scholarly journals Quantifying Acoustic and Pressure Sensing for In-Pipe Leak Detection

2010 ◽  
Author(s):  
Atia E. Khalifa ◽  
Dimitris M. Chatzigeorgiou ◽  
Kamal Youcef-Toumi ◽  
Yehia A. Khulief ◽  
Rached Ben-Mansour
Keyword(s):  
Flow Rate ◽  
Pipe Flow ◽  
Pressure Transducer ◽  
Detection System ◽  
Dynamic Pressure ◽  
Low Frequency ◽  
Leak Detection ◽  
Pressure Sensing ◽  
Flow Rates ◽  
Absolute Value

Experiments were carried out to study the effectiveness of using inside-pipe measurements for leak detection in plastic pipes. Acoustic and pressure signals due to simulated leaks, opened to air, are measured and studied for designing a detection system to be deployed inside water networks of 100 mm (4 inch) pipe size. Results showed that leaks as small as 2 l/min can be detected using both hydrophone and dynamic pressure transducer under low pipe flow rates. The ratio between pipe flow rate and leak flow rate seems to be more important than the absolute value of leak flow. Increasing this ratio resulted in diminishing and low frequency leak signals. Sensor location and directionality, with respect to the leak, are important in acquiring clean signal.

Dynamic pressure sensing with a fiber-optic polarimetric pressure transducer with two-wavelength passive quadrature readout

1998 ◽  
Vol 37 (4) ◽  
pp. 663 ◽  
Author(s):  
Norbert Fürstenau ◽  
Markus Schmidt ◽  
Wojtek J. Bock ◽  
Waclaw Urbanczyk
Keyword(s):  
Pressure Transducer ◽  
Fiber Optic ◽  
Dynamic Pressure ◽  
Pressure Sensing

Pipeline Leak Detection Based on Double Sensor Negative Pressure Wave

2013 ◽  
Vol 313-314 ◽  
pp. 1225-1228 ◽  
Author(s):  
Chun Xia Hou ◽  
Er Hua Zhang
Keyword(s):  
False Alarm ◽  
Negative Pressure ◽  
Pressure Wave ◽  
Detection System ◽  
Low Frequency ◽  
Leak Detection ◽  
Frequency Component ◽  
Economic Losses ◽  
Single Sensor ◽  
Negative Pressure Wave

Pipeline leak lead to huge economic losses and environmental pollution. Leak detection system based on single sensor negative pressure wave often causes false alarm. In this paper the double sensor method is adopted to exclude false alarm by determining the propagation direction of the pressure wave. In order to remove the inverse coherent interference caused by pump running, the phase difference of primary low frequency component is used to identify the sign of the time delay between the double sensors. The experiment shows the mothod is effective.

scholarly journals A Study of the Flow Characteristics in the Inducer Bleed Slot of a Centrifugal Compressor

1996 ◽  
Author(s):  
P. A. Eynon ◽  
A. Whitfield ◽  
M. R. Firth ◽  
A. J. Parkes ◽  
R. Saxton
Keyword(s):  
Flow Rate ◽  
Pressure Ratio ◽  
Low Frequency ◽  
Flow Reversal ◽  
Flow Visualisation ◽  
Pressure Measurements ◽  
Flow Rates ◽  
Operating Range ◽  
Flow Pulsations ◽  
Inlet Duct

A broad operating range between surge and choke is so important for turbocharger compressors and many other applications that a vaneless diffuser, with its reduced efficiency, is usually adopted. With the demand for increased pressure ratio the operating range naturally reduces and techniques to extend the range are necessary. The inducer bleed slot is a technique which has been adopted in turbocharger compressors. This approach was first reported by Fisher (1988) and was described as a Map Width Enhancement slot (MWE). The flow conditions in the MWE slot and impeller inlet duct were investigated with a view to developing an improved understanding of the flow mechanisms involved as the flow rate was reduced from choice to surge. Mean temperature and pressure measurements were recorded in the MWE passage, the main inducer duct to the impeller and the inlet duct upstream of the compressor. In addition the development of flow pulsations were monitored with pressure transducers in the MWE passage, the main inducer duct and the inlet duct, together with the application of flow visualisation techniques. The transient pressure measurements showed that low frequency flow pulsations developed in the MWE passage at high flow rates. As the flow rate was reduced the low frequency pulsations disappeared and flow reversal through the MWE passage developed. It was shown that flow reversal through the MWE passage commenced at flow rates close to the peak efficiency point for the compressor.

Leak Detection Method for Long Pipeline Based on Dynamic Pressure and Wavelet Analysis

2010 ◽  
Author(s):  
Bin Xu ◽  
Likun Wang ◽  
Hongchao Wang ◽  
Min Xiong ◽  
Dongliang Yu ◽  
...  
Keyword(s):  
Wavelet Analysis ◽  
Pressure Sensor ◽  
Static Pressure ◽  
Detection Method ◽  
Detection System ◽  
Dynamic Pressure ◽  
Field Tests ◽  
Leak Detection ◽  
Analysis Method ◽  
System A

Architecture of the leak detection system is presented, and the leak detection method based on dynamic pressure and wavelet analysis is studied in this paper. The feature of dynamic pressure which is generated by the leakage of pipeline is analyzed. The dynamic pressure signal of pipeline internal pressure is acquired by dynamic pressure sensor when leakage occurs, and the signal is analyzed by wavelet analysis method to detect the singularity, and the singularity is used to recognize and locate the leak. From the comparison of analysis results between dynamic pressure and static pressure, in order to improve the sensitivity and stability of the leak detection system, a polling rule between dynamic and static pressure is implemented. Field tests of the leak detection system are presented and analyzed. The results of the field tests demonstrate that the leak detection method based on dynamic pressure and wavelet analysis can detect pipeline leak rapidly and locate the leak precisely. This leak detection system has been applied in 5000 km pipeline or so.

Obtaining Time-Varying Pulsatile Gas Flow Rates With the Help of Dynamic Pressure Difference and Other Measurements for an Orifice-Plate Meter

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
A. Narain ◽  
N. Ajotikar ◽  
M. T. Kivisalu ◽  
A. F. Rice ◽  
M. Zhao ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Difference ◽  
Dynamic Pressure ◽  
Orifice Plate ◽  
Absolute Pressure ◽  
Time Varying ◽  
Flow Rates ◽  
The Mean

Use of a conventional orifice-plate meter is typically restricted to measurements of steady flow rates. For any gas flowing within a duct in a pulsatile manner (i.e., large amplitude mass flow rate fluctuations relative to its steady-in-the-mean value), this paper proposes a new and effective approach for obtaining its time-varying mass flow rate at a specified cross section of an orifice meter. The approach requires time-varying (dynamic) pressure difference measurements across an orifice-plate meter, time-averaged mass flow rate measurements from a separate device (e.g., Coriolis meter), and a dynamic absolute pressure measurement. Steady-in-the-mean turbulent gas flows (Reynolds number ≫2300) with low mean Mach numbers (<0.2) exhibit effectively constant densities over long time-durations and are often made pulsatile by the presence of rotary or oscillatory devices that drive the flow (compressors, pumps, pulsators, etc.). In these pulsatile flows, both flow rate and pressure-difference fluctuation amplitudes at or near the device driver frequency (or its harmonics) are large relative to their steady mean values. The time-varying flow rate values are often affected by transient compressibility effects associated with acoustic waves. If fast Fourier transforms of the absolute pressure and pressure-difference measurements indicate that the predominant frequency is characterized by fp, then the acoustic effects lead to a nonnegligible rate of change of stored mass (associated with density changes) over short time durations (∼ 1/fP) and modest volumes of interest. As a result, for the same steady mean mass flow rate, the time variations (that resolve these density changes over short durations) of mass flow rates associated with pulsatile (and turbulent) gas flows are often different at different cross sections of the orifice meter (or duct). Together with the experimental measurements concurrently obtained from the three recommended devices, a suitable computational approach (as proposed and presented here) is a requirement for effectively converting the experimental information on time-varying pressure and pressure-difference values into the desired dynamic mass flow rate values. The mean mass flow rate measurement assists in eliminating variations in its predictions that arise from the use of turbulent flow simulation capabilities. Two independent verification approaches establish that the proposed measurement approach works well.

Oil Pipeline Leak Detection System Based on Acoustic Wave Technology

2012 ◽  
Vol 220-223 ◽  
pp. 1628-1632
Author(s):  
Li Kun Wang ◽  
Bin Xu ◽  
Hong Chao Wang ◽  
Shi Li Chen ◽  
Jia Yong Wu ◽  
...  
Keyword(s):  
Wavelet Analysis ◽  
Acoustic Wave ◽  
Internal Pressure ◽  
Detection System ◽  
Dynamic Pressure ◽  
Field Tests ◽  
Leak Detection ◽  
Oil Pipeline ◽  
Pressure Signal ◽  
Pressure Transmitter

Principle of the pipeline leak detection system is presented, and the leak detection method based on acoustic wave and wavelet analysis is studied in this paper. The dynamic pressure transmitter based on piezoelectric dynamic pressure transducer is designed. The characteristic of dynamic pressure transmitter when pipeline leak happened is analyzed. The dynamic pressure signal is suitable for pipeline leak detection for quick-change of pipeline internal pressure, while the static pressure is suitable for slow-change of pipeline internal pressure. The signal is analyzed by wavelet analysis method to detect the singularity, and the singularity is used to recognize and locate the leak. This paper indicated that the dynamic pressure signal could be adjust to this detection that the pressure changes in the pipeline. Field tests in 68.2 km pipeline segment show that the method detects pipeline leak rapidly and precisely.

DEVELOPMENT OF THE VISUALIZATION PROGRAM LOW NATURAL GAS FLOW MEASUREMENTS “CONTROL OF ENERGY RESOURCES: KER2 – HIGHWAY”

2020 ◽  
pp. 24-31
Author(s):  
О. А. Гнездилова
Keyword(s):  
Measurement Error ◽  
Flow Rate ◽  
Gas Flow ◽  
Energy Resources ◽  
Gas Flow Rate ◽  
Gas Industry ◽  
Flow Rates ◽  
Absolute Value ◽  
Operation Algorithm ◽  
Gas Consumption

Постановка задачи. Требуется усовершенствовать алгоритм программы «Контроль энергетических ресурсов: КЭР1 - газ», предназначенной для быстрого вычисления максимально допустимой погрешности измерения счетчиком газа в относительных единицах (%) и в абсолютном значении (м/ч) по текущему заданному расходу газа для различных типов счетчиков. Результаты. Рассмотрены основные проблемы программирования физических процессов измерения малых расходов газа. Показано описание программы измерения малых расходов газа. Разработана программа для ЭВМ и алгоритм работы «Контроль энергетических ресурсов: КЭР2 - магистраль», автоматизирующая вычисление максимально допустимой погрешности измерения счетчиком газа в относительных единицах (%) и в абсолютном значении (м/ч) по текущему заданному расходу газа, диаметру, давлению для различных типов счетчиков с учетом линейной скорости частиц в газовом потоке. Выводы. Впервые разработана программа ЭМВ «Контроль энергетических ресурсов: КЭР2 - магистраль», предназначенная для быстрого вычисления максимально допустимой погрешности измерения счетчиком газа в относительных единицах (%) и в абсолютном значении (м/ч) по текущему заданному расходу газа, диаметру трубопровода, давлению для различных типов счетчиков, что упрощает проверку их работоспособности во время периодической поверки. Полученные результаты отвечают задачам, поставленным в «Энергетической стратегии России на период до 2030 года» (№ 1715-р от 13.10. 2009), и предназначаются для использования при модернизации систем газопотребления и учета малых расходов энергоносителя. Проведенные исследования предполагают адаптацию базовых методик оценки надежности, рисков и безопасности систем в теории газоснабжения и регулирования учета расхода газа, используемых для работы региональными предприятиями газовой отрасли. Statement of the problem. It is required to improve the algorithm of the program “Control of Energy Resources: KEP 1-Gas” designed to quickly calculate the maximum permissible error of measurement by the gas meter in relative units (%) and in absolute value (m/h) at the current set gas flow rate for various types of meters. Results. The major issues of programming physical processes for measuring low gas flow rates are investigated. A description of the program for measuring low gas flow rates is shown. A software package and an operation algorithm “Energy Resources Control: KER2-Main” have been developed which automate the calculation of the maximum permissible measurement error by the gas meter in relative units (%) and in absolute value (m/h) at the current specified gas flow rate, diameter, pressure for various types of counters considering the linear velocity of particles in the gas flow. Conclusions. For the first time, the EMV software “Energy Resources Control: KER 2-Main” has been developed which is designed to quickly calculate the maximum permissible measurement error of the gas meter in relative units (%) and in absolute value (m/h) for the current specified gas flow rate, pipeline diameter, pressure for various types of meters, which makes it easier to check their performance during periodic verification. The results obtained are in compliance with the objectives specified in “Energy Strategy of Russia for the Period Up to 2030” (No. 1715-r from October 13, 2009) and are intended for use in the modernization of gas consumption systems and accounting for low energy costs. The studies assume the adaptation of the basic methods for assessing the reliability, risks and safety of systems in the theory of gas supply and regulation of gas consumption metering used for the operation of regional enterprises of the gas industry. Statement of the problem. It is required to improve the algorithm of the program “Control of Energy Resources: KEP 1-Gas” designed to quickly calculate the maximum permissible error of measurement by the gas meter in relative units (%) and in absolute value (m3/h) at the current set gas flow rate for various types of meters. Results. The major issues of programming physical processes for measuring low gas flow rates are investigated. A description of the program for measuring low gas flow rates is shown. A software package and an operation algorithm “Energy Resources Control: KER2-Main” have been developed which automate the calculation of the maximum permissible measurement error by the gas meter in relative units (%) and in absolute value (m3/h) at the current specified gas flow rate, diameter, pressure for various types of counters considering the linear velocity of particles in the gas flow. Conclusions. For the first time, the EMV software “Energy Resources Control: KER 2-Main” has been developed which is designed to quickly calculate the maximum permissible measurement error of the gas meter in relative units (%) and in absolute value (m3/h) for the current specified gas flow rate, pipeline diameter, pressure for various types of meters, which makes it easier to check their performance during periodic verification. The results obtained are in compliance with the objectives specified in “Energy Strategy of Russia for the Period Up to 2030” (No. 1715-r from October 13, 2009) and are intended for use in the modernization of gas consumption systems and accounting for low energy costs. The studies assume the adaptation of the basic methods for assessing the reliability, risks and safety of systems in the theory of gas supply and regulation of gas consumption metering used for the operation of regional enterprises of the gas industry.

Hydraulic model of a water cooling system in a chemical plant

1988 ◽  
Vol 53 (4) ◽  
pp. 788-806
Author(s):  
Miloslav Hošťálek ◽  
Jiří Výborný ◽  
František Madron
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Cooling Water ◽  
Graph Algorithm ◽  
Automatic Generation ◽  
Hydraulic Calculation ◽  
Return Flow ◽  
Flow Rates ◽  
Pressure Losses ◽  
Controlled Flow

Steady state hydraulic calculation has been described of an extensive pipeline network based on a new graph algorithm for setting up and decomposition of balance equations of the model. The parameters of the model are characteristics of individual sections of the network (pumps, pipes, and heat exchangers with armatures). In case of sections with controlled flow rate (variable characteristic), or sections with measured flow rate, the flow rates are direct inputs. The interactions of the network with the surroundings are accounted for by appropriate sources and sinks of individual nodes. The result of the calculation is the knowledge of all flow rates and pressure losses in the network. Automatic generation of the model equations utilizes an efficient (vector) fixing of the network topology and predominantly logical, not numerical operations based on the graph theory. The calculation proper utilizes a modification of the model by the method of linearization of characteristics, while the properties of the modified set of equations permit further decrease of the requirements on the computer. The described approach is suitable for the solution of practical problems even on lower category personal computers. The calculations are illustrated on an example of a simple network with uncontrolled and controlled flow rates of cooling water while one of the sections of the network is also a gravitational return flow of the cooling water.

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