scholarly journals Study on the influence of elbow with different curvature radii on pipeline leak location

2021 ◽  
Vol 13 (10) ◽  
pp. 168781402110534
Author(s):  
Peifeng Lin ◽  
Donghui Lei ◽  
Jiang Liao
Keyword(s):  
Numerical Methods ◽  
Negative Pressure ◽  
Pressure Wave ◽  
Measurement Accuracy ◽  
Inlet Pressure ◽  
Radius Of Curvature ◽  
Curvature Radius ◽  
Location Accuracy ◽  
Leak Location ◽  
Leakage Location

Experimental and numerical methods are used to locate the pipeline leakage in the present work. The weak compressibility of the fluid is taken into account when simulating the propagation of negative pressure wave (NPW) in the pipeline. The NPW attenuation coefficient is used to describe the influences of curvature radius on location accuracy. The results indicate that when the curvature radius is small, the location accuracy of pipeline leakage is low. When the radius of curvature increases or the inlet pressure increases, the accuracy of pipeline leak location is improved. Besides, with the change of inlet pressure, pressure, and velocity distributions in the elbow with different curvature radii are investigated. When the curvature radius of the elbow is three to four times of pipe diameter, the measurement accuracy of leakage location is the best. When the inlet pressure of the pipeline is 0.7 MPa, the sensitivity of the pipeline detection is the highest. The cavitation corrosion at the elbow is the most obvious. Therefore, the elbow is the area where pipeline leakage occurs most frequently.

Effect of rubber washers on leak location for assembled pressurized liquid pipeline based on negative pressure wave method

2018 ◽  
Vol 119 ◽  
pp. 181-190 ◽  
Author(s):  
Qiang Chen ◽  
Guodong Shen ◽  
JunCheng Jiang ◽  
Xu Diao ◽  
Zhirong Wang ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Pressure Wave ◽  
Wave Method ◽  
Leak Location ◽  
Negative Pressure Wave

scholarly journals An Improved Negative Pressure Wave Method for Natural Gas Pipeline Leak Location Using FBG Based Strain Sensor and Wavelet Transform

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Qingmin Hou ◽  
Liang Ren ◽  
Wenling Jiao ◽  
Pinghua Zou ◽  
Gangbing Song
Keyword(s):  
Wavelet Transform ◽  
Natural Gas ◽  
Negative Pressure ◽  
Pressure Wave ◽  
Strain Sensor ◽  
Wave Method ◽  
Positioning Accuracy ◽  
Natural Gas Pipeline ◽  
Leak Location ◽  
Negative Pressure Wave

Methods that more quickly locate leakages in natural gas pipelines are urgently required. In this paper, an improved negative pressure wave method based on FBG based strain sensors and wavelet analysis is proposed. This method takes into account the variation in the negative pressure wave propagation velocity and the gas velocity variation, uses the traditional leak location formula, and employs Compound Simpson and Dichotomy Searching for solving this formula. In addition, a FBG based strain sensor instead of a traditional pressure sensor was developed for detecting the negative pressure wave signal produced by leakage. Unlike traditional sensors, FBG sensors can be installed anywhere along the pipeline, thus leading to high positioning accuracy through more frequent installment of the sensors. Finally, a wavelet transform method was employed to locate the pressure drop points within the FBG signals. Experiment results show good positioning accuracy for natural gas pipeline leakage, using this new method.

A Novel IoT-Based Method for Real-Time Detection of Spontaneous Leaks in Pipelines, Gathering Systems, and Offshore Risers

2021 ◽  
Author(s):  
Matthew Grimes ◽  
Nico Van Rensburg ◽  
Stuart Mitchell
Keyword(s):  
Signal Processing ◽  
Transmission Lines ◽  
Negative Pressure ◽  
Pressure Wave ◽  
Long Distance ◽  
Non Invasive ◽  
Long Distance Transmission ◽  
Offshore Production ◽  
Offshore Risers ◽  
Oil Gas

Abstract This paper presents on a non-invasive, IoT-based method for rapidly determining the presence and location of spontaneous leaks in pressurized lines transporting any type of product (e.g., oil, gas, water, etc.). Specific applications include long-distance transmission lines, gathering networks at well sites, and offshore production risers. The methodology combines proven negative pressure wave (NPW) sensing with advanced signal processing to minimize false positives and accurately identify the presence of small spontaneous leaks within seconds of their occurrence. In the case of long-distance transmission pipelines, the location of the leak can be localized to within 20-50 feet. The solution was commercialized in 2020 and has undergone extensive testing to verify its capabilities. It is currently in use by several operators, both onshore and offshore.

scholarly journals Study on the influence of radius of curvature on flow resistance in spiral pipe

2021 ◽  
Vol 237 ◽  
pp. 03013
Author(s):  
Wenqiang Li ◽  
Hui Qi ◽  
Yongfeng Yang ◽  
Guojun Zhao ◽  
Rong Liu ◽  
...  
Keyword(s):  
Numerical Calculation ◽  
Wind Speed ◽  
Flow Resistance ◽  
Fluid Flows ◽  
Radius Of Curvature ◽  
Curvature Radius ◽  
Change Rate ◽  
Linear Pattern ◽  
Offset Distance ◽  
Numerical Calculation Method

With the continuous development of west of China, a new kind of tunnel, namely spiral tunnel, has appeared in the expressway. Due to the special linear pattern, the resistance of airflow in spiral tunnel has been found to change, but there are few relevant researches at present. Therefore, numerical calculation method is used to study the variation of flow resistance in spiral pipe with different curvature. The results show that when the fluid flows in the spiral pipe, the wind speed is not uniformly distributed. The highest speed is not in the center of the pipe, but on the outside of the pipe, and the offset distance decreases with the increase of the radius of curvature. In addition, the change of flow resistance in spiral pipe is studied, and it is found that the change rate of flow resistance decreases with the increase of curvature radius. It shows that the radius of curvature is negatively correlated with the flow resistance.

IDENTIFICATION OF CURVATURE RADIUS FOR CURVED SECTIONS ON FOREST ROADS IN THE PROCESS OF UTILISATION

2021 ◽  
Vol 14(63) (1) ◽  
pp. 47-56
Author(s):  
Ihor RUDKO ◽  
Borys BAKAY ◽  
Abdullah AKAY ◽  
Vasyl BARYLIAK ◽  
Stanislav HORZOV
Keyword(s):  
Technical Information ◽  
Radius Of Curvature ◽  
Curvature Radius ◽  
Forest Roads ◽  
Forest Road ◽  
Advantages And Disadvantages ◽  
Natural Production ◽  
Angle Deviation ◽  
Road Projects ◽  
Selection Of

This article reviews the problem of measuring the actual radius of curvature for curved sections of existing forest roads, as forestry enterprises require reliable technical information about the current conditions of operated transport networks. It was identified that at this moment, a selection of methods are used for measuring the radii of horizontal curved sections of roads, which have certain advantages and disadvantages in specific natural production conditions. For calculating the radius of curvature for auto forest road projects it is recommended to apply the method of measured angles by chord angle deviation, which is sufficiently accurate for engineering purposes and does not require usage of special high-precision equipment and tools.

Projective Noise Reduction Algorithm for Negative Pressure Wave Signal Processing

2008 ◽  
Author(s):  
Dongliang Yu ◽  
Laibin Zhang ◽  
Liang Wei ◽  
Zhaohui Wang
Keyword(s):  
Noise Reduction ◽  
Negative Pressure ◽  
Pressure Wave ◽  
Random Noise ◽  
Background Signal ◽  
Long Distance ◽  
Noise Component ◽  
Wave Signal ◽  
Non Linear ◽  
Negative Pressure Wave

The appearance of a rupture, leak or damage in the long-distance oil & gas pipeline, which could cause a leak, usually generates a non-linear & chaotic negative pressure wave signal. By properly interpreting the negative pressure wave signature, it is possible to detect a leak along the pipeline. Most traditional noise reduction methods are established based on the linear system, which are not in line with the actual non-linear & chaotic situation. Therefore, the weak negative pressure wave signals, generated by small leaks, are often filtered out and cause false alarm and failure alarm. In order to resolve the problem, this paper uses the non-linear projective algorithm for noise reduction. First, the weak negative pressure wave signal series would be reconstructed using delay coordinates, in the high dimensional phase space, the background signal, the negative pressure wave signal and the noise signal are separated into different sub-spaces. Through the reconstruction of sub-spaces, the weak pressure wave signal can be isolated from the background signal as well as the random noise component reduced.

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