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Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campusesChen, Qiang 29 August 2005 (has links)
Following an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied.
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Nonintrusive intelligent monitoring for nuclear power plant emergency classificationGreene, Kenneth R. (Kenneth Ray), 1958- 13 May 1991 (has links)
A prototype real-time process monitoring emergency
classification expert system, RT/EM-CLASS, has been developed
for use at the Trojan Nuclear Power Plant. This knowledge-based
system features the integration of electronically sensed plant
data with the menu selection data representation of its
predecessor, EM-CLASS. This prototype demonstrates the
techniques required to acquire plant process data from another
computer and use that data in an expert system to determine the
proper Emergency Action Level.
Several benefits are realized by the RT/EM-CLASS application.
These include:
The resources required to make a classification are
reduced thereby freeing the responsible person to devote
time to other important tasks.
The classification may be completed more often and with
better data than the current system allows.
The human user is less likely to make an erroneous
Emergency Action Level classification.
Prototype implementation required resolution of an efficiency
problem of relating plant process data to the expert system data
forms. This was achieved through the development of multi-conditional
rules that significantly reduce the size of the rule set.
The development of RT/EM-CLASS presents a methodology
for building knowledge based applications that perform nonintrusive
real-time monitoring of dynamic systems. This
methodology features
Use of existing analytical and Al tools where possible
Monitoring of a dynamic system
Non-intrusive acquisition of data from the system
This technology might be applied to portions of the nuclear
engineering design process (control rod programming in Boiling
Water Reactors, for example) to emulate the guidance and
activities of an expert. A substantial portion of the effort by the
expert engineer involves preparation of the code input, running the
computer code, analyzing the results, and based on the results,
deciding what case to submit next. A suitably designed expert
system could act in the place of the engineer in this dynamic
design process.
This methodology has been tested against the 1988 emergency
exercise at the Trojan Nuclear Power Plant. / Graduation date: 1992
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Feasibility study of a VirtualPower Plant for LudvikaLundkvist, Johanna January 2013 (has links)
This thesis is a feasibility study of avirtual power plant (VPP) in centralSweden and part of a project withInnoEnergy Instinct and STRI. The VPPconsists of a wind park, small hydroplant as well as solar photovoltaic andenergy storage. The 50 kVsubtransmission network was modeled inorder to evaluate the network servicesthat could be provided by coordinatingexisting distributed energy resources inthe network. Simulations where performedusing measured hourly variations inproduction and consumption of allnetwork nodes. The studied networkservices included both reactive andactive power control.The aim of this thesis is to evaluatethe potential contribution from the VPPfor capacity firming in order to allow abalance responsible party to meet placedbids on the day-ahead spot market,minimize peak load in order to reducesubscribed power, decrease networklosses, the contribution from reactivepower control using the power convertersis studied. Comparisons of the economicgains from spot and balance markets ofthe VPP distributed energy resources aremade for each operation case.Sponsor: InnoEnergy / InnoEnergy Instinct
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Effect of temperature on mechanical response of austenitic materialsCalmunger, Mattias January 2011 (has links)
Global increase in energy consumption and global warming require more energy production but less CO2emission. Increase in efficiency of energy production is an effective way for this purpose. This can be reached by increasing boiler temperature and pressure in a biomass power plant. By increasing material temperature 50°C, the efficiency in biomass power plants can be increased significantly and the CO2emission can be greatly reduced. However, the materials used for future biomass power plants with higher temperature require improved properties. Austenitic stainless steels are used in most biomass power plants. In austenitic stainless steels a phenomenon called dynamic strain aging (DSA), can occur in the operating temperature range for biomass power plants. DSA is an effect of interaction between moving dislocations and solute atoms and occurs during deformation at certain temperatures. An investigation of DSA influences on ductility in austenitic stainless steels and nickel base alloys have been done. Tensile tests at room temperature up to 700°C and scanning electron microscope investigations have been used. Tensile tests revealed that ductility increases with increased temperature for some materials when for others the ductility decreases. This is, probably due to formation of twins. Increased stacking fault energy (SFE) gives increased amount of twins and high nickel content gives a higher SFE. Deformation mechanisms observed in the microstructure are glide bands (or deformations band), twins, dislocation cells and shear bands. Damage due to DSA can probably be related to intersection between glide bands or twins, see figure 6 a). Broken particles and voids are damage mechanisms observed in the microstructure.
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Management System for Operations Mantenanace in Offshore Wind Turbine PlantGhanbari, Ahmad, Oyelakin, Muhydeen January 2012 (has links)
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.
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Simulation of Heat Recovery Steam Generator in a Combined Cycle Power PlantHorkeby, Kristofer January 2012 (has links)
This thesis covers the modelling of a Heat Recovery Steam Generator (HRSG) in a Combined Cycle Power Plant(CCPP). This kind of power plant has become more and more utilized because of its high efficiency and low emissions. The HRSG plays a central role in the generation of steam using the exhaust heat from the gas turbine. The purpose of the thesis was to develop efficient dynamic models for the physical components in the HRSG using the modelling and simulation software Dymola. The models are then to be used for simulations of a complete CCPP.The main application is to use the complete model to introduce various disturbances and study their consequences inthe different components in the CCPP by analyzing the simulation results. The thesis is a part of an ongoingdevelopment process for the dynamic simulation capabilities offered by the Solution department at SIT AB. First, there is a theoretical explanation of the CCPP components and control system included in the scope of this thesis. Then the development method is described and the top-down approach that was used is explained. The structure and equations used are reported for each of the developed models and a functional description is given. Inorder to ensure that the HRSG model would function in a complete CCPP model, adaptations were made and tuning was performed on the existing surrounding component models in the CCPP. Static verifications of the models are performed by comparison to Siemens in-house software for static calculations. Dynamic verification was partially done, but work remains to guarantee the validity in a wide operating range. As a result of this thesis efficient models for the drum boiler and its control system have been developed. An operational model of a complete CCPP has been built. This was done integrating the developed models during the work with this thesis together with adaptations of already developed models. Steady state for the CCPP model is achieved during simulation and various disturbances can then be introduced and studied. Simulation time for a typical test case is longer than the time limit that has been set, mainly because of the gas turbine model. When using linear functions to approximate the gas turbine start-up curves instead, the simulation finishes within the set simulation time limit of 5 minutes for a typical test case.
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Addressing the Electricity Shortfall in Pakistan through Renewable resourcesHameedi, Ayoub January 2012 (has links)
This report focuses on addressing the electricity shortfall in Pakistan with the help of renewable resources. At present, the country is facing a shortfall of almost 7,000 megawatts (MW) which is affecting every walk of life and causing almost 1.5 to 2% GDP loss on annual basis. Previous research done on this subject reveals that electricity demand has always remained high then the total generation capacity of Pakistan. Similarly, it has been pointed out that the country is not taking maximum benefit from its available hydro, solar and wind resources. This leads us to the basic purpose of this research which is to have an exploratory understanding of the strategies adopted by India, China, Brazil and Spain for electricity generation in a green fashion and how can these strategies be implemented in Pakistan. Case study has been adopted as methodology for this purpose. This research work also discusses the factors contributing in the lack of promotion of renewable energy resources in Pakistan and provide detailed analyses of positive changes these projects can bring in lives of masses in Pakistan. The sustainable management of surface water resource in the country has been discussed in particular as the country faced worst floods in its history during years 2010 & 2011. It will result in enhancing the surface water storage ability of Pakistan which will significantly reduce our dependence on underground water reserves and will directly increase our electricity generation capacity through hydro dams. Similarly, sustainable forest management has been discussed at length as it will not only ensure environmental sustainability but will also result in increase availability of biomass. Not to mention the fact that wood biomass is much cheaper then conventional source of electricity generation provided it is obtained through sustainable forest management. Finally, if all the green strategies discussed in this research work will be implemented, it will increase the overall electricity generation capacity of Pakistan up to 9% respectively.
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CO<sub>2</sub> Capture With MEA: Integrating the Absorption Process and Steam Cycle of an Existing Coal-Fired Power PlantAlie, Colin January 2004 (has links)
In Canada, coal-fired power plants are the largest anthropogenic point sources of atmospheric CO<sub>2</sub>. The most promising near-term strategy for mitigating CO<sub>2</sub> emissions from these facilities is the post-combustion capture of CO<sub>2</sub> using MEA (monoethanolamine) with subsequent geologic sequestration. While MEA absorption of CO<sub>2</sub> from coal-derived flue gases on the scale proposed above is technologically feasible, MEA absorption is an energy intensive process and especially requires large quantities of low-pressure steam. It is the magnitude of the cost of providing this supplemental energy that is currently inhibiting the deployment of CO<sub>2</sub> capture with MEA absorption as means of combatting global warming.
The steam cycle of a power plant ejects large quantities of low-quality heat to the surroundings. Traditionally, this waste has had no economic value. However, at different times and in different places, it has been recognized that the diversion of lower quality streams could be beneficial, for example, as an energy carrier for district heating systems. In a similar vein, using the waste heat from the power plant steam cycle to satisfy the heat requirements of a proposed CO<sub>2</sub> capture plant would reduce the required outlay for supplemental utilities; the economic barrier to MEA absorption could be removed.
In this thesis, state-of-the-art process simulation tools are used to model coal combustion, steam cycle, and MEA absorption processes. These disparate models are then combined to create a model of a coal-fired power plant with integrated CO<sub>2</sub> capture. A sensitivity analysis on the integrated model is performed to ascertain the process variables which most strongly influence the CO<sub>2</sub> energy penalty. From the simulation results with this integrated model, it is clear that there is a substantial thermodynamic advantage to diverting low-pressure steam from the steam cycle for use in the CO<sub>2</sub> capture plant. During the course of the investigation, methodologies for using Aspen Plus® to predict column pressure profiles and for converging the MEA absorption process flowsheet were developed and are herein presented.
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Ecological Interface Design for Turbine Secondary Systems in a Nuclear Power Plant: Effects on Operator Situation AwarenessKwok, Jordanna January 2007 (has links)
Investigations into past accidents at nuclear power generating facilities such as that of Three Mile Island have identified human factors as one of the foremost critical aspects in plant safety. Errors resulting from limitations in human information processing are of particular concern for human-machine interfaces (HMI) in plant control rooms. This project examines the application of Ecological Interface Design (EID) in HMI information displays and the effects on operator situation awareness (SA) for turbine secondary systems based on the Swedish Forsmark 3 boiling-water reactor nuclear power plant. A work domain analysis was performed on the turbine secondary systems yielding part-whole decomposition and abstraction hierarchy models. Information display requirements were subsequently extracted from the models. The resulting EID information displays were implemented in a full-scope simulator and evaluated with six licensed operating crews from the Forsmark 3 plant. Three measures were used to examine SA: self-rated bias, Halden Open Probe Elicitation (HOPE), and Situation Awareness Control Room Inventory (SACRI). The data analysis revealed that operators achieved moderate to good SA; operators unfamiliar with EID information displays were able to develop and maintain comparable levels of SA to operators using traditional forms of single sensor-single indicator (SS-SI) information displays. With sufficient training and experience, operator SA is expected to benefit from the knowledge-based visual elements in the EID information displays. This project was researched in conjunction with the Cognitive Engineering Laboratory at the University of Toronto and the Institute for Energy Technology (IFE) in Halden, Norway.
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Design with Constructal Theory: Steam Generators, Turbines and Heat ExchangersKim, Yong Sung January 2010 (has links)
<p>This dissertation shows that the architecture of steam generators, steam turbines and heat exchangers for power plants can be predicted on the basis of the constructal law. According to constructal theory, the flow architecture emerges such that it provides progressively greater access to its currents. Each chapter shows how constructal theory guides the generation of designs in pursuit of higher performance. Chapter two shows the tube diameters, the number of riser tubes, the water circulation rate and the rate of steam production are determined by maximizing the heat transfer rate from hot gases to riser tubes and minimizing the global flow resistance under the fixed volume constraint. Chapter three shows how the optimal spacing between adjacent tubes, the number of tubes for the downcomer and the riser and the location of the flow reversal for the continuous steam generator are determined by the intersection of asymptotes method, and by minimizing the flow resistance under the fixed volume constraints. Chapter four shows that the mass inventory for steam turbines can be distributed between high pressure and low pressure turbines such that the global performance of the power plant is maximal under the total mass constraint. Chapter five presents the more general configuration of a two-stream heat exchanger with forced convection of the hot side and natural circulation on the cold side. Chapter six demonstrates that segmenting a tube with condensation on the outer surface leads to a smaller thermal resistance, and generates design criteria for the performance of multi-tube designs.</p> / Dissertation
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