Visualization of Gas–Oil–Water Flow in Horizontal Pipeline Using Dual-Modality Electrical Tomographic Systems

Employing dual-modality tomography inherently involves data from multiple dimensions, and thus a coherent approach is required to fully exploit the information from various dimensions. This paper describes a novel approach for dual-modality electrical resistance and capacitance tomography (ERT-ECT) to visualize gas-oil-water flow in horizontal pipeline. Compared with the conventional methods with dual-modality tomographic systems, the approach based on thresholding takes the account of multi-dimensional data, which therefore is capable of providing insights into investigated flow in both spatial and temporal terms. The experimental results demonstrate the feasibility of the approach, by which six common flow regimes in horizontal pipeline flow are visualized based on the multi-dimensional data with ERT-ECT systems, including (wavy) stratified flow, plug flow, slug flow, annular flow, and bubbly flow. Although the present approach is proposed for data acquired with an ERT-ECT system, it is potentially adaptable to other dual-modality tomographic systems that use concentration tomograms as inputs

Image Reconstruction for Solid Profile Measurement in ERT using Non-invasive Approach

Image reconstruction software and its image reconstruction algorithm are an important step towards constructing a tomography system. This paper demonstrates an image reconstruction of solid profile using linear back projection (LBP) algorithm and global threshold. A forward problem and inverse problem are discussed. The modelled of sensitivity distributions using COMSOL proved that the system is able to detect the liquid-solid regime in vertical pipe. Additionally, the location of the phantom can be easily distinguished using LBP algorithm and thresholding technique. The simulations and experiments results indicate that the sensitivity distribution of non-invasive ERT system can be applied in getting a tomogram of the medium of interest

Development of Foreign Material Detection in Food Sensor Using Electrical Resistance Technique

Food inspection has been a serious matter in the food industry as the contamination by foreign materials such as metals, bone, plastics and glass in food plays a major impact on the industry. In spite of a great deal of effort to prevent mixing foreign bodies in food materials, food manufacturers have still not been able to detect them. Electrical Resistance Sensor to detect the foreign material in food detection sensor is constructed and presented in this work. This project focuses on how to design and implement the system to detect and distinguish between food and foreign material using resistance concept. The electrode plate of Electrical Resistance Sensor (ERS) is designed using COMSOL Multiphysics Software to see the electric field and contour of the electric potential of the system. The resistance value from the sensor is measured based on the AC Circuit concept. The alternating current from the sensor flows to the charge detector circuit providing the voltage corresponding to the resistance between the electrode pair. The voltage from the charge detector circuit has been amplified by the amplifier circuit to obtained DC output from an AC input signal. The voltage form circuit has been converted from the analog to digital signal using Bluetooth Electronics Application via Arduino Uno through HC-05 Bluetooth module. The Bluetooth Electronics Application is used as a graphical user interface (GUI) to display the condition of the material tested including food and foreign material to a smartphone.  The experiment results show that the electrical resistance sensor are able to detect the foreign material in food by changes of the resistance value. If the food was detected with the foreign material (non-conductive), the value of resistance will decrease due to the flow of electric current

Image reconstruction for solid profile measurement in ERT using non-invasive approach

Image reconstruction software and its image reconstruction algorithm are an important step towards constructing a tomography system. This paper demonstrates an image reconstruction of solid profile using linear back projection (LBP) algorithm and global threshold. A forward problem and inverse problem are discussed. The modelled of sensitivity distributions using COMSOL proved that the system is able to detect the liquid-solid regime in vertical pipe. Additionally, the location of the phantom can be easily distinguished using LBP algorithm and thresholding technique. The simulations and experiments results indicate that the sensitivity distribution of non-invasive ERT system can be applied in getting a tomogram of the medium of interest

Capability of dual-modality electrical tomography for gas-oil-water three-phase pipeline flow visualisation

Numerous dual-modality tomography systems have previously been studied for multiphase flow characterisation, however, the capability of the majority of these systems was only demonstrated under limited flow regime conditions, such as stratified flow and slug flow. This paper reports a dual-modality electrical tomography for visualisation of industrial-scale, horizontal gas-oil-water three-phase flows. Experimental conditions include water-to-liquid ratio (WLR) from 0% to 100% in parallel with gas volume fractions (GVF) from 0% to 100%, which produced a variety of flow patterns, typically stratified flow, slug flow, plug flow, bubbly flow, and annular flow. A commercial dual-modality electrical tomographic system was utilised to carry out the measurement. A threshold-based data fusion method was also deployed for the fusion of oil-continuous and water-continuous data to provide full three phase images. The tomography visualisation is validated against optical photographs derived from a high-speed video logger located one diameter upstream of the device. The results demonstrate that a subcomponent of the dual modality sensor, an electrical resistance tomography (ERT) system, is able to visualise water continuous flow with WLR higher than 40%, providing good agreement with previous reports. The remaining subcomponent, the electrical capacitance tomography (ECT) system, is able to provide stable measurement during WLR from 0% to 90%, which is far beyond initial expectations and previous findings. Mean concentrations measured with the dual-modality system reveal the potential capability of the tomography system for phase fraction measurement. The visualisation results with the advanced data fusion method and mean concentration measurement verify the capability of the system in the application of gas-oil-water flow characterisation

Fuzzy Logic Based Multi-Dimensional Image Fusion for Gas–Oil-Water Flows With Dual-Modality Electrical Tomography

This paper proposes a novel approach, whereby fuzzy logic and decision tree are utilized to overcome the challenges in analyzing images of gas–oil–water pipeline flow obtained using electrical resistance and capacitance dual-modality tomography. The first approach generates two axially stacked concentration images from two stacks of the cross-sectional concentration tomograms reconstructed from different modalities, respectively, and then registers two generated images in temporal and spatial terms. Afterward, a fuzzy logic method is applied to perform a pixel-level fusion to integrate the registered images based on the characteristics of electrical tomograms for multiphase pipeline flow. Later, a decision tree is utilized to derive the local concentration of each individual phase according to the fusion results. Using the data from real industrial cases, both feasibility and robustness of the proposed approach are demonstrated. In addition, the proposed approach also overcomes the limitations of conventional threshold-based methods on the request of a priori knowledge for the qualitative and quantitative analyses of gas–oil–water pipeline flow

2 mhz electrical resistance tomography for static liquid- solid profile measurement

Tomography is a technique used to reconstruct cross-sectional image of a pipeline for flow monitoring applications. There are several types of tomography system such as X-ray tomography, ultrasonic tomography, and electrical resistance tomography (ERT). ERT has many advantages compared to other types of tomography such as low cost, robust and no radiation. Thus, it becomes particularly suitable for industrial applications. However, it has been observed that the conventional practice of ERT through invasive sensing technique has exposed the ERT metal sensor to corrosion and limited its application because of inaccurate measurement of the data. Consequently, non-invasive ERT has also been introduced in low frequency (in kHz) applied to the ERT system. The low frequency ERT makes use of the phase-sensitive demodulation (PSD) approach and is a complicated technique to implement. Hence, the goal of this research is to design and develop a non-invasive ERT system with a high frequency (2 MHz) source. A total impedance of coupling capacitances (between metal electrode and conductive medium) series with resistance (conductive medium) for each pair of electrodes was assumed in the research. Based on the mathematical equation of the total impedance, the real part is the resistance (conductive medium) must be larger than the imaginary part (capacitances), so that it can easily detect the concentration profile of the conductive medium. Therefore, the minimum frequency needed to ensure that the real part is bigger than the imaginary one is 2 MHz. Simultaneously, the independent and flexible sixteen ERT electrodes designed for the system make it easier to replace and troubleshoot any problems with the sensor. In addition, the experiment was carried out on a two-phase static liquid–solid regime for a linear back-projection algorithm using online configuration, with MATLAB as a software platform. It was also able to detect and visualize the non-homogenous system of the two-phase regime. Later, the reconstructed image was improved using a global threshold technique through offline configuration. The experiment results indicate that it could detect obstacles in a vertical pipe with minimum 12 mm in diameter and 4.5 cm in height