Leakage detection method of underground pipe leakage characteristics.

Characteristics of underground pipe leakage

Pipe leakage is a phenomenon of water injection under pressure, ejected from the perforation or fracture and fill the soil to form a cavity, resulting in a certain frequency of sound, the frequency band of this sound is generally from a few tens of Hz to a few thousand Hz, after the soil medium on the high-frequency sound part greatly attenuated. Nevertheless, the sound of water leakage to the ground still has a certain sound pressure, its frequency is roughly between 100 Hz and 2000 Hz, the sound intensity of water leakage to the ground and the size of the water pressure, the size of the leakage hole, the type of pipe, the thickness of the pipe diameter, the nature of the soil and other factors. The characteristic of sound generated by water leaks provides a prerequisite for finding water leaks and determining the location of leaks.

Underground pipe leakage detection method

At present, China's underground water pipeline leak detection mainly uses passive maintenance method and sound listening method. Passive overhaul method is a method of sending people to overhaul only after the discovery of bright leaks. The sound listening method of leak detection is a method of using the sound generated by underground pipe leaks to estimate the leaky parts of pipes on the ground:

1) Sometimes the sound is large, and the range of sound heard is too large, making it difficult to determine the correct location of the leak;

2) (Sometimes the sound of leaking water is not necessarily the leak point, relying mainly on human experience;

3) in the busy traffic, strong noise areas, sound listening method is difficult to work properly;

4) some sound is too small, but also difficult to detect with the sound method. Although the sound method has been improved by many, the performance of the instrument and the operator's skills continue to improve, but there are still many cases of leakage detection can not be carried out, especially when the noise is too large, the pipeline is buried too deep, the inference of the location of the leak is very difficult, or impossible. Leak detection by correlation method is one of the methods based on overcoming the above disadvantages.

Buried pipeline leak detector

The PQWT-CL900 automatic pressure pipeline leak analyzer produced by Hunan Puqi Geological Exploration Equipment Research Institute is a fully automatic leak detector with superior performance, which overcomes the problem of misjudgment due to changes in liquid or gas flow rate or pressure in the pipeline that exists in a single leak detector. The specific pipeline leak detection method includes: arranging a group of samplers in a line array or matrix in the leak detection area of the pipeline; setting the working mode of the host in wireless mode, then instructing the samplers in the group to carry out data acquisition at the same time, and storing the sampling data of each sampler in blocks according to the sampler number, and determining the location of the leak by comparing and analyzing the synchronous sampling data of each sampler.

The main features of the product are.

1、Adopted foreign * digital signal processing chip and digital filter chip, controller integrated 16M cache, more responsive.

2, using 7-inch high-definition digital touch color LCD screen, resolution up to 800 by 480, full touch design, easy to operate.

3、9 probes use wireless module to send signal, no wiring, transmission distance up to 1000 meters. And 9 probes can measure at the same time, so that the measurement range is greatly increased, saving the user the time to find the water leakage.

4、Users can adjust the frequency range at will within 70HZ-9000HZ.

5、In the range of 70HZ-9000HZ, it can display the distribution of the noise signal at each frequency in real time.

6, the sensor built-in preamplification circuit, the use of rubber ring seal and buffer, as well as the application of professional acoustic methods, making the ability to capture the noise higher than similar products.

7, using a large-capacity battery, can work continuously for more than ten hours.

8, super anti-interference circuit design, effective isolation of digital signals and analog signals, eliminating the noise generated by the digital circuit.