coefficient R in the fitting result report can be generated according to the Origin software 2 , determine the deviation between the fitted level-flow relationship and the measured value: generally 0≤R 2 ≤1, R 2 The closer it is to 1, the higher the goodness of fit, and the more consistent the fitted level-flow relationship is with the measured situation.

[0055] The monitoring method of the present invention is analyzed and explained below with reference to specific cases.

[0056] In a certain implementation case, the drainage pipe is a HDPE double-wall corrugated pipe with a pipe diameter D of DN300 (the actual inner diameter is 297mm) and a slope i of 5‰. Through temporary monitoring, the pipe flow rate Q corresponding to different measured liquid levels y when the liquid level y in the pipe is within the range of 30 to 110mm is obtained, with a total of 20 sets of data. Open the Origin software, create a new worksheet, and enter the liquid level and flow data into the X and Y columns respectively, as shown in the following example: Figure 3As shown, open the nonlinear curve fitting tool, select New in the function type, open the fitting function generator, define the independent variable and dependent variable as y and Q, the parameter as n, the constant as D and i, and enter the formula 2 represented by θ in the function body and substitute it into the formula 1 (i.e.

[0057] Q=D^2*i^0.5*(2*acos(1-2*y / D)-sin(2*acos(1-2*y / D)))*(D*(1-sin(2*acos(1-2*y / D)) / 2 / acos(1-2*y / D)) / 4)^(2 / 3) / 8 / n*3600)(Q unit is m 3 / h, y and D are in m), set the initial value of n to 0.095, and the range is 0≤n≤0.02, such as Figure 3 As shown, select the newly created function for fitting and generate the fitting results and images as shown in Figure 5 and Figure 6 As shown, the fitting status is successful, R 2 The fitting effect is good, and the fitting n is 0.01177. Substituting the actual pipe diameter D, slope i and the fitted n value of the monitoring point into formula 1, the liquid level-flow relationship of the monitoring point can be obtained as follows:

[0058]

[0059] θ=2cos -1 (1-6.73y) (4);

[0060] In the subsequent long-term monitoring process, the measured liquid level y at the monitoring point is substituted into equations 3 and 4 to obtain the corresponding flow rate data. For example, in this embodiment, according to the monitoring data of the liquid level gauge at the monitoring point, the liquid level y = 0.105m at a certain moment, and after substituting it into the equation, the corresponding flow rate Q in the pipe should be 71.44m 3 / h.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A drainage pipe flow monitoring device, characterized by: The invention comprises a blocking system (1), a pumping system (2) and a monitoring system (3), wherein the blocking system (1) is used to block the upstream water in the drainage pipe, the pumping system (2) is used to lift the water in the drainage pipe to the monitoring system (3), so that all the upstream water enters the monitoring system (3) through the pumping system (2), and the monitoring system (3) is used to monitor the real-time flow rate; wherein, The blocking system (1) comprises an annular water inlet (101) and a water inlet pipe (102), one end of the water inlet pipe (102) is connected to the water inlet (101), and the other end is connected to the water inlet end of the hollow bag (104) through a connecting flange (103); a hollow bag tube (105) runs through the middle of the hollow bag (104); an air pipe interface (106) is provided on one side of the water outlet end of the hollow bag (104); the air pipe interface (106) is connected to an air pipe (107); the upper end of the air pipe (107) is connected to an air pump (108) for controlling the air pressure of the hollow bag (104); The water pumping system (2) includes a water inlet connecting pipe (201), a water pump (202), a cable (203) and a water outlet connecting pipe. The two ends of the water inlet connecting pipe (201) are respectively connected to the water outlet end of the airbag hollow pipe (105) and the water inlet end of the water pump (202) through connecting flanges. The water pump (202) is used to lift the water in the drainage pipe to the monitoring system (3) on the ground. The cable (203) is connected to the distribution box (204) and the generator (205) to supply power to the water pump (202). The water outlet connecting pipe (206) is used to transport the water discharged by the water pump (202) to the monitoring system (3) on the ground. The monitoring system (3) comprises a valve (301), a flow meter water inlet pipe (302), an electromagnetic flow meter (303), a flow meter water outlet pipe (304), a drain pipe (305) and a liquid level meter (306). The drain pipe (305) is used to discharge the water body after detection. The liquid level meter (306) is installed at the center of the bottom of the straight section of the drainage pipe downstream of the water outlet inspection well of the drain pipe (305) and is used to detect the pipeline liquid level. The valve (301) is connected between the water outlet connecting pipe (206) and the flow meter water inlet pipe (302), the electromagnetic flow meter is connected between the flow meter water inlet pipe (302) and the flow meter water outlet pipe (304), and the drain pipe (305) is connected to the flow meter water outlet pipe (304).

2. A drainage pipe flow monitoring device according to claim 1, characterized in that: The plugging system (1), the pumping system (2) and the monitoring system (3) are partially installed in a mobile engineering vehicle, and the air pump (108), the distribution box (204), the generator (205), the valve (301), the electromagnetic flowmeter (303), the flowmeter water inlet pipe (302) and the flowmeter water outlet pipe (304) are all fixedly installed in the engineering vehicle.

3. A drainage pipe flow monitoring method, characterized in that: The drainage pipe flow monitoring device according to claim 1 or 2 includes a temporary monitoring stage and a long-term monitoring stage, wherein the temporary monitoring stage specifically includes the following steps: Selection of S1 point: Combined with the flow monitoring requirements, a preliminary survey of the municipal drainage pipeline to be monitored is conducted, and the monitoring location is selected according to the following requirements: (1) The maximum fullness of the liquid level in the pipeline at the monitoring location on a sunny day does not exceed 75%; (2) The pipeline at the monitoring location is straight, and there are no branch pipes connected to the inspection well (M1) where the water pump is to be placed and the two consecutive inspection wells (M2 and M3) downstream; (3) There is no hidden branch pipe connection or external water infiltration caused by pipeline damage in the pipeline between the two consecutive inspection wells (M2 and M3) downstream, and the hydraulic elements of the entire pipeline section of the two consecutive inspection wells (M2 and M3) downstream are consistent; S2 system equipment selection and assembly: Obtain the pipe diameter D, slope i, buried depth h and basic pipe material information of the monitoring pipe section according to the drainage drawing, calculate the flow rate when the pipe is 75% full as the maximum flow rate of the water pump (202), use the depth of the inspection well M1 as the required lift of the water pump, and select the water pump (202) so that the flow monitoring upper limit value of the electromagnetic flowmeter (303) is higher than the flow value when the pipe is 75% full; S3 On-site installation: The required equipment shall be collected by a special engineering vehicle and transported to the monitoring point in a unified manner. Before monitoring, the pipe sections of the inspection well M1 and inspection well M2 shall be fenced off in accordance with the municipal roads and the parking range of the engineering vehicle. During on-site installation, all the connected accessories of the plugging system (1), the pumping system (2) and the monitoring system (3) shall be placed on the ground, wherein the valve (301), the distribution box (204) and the air pump (108) shall be adjusted to the closed state. Then, a triangular crane shall be installed above the wellhead of the inspection well M1, and the hollow air bag (104) and the water pump (202) shall be hoisted to the bottom of the inspection well M1. Then, the position of the hollow air bag (104) shall be adjusted by using a hook so that it is completely placed at the bottom of the upstream pipeline of the inspection well M1. Finally, the outlet end of the drain pipe (305) shall be placed in the downstream inspection well M2. S4 system start-up: first, turn on the mobile power supply in the engineering vehicle, start the air pump (108) through the distribution box (204) to inflate the hollow bag (104), stop inflating when the upstream pipeline of the inspection well M1 is completely blocked, open the valve (301) to the maximum opening, start the water pump (202), and start draining the water through the drain pipe (305); S5 Data Observation: During the monitoring process, the flow meter water inlet pipe (302) is observed. The opening degree of the valve (301) should be adjusted so that the flow meter water inlet pipe (302) is always kept in a state of just full flow, so as to ensure that the electromagnetic flow meter (303) monitors accurately. During the monitoring process, the flow rate and liquid level data reading intervals are set according to the monitoring requirements, and the readings of the electromagnetic flow meter (303) are read regularly, so as to complete the temporary monitoring of the instantaneous flow of the drainage pipe. S6 Temporary monitoring system removal: After obtaining sufficient data, the plugging system (1), the pumping system (2) and the monitoring system (3) can be removed and kept, and the liquid level meter (306) is retained for liquid level monitoring.

4. A drainage pipe flow monitoring method according to claim 3, characterized in that: The long-term monitoring phase includes: Step 1 Liquid level-flow relationship analysis: Input the measured drainage pipe liquid level y and flow Q data into the data analysis software Origin. Use the liquid level y as the independent variable and the flow Q as the dependent variable. Use the nonlinear curve fitting tool to enter the following two fitting formulas: Where: Q is the flow rate in the pipe, i is the pipe slope, D is the pipe diameter, n is the pipe roughness coefficient, is the angle between the center of the pipe and the two ends of the liquid surface line, and y is the liquid level in the pipe; The pipe diameter D and slope i values ​​at the monitoring point are calculated iteratively to obtain the fitted yQ curve and n value, and the liquid level-flow relationship at the monitoring point can be obtained, which is expressed as follows: θ=2cos -1 (1-6.73y) (4); Step 2 Analysis of long-term monitoring data: During long-term monitoring, by substituting the acquired measured liquid level y monitoring data into the liquid level-flow relationship, the flow value represented by the liquid level can be obtained so as to analyze and judge the pipeline operation status.

Images