A method of monitoring and calculating the effect of a catch of rainfall on a power transmission tower

Abstract

A method for monitoring and calculating the rainfall collection effect of transmission towers includes the following steps: constructing a rainfall trough; constructing a diversion trough; constructing a measuring trough; installing a Parshall flume; installing a rigid frame, an ultrasonic probe, and a flow meter; calculating the catchment level; calculating the catchment flow rate; calculating the equivalent rainfall intensity; and calculating the rainfall collection effect. This invention provides a method for monitoring and calculating the rainfall collection effect of transmission towers, capable of calculating equivalent rainfall intensity and rainfall collection effect, filling the gap in the lack of indicators and calculation methods for quantifying the rainwater collection effect of transmission towers.

Description

Technical Field

[0001] This invention relates to the field of disaster prevention and mitigation for power transmission lines, and in particular to a method for monitoring and calculating the effect of rainfall collection on power transmission towers. Background Technology

[0002] Overhead power transmission lines traverse plateaus, hills, and mountainous areas, where the terrain, surrounding environment, and weather conditions are complex. Transmission towers built on slopes pose significant safety hazards during rainfall. When these areas experience heavy rains, the towers are highly susceptible to landslides, collapses, and mudslides, severely jeopardizing the safe operation of the transmission lines. Landslides near the tower base during heavy rains have become the greatest threat to the safe operation of transmission towers in recent years.

[0003] The main reason for water accumulation at the base of power transmission towers and subsequent landslides is that rainwater falls at a certain angle. Due to the shielding effect of the tower's own materials, the rainwater, which should fall naturally, impacts the tower structure and collects, flowing down the tower. With the continuous influx of rainwater, a large amount eventually accumulates at the base of the tower, continuously eroding the soil on the nearby slope. This softens the soil or forms gullies, ultimately leading to serious accidents such as landslides, tower tilting, and collapse. Therefore, monitoring the water accumulation at power transmission towers allows for decisions on whether to implement targeted remedial measures and for calculating the slope stability that takes into account the water accumulation, ensuring the safety of both the slope and the transmission lines.

[0004] The existing methods for monitoring water flow rate mainly include: 1) Directly measuring the flow velocity in the water flow and then calculating the flow rate by combining the cross-sectional area relies too much on the stability of the steady water flow and the stability of the hydrological cross-section. It lacks the collection of water from the tower and cannot accurately calculate the water flow rate of the tower.

[0005] 2) A non-contact image recognition flow monitoring method was established by using drones equipped with cameras to calculate surface flow velocity and river cross-sectional flow. However, drones are greatly limited by weather conditions (such as heavy rain, fog, etc.), making real-time monitoring impossible. Furthermore, they cannot distinguish whether the monitored flow is due to water runoff caused by the tower, leading to misjudgments. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for monitoring and calculating the rainfall collection effect of transmission towers, which can monitor the water collection volume in real time and convert it into equivalent rainfall and rainfall collection effect, providing data support for analyzing the slope stability near transmission towers and guiding the construction of drainage facilities.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for monitoring and calculating the rainfall collection effect of transmission towers includes the following steps: Step 1: Construct rain gutters; Step 2: Construct a diversion channel; Step 3: Construct a measuring water tank; Step 4: Install the Parshall flue; Step 5: Install the rigid frame, ultrasonic probe, and flow meter; Step 6: Calculate the water level height; Step 7: Calculate the catchment flow; Step 8: Calculate the equivalent rainfall intensity; Step 9: Calculate the combined rainfall effect.

[0008] The rain trough surrounds the four legs of the transmission tower and collects water from the tower.

[0009] One end of the diversion channel is connected to the outlet of the rain trough, and the other end is tilted downwards towards the measurement point at a lower elevation near the iron tower.

[0010] The measuring tank is a hollow cuboid structure, and the base platform and bottom surface of the measuring tank are kept horizontal.

[0011] The rigid frame is erected upstream of the contraction section of the Parshall flume, at a distance of 1 / 3 of the length of the throat of the Parshall flume.

[0012] The ultrasonic probe is fixed to a rigid frame by an adjustable clamp and is directly facing the water surface in the tank; the flow meter is placed on one side of the measuring tank and is electrically connected to the ultrasonic probe.

[0013] In step 6, the water level is: ; In the formula: D is the distance from the probe to the bottom of the channel; A is the speed of the ultrasonic wave in the air; t is the time difference between the ultrasonic wave transmission and reception; H is the liquid level in the Parshall flume.

[0014] In step 7, the water flow rate is: ; In the formula: Q is the flow rate; H is the liquid level height; K and n are constants related to the throat width.

[0015] In step 8, the equivalent rainfall intensity is: ; In the formula: Q is the flow rate; S is the area of ​​the rectangle enclosed by the base of the transmission tower; This represents the equivalent rainfall intensity.

[0016] In step 9, the rainfall effect is collected: ; In the formula: Equivalent rainfall intensity; This represents the actual rainfall intensity.

[0017] This invention provides a method for monitoring and calculating the rainfall collection effect of power transmission towers, which has the following technical advantages: 1) Existing technologies for monitoring water flow generally rely on surface velocity calculation based on image-based intelligent recognition and methods such as river cross-section flow monitoring. However, these methods have a large measurement range, depend on cross-sectional integration, and require stable hydrological cross-sections. Under rainfall conditions, the catchment area of ​​transmission towers is small, the flow is low, and the water flow is dispersed and discontinuous, making it impossible to form a stable measurement cross-section. Therefore, existing water flow measurement methods are not applicable. Furthermore, there is no method for calculating the rainfall collection effect on transmission towers.

[0018] To address these shortcomings, this invention proposes a method for convenient and rapid monitoring and calculation of the rainfall collection effect of power transmission towers, directly applicable to areas near different towers. During periods of heavy rainfall, rainwater collected by the towers flows through a collection trough, concentrating the dispersed, low-flow water at the tower's base. This water then flows into a measuring trough and Parshall flume located at monitoring points via a drainage channel. By measuring the real-time water level in the troughs in a non-contact manner, the tower's water collection flow rate, equivalent rainfall intensity, and rainfall collection effect can be calculated. This monitoring method not only effectively overcomes the challenge of monitoring low-flow, discontinuous water collection at the base of power transmission towers in mountainous areas but also fills a gap in methods for calculating the rainfall collection effect of power transmission towers in mountainous regions.

[0019] 2) This invention collects discrete and unstable water from the transmission tower by constructing rainwater collection channels and water diversion channels at the base of the tower, making it convenient to measure the water flow rate of the tower.

[0020] 3) This invention supports continuous and automatic data acquisition, and can monitor water runoff data in real time. It can promptly detect water runoff phenomena on transmission towers during rainfall, thus gaining valuable time for early warning and rapid response to geological disasters such as landslides, and improving the safety level of transmission lines.

[0021] 4) This invention proposes an index for calculating and quantifying the equivalent rainfall intensity and rainwater collection effect of iron towers, filling the gap in the lack of an index and calculation method for quantifying the rainwater collection effect of iron towers. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the present invention.

[0023] Figure 2 This is a flowchart of the present invention.

[0024] In the diagram: 1. Rainfall trough; 2. Diversion trough; 3. Measuring water trough; 4. Parshall flume; 5. Rigid frame; 6. Ultrasonic probe; 7. Flow meter. Detailed Implementation

[0025] like Figure 1 As shown, a method for monitoring and calculating the rainfall collection effect of transmission towers includes the following steps: Step 1: Construct rain troughs 1 around the four bases of the iron tower according to the terrain to ensure that scattered and discontinuous rainwater blocked by the iron tower can be collected efficiently.

[0026] Identify the natural rainwater collection areas around the four tower feet of the transmission tower. Based on the terrain, construct rectangular rainwater troughs 1 around the tower feet using concrete to collect the rainwater collected from the tower. Apply waterproof sealant to all joints to ensure that the troughs themselves are waterproof and durable.

[0027] The area of ​​rain trough 1 is equal to or slightly larger than the area of ​​the rectangle enclosed by the base of the transmission tower. S , , and These are the length and width of the rectangle enclosed by the four tower legs, respectively.

[0028] Step 2: Construct a diversion channel 2 with a certain slope that extends from the rainwater collection trough to the low-lying measurement point to ensure that rainwater flows smoothly and reliably to the designated measurement location under the action of gravity.

[0029] Based on the planned route and terrain from the site survey, a diversion channel 2 was constructed starting from the outlet of rainwater trough 1 to guide the water to a measurement point at a lower elevation near the tower. During construction, it was ensured that the diversion channel was continuous, uniform, and had a slope of no less than 3% to ensure that rainwater could flow smoothly to the measurement point under the influence of gravity.

[0030] Step 3: Set up an independent and horizontal measuring water tank 3 at the end of the guide channel to provide a stable and accurate installation reference for the subsequent flow measurement device and eliminate measurement errors caused by uneven foundation.

[0031] At the lowest point at the end of the guide channel 2, a hollow rectangular measuring water tank 3 is constructed using concrete. The base platform and bottom surface of the measuring water tank 3 are kept level. Keeping it level can prevent the bottom surface from tilting and changing the water flow velocity, which would lead to unstable flow velocity and thus measurement errors.

[0032] Step 4: By installing a standard Parshall flume 4 on this horizontal foundation and sealing and anchoring it, a seepage-proof and stable standard flow section is constructed to ensure that all incoming flow passes through a single throat and meets the metering conditions.

[0033] A standard-sized Parshall flume 4 is installed inside the measuring water tank 3. The Parshall flume 4 is made of stainless steel. All gaps between the Parshall flume 4 and the measuring water tank 3 are filled with cement mortar to achieve full circumference sealing and fixation of the flume, prevent displacement, and ensure that all the water flow is uniquely passed through the throat section of the Parshall flume. Step 5: By erecting a rigid frame 5 (gantry bracket) above the Parshall tank 4 and installing an ultrasonic probe 6, non-contact, high-precision, and interference-resistant continuous monitoring of the liquid level in the tank can be achieved.

[0034] Above the contraction section of the Parshall flume 4 (approximately one-third of the way down the throat), a rigid, U-shaped frame 5, welded from stainless steel, is erected. An ultrasonic probe 6 is fixed to the crossbeam of the rigid frame 5 using adjustable clamps, with the probe facing the water surface below. A flow meter 7 is placed to the side of the flume, and the ultrasonic probe 6 is connected to the flow meter 7 via a cable. The ultrasonic probe 6 is a TD-1D integrated ultrasonic probe.

[0035] Step 6: Calculate the water level height.

[0036] The drainage system collects water from the tower into Parshall flume 4. Ultrasonic probe 6 emits and receives the returned ultrasonic waves to measure the water level. The water level is then calculated using the following formula: ; In the formula: D: distance from the ultrasonic probe 6 to the bottom of the channel (unit: A: Speed ​​of ultrasound in air (unit: ); t: Time difference between ultrasonic wave transmission and reception (unit: H: Liquid level height in the Parshall flume (unit: ).

[0037] Step 7: Calculate the catchment flow.

[0038] Calculate the flow rate in Parshall Flume 4 using the following formula: ; Where: Q: flow rate (unit: H: Liquid level height (unit: K and n are constants related to the width of the throat.

[0039] The values ​​of K and n are shown in the table below:

[0040] Step 8: Calculate the equivalent rainfall intensity.

[0041] The equivalent rainfall intensity is calculated using the following formula: ; Where: Q: flow rate (unit: S: Area of ​​the rectangle enclosed by the bases of the transmission tower (unit: ); Equivalent rainfall intensity (unit: ).

[0042] Step 9: Calculate the combined rainfall effect.

[0043] The equivalent rainfall intensity of the catchment flow is compared with the actual rainfall intensity to calculate the runoff effect: ; In the formula: Equivalent rainfall intensity (unit: ); Actual rainfall intensity (unit: ).

Claims

1. A method for monitoring and calculating the rainfall collection effect of transmission towers, characterized in that, Includes the following steps: Step 1: Construct rain troughs (1); Step 2: Construct the diversion channel (2); Step 3: Construct a measuring water tank (3); Step 4: Install the Parshall flue (4); Step 5: Install the rigid frame (5), ultrasonic probe (6), and flow meter (7); Step 6: Calculate the water level height; Step 7: Calculate the catchment flow; Step 8: Calculate the equivalent rainfall intensity; Step 9: Calculate the combined rainfall effect.

2. The method for monitoring and calculating the rainfall collection effect of transmission towers according to claim 1, characterized in that: The rain trough (1) surrounds the four legs of the power transmission tower and collects water from the tower.

3. The method for monitoring and calculating the rainfall collection effect of transmission towers according to claim 1, characterized in that: One end of the diversion channel (2) is connected to the outlet of the rain trough (1), and the other end is tilted downwards and points to the measurement point at a lower elevation near the iron tower.

4. The method for monitoring and calculating the rainfall collection effect of transmission towers according to claim 1, characterized in that: The measuring tank (3) is a hollow cuboid structure, and the base platform and bottom surface of the measuring tank (3) are kept horizontal.

5. The method for monitoring and calculating the rainfall collection effect of transmission towers according to claim 1, characterized in that: The rigid frame (5) is erected above the upstream of the Parshall channel contraction section, at a distance of 1 / 3 of the length of the Parshall channel throat.

6. The method for monitoring and calculating the rainfall collection effect of transmission towers according to claim 5, characterized in that: The ultrasonic probe (6) is fixed on the rigid frame (5) by an adjustable clamp and is directly opposite the water surface in the tank; the flow meter (7) is placed on one side of the measuring tank (3) and is electrically connected to the ultrasonic probe (6).

7. The method for monitoring and calculating the rainfall collection effect of transmission towers according to claim 1, characterized in that: In step 6, the water level is: In the formula: D is the distance from the probe to the bottom of the channel; A is the speed of the ultrasonic wave in the air; t is the time difference between the ultrasonic wave transmission and reception; H is the liquid level in the Parshall flume.

8. The method for monitoring and calculating the rainfall collection effect of transmission towers according to claim 1, characterized in that: In step 7, the water flow rate is: In the formula: Q is the flow rate; H is the liquid level height; K and n are constants related to the throat width.

9. The method for monitoring and calculating the rainfall collection effect of transmission towers according to claim 1, characterized in that: In step 8, the equivalent rainfall intensity is: In the formula: Q is the flow rate; S is the area of ​​the rectangle enclosed by the legs of the transmission tower; This represents the equivalent rainfall intensity.

10. The method for monitoring and calculating the rainfall collection effect of transmission towers according to claim 1, characterized in that: In step 9, the rainfall effect is collected: ； In the formula: Equivalent rainfall intensity; This represents the actual rainfall intensity.

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