Leakage Monitoring Research Articles

Research on leak monitoring of the primary circuit of a pressurized water reactor based on the 13N coincidence method

To assess the characteristics of 13N decay, a monitoring method of the primary loop leakage rate based on the ?-? coincidence method was proposed. In this work, sampling and measurement devices were designed, in which NaI (Tl) crystals were used as coincidence detectors. The Geant4 simulation method was used to study the relationship between the efficiency e and capacity V change of different devices, and the eV value under the corresponding capacity was obtained. According to the value of eV, the optimal sampling and measurement device was determined, and then the detection efficiency of the device was calibrated experimentally. Taking the 600 000 kW reactor of Qinshan Phase II as the research object, the lower limit of detection was discussed. When the sampling point was located in the fume hood of the control rod drive mechanism, the theoretical lower limit of the coincidence method was 0.756 Lh-1.

Field Applications of Distributed Fiber Optic Strain and Temperature Sensing for Caprock - Well Integrity and CO2 Leakage Monitoring

Field Applications of Distributed Fiber Optic Strain and Temperature Sensing for Caprock - Well Integrity and CO2 Leakage Monitoring

China actively promotes CO2 capture, utilization and storage research to achieve carbon peak and carbon neutrality

China actively promotes CO2 capture, utilization and storage research to achieve carbon peak and carbon neutrality

Calibration and field deployment of low-cost sensor network to monitor underground pipeline leakage

Recent technological advances in methane detection have improved leak detection and repair. However, current methods to reliably measure methane concentrations rely on expensive instruments or demand significant labor input. There is interest in using affordable methane sensors that are responsive to ppmv level changes in methane concentrations in both urban and rural environments for monitoring underground natural gas pipeline leaks. This is especially relevant for situations where potentially significant leaks cannot be repaired immediately or smaller leaks that require long-term monitoring and further evaluation. In this work, a low-cost sensor unit, equipped with a metal oxide sensor, was designed, built, and calibrated over a wide range of methane concentrations and environmental conditions in preparation for field application. A network of these sensors was then installed at the test site and used to measure methane concentrations at ground level above known sub-surface natural gas emissions which emulated underground gas pipeline leaks. This low-cost sensor network measured over 4 days total for the two different known leakage rates. Results demonstrate that the sensors can continuously measure relative methane variability for extended periods but require calibration for a wide range of temperature and humidity conditions to properly determine absolute gas (i.e., methane) concentrations. When a regression analysis was conducted to evaluate the effects of meteorological parameters on methane concentration, air temperature and wind speed have strong impacts on the concentration. Overall, the network approach allows improved identification of leak location and monitoring of underground natural gas leaks.

Detecting Gas Leaks: A Case Study in IoT Technologies

This paper presents a case study in the creation and utilization of an Internet of Things (IoT) device. An Arduino-based gas leak detector is utilized for the demonstration of IoT technologies and their advantages. The gas leak detection device focuses on detection of Liquified Petroleum gas. Upon detection of a leak, the device can communicate over the internet using cellular networks, thus helping to alleviate Wi-Fi and ethernet failure issues such as loss of power in a natural disaster. Because of the device’s resilience, it can help ensure the user is notified of the emergency as soon as possible. This automated gas leak monitoring system is reliable and will not be put out of action in a disaster or emergency situation.

Detecting Gas Leaks: A Case Study in IoT Technologies

This paper presents a case study in the creation and utilization of an Internet of Things (IoT) device. An Arduino-based gas leak detector is utilized for the demonstration of IoT technologies and their advantages. The gas leak detection device focuses on detection of Liquified Petroleum gas. Upon detection of a leak, the device can communicate over the internet using cellular networks, thus helping to alleviate Wi-Fi and ethernet failure issues such as loss of power in a natural disaster. Because of the device’s resilience, it can help ensure the user is notified of the emergency as soon as possible. This automated gas leak monitoring system is reliable and will not be put out of action in a disaster or emergency situation.

Application of Electrical Tomography Imaging Using Machine Learning Methods for the Monitoring of Flood Embankments Leaks

This paper presents an application for the monitoring of leaks in flood embankments by reconstructing images in electrical tomography using logistic regression machine learning methods with elastic net regularisation, PCA and wave preprocessing. The main advantage of this solution is to obtain a more accurate spatial conductivity distribution inside the studied object. The described method assumes a learning system consisting of multiple equations working in parallel, where each equation creates a single point in the output image. This enables the efficient reconstruction of spatial images. The research focused on preparing, developing, and comparing algorithms and models for data analysis and reconstruction using a proprietary electrical tomography solution. A reliable measurement solution with sensors and machine learning methods makes it possible to analyse damage and leaks, leading to effective information and the eventual prevention of risks. The applied methods enable the improved resolution of the reconstructed images and the possibility to obtain them in real-time, which is their distinguishing feature compared to other methods. The use of electrical tomography in combination with specific methods for image reconstruction allows for an accurate spatial assessment of leaks and damage to dikes.

New solutions for remote monitoring of pre-cast concrete service reservoir and sludge lagoon

The use of distributed temperature and/or strain measurements for embankment and reservoir monitoring has grown in recent years. The paper elaborates on two different methods applied through two installation examples in the UK. To reduce risk, a leakage monitoring system using distributed fibre optic temperature sensing (DTS) with a spatial resolution of 0.7 m has been installed at the newly constructed 45ML Hanchurch Service Reservoir. The gradient method provides information regarding possible seepage by monitoring absolute temperatures over time. Heat pulse method consists of measuring the temperature changes over time using DTS following heating the hybrid cable with a known electrical power input. Central to the £7 million investment on the century-old Curdworth sludge lagoon is the installation of a novel combined leakage and movement of the early detection system. The system is based on distributed fibre optic sensing methods for measuring strain and temperature, both fully automated with a time resolution of about an hour. Instrumentation can be analysed in real time. Trigger levels are being established during a trial period, linked to an automatic alarm system, which supplements site-based surveillance. This will facilitate the early detection of potential embankment/reservoir integrity issues and, in turn, will enable prompt action to be taken to reduce risk and in an extreme case the implementation of essential repairs in order to prevent a dam failure.

Development and Application of Methane Leakage Monitoring System for Gas Transmission Pipeline

Oil and gas pipeline transportation, as a relatively safe way of oil and gas transportation, undertakes most of the transportation tasks of crude oil and natural gas. Oil and gas pipeline accidents affect a wide range of consequences. Therefore, the oil and gas pipeline leakage detection is paid more and more attention. In this paper, ultra-low power methane gas sensor is selected to collect methane gas concentration in the air, and wireless network technology is used to build a wireless network sensor system with 4G function. Through the sensor distribution along the pipeline, it can intuitively and accurately judge whether there is a micro-leakage in the pipeline, and understand the diffusion situation after the leakage. The sensor system has high reliability and stability, and has high value of popularization and application.

Reply to comment on “Greenhouse gas emissions from marine decommissioned hydrocarbon wells: Leakage detection, monitoring and mitigation strategies”

Reply to comment on “Greenhouse gas emissions from marine decommissioned hydrocarbon wells: Leakage detection, monitoring and mitigation strategies”

Design of leakage monitoring system based on optical fiber side coupling effect

Aiming at the problems of the existing quasi-distributed optical fiber sensing measurement technology, such as complexity, low accuracy and slow response time, a quasi-distributed optical fiber water leakage monitoring system with high real-time performance and lower cost is designed; the system is mainly composed of sensitive detection. It is composed of needle, low light detection unit, main control unit and data transmission unit. The lateral coupling effect forms a series of sensing probes after the LED light source is scanned. Light enters the polymer fiber through the lateral coupling structure. When the medium between the LED and the coupling structure changes, the coupling light intensity increases, and the output light intensity at both ends of the fiber increases accordingly, so the liquid leakage event can be converted into a coupling medium change To measure and cooperate with several other modules to complete the construction of a water leakage monitoring system; the results show that the designed fiber-optic water leakage monitoring system has the ability to detect and locate water leakage signals, and the positioning accuracy is less than or equal to 10 cm. Basically realize the functions of liquid leakage detection and leakage point positioning, which conforms to the characteristics of quasi-distributed measurement.

Multi-cylinder-based hybridized electromagnetic-triboelectric nanogenerator harvesting multiple fluid energy for self-powered pipeline leakage monitoring and anticorrosion protection

With the continuous development of human society and urban construction, exploring sustainable power sources of monitor and protection systems for city’s infrastructure is becoming more and more urgent. Scavenging ambient fluid flow energy to efficiently and conveniently power electric devices has potential applications for pipeline systems, especially in remote areas. Here, a multi-cylinder-based hybridized electromagnetic-triboelectric nanogenerator (MCNG) is reported to harvest two types of fluid energy at the same time to double the working frequency of the hybrid NG. The introduction of Nylon film effectively improved the durability and output performance. And the structure to transmit external mechanical through magnetic coupling is easy to packaging and assembly, which provides a stable inner environment. Moreover, the hybrid nanogenerator was demonstrated to effectively harvest energy from wind and water flow to power 1075 LEDs and a temperature sensor. Furthermore, a self-powered wireless pipeline leakage monitoring system and a self-powered cathodic protection system based on the MCNG are developed and illustrated. This work provides a prospective strategy for hybrid nanogenerator to improve working frequency and output stability for practical applications.

Small Leak Detection Based on the Combination of Improved Fast Differential Algorithm and Integral Algorithm

Detecting small leaks in time can prevent an accident from getting worse, which plays an extremely important role in safe pipeline transportation. In order to improve the ability to detect small leaks, this paper proposes a new pipeline leak detection method based on the combination of the improved fast differential algorithm and integral algorithm. This paper first reviews and analyzes the advantages and disadvantages of the fast differential algorithm; on this basis, to further improve the signal-to-noise ratio (SNR) of small leaks and the robustness of the leakage monitoring system, an integral algorithm with adaptive initialization is proposed; Next, to improve the location accuracy of small leaks, historical data are used to estimate the wave speed. The application of actual leakage test data shows that the proposed method can detect a leakage rate of about 0.3%; the false alarm rate is significantly reduced, and the positioning accuracy is improved. All of those verify the effectiveness and practicability of the proposed method.

IoT Based LPG Gas Level Detection & Gas Leakage Accident Prevention with Alert System

Liquefied Petroleum Gas (LPG) is widely used for cooking fuel in developing countries for economic reasons, for energy-rich fuel source that contains the higher calorific value, for clean fuel with low carbon emission and for a portable that is available in even the faraway of areas. Therefore the proposed gas leakage detection and monitoring system for the gasoline content present in household LPG cylinder is developed. Usually, the capacity of LPG in cylinder is not determined in an exact manner and a cylinder when the gas is about to empty will be a difficult situation for the one who uses LPG gas for cooking continuously. By using IoT, the information of the near to the empty level of LPG gas in the cylinder will send to the user and the gas refill method by using telephonic ordering can be conducted. The purpose of this research is the detection of gas leakage and monitoring the LPG gas cylinder weight regularly to know the remaining value of gas in the cylinder. When the gas leakage is sensed, the warning signal and alarm sound will be active and also switch on exhaust fan automatically to decrease the gas concentration. The weight of LPG is measured using the load sensor (SEN-10245) and the output of the sensor is connected with Arduino MKR Wifi 1010 microcontroller. The user can know the validity of LPG usage daily because the amount of LPG gas will publish as events and watch them come through in real-time using the Wia IoT cloud platform. Consequently, the user is alerted by giving SMS notification to their mobile phone when the LPG level is critically low (below 20%) by use of the integration function of the Wia IoT platform call Twilio, using its web service APIs. Then by detecting the gas leakage with MQ6 gas sensor, this research work indicates for gas leakage condition and also helps to prevent the LPG gas burst accidents in the home.

Нормализованный метод определения влияния технологии обработки герметизирующих поверхностей неподвижных соединений на их герметичность

The existing approaches for determining and evaluating the sealing properties of seals for fixed sealants, as well as methods of leakage monitoring are considered. The description of a normalized method for leak-tightness assessment is given, which allows solving a sufficiently large number of evaluation tasks, for example, technological task: assessment of the influence of the technology sealing surfaced job; design: assessment of the influence of the seals surface layer quality of sealants and geometric parameters of them on sealing capacity (service property).

Pipeline leak and volume rate detections through Artificial intelligence and vibration analysis

Pipeline monitoring provides operators with invaluable information regarding the potential risks that may pose threats to the integrity of the entire line. Pipeline leakage results in serious environmental and financial costs that can be avoided through leak detection systems. This study introduces a comprehensive leak monitoring system that allows leak detection, localization, and volume rate estimation in liquid pipelines installed above ground, simultaneously. To minimize the leak interpretation errors an artificial intelligence (AI)-based leak detection algorithm is developed. Pressure sensors are utilized to capture real-time variations of fluid pressure to localize pipeline leakage through the application of the pressure gradient intersection method. Vibrations of the pipeline are also acquired in real-time through accelerometers, the signals of which are then used to estimate the leak forces through the inverse dynamics of the pipeline between the leak location and the location of the accelerometers. This is achieved by developing a leak-induced vibration (LIV) model that simulates the dynamics of the pipe through a finite element (FE) vibration model. The transfer function of the pipe assembly is then used to design a Kalman filter. The Kalman filter predicts the leak forces and is used to estimate the fluid release through correlation analysis of the leak forces and leak volume rate, experimentally. A lab-scale experimental setup is manufactured to verify the dynamic LIV model and to test the proposed methodology. The performance of the proposed methodology shows 97 %, 96 %, and 92 % of accuracy on average for leak detection, localization, and leak volume rate estimation, respectively.

Analysis and Prediction of Methane Invasion Distance Considering Real Ground Boundary.

Natural gas has become a global energy consumption hotspot because of its large reserves and clean combustion. Due to soil corrosion, construction damage, and natural disasters, leakage accidents of buried natural gas pipelines often occur. In this paper, the steady simulation method was used to study the methane invasion limit state (MILS) and the methane invasion limit distance (MILD) under the conditions of hardened surface ground (HSG), unhardened surface ground (UHSG), and semihardened surface ground (SHSG), and the transient simulation of methane invasion distance (MID) under the condition of HSG with the largest MILD was carried out. The results showed that regardless of ground conditions, with the increase of leakage time, the diffusion range of methane in soil will not increase all the time, and there was a limit state (MILS). The distribution range and concentration of methane in the soil under HSG condition were the largest, followed by the SHSG condition, and the UHSG condition was the smallest. When the ground condition changed from UHSG to HSG, the MILD increased from 3.41 to 9.32 m. The HSG condition will increase the MILD and the range of dangerous areas. The buried depth of the pipeline had a serious impact on the MILD. When the buried depth of the pipeline increased from 0.3 to 1.5 m, the MILD increased from 1.75 to 3.49 m under the condition of UHSG and exceeded 10 m under the condition of HSG. The average error of the MID prediction model was 2.37% under the condition of HSG, which can accurately predict the leakage of buried pipeline. The MID provides a reference for the layout of urban underground gas leakage monitoring points. The MILD can provide guidance for the safe distance between natural gas pipeline and structures in the design code of natural gas pipeline.

Pulse Coding in Distributed Optical Fiber Vibration Sensor: A Review

Distributed optical fiber vibration sensor (DOFVS) is suitable for remote monitoring of vibration signals generated by external perturbations. In order to improve the sensing performance, various pulse coding techniques are applied in DOFVS, which have attracted an increasing amount of research attention. In this paper, recent advances of pulse coding methods used in DOFVS are reviewed, from pulse compression, including linear frequency modulation (LFM) and nonlinear frequency modulation (NLFM), pulse coding modulation based on the linear combination and correlation operation, such as Simplex code, Golay code and random code, as well as pulse sequence modulation (PSM), such as phase-shift pulses, differential frequency pulses, etc. Characteristics, working principles and the latest research results of pulse coding methods are discussed. Furthermore, some application progresses of pulse coding for performance enhancement in DOFVS are also introduced. By combining these technologies, the sensing performance could be improved in aspects of sensing distance, spatial resolution (SR), and frequency response, which show considerable potential applications in perimeter security, oil and gas monitoring, pipeline leakage, and structural health monitoring.

Design of a Weak Fiber Bragg Grating Acoustic Sensing System for Pipeline Leakage Monitoring in a Nuclear Environment

We propose a design method of a weak fiber Bragg grating (FBG) array, in which the reflectivity of the FBG increases along the fiber, and this increase is limited by the dynamic range of the distributed optical fiber sensing (DOFS) system. For a DOFS system, this design method can not only well compensate for the impact of fiber loss, within a certain range and caused by radiation, on the deterioration of the system performance, but also can reduce the requirements for the dynamic range of the system in nuclear environments. Based on this design method, we propose a short-distance acoustic detection system based on broadband ultraweak FBGs assisted phase-sensitive optical time domain reflectometry ( $\Phi $ -OTDR), and assess the system’s ability to detect pipeline leakages. This work not only provides guidance for the design of FBG sensing systems but also provides a new promising scheme for the application of DOFS system in nuclear environments.

Numerical and experimental study on leakage detection for buried gas pipelines based on distributed optical fiber acoustic wave

Buried natural gas pipeline leakage can cause severe environmental pollution and human casualties. The currently used fiber optic temperature sensors cannot detect pipeline leakage in all directions, and there are monitoring blind spots. Besides, there is a lack of field tests and verification of the acoustic characteristics caused by leakage. In this work, a sound wave attenuation model considering gas flow in viscous porous media is established based on the Φ-optical time-domain reflectometry (Φ-OTDR) principle, combined with fluid dynamics and acoustic wave propagation mode in porous media (soil). The attenuation characteristics of acoustic wave propagation in soil are studied by varying the leakage hole size and leakage pressure. It is found that the acoustic source of buried natural gas pipeline leakage belongs to broadband noise. The acoustic signals detected by optical fiber acoustic sensors are vary with different leakage holes and leakage pressures. In particular, the leaked acoustic wave’s energy is prominent in the low-frequency band of 15 kHz, and the sound pressure level (SPL) oscillates and attenuates with the increase in frequency. With the increase in the transmission distance, the amplitude of the pipeline leakage signal gradually attenuates. Eventually, the acoustic wave decays to the point where the fiber-optic acoustic sensor cannot detect it. The optimum frequency of acoustic wave propagation in soil is obtained through experimental research. The propagation characteristics of acoustic waves in the soil are not a fixed value. The simulation results are in good agreement with the experimental results, indicating that the SPL in the low-frequency band is significant for pipeline leakage monitoring. The above research results can provide valuable guidance for field optical fiber installation.