The process industry is concerned with the processing of crude resources into other products. Such crudes consist of multiphase components that introduce major challenges to the operators; hence the need for efficient instrumentations that address such challenges is highly desirable. One major need is an early deposit detection system that detects deposit before it builds-up in a pipeline or equipment to prevent any possible hazard. Another critical requirement is the need to continuously monitor the flow and deduce the flow rate of every individual phase in order to study and analyse the produced product. Hence, in order to ensure safety, increase profits, optimize production and ensure production quality, the multiphase flow must be adequately monitored and controlled. This thesis demonstrated the efficiency of novel ECT algorithms for early deposit detection and multiphase flow measurement in order to measure the flow rate of all separate phases. This thesis focuses on developments in ECT image reconstruction specifically the inverse solutions and is divided into three main studies where they all build up to complete each other. In the first study, ECT is used for the first time with a narrowband pass filter to focus on targeted locations in a pipe where dielectric contaminants are expected to deposit in order to enhance the resolution of the produced images. The experimental results showed that different deposit regimes and accumulated fine deposits could be detected with high resolution. The second study allowed a better understanding of how conductive material could be imaged using a conventional ECT device and how state of the art algorithms such as iterative total variation regularisation method and the level set method could enhance this application. Also, absolute ECT imaging is presented for the first time where the level set algorithm uses only one set of ECT measurement data. This study gives a novel solution for detecting conductive deposits as well as paves the way to use the new level set algorithm for multiphase flow measurement. In the third study, the novel narrowband level set algorithm was modified to image multiphase media in order to correctly determine the number, location and concentration of the present phases. The innovative absolute ECT imaging using level set method is tested with high contrast and low contrast multiphase data, which adds more to the challenge.
|Date of Award||23 Nov 2016|
|Supervisor||Manuchehr Soleimani (Supervisor)|
- Electrical capacitance tomography
- multiphase flow
- level set
- image reconstruction