Drainage pipeline fluid flow monitoring method and monitoring device

Abstract

The present invention provides a method for monitoring fluid flow in a drainage pipe, comprising: installing a pressure sensor in the pipe to be tested, for measuring the pressure change of the fluid at that position, installing a liquid level measuring device in the inspection well, for measuring the liquid level of the pipe to be tested or the inspection well; calculating the fluid velocity in the pipe to be tested according to the pressure detected by the pressure sensor and the liquid level monitored by the liquid level measuring device, and finally calculating the liquid flow in the pipe according to the pipe diameter and fluid velocity of the pipe to be tested. The present invention also provides a device for monitoring fluid flow in a drainage pipe. The present invention does not require the installation of special devices or components in the pipe, is applicable to pipes of various types and specifications, does not require the consumption of additional energy or resources, and does not require accurate measurement or assumptions of fluid properties, temperature, viscosity, etc. The method is simple and reasonable, has a wide range of applications, high work efficiency, and strong practicality.

Description

Technical field:

[0001] The present invention belongs to the technical field of liquid flow monitoring, and in particular relates to a drainage pipeline fluid flow monitoring method and a monitoring device. Background technology:

[0002] Flow rate refers to the volume or mass of fluid passing through a pipe or opening per unit time. Flow monitoring is an important technical means in the fields of industrial production, environmental protection, water conservancy management, etc., and can be used to control and optimize the process of fluid transportation, distribution and utilization. At present, the commonly used flow monitoring devices or systems are of the following types: (1) Flow monitoring devices or systems based on the differential pressure principle, such as orifice plates, nozzles, venturi tubes, etc., which set a throttling device of a certain shape in the pipeline to cause local acceleration and pressure reduction of the fluid, and then calculate the flow rate based on the pressure difference at both ends. This method is simple and easy to implement, but there is a certain amount of energy loss and measurement error, and it has high requirements for the properties, temperature, viscosity, etc. of the fluid. (2) Flow monitoring devices or systems based on the principle of electromagnetic induction, such as electromagnetic flowmeters, etc., which set a pair of mutually perpendicular electrodes and magnetic fields in the pipeline to generate an induced electromotive force when the fluid passes through, and then calculate the flow rate based on the magnitude of the electromotive force. This method is not affected by the properties, temperature, viscosity, etc. of the fluid, but requires the fluid to have a certain conductivity, and it has high requirements for the pipeline material, electrode material, magnetic field strength, etc. (3) Flow monitoring devices or systems based on the ultrasonic principle, such as ultrasonic flowmeters, etc., which set a pair of relative ultrasonic transmitters and receivers in the pipeline to allow ultrasonic waves to propagate in the forward and reverse directions in the fluid, and then calculate the flow rate based on the propagation time difference in the two directions. This method does not require contact with the fluid and is not affected by the fluid properties, temperature, viscosity, etc., but it requires calibration of the propagation speed of ultrasonic waves and has high requirements for pipe diameter, wall thickness, inner surface smoothness, etc. (4) Flow monitoring devices or systems based on the Doppler effect, such as Doppler flowmeters, which set a high-frequency sound wave or ultrasonic wave transmitting and receiving probe in the pipeline and calculate the fluid velocity by measuring the echo frequency changes of suspended particles or bubbles in the fluid. This method is not affected by the fluid properties, temperature, viscosity, etc., but cannot provide accurate measurement results for low flow rate liquids.

[0003] The above types of flow monitoring devices or systems have their own advantages and disadvantages, but they all have some common problems and disadvantages: (1) Special devices or components need to be installed in the pipeline, which increases the cost and difficulty of installation and maintenance; (2) Pipeline materials, sizes, shapes, etc. need to be strictly selected and designed, which limits the scope of application and flexibility; (3) Accurate measurements or assumptions are required for fluid properties, temperature, viscosity, etc., which increases measurement errors and uncertainties; (4) Doppler flowmeters have a limited measurement range, especially when the fluid flows at a low speed, and may not provide accurate measurement results; at the same time, it is only applicable to situations where the liquid contains suspended particles or bubbles. For single-phase fluids (i.e. pure liquids without suspended particles or bubbles), it cannot provide accurate measurements. (5) It requires the consumption of a certain amount of energy or resources, which reduces efficiency and environmental protection.

[0004] Therefore, there is no device or system in the prior art that can be applied to various situations and conditions to simply and reliably monitor fluid flow. Based on this, the present invention provides a drainage pipeline fluid flow monitoring method and monitoring device to solve the above problem. Summary of the invention:

[0005] The first object of the present invention is to provide a method for monitoring fluid flow in a drainage pipe in view of the deficiencies of the prior art, which can be applied to various situations and conditions and monitor fluid flow simply and reliably;

[0006] A second object of the present invention is to provide a drainage pipe fluid flow monitoring device.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] (I) The present invention provides a method for monitoring fluid flow in a drainage pipe, comprising: installing a pressure sensor in the pipe to be tested to measure the pressure change of the fluid at that position; installing a liquid level measuring device in an inspection well to measure the liquid level of the pipe to be tested or the inspection well; calculating the fluid velocity in the pipe to be tested based on the pressure detected by the pressure sensor and the liquid level monitored by the liquid level measuring device, and finally calculating the liquid flow in the pipe based on the pipe diameter and fluid velocity of the pipe to be tested.

[0009] Furthermore, the present invention specifically comprises the following steps:

[0010] S1. The pressure at the measuring point in the pipeline to be tested is detected by the pressure sensor as P;

[0011] S2, measuring the distance h1 between the liquid level measuring device and the liquid level by means of the liquid level measuring device;

[0012] S3, calculating the distance h2 between the pressure sensor and the liquid surface according to the vertical distance h between the pressure sensors and the distance h1 between the liquid level measuring device and the liquid surface;

[0013] S4, calculating the theoretical height hs detected by the pressure sensor;

[0014] S5. The height difference detected by the pressure sensor is Δh. The fluid velocity v in the pipeline to be tested is calculated based on Δh. The liquid flow in the pipeline is calculated based on the pipe diameter and fluid velocity of the pipeline to be tested.

[0015] Furthermore, in step S4, the theoretical height hs detected by the pressure sensor is = P / (ρg); wherein P is the fluid pressure at the measuring point in the pipeline to be measured, ρ is the density of the fluid, and g is the acceleration due to gravity.

[0016] Furthermore, in step S5, the height difference detected by the pressure sensor is Δh=h2-hs, and Δh=v 2 / (2g), the fluid velocity v in the measured pipeline can be calculated.

[0017] Furthermore, the pressure sensor is installed inside the pipeline to be tested, and the pressure sensor is distributed below the liquid surface; the height measuring device is fixedly arranged on the side wall of the inspection well, and the height measuring device is distributed above the liquid surface.

[0018] Furthermore, the height measuring device is a laser level meter.

[0019] (ii) The present invention also provides a drainage pipe fluid flow monitoring device, including a pressure sensor and a liquid level height measuring device; the pressure sensor is fixedly installed at any position inside the pipe to be tested, and the pressure sensor is distributed below the liquid level; the height measuring device is fixedly arranged on the side wall of the inspection well, and the height measuring device is distributed above the liquid level.

[0020] Furthermore, the inspection well is arranged above the pipeline to be tested, and the inspection well and the pipeline to be tested are perpendicular to each other.

[0021] Furthermore, a fixed bracket is provided on the side wall of the inspection well; the fixed bracket includes a supporting platform and an inclined brace, the supporting platform is horizontally fixed on the side wall of the inspection well, the inclined brace is obliquely arranged below the supporting platform, and the two ends of the inclined brace are respectively fixedly connected to the supporting platform and the inspection well; the liquid level measuring device is fixedly installed on the supporting platform.

[0022] Beneficial effects of the present invention:

[0023] (1) The present invention provides a novel flow monitoring device, which does not require the installation of special devices or components in the pipeline. It only requires the installation of a pressure sensor inside the pipeline and the installation of a liquid level measuring device at the inspection well wall, thereby simplifying the installation and maintenance process;

[0024] (2) The present invention is not limited by pipeline materials, sizes, shapes, etc., and can be applied to pipelines of various types and specifications, thereby increasing the scope of application and flexibility;

[0025] (3) The present invention does not require precise measurements or assumptions about fluid properties, temperature, viscosity, etc., but only requires calculations based on Bernoulli's theorem and continuity equations, thus reducing measurement errors and uncertainties;

[0026] (4) The present invention does not require consumption of additional energy or resources, and only requires utilizing the pressure change and flow rate change of the fluid itself to monitor the fluid flow, thereby improving efficiency and environmental protection. Description of the drawings:

[0027] Figure 1 is a flow chart of a flow monitoring method according to an embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of the structure of a flow monitoring device according to an embodiment of the present invention;

[0029] The symbols in the accompanying drawings are:

[0030] 1. Main unit; 2. Pressure sensor; 3. Outflow pipe; 4. Fixed bracket; 5. Liquid level measuring device; 6. Inspection well; 7. Inflow pipe. Specific implementation method:

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] Reference Figures 1-2An embodiment of the present invention provides a method for monitoring fluid flow in a drainage pipe, comprising: installing a pressure sensor 2 in the pipe to be tested, for measuring the pressure change of the fluid at that position; installing a liquid level measuring device 5 in an inspection well 6, for measuring the liquid level height of the pipe to be tested or the inspection well 6; calculating the fluid velocity in the pipe to be tested according to the pressure detected by the pressure sensor 2 and the liquid level height monitored by the liquid level measuring device 5, and finally calculating the liquid flow in the pipe according to the pipe diameter of the pipe to be tested and the fluid velocity.

[0034] Specifically, the embodiment of the present invention includes the following steps:

[0035] Step 1: The pressure at the measuring point in the pipeline to be tested is detected by the pressure sensor 2 as P;

[0036] Step 2: Using the liquid level measuring device 5, measure the distance h1 between the liquid level measuring device 5 and the liquid surface;

[0037] Step 3: Calculate the distance h2 between the pressure sensor 2 and the liquid surface according to the vertical distance h between the pressure sensor 2 and the pressure sensor 2 and the distance h1 between the liquid surface height measuring device 5 and the liquid surface;

[0038] Step 4: Calculate the theoretical height hs detected by the pressure sensor 2, hs=P / (ρg); wherein P is the fluid pressure at the measuring point in the pipeline to be measured, ρ is the density of the fluid, and g is the acceleration due to gravity.

[0039] Step 5: The height difference detected by the pressure sensor 2 is Δh, Δh=h2-hs, and Δh=v 2 / (2g), the fluid velocity v in the measured pipeline can be calculated based on Δh, and the liquid flow in the pipeline can be calculated based on the pipe diameter and fluid velocity v of the measured pipeline.

[0040] In the embodiment of the present invention, the pressure sensor 2 is installed inside the pipeline to be tested, and the pressure sensor 2 is distributed below the liquid surface; the height measuring device is fixedly arranged on the side wall of the inspection well 6, and the height measuring device is distributed above the liquid surface. The height measuring device is a laser level meter.

[0041] Example 2

[0042] Reference Figure 2 An embodiment of the present invention provides a drainage pipe fluid flow monitoring device, including a pressure sensor 2 and a liquid level height measuring device 5, wherein the pressure sensor 2 is fixedly installed at any position inside the pipe to be tested, and the pressure sensor 2 is distributed below the liquid level, and is used to sense the pressure change of the fluid at this position; the height measuring device is fixedly arranged on the side wall of the inspection well 6, and the height measuring device is distributed above the liquid level, and is used to measure the liquid level height of the pipe to be tested or the inspection well 6.

[0043] In this embodiment, the inspection well 6 is arranged above the pipeline to be tested, and the inspection well 6 and the pipeline to be tested are perpendicular to each other. A fixed bracket 5 is arranged on the side wall of the inspection well 6; the fixed bracket 5 includes a support platform and an inclined brace, the support platform is horizontally fixed on the side wall of the inspection well 6, the inclined brace is obliquely arranged below the support platform, and the two ends of the inclined brace are respectively fixedly connected to the support platform and the inspection well 6; the liquid level height measuring device 5 is fixedly installed on the support platform.

[0044] In this embodiment, the pressure sensor 2 may be a piezoresistive pressure sensor, and the height measuring device 5 may be a laser level meter.

[0045] The working principle of the present invention is as follows:

[0046] When the fluid passes through the pipe, according to Bernoulli's theorem, when the fluid flow rate on one side increases, the pressure on that side will decrease. Therefore, when the fluid passes through the location of the pressure sensor 2, a pressure difference will be generated, and this pressure difference will cause the value detected by the pressure sensor 2 to change.

[0047] At the same time, the liquid level in the pipeline or inspection well is monitored by the liquid level measuring device 5, and the theoretical pressure detected by the pressure sensor 2 is compared and analyzed with the actual pressure at the preset static liquid level, and the current fluid flow rate is obtained by calculation based on Bernoulli's theorem and continuity equation.

[0048] The host combines the current fluid flow rate, liquid level, and pipe diameter to derive the flow rate at the monitoring point. The host can also transmit the flow rate and flow rate data to the cloud terminal, or display it on a display, or transmit it to other devices or systems. The cloud terminal can receive the data transmitted by the host and perform functions such as storage, analysis, display, and control. The cloud terminal can also communicate and coordinate with other devices or systems to achieve remote monitoring and management.

[0049] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A method for monitoring fluid flow in a drainage pipeline, characterized in that: include: A pressure sensor is installed in the pipeline to be tested to measure the pressure change of the fluid at that position; A liquid level measuring device is installed in the inspection well to measure the liquid level height of the pipeline to be tested or the inspection well; According to the pressure detected by the pressure sensor and the liquid level monitored by the liquid level measuring device, the fluid velocity in the pipeline to be tested is calculated, and finally the liquid flow in the pipeline is calculated according to the pipe diameter and fluid velocity of the pipeline to be tested; specifically, the following steps are included: S1. The pressure at the measuring point in the pipeline to be tested is detected by the pressure sensor as P; S2, measuring the distance h1 between the liquid level measuring device and the liquid level by means of the liquid level measuring device; S3, calculating the distance h2 between the pressure sensor and the liquid surface according to the vertical distance h between the pressure sensors and the distance h1 between the liquid level measuring device and the liquid surface; S4, calculating the theoretical height hs detected by the pressure sensor; S5. The height difference detected by the pressure sensor is Δh. The fluid velocity v in the pipeline to be tested is calculated based on Δh. The liquid flow in the pipeline is calculated based on the pipe diameter, liquid level and fluid velocity of the pipeline to be tested.

2. The method for monitoring fluid flow in a drainage pipeline according to claim 1, characterized in that: In step S4, the theoretical height hs detected by the pressure sensor is = P / (ρg); Among them, P is the fluid pressure at the measuring point in the pipeline to be measured, ρ is the density of the fluid, and g is the gravitational acceleration.

3. The method for monitoring fluid flow in a drainage pipeline according to claim 1, characterized in that: In step S5, the height difference detected by the pressure sensor is Δh=h2-hs, and Δh=v 2 / (2g), the fluid velocity v in the measured pipeline can be calculated.

4. The method for monitoring fluid flow in a drainage pipeline according to claim 1, characterized in that: The pressure sensor is installed inside the pipeline to be tested, and the pressure sensor is distributed below the liquid surface; the height measuring device is fixedly arranged on the side wall of the inspection well, and the height measuring device is distributed above the liquid surface.

5. The method for monitoring fluid flow in a drainage pipeline according to claim 1, characterized in that: The height measuring device is a laser level meter.

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