Drainage pipe network management is difficult, which flow monitoring flowmeter to choose?

[ Hot attention from chemical machinery equipment network ] Drainage pipe network is the underground lifeline of the city, which has the characteristics of large flow changes, complex flow patterns, poor water quality, and poor equipment installation environment.
Therefore, the urban drainage pipe network system is the basic security facility of the city, which directly affects the economic development and the stability of people's lives, and plays a vital role in the development of the city.
With the progress and development of cities, its management and maintenance has become an urgent task faced by city managers and decision makers.

 

In addition, in the traditional management mode, the operation of the pipe network can only be understood by opening the manhole cover to observe, and it is impossible to accurately understand the operation of the pipe network, and it is impossible to detect the old or damaged pipe network with time.
Later, although the information processing was introduced to a low level, AutoCAD, Excel and other methods were used to store the drainage pipe network data in blocks, which only realized the basic map display and query functions, and could not reflect the complex network characteristics of the drainage pipe network.
It is impossible to accurately grasp the real-time operation of the pipeline.
It is also unable to provide effective online warning and monitoring for problems such as urban waterlogging, sewage overflow, unlawful discharge of industrial wastewater, excessive discharge of industrial wastewater, and mixed flow of rain and sewage.

 

Therefore, its flow monitoring can provide basic data for solving urban waterlogging, pipeline damage, and pipeline blockage, and provide a basis for urban pipeline network operation and maintenance.
At the same time, the systematic study of the urban pipe network flow can systematically grasp the operation status of the pipe network, and provide specific data support for the reconstruction and construction of the drainage pipe network.
Due to the particularity of the municipal pipeline network, it is necessary to select suitable flow monitoring equipment according to actual needs to obtain accurate flow data for a long time and minimize the amount of equipment maintenance.

 

So, for flow monitoring, which flow meters are suitable for drainage pipe networks?
 

　　First of all, it should be selected with strong adaptability, which can be used in complex media and environments, and is not easily affected by water sediments and suspended solids; it can adapt to rapid changes in flow and liquid level, and has a wide range; it has a certain reverse flow Measuring ability; can deal with the situation of full and partial tubes.

 

　　Secondly, get the flow accurately; installation is simple, daily maintenance is small and maintenance is simple.
Most of the installation environment is in the manhole, where power supply and wired communication are difficult to achieve.
Therefore, the equipment needs its own battery power supply and has a certain endurance to reduce the amount of maintenance.
In addition, the device needs to have wireless communication function, or it can be connected to other devices to realize wireless communication function;
 

　　Furthermore, because the flow equipment located in the manhole is likely to face sudden and complete flooding during the rainy season, the equipment needs a higher waterproof level to prevent equipment damage caused by flooding, and the waterproof level is generally higher than IP68 ; When it is determined according to the environment that the regular methane concentration is close to the explosion limit, explosion-proof flow equipment needs to be considered.

 

　　At present, the flow equipment that can be used in the drainage network is mainly based on the area velocity method.
This equipment is flexible in installation and use, has strong adaptability to the installation environment, and relatively low maintenance.
This kind of flow equipment is called ultrasonic Doppler flowmeter or sewer flowmeter on the market.

 

　　About Doppler Flowmeter
 

　　Ultrasonic waves will be scattered if they encounter tiny solid particles or bubbles in the propagation path, because the time difference method does not work well when measuring fluids containing such things.
It can only be used to measure clean fluids.
The Doppler method is based on the fact that ultrasonic waves are scattered.
Therefore, the Doppler method is suitable for measuring fluids containing solid particles or bubbles.
However, because scattered particles or bubbles exist randomly, the sound transmission performance of the fluid is also different.
.

 

　　In addition, if the fluid with poor sound transmission performance is measured, the scattering is stronger in the low flow velocity area near the pipe wall; while the fluid with good sound transmission performance is scattered in the high velocity area, which makes the Doppler measurement The accuracy is low.
Although the transmitting transducer and the receiving transducer are separated, so that only the scattering in the middle area of ​​the flow velocity profile can be received, but the measurement accuracy is still lower than that of the time difference method.

 

　　After reading this article, do you know which flow meter to choose for flow monitoring?
 

　　Original title: Drainage pipe network management is difficult, which flow monitoring flowmeter to choose?