Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores. Área de Especialização de Energia. Faculdade de Engenharia. Universidade do Porto. 2012

The management of equipment based on Reliability-Centered Maintenance (RCM) has been widely applied with great success in several industries such as military, commodity production, civil airliners, nuclear power plant and the petroleum industry since the reprint of RCM-II written by John Moubray in 1997.The application of RCM not only increases the reliability of the equipment and the assets of a company but also promotes the overall equipment effectiveness (OEE), which includes the excellent ok yield to order and the better productivity of the equipment. As a methodology, RCM differs from the traditional equipment maintenance in the aspect of emphasis of maintaining the ¡§function¡¨ of the equipment instead of the equipment itself. Therefore, the need of equipment maintenance results from the speed and the severity of function loss, which determines the strategy and interval of equipment maintenance. This is the major difference between RCM and time based maintenance (TBM). This article discusses the critical success factors that drive the application of RCM in steel plant. The result reveals that the application of RCM could promote the reliability of equipment, cut the cost of maintenance and increase compatibility of the steel plant. In order to facilitates the implementation of RCM in the steel mill, the basic skills of the management includes the construction of vision¡Bconsensus¡Bthe set up of regulation and the cultivation of innovating culture. so as to build an effective managing teamwork features in strong execution. As for the equipment management both the standardization and the strict deviation of equipment function(6£m) are vital to sustain the excellent equipment reliability. The Integration of Maintenance Management System(IMMS) consists of three components, CMMS(Computerized Maintenance Management System) and RTMS(Real Time Monitoring System) link by RCM. RCM acts as a bridge for the information flow of maintenance management in the IMMS and promotes the effectiveness of maintenance management.

This item contains the agenda, minutes, and attachments for the Faculty Senate meeting on this date. There may be additional materials from the meeting available at the Faculty Center.

Dans le cadre de la formation sélective d'oligomères cycliques à partir du cyclo-octène, des matériaux hybrides organiques-inorganiques mésostructurés bien-définis contenant les unités Ru-NHC dissymétriques le long des canaux poreux de leur matrice de silice ont été développés et caractérisés à un niveau moléculaire. Tous les systèmes obtenus ont montré des fortes activités et sélectivités en oligomères cycliques (dimères : 50% et trimères : 25%) en RO-RCM du cyclo-octène, contrairement aux complexes homogènes Ru-NHC analogues symétriques (G-II et GH-II), qui conduisent préférentiellement à la formation de polymères. La variation de la longueur et de la flexibilité des bras espaceurs, dans le cas des catalyseurs hétérogènes, a prouvé que les bras courts et flexibles stabilisent grandement les sites actifs Ru-NHC pendant la réaction de métathèse et ce, grâce à la présence d'interactions entre les sites Ru-NHC catalytiquement actifs et la surface silicique. La présence de telles interactions a été mise en évidence par RMN du phosphore 31 à l'état solide. Des études supplémentaires concernant les performances catalytiques de complexes organométalliques Ru-NHC dissymétriques (analogues aux sites Ru-NHC contenus dans les catalyseurs hétérogènes) et Ru-NHC symétriques (G-II et Nolan) ont clairement montré que le facteur clé influençant la sélectivité en oligomères cycliques est la dissymétrie des ligands NHC. Cette dissymétrie génère la présence de deux sites actifs de configurations différentes au sein même des espèces Ru-NHC. Un des sites favorise la réaction intramoléculaire de fermeture de cycle par métathèse alors que l'autre site permet la réaction intermoléculaire d'ouverture de cycle conduisant ainsi à la formation des oligomères cycliques de petite taille / In the context of the selective formation of cyclic oligomers from cyclooctene, well-defined hybrid organic-inorganic mesoporous materials containing unsymmetrical Ru-NHC units along the pore channel of their silica matrix have been developed and characterized at a molecular level. All systems displayed high activity and selectivity towards the formation of lower cyclic oligomers in the RO-RCM of cyclooctene yielding mainly the dimer and the trimer with 50% and 25% selectivity, respectively, in contrast to classical symmetrical homogeneous analogues (G-II and GH-II), which yield mainly to polymers. Variation of length and flexibility of the tethers showed that flexible short tethers were critical for high stability of the catalysts during metathesis, which is consistent with the stabilization of Ru-NHC active sites by surface functionalities; this surface interaction was further corroborated by the absence of a PCy3 ligand coordinated to Ru when short flexible linkers are used. Further investigations using homogeneous symmetrical (G-II and Nolan) and unsymmetrical (analogues to heterogeneous catalysts) Ru-NHC catalysts clearly showed that the key factor influencing the selectivity towards low cyclic oligomers is the unsymmetrical nature of NHC ligands, which creates dual site configuration in the catalyst architecture thus alternatively favouring one reaction over another, Ring Opening (ROM) vs. Ring Closing (RCM) Metathesis (propagation vs. backbiting), thus leading to the selective tandem RO RCM of cyclooctene. Finally, we have also investigated Grubbs Hoveyda-II (GH-II) type catalysts immobilized on silica support through adsorption, which showed the same product selectivity as that of the well-defined Ru-NHC materials. This result implies that the adsorbed symmetrical GH-II catalyst “becomes unsymmetrical upon adsorption”. Adsorbing unsymmetrical molecular GH II catalysts did not however improve the performances of these types of catalysts. Overall, the unique property of unsymmetrical NHC Ru catalyst, whether supported or not, opens new perspectives in the selective synthesis of macrocycles from other cyclic alkenes via metathesis

El presente trabajo tiene como objetivo implementar un modelo de gestión de mantenimiento para mejorar la disponibilidad en equipos subterráneos en una empresa de mediana minería en Ayacucho-Perú, utilizando los principios del RCM, fundamentado en un diagnóstico objetiva utilizando herramientas y técnicas de ingeniería industrial como el diagrama de Pareto y el diagrama causa efecto, donde el problema principal se enfocó en la flota Scoop donde se evidencia una disponibilidad del 77%, y el costo anual de $ 1.236.239,00 por mantenimiento. Todo esto conllevo a estructurar una solución a esta problemática fundamentada en la hipótesis obtenida, en el cual se identificó que el problema se generaba a interrupción frecuente en el suministro de la energía necesaria para la operatividad del equipo, interrupción en el suministro de la potencia a las ruedas y la movilidad continua del equipo para su operatividad, y afección a las características tanto internas como externas del equipo, motivo por el cual, con la finalidad de gestionar los problemas identificados se emplearán técnicas y herramientas de ingeniería: AMEF y la implementación del RCM. Las cuales se integrarán en modelo y para su validación, se utilizarán los artículos científicos, los cuales demuestran que dichas herramientas son eficaces alrededor del mundo. Finalmente, se concluye que la metodología RCM propuesta, se constituye como una solución válida, luego de la simulación con el software Arena se identificó un incremento de la disponibilidad del 77% al 83%. Mismo incremento que se ha influido positivamente en otros indicadores de mantenimiento como es el caso del tiempo medio entre fallas (MTTF) que se incrementó de 56 horas a 83 horas, a diferencia del tiempo medio para la reparación (MTTR) que sufrió una reducción de 13 horas/avería a 9 horas/ avería y que también ha conllevado a un incremento de 12,630.62 toneladas en la cantidad de mineral extraído. / The present work has as objective to implement a model of maintenance management to improve the availability of underground equipment for a company of medium mining in Ayacucho-Peru, using the principles of RCM, based on a diagnostic objective using tools and techniques of industrial engineering as the Pareto diagram and the diagram cause-effect, where the main problem is focused on the fleet Scoop where there is evidence of the availability of 77%, and the annual cost of $ 1.236.239,00 for maintenance. All this entails structuring a solution to this problem based on the hypothesis obtained, in which it was identified that the problem was generated by a frequent interruption in the supply of the energy necessary for the operation of the equipment, interruption in the supply of power to the wheels and the continuous mobility of the equipment for its operation, and affect the internal and external characteristics of the equipment, the reason why in order to manage the identified problems will be used engineering techniques and tools: AMEF and the implementation of the RCM. Which will be integrated into the model and for validation, scientific articles will be used, which demonstrate that these tools are effective around the world. Finally, it is concluded that the proposed RCM methodology is constituted as a valid solution, after the simulation with the Arena software, and an increase in availability from 77% to 83% was identified. Same increase that has been positively influenced by other maintenance indicators such as the average time between failures (MTTF) that increased from 56 hours to 83 hours, unlike the average time for repair (MTTR) that suffered a reduction of 13 hours/breakdown to 9 hours/ breakdown and that has also led to an increase of 12,630.62 tons in the amount of mineral extracted. / Trabajo de Suficiencia Profesional

This diploma thesis deals with the maintenance and diagnostic failure conditions for machine tools. It is focused on the selection of appropriate methods of technical diagnostic state for machine tools in company SMC Vyškov. As part of the system design and proactive maintenance measurement methodology machine tools.

Change from a regulated to deregulated structure means that, the centralized maintenance system is not valid any more. In the surveyed published literature, there is not a single model which incorporates all maintenance cost components to analyze the effect of different maintenance strategies for generator companies (GENCOs). The work enclosed in this thesis demonstrates that there is a considerable requirement for accurately modelling cost components of the maintenance model, to be used in maintenance scheduling for deregulated power system, in order to attain a superior schedule with major financial and operational impact. This research investigates and models most cost factors that affect the maintenance activities of the deregulated GENCOs, and demonstrates the utilization of the developed cost models in maintenance scheduling. It also presents the data gathering process for the developed maintenance cost model. A generator maintenance scheduling model that considers direct and indirect maintenance costs, opportunity costs (i.e. loss of customer goodwill), effective maintenance strategies, failures, and interruptions is developed. A Genetic Algorithm (GA) based approach is employed to achieve maintenance schedules to various generators maintenance scenarios. An Analytical Hierarchy Process (AHP) approach is proposed for modelling customer goodwill. The maintenance model was redeveloped under the Reliability Centred Maintenance (RCM) strategy to analyze the effect of a maintenance strategy on maintenance costs. Case studies are presented to demonstrate the utilisation of the developed models.The investigation shows that the market prices, opportunity costs and maintenance strategy have an effect on the final maintenance schedule. The research demonstrates that the cost components are critical factors to achieve an effective maintenance schedule, and they must be considered and carefully modelled in order to reflect more realistic situation for maintenance scheduling of generator units in deregulation environment.

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Asset management is getting increasingly important in nearly all fields, especially inthe electric power engineering. It is mainly due to the following two reasons. First isthe high investment cost include the design cost, construction cost, equipment costand the high maintenance cost. Another reason is that there is always a high penaltyfee for the system operator if an interruption happened in the system. Besides, due tothe deregulation of electricity market in these years, the electricity utilities are payingmore attentions to the investment and maintenance cost. And one of their main goalsis to maximize the maintenance performance. So the challenge for the systems is toprovide high-reliability power to the customs and meanwhile be cost-effective for thesuppliers. Reliability Centered Asset Management (RCAM) is one of the bestmethods to solve this problem.The basic RCAM method is introduced first in this thesis. The model includes themaintenance strategy definition, the maintenance cost calculation and an optimizationmodel. Based on the basic model some improvements are added and a new model isproposed. The improvements include the new improvement maintenance strategy,increasing failure rate and a new objective function. The new model is also able toprovide a time-based maintenance plan.The simulation is done to a Swedish distribution system-Birka system by GAMS. Theresults and a sensitivity analysis is presented. A maintenance strategy for 58components and in 120 months is finally found. The impact on the changing failurerate is also shown for the whole peroid. / Kapitalförvaltning har inom alla områdem blivit allt viktigare, speciellt inomelkraftsteknik. Det beror i huvudsak av två orsaker. Den första är storinvesteringskostnad, vilket inkluderar design, konstruktion, utrustning och underhåll.Den andra är den höga straffavgiften för system operatören vid elavbrott. Dessutom,på grund av den nyligen avreglerade elmarknaden, så fäster elföretagen meruppmärksamhet på investerings och underhållskostnader. En av deras huvudmål är attmaximera underhållsprestandan. Så utmaningen för operatörerna är att levereratillförlitlig elkraft till kunder, samtidigt vara kostnadseffektiva mot leveratörer.Reliability Centered Asset Management (RCAM) är bland de bästa metoderna för attlösa detta problem. En enklare RCAM metod är introducerad först i denna rapport.Modellen inkluderar en underhållsstrategi-definition, underhållskostnad-kalkyl och enIIoptimiserings modell. Grundad på denna enklare modell, andra förbättringar ärtillagda och en ny modell är föreslagen. Förbättringarna inrymmer en nyunderhållsstrategi, ökad felfrekvens och en ny målfunktion. Den nya modellentillhandahåller också en tidsbaserad underhållsplan.