Browsing by Author "Fukuoka, Morio"
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- ItemCatalytic steam reformer tubes non-destructive inspection technology investigation and advancement : a dissertation presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Engineering at Massey University, Manawatu Campus, New Zealand(Massey University, 2018) Fukuoka, MorioCatalytic Steam reforming is a chemical synthesis process used in the production of hydrogen by mixing hydrocarbon with steam in the presence of a metal-based catalyst. This is achieved in a steam reformer plant where the mixture of gases is elevated to high pressure and temperature through a continuous process for efficient mass production of syngas to meet the global hydrogen demand. One of the challenges in operating a steam reformer plant is monitoring and maintaining the tubular reactors (Reformer tube). Under the severe service conditions the tubes a subjected to various degradation mechanism which ultimately determine the service life. With the tubes accounting to over 20% of the capital cost of a reformer plant, it is of great significance to maximise the service life of each tubes, which has been the motivation to the advancement in metallurgy and NDT technology around reformer tubes from the introduction of Catalytic Steam reforming in the early 20th century. Under the influence of long-term exposure of mechanical stressing and elevated temperature, reformer tube is subjected to a material degrading phenomenon call creep deformation. In 1952, F.R. Larson and J. Miller devised the Larson-Miller Parameter which predicts the lifetime of a material based on service temperature and stress-rupture time and for decades this method was used design and managed reformer tubes on a time-based strategy of 10,000 service hour. However, case studies have time and time shown premature rupture of reformer tube causing unexpected downtime resulting in significant loss in production and asset. Hence engineers and researchers have worked on a more direct method of assessing the remaining service life of reformer tubes. Inline pipe inspection is a hot area of research in robotics and automation. Eddy current, laser profilometry, ultrasonic and infrared thermography is the four technology that is currently dominating the Reformer industry, of which laser profilometry assessment being the only method capable of early stage creep detection. While other fields of pipe inspection have advanced and industrially applied over past decades, it is the author's opinion that NDT technology for reformer tube is outdated with areas of innovation. The aim of this research is to investigate an alternative solution to overcome the challenges and limited faced in modern systems and contribute to the advancement of NDT of Catalytic Steam reformer tubes. Presented in this dissertation is a new framework for an autonomous Reformer Tube inspection system, which incorporates a number of innovative elements for improved creep damage assessment. The program for this work is comprised of three studies. In the first study, the challenges around process profilometry dataset is demonstrated, the limitation in the available methods is discussed, and the impacts in regards to detection creep deformation is identified. Based on the finding, a three-stage creep detection algorithm (CDA) is derived, offering a dynamic solution to distinguish two modes of isotropic and anisotropic creep deformation. The system is experimentally assessed using a set of profilometry measurements collected from retire reformer tube. In the second study, a novel method for tracking a motion of an object moving inside a reformer tube is devised. Literature study showed that conventional profilometry system suffers from measurement uncertainty cause from an uncontrolled rotation of measurement instruction during an inspection. Because location information gives valuable insight as to the performance of the plant, the long-range optic solution is conceptualised, based on polarising filters and Malus Law, to overcome these limitations. In this research, a proof of concept experiment is conducted to evaluate and justify the conceptual method through the development of a working prototype. This novel technique is named Optical Position Tracking (OPT) system. Presented in the final study is an autonomous reformer tube inspection system developed on the basis of the results and finding in the first portion of the research. The contribution of this research is demonstrated with a working prototype justifying the practicality of CDA and the OPT system. The design incorporates wireless communication, modular design, and modern semiconductor sensing technology. In conclusion, this research met the first milestone for an ongoing research to progress the NTD industry.
- ItemReformer tube internal diameter measuring system : a thesis in the partial fulfilment of the requirements for the degree of Master of Engineering in Mechatronics at Massey University, Turitea Campus, Palmerston North, New Zealand(Massey University, 2010) Fukuoka, MorioA Reformer Tube is a device used in chemical engineering, commonly in the fuel cell technology, used to perform chemical reactions to produce chemicals products. Commonly the process involves heating the introduced chemicals in the tube to ultra-high temperatures at pressures around 20 bars encouraging rapid reactions. Reformer tube construction is described within which both the desired endothermic catalysed chemical reaction and heat transfer from the reaction products to the incoming reactants are accomplished [10]. The service life of these devices is primary ended when Creeps Shear damage is detected. Due to the complex combination of multiple factors between temperature, stress and aggressive environment during service influencing the generation of Creep damage, it is of significant benefit for process companies using condition-based assessment rather than time-based estimation to judge the retirement of reformer tubes. The aim of this research is to investigate a low-cost, mechatronic reformer tube inspection system that can replace the conventional expensive laser based system employed by New Zealand Methanex Ltd. The system must be a non-destructive examination (NDT) instrument capable of making a full inspection of a vertically standing, 110mm bore, 14m reformer tube within 5 minutes duration. Specification requirements set by the company state that the new system must be able to make measurement of at least 2 diametrical axes at axial increments of 25mm. The measurements are to be of 0.5mm accuracy or better. The nature of the tube stands to handle processing of Methanol stored at temperature of 500 degrees Celsius, gathering internal pressure of up to 20 bars. Due the cyclic repetition of these thermal and pressure changes, the tube will overtime result in internal cavity adaption causing tube failure through Creeping Shear. The device will be used to inspect the internal diameter change caused by creep damage and thus forecast the remaining service life of the tubes to help schedule the retirement of the reformer tubes at the most efficient timing.The project commended with a research investigating the variety of reformer tube inspection techniques available for modern furnaces and reviewed the application methodologies and limitations. Based on the findings, the project proceeded to develop a low cost, mechanical reformer tube inspection system. The new system is branded Reformer Tube Internal Diameter Measuring (RTIDM) system. In the final part of this research, field testing was conducted at the Methanex Ltd furnace to examine the RTIDM systems performance. Analysis performed on the collected data from the field test revealed that the RTIDM system is a working system capable of making diametrical measurement at the precision of +/-0.1668mm. Documented in this thesis is an in-depth discussion on the development of the Reformer Tube Internal Diameter Measuring (FTIDM) system. Conclusively, the RTIDM system developed in this research provided new method for reformer tube inspection. With the cost of the prototype is under $2000 NZD, the design is a much cost friendly instrument compared with its rival devices while capable of making diametrical inspection at competitive precision and accuracy.