1. Application background
At present, the treatment capacity of urban sewage treatment plants has basically met the requirements of urban sewage treatment capacity. However, there is a serious imbalance in the amount of sewage water in some sewage treatment basins. Therefore, the fundamental solution to this problem is to use advanced detection equipment to accurately obtain the variation law of the water quantity of the drainage pipe network system in each sewage treatment basin, and to adopt necessary means to allocate water quantity.
2、 application occasions
The product is suitable for the monitoring of water level, flow rate, flow rate of, open channel, sewage outlet monitoring, municipal pipe network and other occasions, and is also suitable for laboratory simulation flow rate, tidal power generation energy flow rate and flow direction monitoring, while cooperating with the cable system for flow measurement applications.
3. Technical principles
1. Principle of flow measurement
The principle of acoustic Doppler effect is applied to velocity measurement. When the ultrasonic wave is incident in water, the scatterers in water (such as suspended particles, bubbles, microorganisms) scatter the sound wave. Due to the existence of water flow, there is relative motion between the scatterers and the transmitter and receiver, and the received signal has a certain frequency offset relative to the transmitted signal, that is, the Doppler frequency shift, and the frequency shift value is related to the flow rate. According to the Doppler frequency shift equation, the Doppler frequency shift ①
In the formula, △fd - Doppler shift, f0 - ultrasonic emission frequency, C - water sound speed, V - flow rate, θ - transmitting wave speed (receiving beam) and the Angle between the direction of water flow.
From the formula (1) f0 in formula 2 is a constant, θ is fixed after the installation is unchanged, is also a constant, from ② it can be seen that the flow rate V and Doppler shift △fd are proportional, as long as the Doppler shift △fd and the sound speed C in water are measured, the flow rate V can be calculated.
4. Technical characteristics
① High precision, wide range, weak flow measurement, can also measure strong flow.
Sensitive sensing, high resolution, not limited by starting flow rate.
③ The response speed is fast, the instantaneous flow rate can be measured, and the average flow rate can be measured.
④ The measurement is linear, and there is no K and C value of the correction curve.
⑤ No mechanical rotating parts, there is no sediment blockage or water grass, debris entanglement and other problems;
It is suitable for the measurement and use of unattended long-term automatic online monitoring in various waters with high content of suspended sediment and many floating weeds.
5. Solve problems
The product can not only meet the requirements of conventional measurement, but also solve the problem that ordinary flow measurement equipment can not be used in low water level, low flow rate, high sediment content, a wide variety of water weeds, complex winter ice conditions and other occasions. The monitoring of water flow data in urban drainage pipes, farmland irrigation canals and non-full pipes is helpful to accurately evaluate the operation of pipelines and improve the management and operation level of drainage systems.
6. Technical parameters
| Velocity measurement range | -1.50m/s ~ 7.00m/s positive and negative two-way flow rate measurement |
| Velocity accuracy | 1%±1cm/s; Resolution: 1mm/s |
| Water temperature measuring range | -5℃～60℃ |
| Water temperature accuracy | ±0.5℃ |
| Water level range | 0-10m |
| Water level accuracy | 0.2%±0.2cm The lowest water level can be measured by 2cm |
| sensor | The beam is transmitted horizontally or diagonally by acoustic Doppler flow measurement |
| Waterproof class | Sensor IP68, host IP65 |
| Flow range | 1L/s～99999999m3/h |
| Storage temperature | -20℃ ~ 60℃ |
| Output interface | RS485 and RS232, providing standard MODBUS protocols |
| Power supply | DC12V±10%，AC220V±10% |
| Measurement parameter | Velocity, water level, instantaneous flow, cumulative flow |
7. the whole system composition
Ecological traffic monitoring equipment is divided into video image monitoring and real-time traffic data acquisition two parts. In accordance with the requirements of combining dynamic and static, qualitative and quantitative, real-time and random inspection, and in accordance with the principles of reasonable technology and economic applicability, image monitoring, video monitoring, real-time traffic data monitoring or real-time traffic data superimposed on video images can be selected.
The system is composed as follows:
(1) Ultrasonic Doppler flow meter: measure water level, flow rate, instantaneous flow and cumulative flow.
(2) Data acquisition instrument or telemetry terminal RTU: The main function of the remote data acquisition instrument or telemetry terminal RTU is to summarize and calculate the flow rate information of each measuring point, and send it to the server through the GPRS wireless network, and you can view the real-time water level and flow information through the platform.
(3) Camera (optional) : based on site requirements
(4) Power supply system (mains 220V or external DC12V) solar panels and batteries: mainly used for sensor probes and telemetry terminal power supply, generally using 65AH/12V battery and 100W solar panel power supply, the default is collected once every 5 minutes.
(5) Vertical rod and cross rod: used to install radar flowmeter equipment, cable through the PVC pipe through the rod.
(6) Equipment chassis: used to place the radar host, controller, battery, charger, signal lightning arrester, etc
(7) Water conservancy information platform or environmental protection platform: the data acquisition instrument supports 212 environmental protection agreements, and the telemetry terminal supports hydrology and water resources agreements that can be connected to the owner's platform.
8.Application site
