Dissertations / Theses on the topic 'Plant Maintenance and Operation'

In recent years the electric power industry has been challenged by a high level of uncertainty and volatility brought on by deregulation and globalization. A power producer must minimize the life cycle cost while meeting stringent safety and regulatory requirements and fulfilling customer demand for high reliability. Therefore, to achieve true system excellence, a more sophisticated system-level decision-making process with a more accurate forecasting support system to manage diverse and often widely dispersed generation units as a single, easily scaled and deployed fleet system in order to fully utilize the critical assets of a power producer has been created as a response. The process takes into account the time horizon for each of the major decision actions taken in a power plant and develops methods for information sharing between them. These decisions are highly interrelated and no optimal operation can be achieved without sharing information in the overall process. The process includes a forecasting system to provide information for planning for uncertainty. A new forecasting method is proposed, which utilizes a synergy of several modeling techniques properly combined at different time-scales of the forecasting objects. It can not only take advantages of the abundant historical data but also take into account the impact of pertinent driving forces from the external business environment to achieve more accurate forecasting results. Then block bootstrap is utilized to measure the bias in the estimate of the expected life cycle cost which will actually be needed to drive the business for a power plant in the long run. Finally, scenario analysis is used to provide a composite picture of future developments for decision making or strategic planning. The decision-making process is applied to a typical power producer chosen to represent challenging customer demand during high-demand periods. The process enhances system excellence by providing more accurate market information, evaluating the impact of external business environment, and considering cross-scale interactions between decision actions. Along with this process, system operation strategies, maintenance schedules, and capacity expansion plans that guide the operation of the power plant are optimally identified, and the total life cycle costs are estimated.

The deregulation of the electric power market introduced a strong element of competition. Power plant operators strive to develop advanced operational strategies to maximize the profitability in the dynamic electric power market. New methodologies for gas turbine power plant operational modeling and optimization are needed for power plant operation to enhance operational decision making, and therefore to maximize power plant profitability by reducing operations and maintenance cost and increasing revenue. In this study, a profit based, lifecycle oriented, and unit specific methodology for gas turbine based power plant operational modeling was developed, with the power plant performance, reliability, maintenance, and market dynamics considered simultaneously. The generic methodology is applicable for a variety of optimization problems, and several applications for operational optimization were implemented using this method. A multiple time-scale method was developed for gas turbine power plants long term generation scheduling. This multiple time-scale approach allows combining the detailed granularity of the day-to-day operations with global (seasonal) trends, while keeping the resulting optimization model relatively compact. Using the multiple timescale optimization method, a profit based outage departure planning method was developed, and the key factors for this profit based approach include power plant aging, performance degradation, reliability deterioration, and the energy market dynamics. A novel approach for gas turbine based power plant sequential preventive maintenance scheduling was also introduced. Finally, methods to evaluate the impact of upgrade packages on gas turbine power plant performance, reliability, and economics were developed, and TIES methodology was applied for effective evaluation and selection of gas turbine power plant upgrade packages.

Management system for enhancing transfer of knowledge in wind power industry has not received sufficient research attention in recent times. In some cases, the wind power plant owner does not control the management system for operation and maintenance activities. Most of these wind power plants are under contract and rely upon the turbine vendor to perform most of the maintenance works and subsequently share their experience at the initial stage of operation. This research investigates the management system for the operations and maintenance activities of the offshore wind plant in Lillgrund. The research also explores the type of learning method that was adopted by the wind turbine vendor (Siemens) to transfer the operation and maintenance knowledge to the operator and owner (Vattenfall) within the speculated period. It was realized that in the next one year, the Vattenfall would be in full control of the operations and maintenance activities of the offshore wind power plant in Lillgrund. The co-management arrangement will give Siemens a good reputation and gainful experience in the wind power industry. The arrangement is achievable due to Siemens strategy to strive for constructive and long-standing relationships with their customer, based on trust, respect, and honesty. Vattenfall on the other hand, is aiming to be the partner of choice for their suppliers at the same time as best serving their internal customers. The provision for the training during the co-management period enables Siemens to strengthen their relationship with Vattenfall in this industry. In addition, Siemens also maintain close relationship with their customers and develop a large part of their portfolio, frequently on site. Vattenfall improves profitability and value creation, as a fundamental prerequisite for continued growth. The management systems of Vattenfall can be related to professional bureaucracy, this is due to the fact that it was organized to accommodate Siemens experts. Vattenfall benefits from the co-management activities of the operation and maintenance of the Lillgrund wind power plant for a specific period of time. The outcome of the research work has proven that there is an effective time-dependent proportionality for a gradual transfer of the technical knowledge of operation and maintenance from Siemens Wind AB to the Vattenfall personnel. The research started from the perspective of the maintenance method by Swedish standard for wind power, and the way things are being carried out in a more practical way in Lillgrund plant.

Els Sistemes d'Aiguamolls Construïts (SAC) de Flux Subsuperficial Horitzontal (FSH) és una tecnologia apropiada pel sanejament d'aigües residuals procedents de nuclis de població petits. No obstant els SAC de FSH són considerats una tecnologia natural, l'operació i manteniment d'aquestes depuradores és crucial per a garantir el seu correcte funcionament. Aquestes necessitats d'operació i manteniment varien entre depuradores segons (1) les característiques de la comunitat, (2) la configuració de la depuradora i el disseny del SAC de FSH i (3) les característiques del medi receptor. En aquest sentit, en aquesta tesi es presenta el desenvolupament d'un Sistema d'Ajuda a la Decisió (SAD) per a la definició de protocols d'operació i manteniment per a SAC de FSH tenint en compte els factors que causen variabilitat entre aquest tipus de depuradores (1, 2 i 3).
Horizontal Subsurface Constructed Wetlands (HSCW) is an appropriate technology to treat wastewater coming from small communities. Despite HSCW is considered a natural technology, operation and maintenance are crucial to guarantee their performance. These necessities vary according to (1) the characteristics of the community, (2) the wastewater treatment plant configuration and the HSCW design and (3) the characteristics of the receiving media. In this sense, the this thesis presents the development of an Environmental Decision Support System (EDSS) to asses the definition of operation and maintenance protocols for HSCW taking into account the aspects that cause variability among these facilities (1, 2 and 3).

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1999.
Includes bibliographical references (leaves 167-168).
Investigations of unplanned shutdowns at the Seabrook and the Pilgrim Nuclear Power Stations were carried out to improve the understanding of the cause of those events, which had been reported in Boston newspapers. Failures of turbine-generator systems and nuclear steam supply systems reduced plant reliability, while failures of safety-related systems did not. Risk analysis with fault tree modeling was carried out to quantify risk of major components in turbine-generator systems, and in nuclear steam supply systems. The risk was evaluated in terms of the frequency of unplanned shutdowns in order to identify which components are important to plant reliability, As a result, feedwater pumps, major valves installed on main steam lines, the chemical and volume control system, and switchyards are identified as risk significant components, Other equipment was also ranked according to their respective risk significance, Uncertainty analysis for failure rates of components was carried out using Monte Carlo approach to compare the result of fault tree analyses with historical data. Taking uncertainty into consideration, the analytical data and the historical data showed good agreement in regard to reliability over different time spans of operation, Maintenance practices for major components at the Seabrook Nuclear Power Station was investigated in order to correlate this practice and the components I risk significance. Some components, such as Feedwater Pumps and Main Steam Isolation Valves, are maintained by the condition-based methods; however, because they have high risk significance in terms of plant shutdowns, preventive maintenance is preferable for these components.
by Kenichi Tezuka.
S.M.

According to Oliver (2002) the success of turnaround maintenances is measured in terms of the cost of completion, time, safety performance and the performance of the plant afterwards. The Escravos gas plant (EGP) is a gas processing plant that converts associated gas from Chevron owned crude oil wells to liquefied petroleum gas, natural gas and gas condensate (Chevron intranet. Website assessed on September 14, 2007). According to the EGP plant operations coordinator (See interview Appendix A), the plant undergoes a turnaround maintenance exercise once every two years. The major tasks done during these turnaround maintenances are 1. Change–out of three molecular sieve beds. 2. Servicing of three compressor turbines. 3. Servicing of expander turbo–machinery. 4. Clean–out of fired gas heater tubes and burners. 5. Tie–ins for major upgrades. The EGP management does not involve the contractor personnel that carry out the tasks in the management of the turnaround maintenance. The contractor’s personnel simply follow the work plans and instructions developed by the EGP management. The EGP turnaround management team consists of the coordinator who is the head of the turnaround maintenance team, shift supervisors, maintenance supervisors (rotating equipment maintenance supervisor, instrumentation and electrical maintenance supervisor, and static equipment maintenance supervisors), safety supervisors, maintenance planners, process engineers and construction supervisors. All these listed personnel in the preceding paragraph and the supervisors of the contractor teams participate in the pre–turnaround meetings which happen once a month for the first 10 months of the 12 months leading to the turnaround. The meeting frequency increases to once every two weeks during the last two months leading to the turnaround maintenance. The meeting is held daily during the turnaround maintenance and once every two weeks for the first month after the turnaround maintenance. During the preceding months to the turnaround maintenance, the work scope is defined, the job sequence outlined and schedules are developed. Resources requirements are detailed and procured. During the turnaround maintenance the focus of the turnaround meeting is to discuss potential deviations, observe at–risk behaviors and likely challenges. Plans are then made to address these deviations, challenges and at–risk behaviors. After the turnaround maintenance, “lessons learnt” are captured and the turnaround maintenance is closed out. According to the EGP coordinator (see interview in appendix A), the success of its turnaround maintenance is measured by the time used to complete the turnaround maintenance, the total recordable incident rate during the turnaround maintenance, the days away from work, the lost time injury(LTI) and the cost incurred. Poling et al noted that it is difficult to rate turnaround maintenance projects because no two turnaround maintenances strategies are exactly the same. They iterated that the most common tactics used is benchmarking and that benchmarking enables a company to measure and compare its performance against peer companies in a constructive and confidential manner. They pointed out that the quantitative differences computed between a plant and other similar plants using detailed data taxonomy can provide invaluable information regarding improvement opportunities. This is a way of effectively extending a “lessons learned” exercise across multiple companies. According to then however a critical attribute of effective reliability and maintenance benchmarking is the ability to compare disparate assets; but even small differences for similar plants can alter the value of the comparison. Existing literature indicate that the parameters the gas plant management use to rate the safety of its turnaround maintenance (i.e. the total recordable incident rate, the days away from work and the lost time injury)are reactive in nature. They are otherwise called lagging indicators. Lagging indicators are safety performance metrics that are recorded after the accident or incidents has occurred. For example lost time injury is any work related injury or illness which prevents that person from doing any work day after accident (E&P Consultancy Associates. Website assessed on June 15, 2009). In contrast the other group of metrics called pro–active metrics or leading indicators such as at–risk behaviors, near misses and preventive maintenance not completed are parameters that measure safety performance before accident occurs. Leading indicators gained popularity in the 1930’s after Heinrich postulate his iceberg theory (Wright, 2004). Heinrich’s used the iceberg analogy to explain reactive (lagging) and proactive (leading) indicators. Heinrich likened accident and at–risk behaviors to two parts of an Iceberg; the part you see above water and the part hidden under the water. The size of the iceberg above water is relatively small compared to that under water. The iceberg starts to grow under the water and only after they reach a certain size does part of the ice begin to appear above water. Heinrich believed that accidents are the result of root causes such as at–risk behaviors, inconsistencies, wrong policies, lack of training and lack of information. When the number of accidents that occur in an endeavor is measured you get relatively smaller numerical quantities when compared to the number of at–risk behaviors. Heinrich suggested that to eliminate accidents that occur infrequently, organizations must make effort to eliminate the root causes which occur very frequently. This makes sense because imagine a member of personnel coming to work intoxicated every day. Binging intoxicated at work is an at–risk behavior. The employee is very likely to be involved in an accident at some time as a result of his drinking habit. The number of times he is intoxicated if counted will be huge when compared to the impact of the accident when it does occur. The iceberg theory is supported by work from Bird (1980) and Ludwig (1980) who both attempted to establish the correct ratio of accidents to root causes in different industries. Heinrich suggested a ratio of three hundred incidents to twenty nine minor injuries to one major injury. This researcher chose to use the number of at–risk behavior exhibited by the turnaround maintenance teams to rate the safety performance of tasks despite criticism from individuals like Robotham (2004) who said that from his experience minor incidents do not have the potential to become major accidents and Wright et al (2004). Leading indicators are convenient to analysis because of their relative large quantity. In a turnaround environment, the numbers of accidents that occur are relatively few unlike the number of near misses (Bird, 1980). It is easy to statistically analyze thirty at–risk behaviors than four accidents. In addition Fleming et al (2001) noted that data from industry show much success by companies in the reduction of accidents by efforts at reducing the number of at–risk behaviors, increase the number of safety audits, and reduce the number of closed items from audits etc. Phimister et al made similar claims when they said Near miss programs improve corporate environmental, health and safety performance through the identification of near misses. Existing literature also reveals many theories about management styles and their possible impact on performance. The theories are grouped into trait theories, situational theories and behavioral theories. The trait theories tries to explain management styles by traits of the managers like initiative, wisdom, compassion and ambitious. Situational theories suggest that there is no best management style and managers will need to determine which management style best suit the situation. Behavioral theories explain management success by what successful managers do. Behavioral theorists identify autocratic, benevolent, consultative and participatory management styles. Vroom and Yetton (1973) identified variables that will determine the best management style for any given situation. The variables are; 1. Nature of the problem. Is it simple, hard, complex or clear? 2. Requirements for accuracy. What is the consequence of mistakes? 3. Acceptance of an initiative. Do you want people to use their initiative or not? 4. Time–constraints. How much time do we have to finish the task? 5. Cost constraints. Do we have enough or excess to achieve the objective? A decision model was developed by Vroom and Yago (1988)to help managers determine the best management style for different situations based on the variables listed above (See figure six). They also defined five management style could adopt, namely the; 1. Autocratic I style 2. Autocratic II style. 3. Consultative I style 4. Consultative II style 5. Group II style The autocratic I management style is a management style where the leader solves the problem alone using information that is readily available to him/her, is the normal management style of the Escravos gas plant management in all turnarounds prior to 2009. However the Vroom and Yago model recommends the Consultative II management style for the type of work done during the Escravos gas plant turnaround maintenance. According to Coye et al (1995), participatory management or consultative style II creates a sense of ownership in organization. In this management style the leader shares problem with group members individually, and asks for information and evaluation. Group members do not meet collectively, and leader makes decision alone (Vroom and Yago, 1988). Coye et al believe that this management styles instills a sense of pride and motivate employees to increase productivity. In addition they stated that employees who participate in the decisions of the organization feel like they are a part of a team with a common goal, and find their sense of self–esteem and creative fulfillment heightened. According to Filley et al (1961), Spector and Suttle did not find any significant difference in the output of employees under autocratic and participatory management style. This research studies if and how the Escravos gas plant turnaround maintenance can be improved by changing the management style from autocratic I style to consultative II style. Two tasks in the turnaround were studied; namely the change out of the molecular sieve catalyst beds and the servicing of the turbine engines. The turnaround contractor Techint Nigeria Limited divides the work group into teams responsible for specific tasks. Six teams (team A, B, C, D, E and F) were studied. EGP management will not allow the researcher to study more than these six teams for fear of the research disrupting the work. The tasks completed by these teams are amongst those not on the projects critical path so delays caused by the research will not impact the entire turnaround project provided the float on these activities were not exceeded. They also had the fewest number of personnel, so cost impact of the research work could be easier to manager. Teams A, B and C are different maintenance teams comprising of eight personnel each. They were responsible for changing the EGP molecular sieve beds A, B and C respectively in the 2007 and 2009 turnaround. Their tasks are identical because the molecular sieve beds are identical. Teams E, D and F are also maintenance teams comprising of six personnel each. They were responsible for servicing the EGP turbine engines A, B and C during the 2007 and 2009 turnaround maintenance. Their tasks are also identical because the turbine engines are identical. Consultative management style II is exercised by involving team A and team D in the development of the procedures, processes and job safety analysis of all tasks that they were assigned to complete during the 2009 turnaround maintenance. They were also permitted to participate in the turnaround maintenance meetings and to make contributions in the meetings. In the 2007 turnaround maintenance team A and team D only carried out their tasks. They did not participate in the development of procedures and job safety analysis neither did they participate in the turnaround maintenance meetings. The other four teams; team B, team C, team E and team F are used as experimental controls for the research. They did not participate in the development of the procedures, processes nor the job safety analysis for the tasks in either of the turnaround maintenance. They were also not permitted to attend the daily turnaround meetings. They only completed their tasks based on instructions given to them during the 2007 and 2009 turnaround maintenance. It was necessary to study the experimental control teams as the researcher was not sure whether task repetition, increased knowledge or improved team cohesion would lead to a reduced time or a reduced numbers of at–risk behavior. ix The research tested the hypothesis 1H0 and 1H1 and 2H0and 2H1 at the 0.025 and 0.05 level of significance as follows; Null hypothesis, 1H0: There is no significant difference in the time spent by team A and team Din 2007 when they did not participate in the development of the procedures and processes with the time in 2009 when they did(u1-u2=0). Alternate hypothesis, 1H1: There is a significant difference in the time spent by the team A and Din 2007 when they did not participate in the development of the procedures and processes with the time in 2009 when they did (u1-u2!=0). Null hypothesis, 2H0: There is no significant difference in the number of at–risk behaviors observed to have been exhibited by the team A and team D in 2007 when they did not participate in the development of the procedures and processes with the number in 2009 when they did (u1-u2=0). Alternate hypothesis, 2H1: There is a significant difference in the number of at–risk behaviors observed to have been exhibited by the team A and team D in 2007 when they did not participate in the development of the procedures and processes with the number in 2009 when they did (u1-u2!=0). The student t test was used to analyze these times and number of at–risk behavior. At the 0.025 and the 0.05 level of significance, the data show that there is no difference in the times all the teams used to complete their task in 2007 and in 2009. The researcher concludes that a change in the management style from autocratic I style to consultative II style did not lead to a reduction in the time used by any team to complete their task. However at the 0.025 and the 0.05 level of significance, there is a significant difference in the number of at–risk behaviors of the research team A and team D. There is however no significant difference in the number of at–risk behavior of the control team B, team C, team E and team F at the same level of significance. The researcher concludes that a change in the management style from autocratic I style to consultative II style lead to a reduction in the number of at–risk behavior of team A and team D. In addition the reduction in the number of at–risk behavior of team A and team D could not have been because of task repetition, increased knowledge or improved team cohesion since there is no significant difference in the number of at–risk behavior exhibited by team B, team C, team E and team F. The research can be used by the Escravos gas plant management and the management of any similar process plant to fashion out more cost effective, time effective and safer methods for carrying out their turnaround maintenance. A change in management styles may just be a better approach to improving productivity than giving financial incentives to contractors and personnel. Changes in management style will have to be managed. The change must be gradual because sudden change can be detrimental as people may just need to understand and adapt to the change. The turnaround personnel must also understand the intent so as to prevent conflicts.
Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2012.

Thesis (MScEng)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The aim of this thesis is to compare the aviation derived reliability metric known as the Maintenance Free Operating Period (MFOP), with the traditionally used, and commonly found, reliability metric Mean Time Between Failure (MTBF), which has over the years shown some innate disadvantages in the field of maintenance. It will be shown that this is mainly due to MTBF’s inherent acceptance of failure and the unscheduled maintenance therewith directly connected. Moreover, MFOP is successfully applied to a mining specific case study, as to date, no other application of the MFOP concept to the mining sector is known. An extensive literature study is presented, which covers concepts relevant to the overall study and which helps to contextualise the problem, revealing the major shortcomings of the commonly accepted MTBF metric. A methodology to analyse systems MFOP performance, making use of failure statistics to analyse both repairable and non-repairable systems, is presented. Validation makes use of a case study which applies the MFOP methodology to a system, specifically in the mining sector. It was shown that MFOP could be applied to the data obtained from the mining sector, producing estimates which were accurate representations of reality. These findings provide an exciting basis on which to begin to facilitate a paradigm shift in the mind set of maintenance personnel, setting reliability targets and dealing with unscheduled maintenance stops. KEYWORDS: Maintenance Free Operating Period, Mean Time Between Failure, Maintenance, Mining
AFRIKAANSE OPSOMMING: Die doel van hierdie tesis is om die Onderhoudvrye Bedryf Tydperk (OBT), ’n betroubaarheidsmaatstaf afkomstig van die lugvaart industrie, te vergelyk met die Gemiddelde Tyd Tussen Falings (GTTF) maatstaf wat tradisioneel in algemene gebruik is, maar wat oor die jare inherente nadele met betrekking tot instandhouding geopenbaar het. Dit sal bewys word dat hierdie nadele hoofsaaklik ontstaan as gevolg van die GTTF se inherente aanvaarding van failure en die ongeskeduleerde instandhouding wat daarmee gepaard gaan. OBT word ook suksesvol aangewend in ’n mynwese-spesifieke gevallestudie, wat aaangegaan is aangesien geen ander sooortgelyke aanwending in die mynwese sektor tot datum bekend is nie. ’n Breedvoerige literatuurstudie word voorgelê wat relevante konsepte dek en die probleem binne konteks plaas, en daardeur die hoof tekortkominge van die algemeen aanvaarde GTTF metriek ontbloot. ’n Metodologie waardeur analise van die stelsel werkverrigting van die OBT uitgevoer kan word met gebruik van onderbrekings statistiek om herstelbaar sowel as onherstelbare stelsels te analiseer, word voorgestel. Geldigheid word getoets deur ’n gevallestudie wat die OBT metodologie aangewend word spesifiek vir ’n stelsel in die mynwese Dit is bewys dat OBT toegepas kan word op data afkomstig van die mynwese sector, en skattings lewer wat akkurate voorstellings is van die werklikheid. Hierdie bevindinge is opwindend, en dit dien as die basis vir ’n die aanwending van ’n paradigmaskuif in die benadering van instandhoudingspersoneel tot die daarstelling van teikens vir betroubaarheid en ook in hul hantering van ongeskeduleerde instandhoudingsophoud. SLEUTELWOORDE: Onderhoudvrye Bedryf Tydperk, Gemiddelde Tyd Tussen Falings, Onderhoud, Mynbou

In order to successfully compete against the use of fossil fuels to generate electricity, one of the challenges in the photovoltaic (PV) business currently in focus is on the asset management of large PV plants, in which developing control techniques to prognosticate and evaluate the future energy performance will be essential. Infrared thermography inspections can give meaningful support to assess the quality and performance of PV modules. However, the implementation of a cost-effective method to scan and check huge PV plants represents different challenges, such as the cost and time of detecting PV module defects with their classification and exact localization within the solar plant. In this context, it has recently been investigated the potential of a new innovative technology in the PV plants monitoring operations by using drones. The main purpose of this work is to establish a scientific basis for the interpretation of thermographic images taken by drones, in particular, regarding the influence of thermographic irregularities which will negatively influence the performance of PV plants. The drone is employed to monitor PV modules conditions by using special thermography sensors mounted on it in order to scan images. The captured images are then automatically sent to a technical office database for the image processing software. This special software receives, stores and analyses the captured images to detect the specific defect on the PV modules. Then, all information is processed and reported to the final decision-making team to decide about the best solution for the particular degraded PV module, in relation with the requirements from the operation and maintenance (O&M) services. In this particularly study project of the inspected PV plant situated in the UK, which has been carried out by trained personnel at Quintas Energy (QE), the majority of identified faults, which influence the PV module performance (especially the power output significantly), are on a sub-panel level, either individual cells or uneven hot spots. There are also some modules with bypass diode faults as well as a string fault was detected. Such faults must be repaired by the PV module manufacturer, in relation to the manufacturer’s warranties, without any cost at all since the PV modules are indeed still in warranty. It has been concluded that, in comparison with traditional manned systems by using hand-held cameras, the main functionality of using drones is the early fault diagnosis which could reduce corrective maintenance activities, since defects are easily and quickly identified and, then, repaired. This fact could reduce defects to become more serious and, thus, more difficult to be repaired, along with their correspondent production losses and costs. QE has learned by making mistakes during this project study and gained experience of this unmanned aerial vehicles (UAV) technology. Currently, they are in the process of improving this technique and will continue to implement it to all their PV plants since the efficiency of PV systems can be significantly improved by appropriate use of O&M instruments and benefit from innovative monitoring tools, such as the unmanned aerial technology.

The safety record of most petrochemical industries in the world and Nigeria in particle, has not been able to come down to the maximum allowable range of 0 - 0.1 percent of tolerance on recordable injuries, due to increasing failure rates of equipment within the plant. Investigations on the maintenance audit carried out on the Nigerian Gas Company (NGC) revealed that 85 percent of such failures are directly linked to improper adaptability of an effective maintenance management strategy and plan within the petrochemical industries in Nigeria. Equally, the growth and continuous operation of any plant depends to a large extent on the maintenance of the equipment that refines the Crude Oil and natural Gas. As such, various maintenance management systems have been used over the years for the actualisation of the above purpose but with minimal success. This is evident in the fact that the level of maintenance performance of most Nigerian Petroleum Companies is always on the corrective maintenance model, which indirectly implies that the plant normally breaks down before maintenance management is applied. A critical look at the deficiency of improper adaptability of these maintenance management plans have conspicuously manifested in five major categories of maintenance failures which includes the following; * Failure of safety critical equipment due to lack of maintenance * Human error during maintenance * Static or spark discharge during maintenance in an intrinsically unsafe zone * Incompetence of maintenance staff, and * Poor communication between maintenance and production staff. These gaps as identified in this research must be corrected in the Nigerian Gas Industry if meaningful progress is to be made. Gas – To – Liquid technology is a very complex technology and with natural gas as the basic raw material, the technology not only looks intimidating but also is full of potential hazards. People are naturally afraid of the complex nature of gas in a confined environment (because of its highly combustible nature), its gaseous state makes it more complex for it to be kept under control and at the same time be moved from one form to another at different temperatures and pressures. The maintenance audit carried out on the Nigerian Gas Company (NGC) revealed some major loopholes in the maintenance management strategies adopted in the country. The audit reveals that the degree of adherence to conditions attached towards the maintenance management strategy of this equipment (in this case Gas field equipment) was too poor. Based on the above, this research is meant to improve the existing maintenance management strategy, by developing a Maintenance Management Strategy (MMS) that will be suitable for gas field equipment in the Escravos Gas–To– Liquid (EGTL) plant, planned to be commissioned in Nigeria early 2011. The need to research the above mentioned Maintenance Strategy became imperative due to the fact that the rate at which most of the petrochemical plants in the world are being gutted by fire, mainly due to poor maintenance management systems is alarming. This research work proffered solutions that will reduce or completely eliminate the highlighted problems above. This was based on investigations and analysis carried out in the chosen research area. Models were developed for the actualization of this Improved Maintenance Management Strategy (IMMS), so that the desired safe operability of the gas field equipment in the Escravos Gas–To– Liquid (EGTL) plant will be achieved without maintenance failure of any kind.
Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2011.

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division; in conjunction with the Leaders for Manufacturing Program at MIT, 2007.
Includes bibliographical references (p. 40-42).
Outsourcing maintenance to third-party contractors has become an increasingly popular option for manufacturers to achieve tactical and/or strategic objectives. Though simple in concept, maintenance outsourcing is difficult in execution, especially in a cost-sensitive environment. This project examines the Full Service business under ABB Ltd to understand the key factors that drive the success of an outsourced maintenance operation. We present a qualitative causal loop diagram developed based on the case study of Kinleith Pulp and Paper Mill in New Zealand. The diagram describes the interconnections among various technical, economic, relationship, and humanistic factors and shows how cost-cutting initiatives can frequently undermine labor relationship and tip the plant into the vicious cycle of reactive, expensive work practices. The model also explains how Kinleith achieved a remarkable turnaround under ABB, yielding high performance and significant improvements in labor relations. A case study of Tasman Pulp and Paper Mill provides a contrasting case where success has been more difficult. Results point to the importance of creating sufficient resources ("slack") to implement improvement activities and pace implementation based on pre-existing dynamics on site.
by Jacqueline Ming-Shih Ye.
S.M.
M.B.A.

Thesis (MBA)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: Providing basic access to water and sanitation is critical for poverty alleviation and stimulating economic growth, but at the same time it is putting a huge strain on South Africa’s existing economic infrastructure. Local governments allow their existing wastewater infrastructure to deteriorate to the extent that it no longer functions according to its design, and then apply for capital funding for refurbishment. Capital investment alone will not provide a sustainable solution to meet the increased demand on the ageing wastewater infrastructure, since local governments do not have the financial means and technical capacity to adequately maintain and operate their infrastructure. A paradigm shift is required to develop alternative and innovative business models to ensure a sustainable solution providing continued and consistent capacity as a basis for further expansion. Public-private partnerships (PPP) could provide a feasible solution towards building a sustainable technical capacity at local governments. Engaging the private sector must however not be aimed towards access to private sector finance, but rather the improvement in operational efficiency and increased level in service. Obtaining private sector finances will be the wrong focus for engaging in PPP undertakings in South Africa. Private operation must be combined with public financing. The design-build-operate (DBO) model with public financing would be highly viable. Such an arrangement will hold no financial risk to the private sector entity with revenue collection strictly remaining a local government function. The DBO method of delivery (with public funding) will be an effective way to realize cost savings, achieve efficiencies in construction and operation, utilize expertise, and most importantly, for skills transfers and capacity building at local government level. Ultimate sustainability will only be achieved once local government is able to raise the majority of its own funds for operation and maintenance through tariffs and other instruments, including some towards capital redemption. Grant funding must make provision for maintenance and operation of all capital funded projects. All shareholders must join forces in lobbying this concept at the highest political echelons because in terms of Section 154 of the Bill of Rights, national and provincial governments have a duty towards local governments to support and strengthen their capacity, to effectively perform their functions.

Purpose The purpose is to identify responsibility of owners and operators for maintenance of assets, fixtures and fittings, to identify maintenance management strategies adopted for the efficient operation of hotels and to find out difficulties faced by operators in implementing these strategies. Methodology Four interviews provided supplementary data for the main data collection phase involving administration of 64 questionnaires to hotel operators and maintenance managers. Findings The hotel owner and operator have individual and joint responsibility for asset maintenance. Outsourcing is a maintenance strategy used to minimise operating costs, an important factor that guides this decision is time constraint required to deliver work. In house maintenance it is also influenced by the strategic value of the service and the availability of the resource in the market. In maintenance practice an important challenge is maintaining energy efficiency because of the increasing electronic equipment and high volume of lights.

In the modern commercial environment, companies are continuously trying to reduce costs by improving manufacturing efficiency. As equipment reliability directly affects manufacturing efficiency an investigation of equipment would be the first step to reducing equipment downtime. The most common method of identifying the contributors to poor performance is Reliability Centred Maintenance (RCM). This technique however, has had relatively few applications, as it has been perceived as too rigorous and requiring excessive financial and manpower investment. The sponsoring company, Wolfson Maintenance (WM), identified a market opportunity in that a simple cost effective method of analysing maintenance performance did not exist. They developed a process called Review of Equipment Maintenance (REM), which utilises Failure Mode & Effects Criticality Analysis (FMECA) techniques to gather together the knowledge gained through the application of an existing maintenance plan. This process has had notable success in a number of applications but WM feel that because of its lack of structure it has not reached its full potential consequently, this project was proposed to research and formalise the REM process.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1994, and Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1994.
Includes bibliographical references (p. 122).
by Daniel J. Hommes.
M.S.

2 pp.
Originally published: 2000
Properly sited, designed, constructed, and maintained septic systems can provide an efficient and economical wastewater treatment alternative to public sewer systems. Onsite/septic system owners need information on how septic systems work, how to maintain them, and precautions to take to decrease the potential for the septic system to contaminate groundwater or surface water. This publication provides operation and maintenance tips for managing your septic system.

Includes bibliographical references.
The phenomenal growth rate of Internet traffic as well as the increasing demand for high bandwidth services such as video-on-demand (VoD), high definition TV (HDTV), video-conferencing etc., have created a new networking environment in which flexibility, scalability and high bandwidth capacity are of utmost importance. All Optical Networks has emerged as a promising technology to deliver the high capacity demands of current and envisaged future applications.

Thesis (M. of Military Art and Science)--U.S. Army Command and General Staff College, 2007.
The original document contains color images. Title from title page of PDF document (viewed on May 27, 2008). Includes bibliographic references.

There are ambitious plans for renewable energy sources to provide a significant contribution to the future energy mix. The huge potential capacity and relative maturity compared to other offshore technologies has resulted in a strong commercial focus on offshore wind, particularly in Europe. However, costs of offshore wind remain significantly higher than conventional generation approaches as well as onshore wind. Reducing the cost associated with operations and maintenance of offshore wind remains a key challenge in decreasing lifetime cost of energy and achieving cost parity with alternative generation technologies. The combination of nascent turbine and infrastructure design, moving into more challenging sea state and wind environments and the highly commercial nature of the industry has prevented the maintenance costs of offshore wind being adequately reduced through early operating experience alone. In order to accelerate the reduction of costs and critically to understand the uncertainty associated with future sites and novel operating strategies, it is necessary to simulate maintenance operations. This thesis has developed an offshore wind operations and maintenance expenditure model and specified a decision support methodology for this purpose. The models enable the quantification of the influence of cost drivers for current and future offshore wind farms and provide an improved understanding of the uncertainty associated with operating decisions. Using the developed models, a detailed sensitivity analysis of the influence on lifetime costs from operational climate, failure behaviour, wind farm configuration and external cost drivers has been carried out to provide new insights on the industry. Operational climate and failure behaviour are identified as the critical cost drivers and sources of uncertainty currently. In addition, a detailed analysis of operational strategies for major repairs that involve the use of high cost, specialist vessels has been carried out for the first time, identifying the strengths and weaknesses of different strategies. Finally, a case study demonstrating how decision support models can be used to determine the optimal strategy choices for operators and reduce uncertainty has been performed. The analysis in this thesis provides new insights on the industry and the developed methodologies have the potential to deliver significant financial savings in the future.

Thesis (M.S.)--Air Force Institute of Technology, 2003.
Title from title screen (viewed July 1, 2004). "March 2003." Vita. "AFIT/GOR/ENS/03-06." "ADA412960"--URL. Includes bibliographical references (p. 87-90). Also issued in paper format.

Orientadores: Sergio Valdir Bajay, Paulo Sergio Franco Barbosa
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
Made available in DSpace on 2018-08-08T23:23:08Z (GMT). No. of bitstreams: 1 Pereira_AndreFlavioSoares_M.pdf: 1792951 bytes, checksum: a865e5b33783ba4a8f044bcff70f9809 (MD5) Previous issue date: 2006
Resumo: Nesta dissertação se avalia o estado da arte do planejamento da operação energética e da manutenção de usinas em sistemas hidrotérmicos de potência e se propõe algumas inovações. Neste contexto, se faz uma revisão crítica das metodologias de planejamento empregadas no setor elétrico brasileiro, incluindo as bases de dados que dão suporte a estas metodologias e dando destaque às práticas atuais do Operador Nacional do Sistema Elétrico (ONS); várias propostas de avanços metodológicos são feitas ao longo desta parte do trabalho. Uma outra parte desta dissertação envolve a aplicação de um modelo de otimização, a médio prazo, da operação de algumas usinas do Sistema Interligado Nacional (SIN), pertencentes a uma concessionária geradora no Estado de São Paulo, satisfazendo as metas de geração impostas pelo planejamento centralizado do SIN, realizado pelo ONS, e restrições associadas ao uso múltiplo da água nos reservatórios destas usinas, dentre outras. Várias funções-objetivo podem ser utilizadas neste modelo, dependendo das finalidades a serem atingidas nas simulações. O modelo foi aplicado ao parque gerador hidrelétrico da empresa AES, nos rios Tietê e Pardo; algumas simulações foram feitas, discutindo-se os resultados alcançados
Abstract: The state-of-the-art of power plant scheduling and maintenance planning in hydro-thermal power systems is evaluated in this thesis and some innovations are proposed. In this context, a critical review of the planning methodologies employed in the Brazilian power sector is carried out, including the data bases which support these methodologies and pointing out the current practices of the National Operator of the Power System (ONS); several proposals concerning advances in these methodologies are put forward along this work. In another part of this thesis, the medium-term scheduling of some power stations of the National Interlinked System (SIN) belonging to a utility in the State of São Paulo are modeled through an optimization algorithm, which meets the generation targets imposed by the centralized planning of SIN, carried out by ONS, and constraints associated to multiple uses of water in the reservoirs of these plants, among other constraints. Several objective functions can be used in this model, depending on the purposes to be achieved in the simulations. The model was applied to the hydroelectric generation system of the company AES, in the rivers Tietê and Pardo; some simulations were carried out and their results are discussed in the thesis
Mestrado
Planejamento de Sistemas Energeticos
Mestre em Planejamento de Sistemas Energéticos

Der vorliegende 38. Band der Reihe 'Leipziger Beiträge zur Informatik' fasst die Ergebnisse der Fachtagung 'Betriebsführung und Instandhaltung regenerativer Energieanlagen (BIREA)' am 24. und 25. September 2012 in Leipzig zusammen. Die Fachtagung adressierte aktuelle Herausforderungen der Energiewirtschaft im Allgemeinen und der Branche der Erneuerbaren Energien im Speziellen. Der Anteil erneuerbarer Energien am Bruttostromverbrauch wird sich von derzeit ca. 17 % im Jahre 2020 auf 35% verdoppeln und langfristig bis auf 80% steigen. Mit der wachsenden Bedeutung steigen auch die Anforderungen an die regenerative Energiebranche. Dabei stehen im Vordergrund: a) die Versorgungssicherheit und Netzstabilität, b) sinkende Einspeisevergütungen, c) die Betriebsoptimierung regenerativer Energieanlagen, d) die effiziente Instandhaltung regenerativer Energieanlagen, e) die Vernetzung von Energieerzeugern und -verbrauchern zu virtuellen Kraftwerken, f) Verfügbarkeitsgarantien für Energieanlagen sowie Strom- und Ausfallprognosen. Die Fachtagung fokussierte folgende Themen des Betriebs und der Instandhaltung regenerativer Energieanlagen: a) neuartige Dienstleistungen (z. B. Wirkungsgradanalyse, Ertragsprognosen, Ausfallprognosen), b) Standardisierungsprozesse (z. B. RDS-PP, IEC 61850 / IEC 61400-25), c) die IKT-unterstützte Optimierung (z. B. Lebenslaufakte, Betriebsführung, Instandhaltungsplanung).

In many technical systems it is an essential factor to have functional equipment when needed. To prevent unexpected breakdowns preventive maintenance of the equipment is done regularly and maintenance planning is necessary to achieve an efficiently running system at an optimal cost. In this study, mixed integer linear programming (MILP) is used to optimize preventive maintenance planning and operation for a generic fleet of equipment. The maintenance requirements are mixed conditions of calendar based and operation based constraints. Also, maintenance of hierarchy types are handled. The objective is to minimize the number of maintenance events. Even operation and spread in planned maintenance are desired. The results show that it is possible to optimize preventive maintenance and operation scheduling with MILP. There are some limitations in size depending of included constraints and parameter values. Limitations in size can be handled with step-wise calculations, manual manipulations of the results, or if satisfying end conditions can be achieved, splitting of the planning period.
I många tekniska system är en viktig faktor att ha tillgänglig utrustning vid behov. För att undvika oväntade driftavbrott görs regelbundet förebyggande underhåll av utrustningen och underhållsplanering är nödvändigt för att upprätthålla ett effektivt fungerade system till optimal kostnad. I den här studien används linjär blandad heltalsprogrammering (MILP) för att optimera förebyggande underhålls- och driftplanering för en generell flotta av utrustning. Underhållskraven består av mixade kalender- och driftbaserade villkor. Underhåll av hierarkisk typ är också hanterat. Målet är att minimera antalet underhållstillfällen. Jämn drift och spridning i planerade underhåll är också önskat. Resultaten visar att det är möjligt att optimera förebyggande underhålls- och driftscheman med MILP. Det finns vissa begränsningar i storlek, beroende på vilka bivillkor som är inkluderade och parametervärden. Storleksbegränsningar kan hanteras med stegvisa beräkningar, manuell manipulering av resultaten, eller om tillräckliga slutvillkor kan erhållas, uppdelning av planeringsperioden.

The Swedish National Rail Administration, Banverket, has the overarching sector responsibility for Swedish railways, including a responsibility for implementing and managing the government decision for an ecologically sustainable development. In support of achieving ecologically sustainable development and fulfilment of the national environmental objectives and environmental legislation, Banverket initiated the implementation of an Environmental Management System (EMS) in 1998. The overall aim of this thesis is to examine the EMS applied at Banverket with regard to the identification and monitoring of environmental aspects at the administrative Railway Regions of Banverket. The analysis is based on a qualitative approach comprising questionnaires, interviews, document analysis and participating observations.

Areas for potential improvements are identified. A more stringent use of the EMS is needed in the organisation. Furthermore, a link between activity, aspect and impact when identifying environmental aspects would improve the procedure. Like in other public organisations, the monitoring of environmental aspects at Banverket is insufficient. Introducing indicators and integrating different Government requirements for environmental monitoring into one system, using EMS as a tool would make the system more effective. In the thsesis a framework is proposed for the identification of environmental aspects pertaining to operation and maintenance at Banverket. This framework has an input–output perspective and provides a clear connection between activity, aspect and impact. Furthermore, by establishing the framework on a system used mainly for environmental performance evaluation, a better connection between the identification and monitoring of aspects is created, possibly improving both processes. The framework for the identifica-tion of environmental aspects, as proposed in the thesis, could also be modified and applied in other organisations.

A major conclusion of the study is that the EMS applied at Banverket, in its present form, is not an effective environmental management tool for achieving ecologically sustainable development within the rail sector. Adapted methods for identification and monitoring of environmental aspects for public organisations such as Banverket would facilitate the application of EMS and increase its effectiveness as an environmental tool.

Congestion of roads and sky, increasing energy costs and a demand to reduce emissions, have created a need to shift transportation from road and air to rail. Consequently, rail utilisation is increasing, adding stress to the rail infrastructure and time constraints to maintenance. At the same time, the performance and capacity of rail infrastructure are expected to be preserved or even improved. Railway performance and capacity can be enhanced by: expanding infrastructure; introducing better technology; and improving the efficiency and effectiveness of operation and maintenance. Performance measurement has shown to improve the efficiency and effectiveness of organisations, but the development and integration of performance measurements are essential. A key issue in performance measurement is the process of collecting, storing and converting data into information and knowledge, i.e. data analysis and presentation. Organisations use various systems and methods to collect and analyse data, but the analysis of the collected data to extract relevant information is often a challenge. With improved data analysis and performance measurement, rail transportation can meet the requirements of performance and capacity. Specifically, maintenance planning and optimisation of preventive maintenance can be made more effective, which can decrease interruptions of train operation, reduce costs and ensure safety.In this thesis, a model for monitoring and analysis of operation and maintenance performance of rail infrastructure is developed. The model includes various methods for analysis of operation and maintenance data. The work aims to facilitate improvements and optimisation of decision-making in railways.The thesis consists of two parts. The first part gives an introductory summary of the subject and research, followed by a discussion of the appended papers, an extension of the research and conclusions. The second part consists of five appended papers. The first paper concerns the development of a model for improving performance measurement of rail infrastructure. The second paper is a study of indicators related to rail infrastructure performance. The three subsequent papers are development of data analysis methods for: operational availability of rail infrastructure, composite indicators and maintenance costs.Keywords: operation and maintenance, indicators, performance measurement, maintenance cost, rail infrastructure, linear assets, preventive maintenance, corrective maintenance, aggregation, composite indicators, cost-benefit analysis, decision support
Godkänd; 2014; 20140904 (chrste); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Christer Stenström Ämne: Drift och underhållsteknik/Operation and Maintenance Uppsats: Operation and Maintenance Performance of Rail Infrastructure Model and Methods Opponent: Professor Rommert Dekker, Director of the Econometrics Institute, Erasmus University Rotterdam, Nederländerna Ordförande: Professor Uday Kumar, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Tisdag den 11 november 2014 kl 10.00 Plats: F1031, Luleå tekniska universitet

Rapporten baseras på en litteratur- och intervjustudie kring underhållsstrategier och komponentutbyten i kärnkraftverk, med fokus på komponenter som tenderar till att påverkas av åldring i en högre grad. Exemplifiering sker genom en kompletterande fallstudie kring kabel- och rörgenomföringar av typen Brattbergare som har packbitar bestående av ett polymert material. Erhållet resultat av litteratur- och intervjustudien belyser vilka säkerhetsföreskrifter som råder för all kärnteknisk verksamhet i Sverige. Utöver det erhålls information om hur åldring påverkar ett materials egenskaper över tid och att detta ligger till grund för fastställandet av ett system eller en komponents kvalificerade livslängd. I takt med att majoriteten av världens kärnkraftverk närmar sig sin ursprungligt tilltänkta livslängd och planeras underhållas för fortsatt långtidsdrift finns det ett ökat intresse för effektiva underhållsstrategier. Åldershanteringen har en avgörande roll för anläggningens lönsamhet och driftsäkerhet. Fallstudien föreslår två olika underhållsstrategier som stöds av resultatet av litteratur- och intervjustudien. Deras ekologiska påverkan och ekonomiska omfattning beaktas för att utse den metod som har störst potential att öka resurseffektiviteten och minska kostnaderna för underhållsåtgärder. Vald metod går ut på att praktiska tillståndsmätningar tillämpas för att undersöka hårdheten av packbitar till Brattbergare. Hårdhetsmätningarna syftar till att ge indikationer på i vilken grad packbitarna harpåverkats av degraderande åldringsmekanismer under olika förutsättningar. Resultatet av fallstudien överensstämmer med de resultat som noterades i litteratur- och intervjustudien. Packbitarna hårdnar när de åldras. Två miljöbetingelser som tenderar till att påskynda åldringsprocessen är förhöjda temperaturer och stråldoser. Vald metod för fallstudien är praktiskt realiserbar trots vissa begränsningar i befintliga kärnkraftsanläggningar vid Forsmark. Presenterad strategi bör kunna bistå med en ekologisk och ekonomisk optimering av underhållsarbetet för kabel- och rörgenomföringar.
This report is based on a literature study and interviews regarding maintenance strategies and component replacements in nuclear power plants. Focuses of the study are on components which tend to more commonly be affected by degrading aging mechanisms. Exemplification is done with a complementary case study about cable- and pipe transits with packing pieces made of polymeric materials. A frequently used application for cable- and pipe transits in Swedish NPPs is manufactured by MCT Brattberg AB.  Result obtained from interviews with relevant personnel’s and the literature study providing knowledge about prevailing safety regulations at Swedish nuclear facilities. Moreover, information is gained about how aging affects the features of materials over time and that it is the basis for determining the qualified lifetime of systems and components. Further on this could be of specific interest considering that the majority of the worlds NPPs are close to its intended lifetime and soon entering a phase of LTO. A proper aging management is an important factor when it comes to a safe and reliable operation of an NPP.  The case study compares two different maintenance strategies which are supported by the obtained result from interviews and the literature study. Considering ecological and economic impacts of the strategies, the one with the greatest potential to reduce negative influences are exemplified. Chosen method included practical hardness measurement with a portable durometer at packing pieces for cable- and pipe transits. Measured hardness of the packing pieces indicates at what degree which they have been affected by degrading aging mechanisms given different circumstances.   The obtained result from the two different parts of the report is corresponding to each other. Packing pieces consisting polymers hardens as they age. Elevated temperatures and higher dose rates accelerates the aging process. Represented method of the case study is practically viable at existing NPPs at Forsmark. Presented strategy should be able to assist with an ecological and economic optimization maintenance work for cable- and pipe transits.

This dissertation thesis is concerned with the diagnostics of the main production facilities in Czech power engineering with a focus on its integrating role in the process of gaining, saving and processing information for the purpose of evaluating the technical state of the operated facilities and the plan to manage their lifetime. It is divided into two parts, theoretical and practical. The theoretical part presents the conclusions of examination of the needs of involved workers in the areas of diagnostics, maintenance and expert assessment of technical state of equipment. These conclusions were formulated based on the completed analysis of the current status ("as - is" analysis) of performing diagnostics of systems operated in the technological units of both nuclear and classical power engineering. The monitored equipment involves electrical installations and machinery, steel and building constructions, measuring instruments and vibrodiagnostics. Based on the analysis results, process diagrams are created for the solution of partial tasks. The analysis of the proposed solution for problems in question ("should - be" analysis) includes a design of the fundamental scheme of the data model for a software solution and a design of data flows from the individual data sources. The following part presents an application layer which includes a detailed description of major functionalities. Further, important activities and procedures are described that are necessary to evaluate the technical state of equipment. The practical part deals with the implementation of the LTO suite software product in the environment of power engineering in Czech Republic, specifically within ČEZ, a.s.. The LTO suite functionality is demonstrated in this part of the thesis by screens recorded within the LTO suite individual modules, which work above the actual data. It starts with the initial screen for configuration of displayed data, continues to present examples of the equipment register, planning, processing and saving of information collected through the diagnostic activities over to the module of integration – analytical layer, which is designed for evaluation of the technical state of equipment at the entered date with a reporting output. The thesis also includes the chapters on "Aims of the Study" and "Conclusion". The key chapter presents the "Benefits of the Study", whose overview describes the original results of the research as well as those applicable also outside the power engineering area.

The phenomenon of digitization is transforming industries worldwide by introducing new valueproducing opportunities. In the railway industry, market liberalization has resulted in increased competition. To remain profitable in this new market environment, rail operators need to transform and acquire new digital capabilities and tools. By digitizing information-intensive processes with an information system, railway companies can reduce loss of operation time and reduce total maintenance costs. At the same time, the limited research exploring information systems in maintenance management has made it challenging for companies wanting to digitize. Significant attention has been devoted to the separate topics, however research overlapping the two areas of study has been inadequate. The thesis aims to contribute with knowledge to bridge this gap in literature by investigating the opportunities a maintenance organization potentially can capture with an information system and the success factors needed to succeed. By conducting the thesis in collaboration with the Swedish railway maintenance company MTR Tech AB the potential uses of an information system have been identified and assessed. Findings indicate that there are three main business opportunities to obtain from an information system: support of the troubleshooting process, better planning of reactive maintenance and enabling the performance of condition-based maintenance. At the same time, the profitability of an information system was found to be directly linked to its degree of utilization. Our findings have therefore allowed us to conclude that the business opportunity to pursue is the one that is most likely to be carried out fully and successfully in the prevailing circumstances. Lastly, the findings conclude that the success factors needed to capture the desired business opportunities are a dedicated project group, clear communication and information sharing, as well as adequate personnel.
Digitalisering har påverkat och transformerat företag över hela världen genom att erbjuda nya värdeproducerande möjligheter. För att bibehålla konkurrenskraft i en föränderlig omvärld måste järnvägsoperatörer transformera sina företag och förvärva nya digitala lösningar och verktyg kopplade till järnvägsteknologier. Genom att digitalisera informationsintensiva processer med hjälp av informationssystem, blir det möjligt för järnvägsföretag att minska förlust av drifttid samt minska den totala underhållskostnaden. Samtidigt har den begränsade forskningen gällande användning av informationssystem i underhållsorganisationer försvårat digitaliseringsförsöken. Litteratur och tidigare studier har behandlat de två ämnena separat, dock har överlappande forskning varit otillräcklig. Denna studie syftar till att bidra med kunskap för att överbrygga gapet i litteraturen genom att undersöka de vinningar en underhållsorganisation kan erhålla med hjälp av ett informationssystem och de framgångsfaktorer som krävs för att uppnå dem. Genom att utföra denna studie i samarbete med det svenska underhållsbolaget MTR Tech AB har de potentiella användningsområdena av ett informationssystem identifierats. De tre huvudsakliga affärsmöjligheterna som kan erhållas från ett informationssystem är: stödjande av felsökningsprocessen, bättre planering av avhjälpande underhåll, samt möjliggörandet av tillståndsbaserat underhåll. Samtidigt har det visat sig att lönsamheten av ett informationssystem är direkt kopplat till dess utnyttjandegrad. Vi har således dragit slutsatsen att den affärsmöjlighet som bör eftersträvas är den som med största sannolikhet kommer att genomföras framgångsrikt under rådande omständigheter. Slutligen visar våra resultat att de framgångsfaktorer som krävs för att uppnå affärsmöjligheterna är en dedikerad projektgrupp, tydlig kommunikation och informationsdelning, samt lämplig personal.

The provision of a sustainable energy supply is one of the most important issues facing humanity at the current time, given the strong dependence of social and economic prosperity on the availability of affordable energy and the growing environmental concerns about its production. Solar thermal power has established itself as a viable source of renewable power, capable of generating electricity at some of the most economically attractive rates. Solar thermal power plants are based largely on conventional Rankine-cycle power generation equipment, reducing the technological risk involved in the initial investment. Nevertheless, due to the variable nature of the solar supply, this equipment is subjected to a greater range of operating conditions than would be the case in conventional systems. The necessity of maintaining the operational life of the steam-turbines places limits on the speed at which they can be started once the solar supply becomes available. However, in order to harvest as much as possible of the Sun’s energy, the turbines should be started as quickly as is possible. The limiting factor in start-up speed being the temperature of the metal within the turbines before start-up, methods have been studied to keep the turbines as warm as possible during idle-periods. A detailed model of the steam-turbines in a solar thermal power plant has been elaborated and validated against experimental data from an existing power plant. A dynamic system model of the remainder of the plant has also been developed in order to provide input to the steam-turbine model. Three modifications that could potentially maintain the internal temperature of the steam-turbines have been analysed: installation of additional insulation, increasing the temperature of the gland steam and use of external heating blankets. A combination of heat blankets and gland steam temperature increase was shown to be the most effective, with increases in electricity production of up to 3% predicted on an annual basis through increased availability of the solar power plant.
Hållbar energiförsörjning är för närvarande en av de viktigaste frågorna för mänskligheten. Socialt och ekonomiskt välstånd är starkt kopplat till rimliga energipriser och hållbar energiproduktion. Koncentrerad solenergi är nu etablerad som en tillförlitlig källa av förnybar energi och är också ett ekonomiskt attraktivt alternativ. Koncentrerade solenergikraftverk bygger till stor del på konventionella Rankine-cykel elgeneratorer, vilka minskar de tekniskt relaterade riskerna i den initiala investeringen. På grund av solstrålningens skiftande karaktär utsätts denna utrustning för mer varierade driftsförhållanden, jämfört med konventionella system. Behovet av att bibehålla den operativa livslängden på ångturbiner sätter gränser för uppstartshastigheten. För att utnyttja så mycket som möjligt av solens energi bör ångturbinen startas så snabbt som möjligt när solstrålningen blir tillgänglig. Eftersom temperaturen i metalldelar hos turbinerna är den begränsande faktorn, har metoder studerats för att hålla turbinerna så varma som möjligt under tomgångsperioder. En detaljerad modell av ångturbiner i ett solenergikraftverk har utvecklats och validerats mot experimentella data från ett befintligt kraftverk. En dynamisk systemmodell av de övriga delarna av anläggningen har också utvecklats för att ge input till ångturbinsmodellen. Tre modifieringar som potentiellt kan bidra till att upprätthålla den inre temperaturen i ångturbiner har analyserats: montering av ytterligare isolering, ökning av temperaturen hos glänsångan och användning av elvärmefiltar. En kombination av elvärmefiltar och en temperaturökning av glänsångan visade sig vara det mest effektiva alternativet. Åtgärderna resulterade i en ökad elproduktion på upp till 3%, beräknat på årsbasis genom ökad tillgänglighet hos kraftverket.
QC 20110629
TURBOKRAFT

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 113-117).
Optimizations of reverse osmosis (RO) plants typically consider steady state operation of the plant. RO plants are subject to transient factors that may make it beneficial to produce more water at one time than at another. These factors can impact the optimal size of the plant. The electricity price is one factor of importance. When long periods of time are considered, other factors such as weather and seasonal water demand can influence the operation and size as well. With long-term operation, water storage is possibile. This thesis investigates the optimal time-varying operation and size of a single stage RO plant subject to a time-varying electricity price. A single stage RO model is modified to include a variable plant size controlled by the number of modules. The annual capital and operating expenses of the plant are calculated in an RO economics sub-model. In one study, the short-term (single day) operation and design are optimized to minimize the total annualized cost of the plant. The operation and size are optimized for four different electricity price functions: constant, moderately fluctuating, highly fluctuating, and actual electricity prices. The results show that significant savings (1-7%) are obtainable and optimal oversizing of 15% is chosen for the fluctuating electricity price functions considered therein. The plant produces more water when electricity is cheap, and shuts off during periods of high electricity price when oversized. The size and day-by-day operation are optimized for one year subject to Spain's electricity price. Little savings and oversizing are obtainable for the day-by-day optimization due to low fluctuations in the electricity price during the year. In a second study, the long-term (one year) operation with storage of product water is optimized to minimize the cumulative cost of reclaiming the water from the reservoir and/or of the electricity. The operation is optimized for electricity prices for California, Cyprus, Greece and Spain for 2010. Low savings are obtained with variable operation. Shutting off is not chosen in the optimal operation and 1% oversizing typically leads to increased costs. Lower electricity prices with more fluctuations result in better savings. Product water is stored during the winter.
by Christopher Michael Williams.
S.M.

Compressor plant frequently operates under unsteady conditions. This is due to pressure fluctuations, variable flow demand, or unsteady inlet conditions, as well as shaft speed variation. Also, following demand, compressor plants often work intermittently with frequent starts and stops. This may cause premature wear, decrease of compressor performance and even failure, which might cost millions of pounds to industry in downtime. However, there is still a lack of published data which describes intermittent plant behaviour, or predicts the effects of unsteady operation upon compressor plant performance. Thus, there appears to be a need to develop a mathematical model to calculate compressor plant performance during intermittent operating conditions and to verify this model with experimental data. Accordingly, this thesis describes an experimental and analytical study of screw compressor plant operating under unsteady conditions. For this purpose a one-dimensional model of the processes within a compressor was used, based on the differential equations of conservation of mass and energy, extended to include other plant components, such as storage tanks, control valves and connecting pipes. The model can simulate processes in both oil-free and oil-injected compressor plants during transient operation, including the effects of sudden changes in pressure, speed and valve area. Performance predictions obtained from the model gave good agreement with test results. This model can, therefore, be used to predict a variety of events, which may occur in everyday compressor plant operation.

Thesis (Nav.E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2001.
"June 2001."
Includes bibliographical references.
by Mark Robert Galvin.
Nav.E.
S.M.