Transient-based Method Research Articles

Discussion of “Skeletonizing Pipes in Series within Urban Water Distribution Systems Using a Transient-Based Method” by Yuan Huang, Feifei Zheng, Huan-Feng Duan, Tuqiao Zhang, Xinlei Guo, and Qingzhou Zhang

Discussion of “Skeletonizing Pipes in Series within Urban Water Distribution Systems Using a Transient-Based Method” by Yuan Huang, Feifei Zheng, Huan-Feng Duan, Tuqiao Zhang, Xinlei Guo, and Qingzhou Zhang

Closure to “Skeletonizing Pipes in Series within Urban Water Distribution Systems Using a Transient-Based Method” by Yuan Huang, Feifei Zheng, Huan-Feng Duan, Tuqiao Zhang, Xinlei Guo, and Qingzhou Zhang

Closure to “Skeletonizing Pipes in Series within Urban Water Distribution Systems Using a Transient-Based Method” by Yuan Huang, Feifei Zheng, Huan-Feng Duan, Tuqiao Zhang, Xinlei Guo, and Qingzhou Zhang

Leak detection and location in liquid pipelines by analyzing the first transient pressure wave with unsteady friction

Leakages in pipelines can cause serious consequences, such as economic loss, or fire and explosion. Hence, leak detection and location techniques are of crucial importance for pipeline maintenance, safety of industry facilities and environment. A modified transient-based method is proposed in this paper for leak detection and location in a reservoir-pipe-valve (RPV) system. The leak location model is based on the time when a pressure wave propagates from the valve to the leak location and back again. Furthermore, in the leak detection model, the one-dimensional unsteady friction model is introduced into Method of Characteristics (MOC). Then, the governing equations are derived as a ternary system of equations, in which the unknown parameters, especially leak size coefficient, are obtained by analyzing the first transient pressure wave. To validate the method efficiency, both one leak and two leaks situations are taken into consideration in simulation. The simulated results show notable correlations between the model and real leak locations. Additionally, the errors between calculated and actual values of the parameters remain in acceptable ranges. Finally, the developed method is verified by experimental data, and the results demonstrate that it has high accuracy and shows a great performance in leak detection and location.

SIMULATION OF HYDROCARBON PIPELINE LEAK DETECTION USING THEORETICALLY APPROXIMATED MODEL ON A TRANSIENT-BASED METHOD

Detection and localization of small leaks in pipelines were early developed using a nonlinear adaptive state observer and a special correlation technique, based on pressure and flow measurements at the pipeline inlet and outlet. Simulations and experiments show the results for a gas and a liquid pipeline. This paper x-ray pipeline leak Identification using a transient-based method on hydraulic transients of a brake system with oil at two different temperatures, Leak effects at different frequency response were Simulated, measured and leak detection experiment with MATLAB code were also highlighted. The result obtained show that in certain circumstances the brake response is slow due to the temperature and suggests an appropriate pipe diameter to overcome this problem of low flow rate, the transfer function obtained using the proposed method were able to measure the presence of a leak on the pipe system. Simulations, measurements and leak experiments have shown that the early detection and localization of small leaks in liquid and gas pipelines can be considerably improved using theoretically approximated model as the required computational effort is relatively small, as compare to microcomputers which can be used for leak detection including monitoring of the inner pipeline state.

Skeletonizing Pipes in Series within Urban Water Distribution Systems Using a Transient-Based Method

AbstractMany skeletonization methods are available to simplify the configuration of urban water distribution systems (WDS) to enable hydraulic modeling and analysis. However, these approaches are g...

Multiple-fault detection in water pipelines using transient-based time-frequency analysis

Pipe faults, such as leakage and blockage, commonly exist in water pipeline systems. It is essential to identify and fix these failures appropriately in order to reduce the risk of water pollution and enhance the security of water supply. Recently, transient-based detection methods have been developed for their advantages of non-intrusion, efficiency and economics compared to traditional methods. However, this method is so far limited mainly to simple pipelines with a single known type of pipe fault in the system. This paper aims to extend the transient-based method to multiple-fault detection in water pipelines. For this purpose, this study introduced an efficient and robust method for transient pressure signal analysis – a combination of the empirical mode decomposition and Hilbert transform – in order to better identify and detect different anomalies (leakage, blockage and junction) in pipelines. To validate the proposed transient-based time-frequency analysis method, laboratory experimental tests were conducted in this study for a simple pipeline system with multiple unknown types of pipe faults including leakages, blockages and junctions. The preliminary test results and analysis indicate that multiple pipe faults in simple pipelines can be efficiently identified and accurately located by the proposed method.

Designing Collaborative Working Laboratory Sessions for Induction Machine Fault Diagnosis Learning

In this paper, two laboratory sessions, specially designed to instruct students on the operational methodology of different induction motors fault diagnosis techniques, are presented and explained. The sessions are taught within the context of a subject dealing with predictive maintenance of electrical installations and machines. During the laboratory sessions, the students apply the different condition monitoring techniques, using special educational laboratory test benches built to this end. These test benches allow the students to easily capture the necessary current signals in motors with rather different constructive characteristics, operating conditions and faults. Next, the students must process the captured signals by using available software programs. While stationary current signals are analyzed using the Fast Fourier Transform (FFT) — conventional diagnosis approach — the startup current signals are processed using the Discrete Wavelet Transform (DWT) — modern transient-based diagnosis method. The laboratory sessions have been developed from a collaborative perspective, so that the students are encouraged to work in groups in the experimental part with further collective discussion on their diagnostic conclusions, all within an open framework for information sharing.