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1
Muir, L. J. "Simulation and control system design for a liquefied natural gas vaporiser." Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381717.
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Gill, Kenneth Fred. "System modelling and control." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/6193/.
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Liu, Ziyu. "Automatic Control for a Gas System Using PIC Microcontroller." Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-16455.
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In many processes it is important to have automatic control in the modern life. For example, PLC systems are using for machine control, water pressure and flow are able to be controlled by DDC program, even a car can be driven by computer. In this article, author will turn our focus on the control system for fermentation tank. The fermentation tank that produces methane is considered as clean and recycle energy source. It is widely used in house, electronic power machine and vehicle around the world. However, its reaction temperature and output concentration control are usually hard to detect without automation system. In this study, the problem is focused to combine fermentation tank and automatic control system in laboratory testing. In this paper, author will be able to use PIC (Peripheral Interface Controller) microcontroller to solve this problem and automatically control the methane tank output methane gas with certain concentration, which could be used as energy source. The temperature and concentration sensors that are chosen as input data of the controller and corresponding algorithm were performed on the PIC. They will be used to realize the composition and thermal state measurement. With those information, the valves of material and water control can be controlled in methane tank. Limited by the experiment equipment and methane reaction tank system, the controller was just tested in the laboratory environment instead of practical application. The test result shows that the controller has its capability to automatically control the stable output of methane gas. In the test, water and material valves are controlled automatically open or close after monitoring temperature and concentration information of the gas in the tank.
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Fletcher, Ian. "Modelling and control of a gas pressure reduction system." Thesis, University of Sunderland, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327819.
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Parkinson, J. S. "Control system design for low pressure gas distribution networks." Thesis, University of Manchester, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378367.
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Lovelady, April. "Development of a control algorithm for a dynamic gas mixing system." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3775.
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An algorithm was developed to control the partial pressures of N2, O2, and CO2
in a gas mixing tank. The gases were premixed before being introduced into the low
pressure Mars Dome. As an attempt to reduce the effects of pressure, the number of
moles of the component gases was calculated and used to determine when gases needed
to be added to the system or when gas concentrations needed to be diluted. There were
two trial runs during each of the two experiments carried out. The total pressures in both
the mixing tank and the Mars Dome remained within their limits of constraint during
both trials. For the mixing tank, the pressure was maintained between 170kPa and
180kPa with a setpoint of 175kPa. Gas composition was evaluated at 67kPa and 33kPa
in the Mars Dome. Again the pressure remained within its range of ±5kPa of its setpoint.
Adequate control of the partial pressures of N2, and O2 were achieved in the mixing tank
and the Mars Dome. With respect to the control of CO2, the algorithm was unable to
maintain the partial pressure within the operational limits specified. The tendency was
for CO2 to linger above its setpoint. Moreover, at 33kPa the CO2 sensor in the Mars
Dome began to reflect a lower concentration of CO2 in the system than what was
reported by the gas chromatograph or the CO2 sensor in the mixing tank. While
sufficient control of the partial pressures was achieved, there are modifications to be made that should further tighten the control limits of the system. Such modifications
include recalibrating the sensors in the system and adjusting gas flow rates.
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Davitt, James A. "A baseline expert control system for marine gas turbine compressor surge." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/26900.
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United States Navy gas turbine ships are in need of casualty control system updating to reduce demanding conditions on engineering watch standers, to increase equipment longevity, and reduce operating costs. This thesis presents a baseline computer-based expert system controller concept developed for the critical casualty control problem of gas turbine compressor surge. The controller design rests on the building-block components of real-time gas turbine simulation and compressor surge characterization, which is discussed. The logic and rules for the expert system design are presented, as is a dynamic investigation of the expert system diagnostic performance. Expert system, Marine gas turbine, Casualty control, Theses
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Stambaugh, Craig T. (Craig Todd) 1960. "Improving gas turbine engine control system component optimization by delaying decisions." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/91787.
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Chen, Xiao-Qi. "Sensor based automatic control system for narrow gap TIG welding." Thesis, University of Liverpool, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278614.
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Carvalho, G. C. "An adaptive control system for off-line programming in robotic gas metal arc welding." Thesis, Cranfield University, 1997. http://dspace.lib.cranfield.ac.uk/handle/1826/4597.
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The aim of this work was to develop an integration concept for using off-line programming in robotic gas metal arc welding of thin sheet steel. Off line-welding parameter optimization and on-line monitoring and adaptive control of process stability and torch-to-workpiece relative distance were used to ensure weld consistency. The concept developed included four main aspects: a) the use of a CAD system to design the workpiece; b) the use of a welding off-line programming system to design the welds, generate the welding parameters and to extract geometrical information from the CAD models to generate a robot program; c) the use of a graphical simulation system to simulate the robot movements; and d) the use of monitoring and adaptive control for ensuring that the required weld quality is delivered. The CAD system was chosen to be the basis for the development of the welding off-line programming system. The generation of optimized welding parameters was based on empirical welding models and the robot program generation was based on on-line programming experience. A PC based monitoring and control system was developed to provide on-line position and process control. The position control was carried out by pre-weld adjusting the initial position of the workpiece using a wire touch sensor and on-line adjusting the torch-to-workpiece distance by moving the workpiece based on the information provided by a through-the-arc sensor. The process control was carried out by automatically trimming the welding voltage such that the most stable process could be obtained. The stability of the process was estimated by using previously established monitoring indices. It was assumed that the off-line welding parameter optimization would provide the deposition rate necessary to produce the required weld quality. Successful welding control trials were performed showing the effectiveness of the adaptive control strategy. An off-line programming system has been developed and the programs generated have been tested by simulation. This showed that simulated positioning errors, produced by deliberate wrong path data, were successfully compensated for by the control system developed in this work.
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Pearson, D. W. "Robust observer design and application to gas networks." Thesis, Coventry University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380696.
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Eide, Trond Inge. "Modelling and control of a pneumatic starting system for medium-speed gas engines." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-15796.
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This thesis investigates starting systems for marine gas engines. Large combustion engines are usually started by means of pneumatic starting arrangements. The most common ways of starting a combustion engine with compressed air, are to use a pneumatic engine coupled to the engine flywheel, or to inject the air directly into the engine cylinders through a valve in the cylinder air. Pneumatic starting engines are prefered for gas engines with a prechamber. The main challenge related to starting of gas fueled engines, is to avoid ignitable consentrations of gas outside the engine cylinders. Gas engines have an increased emission of unburned gas during starting and stoping. If the consentration of unburnes gases in the exhaust system of the combustion engine gets to large, the gas can be ignited by hot spots or sparks. In addition, we are conserned with the air consume of the starting system. The capacity of the starting system is regulated by class rules. To reduce the cost of the system, we want to reduce the air consume per start. In this thesis, mathematical models of the combustion engine and the starting system are developed and validated against experimental results from starting tests of the real system. The objective is to give means for investigating, by using computer simulations, if the existing starting system can be improved. The validation showed that the model captures the main dynamics of the system. To avoid large concentrations of unburned fuel mixtures in the exhaust system, the starting system is used to purge the engine before allowing fuel to the engine cylinders. In practice, the combustion engine is operated as an air pump which pumps air from the charge air system, via the engine cylinders, and to the exhaust system. A way of improving the safety of the starting sequence by purging the engine for a fixed number of rotations, is proposed. This method gives stricter control of the purged volume, but increases air consume. To reduce air consume, it is advantegous to keep the engine speed low during purging. Three concept for reducing the engine speed are explored. The simulations indicate that the best performance is obtained by using an electrically controlled pressure control valve, in combination with a Proportional-Integral- Derivative feedback controller, to regulate the engine speed. This concept is extensively tested by means of simulations, to evaluate its robustness with regards to system uncertainties and different plant dimensions.
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Silva, Douglas Felipe Rodrigues da. "Design and analysis of a multivariable robust control system for aircraft gas turbines." Instituto Tecnológico de Aeronáutica, 2012. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=2202.
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Gas turbine engines are important thermal machines used in industrial and transportation fields. They convert fuel energy into mechanical power or thrust for aerial and maritime vehicles, as well as generate pneumatic and electrical energy that could be used for a large variety of applications. The constant search for fuel burn savings and low pollutant emissions in aviation demands, along with new hardware and material technologies, highly complex engine control systems to optimize fuel consumption throughout the engine operating envelope, and consequently generate more efficient aircraft, in addition to meet the regulatory requirements in terms of safety and performance. These conflicting objectives normally lead to trade-off solutions which are difficult to precisely estimate given the large number of variables involved, including altitude, Mach number, ambient temperature, power and bleed extraction, among others. Therefore, some decisions to characterize the engine controller still reside on experience from previous designs and, as a result, add subjectivity and increase the potential for wrong parameter selection. These control systems significantly contribute to gas turbine performance increase. In this sense, this work proposes the study, design and analysis of multivariable robust controllers for a particular gas turbine engine. Firstly, an algorithmic approach is applied to design an aircraft gas turbine engine controller in a two-degree-of-freedom configuration, obtaining H-infinity robust stabilization. It introduces an optimized loop shape design procedure, with the use of the Genetic Algorithm (GA), to further improve the control system performance, as well as bring the experience applied by controller designers and engineers to an automated process, when setting the parameters to shape the frequency response of the engine control loops. Secondly, a Linear Quadratic Gaussian (LQG) controller, with the Loop Transfer Recovery (LTR) is developed to allow a comparative analysis. The resulting controllers are evaluated by computer simulations under typical operating conditions and compared against each other. Noise immunity is also verified. The complete system is also evaluated against requirements from the aviation industry for commercial aircraft engines. Finally, robustness is evaluated in a similar engine model by generating uncertain state space models based on the boundaries of its nominal model at extreme operating conditions.
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Yang, Wenli Lee Kwang Y. Smith Elizabeth Bradford. "An intelligent control system for a hybrid fuel cell with gas turbine power plant." [University Park, Pa.] : Pennsylvania State University, 2009. http://etda.libraries.psu.edu/theses/approved/PSUonlyIndex/ETD-4620/index.html.
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Yan, Xinglong. "Dynamic analysis and control system design for an advanced nuclear gas turbine power plant." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/14069.
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Nordström, Lisa. "Construction of a Simulator for the Siemens Gas Turbine SGT-600." Thesis, Linköping University, Department of Electrical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4996.
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<p>This thesis covers the development of a simulator for the Siemens Gas Tur-bine SGT-600. An explanation on how a gas turbine works is also given, as well as the principles behind the control system used by Siemens to control the turbine.</p><p>For Siemens Industrial Turbomachinery to be able to test its control sys-tem before delivering a gas turbine to the customer, a simulator is needed. The control system needs to be adjusted for every unique gas turbine, since there are several options for the customer to choose between when ordering the turbine. A control system standard is under development, which also needs to be tested in a simulator.</p><p>The framework for the simulator, i.e. the hardware and software that form the simulator system, was predefined to suit this specific purpose. The Siemens software SIMIT is used for developing the model. SIMIT is a real time simulation tool where models are constructed using blocks, similar to MATLAB Simulink.</p><p>A gas turbine is basically a heat engine that produces mechanical energy or electricity. The main task of the control system is to control the fuel flow to the combustion chamber and by that keeping the machine at desired speed.</p><p>The gas turbine model was developed using measurement data from a site in Hungary, where a gas turbine of the type SGT-600 is in service. The model is based on simplified relations between the signals. By analyzing measurement data and learning about the functionality of a gas turbine it was found out that the speed of the gas generator affected most other sig-nals, like temperatures and pressures. The gas generator speed was found to be dependent on the heat flow, which is determined by the openings of the gas control valves.</p><p>As a result of this thesis a working simulator for the gas turbine SGT-600 has been developed. The simulator can be used for testing the control sys-tem standard and for testing the control system when adapting it to a spe-cific delivery. It is also suitable for educational purposes, for example to instruct customers.</p>
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Villarreal, Daniel Christopher. "Digital Fuel Control for a Lean Premixed Hydrogen-Fueled Gas Turbine Engine." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/34974.
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Hydrogen-powered engines have been gaining increasing interest due to the global concerns of
the effects of hydrocarbon combustion on climate change. Gas turbines are suitable for operation on hydrogen fuel. This thesis reports the results of investigations of the special requirements of the fuel controller for a hydrogen gas turbine. In this investigation, a digital fuel controller for a hydrogen-fueled modified Pratt and Whitney PT6A-20 turboprop engine was successfully designed and implemented. Included in the design are safety measures to protect the operating personnel and the engine. A redundant fuel control is part of the final design to provide a second method of managing the engine should there be a malfunction in any part of the primary controller.
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Parallel to this study, an investigation of the existing hydrogen combustor design was performed to analyze the upper stability limits that were restricting the operability of the engine. The upstream propagation of the flame into the premixer, more commonly known as a flashback, routinely occurred at 150 shaft horsepower during engine testing. The procedures for protecting the engine from a flashback were automated within the fuel controller, significantly reducing the response time from the previous (manual) method. Additionally, protection measures were added to ensure the inter-turbine temperature of the engine did not exceed published limits. Automatic engine starting and shutdown procedures were also added to the control logic, minimizing the effort needed by the operator. The tested performance of the engine with each of the control functions demonstrated the capability of the controller.
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Methods to generate an engine-specific fuel control map were also studied. The control map would not only takes into account the operability limits of the engine, but also the stability limits of the premixing devices. Such a map is integral in the complete design of the engine fuel
controller.<br>Master of Science
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Leppäkoski, K. (Kimmo). "Utilisation of non-linear modelling methods in flue-gas oxygen-content control." Doctoral thesis, University of Oulu, 2006. http://urn.fi/urn:isbn:9514282418.
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Non-linear methods have been utilised in modelling the processes on a flue-gas oxygen-content control system of a power plant. The ultimate objective is to reduce NOx and CO emissions by enhancing the control system. By investigating the flue-gas emission control strategy, the major factors affecting the flue-gas emissions have been determined. A simulator has been constructed, and it emulates a real process automation system and its physical processes. The process models of the simulator are: a flue-gas oxygen-content model, a secondary air flow model, a primary air flow model and a fuel feeding screw model (a fuel flow). The effort has been focused on two plant models: the flue-gas oxygen-content model and the secondary air flow model. Combustion is a non-linear, timevariant, multi-variable process with a variable delay. The secondary air model is a non-linear, timeinvariant (in principle), multi-variable system. Both phenomenological modelling (mass and energy calculations) and black-box modelling (neural networks) have been utilised in the Wiener/Hammerstein structures. It is possible to use a priori knowledge in model modifying, and therefore the model of flue-gas oxygen-content can be tuned on site. The simulator with precalculated parameters was tested in a full-scale power plant and a pilot-scale circulating fluidised bed boiler. The results in the power plant were remarkable since NOx emissions decreased significantly without increasing CO emissions.
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Öijerholm, Mikael. "Aspects of the choice of sampling frequency in the control system of a gas turbine." Thesis, Linköping University, Linköping University, Automatic Control, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-17678.
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<p>At Siemens, plcs are used to control the gas turbines, and to execute the code in the plcs cyclic interrupts are used. If the execution time for the interrupt becomes close to the cyclic time of the interrupt the load of the plc increases. High load levels can lead to situations were segments of code are not executed on time or even not executed at all. In this thesis an analysis of the regulators used to govern a gas turbine has been performed. The purpose of the analysis is to study the performance of the regulators for different cycle times with the aim to be able to reduce the load by sampling more slowly.</p><p>To determine the load contribution from each regulator a review of the regulators and their execution times has been made. For the analysis the Matlab program Simulink has been used to make models of the regulators, which have then been sampled at different rates. With this information it is possible to determine for which cycle times each regulator has accepetable performance and how much load each regulator contributes with. A save of load of approximately 2 percent can be obtained without loosing too much performance.</p>
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Egener, P. "Design, implementation, and testing of a digital control system for a small gas turbine engine." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0006/MQ44840.pdf.
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Gills, Zelda Y. "Dynamical control of irregular intensity fluctuations in a chaotic multimode solid state laser system." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/29859.
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Behrens, Christopher Karl. "An Experimental Investigation into NOx Control of a Gas Turbine Combustor and Augmentor Tube Incorporating a Catalytic Reduction System." Thesis, Monterey, Califonia : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA231427.
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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, March 1990.<br>Thesis Advisor(s): Netzer, D. W. Second Reader: Shreeve, R. P. "March 1990." Description based on signature page as viewed on August 25, 2009. DTIC Descriptor(s): Air, augmentation, catalysis, catalysts, combustors, configurations, engines, fuels, gas generating systems, gas turbines, measurement, pressure, profiles, ratios, reduction, tubes, velocity. DTIC Identifier(s): Nitrogen oxides, NOx control, Gas turbines, Gas analyzers, Pollution abatement, computer programs, Emissions control, Exhaust augmentor tubes, Thesis. Author(s) subject terms: Nox control, gas turbine combustors; emissions control exhaust augmentor tubes; gas analyzers; pollution control. Includes bibliographical references (p. 73-74). Also available online.
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Darmastuti, Zhafira. "SiC-FET Gas Sensors Developed for Control of the Flue Gas Desulfurization System in Power Plants Experimental and Modeling : Experimental and Modeling." Doctoral thesis, Linköpings universitet, Tillämpad sensorvetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-106224.
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Electricity and power generation is an essential part of our life. However, powergeneration activities also create by-products (such as sulphur oxides, nitrogen oxides,carbon monoxide, etc), which can be dangerous when released to the atmosphere.Sensors, as part of the control system, play very vital role for the fluegas cleaning processes in power plants. This thesis concerns the development ofSilicon Carbide Field Effect Transistor (SiC-FET) gas sensors as sensors for sulfurcontaining gases (SO2 and H2S) used as part of the environmental control systemin power plants. The works includes sensor deposition and assembly, sensinglayer characterization, operation mode development, performance testing of thesensors in a gas mixing rig in the laboratory and field test in a desulfurization pilotunit, and both experimental and theoretical studies on the detection mechanismof the sensors. The sensor response to SO2 was very small and saturated quickly. SO2 is a verystable gas and therefore reaction with other species requires a large energy input.SO2 mostly reacts with the catalyst through physisorption, which results in lowresponse level. Another problem was that once it finally reacted with oxygen andadsorbed on the surface of the catalyst in form of a sulfate compound, it is desorbedwith difficulty. Therefore, the sensor signal saturated after a certain timeof exposure to SO2. Different gate materials were tested in static operation (Pt,Ir, Au), but the saturation phenomena occurred in all three cases. Dynamic sensoroperation using temperature cycling and multivariate data analysis could mitigatethis problem. Pt-gate sensors were operated at several different temperatures in acyclic fashion. One of the applied temperatures was chosen to be very high for ashort time to serve as cleaning step. This method was also termed the virtual multisensor method because the data generated could represent the data from multiplesensors in static operation at different temperatures. Then, several features of thesignal, such as mean value and slope, were extracted and processed with multivariatedata analysis. Linear Discrimination Analysis (LDA) was chosen since itiiiallows controlled data analysis. It was shown that it was possible to quantify SO2with a 2-step LDA. The background was identified in the first step and SO2 wasquantified in the second step. Pt sensors in dynamic operation and 2-step LDAevaluation has also demonstrated promising results for SO2 measurement in thelaboratory as well as in a desulfurization pilot unit. For a commercial sensor, algorithmhave to be developed to enable on-line measurement in real time. It was observed that Ir-gate sensors at 350oC were very sensitive to H2S. The responseobtained by Ir sensors to H2S was almost five times larger than that of Ptsensors, which might be due to the higher oxygen coverage of Ir. Moreover, Irsensors were also more stable with less drift during the operation as a result ofhigher thermal stability. However, the recovery time for Ir sensors was very long,due to the high desorption energy. Overall, the Ir sensors performed well whentested for a leak detection application (presence of oxygen and dry environment).The geothermal application, where heat is extracted from the earth, requires thesensor to be operated in humid condition in the absence (or very low concentration)of oxygen, and this poses a problem. Temperature cycle operation and smartdata evaluation might also be an option for future development. Along with the sensor performance testing, a study on the detection mechanismwas also performed for SO2 sensor, both experimentally and theoretically. The experimentincluded the study of the species formed on the surface of the catalystwith DRIFT (diffuse reflectance infrared frourier transform) spectroscopy and theanalysis of the residual gas with mass spectroscopy. Explanatory investigation ofthe surface reactions was performed using quantum-chemical calculations. Theoreticalcalculations of the infrared (IR) vibration spectra was employed to supportthe identification of peaks in the DRIFT measurement. Based on the study on theresidual gas analysis and quantum-chemical calculations, a reaction mechanismfor the SO2 molecule adsorption on the sensor surface was suggested.
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Ross, Mark. "An embedded control and display system for a laser-based mid-infrared hyperspectral imager /." St Andrews, 2008. http://hdl.handle.net/10023/731.
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Abbassi, Baharanchi Atid. "Multidisciplinary Modeling, Control, and Optimization of a Solid Oxide Fuel Cell/Gas Turbine Hybrid Power System." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_theses/208.
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This thesis describes a systematical study, including multidisciplinary modeling, simulation, control, and optimization, of a fuel cell - gas turbine hybrid power system that aims to increase the system efficiency and decrease the energy costs by combining two power sources. The fuel cell-gas turbine hybrid power systems can utilize exhaust fuel and waste heat from fuel cells in the gas turbines to increase system efficiency. This research considers a hybrid power system consisting of an internally reforming solid oxide fuel cell and a gas turbine. In the hybrid power system, the anode exhaust, which contains the remainder of the fuel, is mixed with the cathode exhaust as well as an additional supply of fuel and compressed air and then burned in a catalytic oxidizer. The hot oxidizer exhaust is expanded through the turbine section, driving an electric generator. After leaving the gas turbine, the oxidizer exhaust passes through a heat recovery unit in which it preheats the compressed air that is to be supplied to the fuel cell and the oxidizer. This research concentrates on multidisciplinary modeling and simulation of the fuel cell-gas turbine hybrid power system. Different control strategies for the power sharing between the subsystems are investigated. Also, the power electronics interfaces and controls for the hybrid power system are discussed. Two different power sharing strategies are studied and compared. Simulation results are presented and analyzed. Transient response of the hybrid energy system is studied through time-domain simulation. In addition, in this effort, Particle Swarm Optimization (PSO) is used to optimize the power sharing for the hybrid power system to increase the efficiency and decrease the fuel consumption.
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Udell, Thomas Gregory. "Reducing emissions of older vehicles through fuel system conversion to natural gas." Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/19896.
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Wang, Chen. "Transient performance simulation of gas turbine engine integrated with fuel and control systems." Thesis, Cranfield University, 2016. http://dspace.lib.cranfield.ac.uk/handle/1826/9881.
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Two new methods for the simulation of gas turbine fuel systems, one based on an inter-component volume (ICV) method, and the other based on the iterative Newton Raphson (NR) method, have been developed in this study. They are able to simulate the performance behaviour of each of the hydraulic components such as pumps, valves, metering unit of a fuel system, using physics-based models, which potentially offer more accurate results compared with those using transfer functions. A transient performance simulation system has been set up for gas turbine engines based on an inter-component volume (ICV). A proportional- integral (PI) control strategy is used for the simulation of engine control systems. An integrated engine and its control and hydraulic fuel systems has been set up to investigate their coupling effect during engine transient processes. The developed simulation methods and the systems have been applied to a model turbojet and a model turboshaft gas turbine engine to demonstrate the effectiveness of both two methods. The comparison between the results of engines with and without the ICV method simulated fuel system models shows that the delay of the engine transient response due to the inclusion of the fuel system components and introduced inter-component volumes is noticeable, although relatively small. The comparison of two developed methods applied to engine fuel system simulation demonstrate that both methods introduce delay effect to the engine transient response but the NR method is ahead than the ICV method due to the omission of inter-component volumes on engine fuel system simulation. The developed simulation methods are generic and can be applied to the performance simulation of any other gas turbines and their control and fuel systems. A sensitivity analysis of fuel system key parameters that may affect the engine transient behaviours has also been achieved and represented in this thesis. Three sets of fuel system key parameters have been introduced to investigate their sensitivities, which are, the volumes introduced for ICV method applied to fuel system simulation; the time constants introduced into those first order lags tosimulate the valve movements delay and fuel spray delay effect; and the fuel system key performance and structural parameters.
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Andersson, Henrik. "Model Based Control of Throttle, EGR and Wastegate : A System Analysis of the Gas Flows in an SI-Engine." Thesis, Linköpings universitet, Fordonssystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-140533.
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Due to governmental requirements on low exhaust gas emissions and the drivers request of fast response, it is important to be able to control the gas flow in a spark ignited engine accurately. The air into the cylinder is directly related to the torque generated by the engine. The technique with recirculation of exhaust gases (EGR) affect the air flow into the cylinder and increase the complexity of the control problem. In this thesis a mean value model for a spark ignited engine has been created. The basis was a diesel model from Linköping University that has been modified and parameterized with data from a test cell. The model has been used to study the gas exchange system with respect to the dynamic behaviors and nonlinearities that occur when the three actuators (throttle, wastegate and EGR-valve) are changed. Based on this analysis, some different control strategies have been developed and tested on the model. The presented results show that different control strategies give different behaviors and there is a trade-off between fast torque response and high precision for controlling the EGR-ratio. A control strategy is proposed containing two main feedback loops, prefiltering of the reference signal and a feedforward part.
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Jonas, Susanne. "Automatic Status Logger For a Gas Turbine." Thesis, Linköping University, Department of Science and Technology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11020.
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<p>The Company Siemens Industrial Turbo Machinery AB manufactures and launches in operation among other things gas turbines, steam turbines, compressors, turn-key power plants and carries out service for components for heat and power production. Siemens also performs research and development, marketing, sales and installations of turbines and completes power plants, service and refurbish.</p><p>Our thesis for the engineering degree is to develop an automatic status log which will be used as a tool to control how the status of the machine is before and after technical service at gas turbines. Operational disturbances will be registered in a structured way in order to get a good possibility to follow up the reliability of the application.</p><p>An automatic log function has been developed and will be activated at start, stop and shutdown of the turbine system. Log files are created automatically and get a name with the event type, the date and the time. The files contain data as timestamp, name, measured values and units of the signals which are going to be analyzed by the support engineers. They can evaluate the cause of the problem using the log files.</p>
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Pitz, Nora [Verfasser], Harald [Akademischer Betreuer] Appelshäuser, and Christoph [Akademischer Betreuer] Blume. "Gas system, gas quality monitor and detector control of the ALICE Transition Radiation Detector and studies for a pre-trigger data read-out system / Nora Pitz. Gutachter: Harald Appelshäuser ; Christoph Blume." Frankfurt am Main : Univ.-Bibliothek Frankfurt am Main, 2012. http://d-nb.info/1044412801/34.
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Wredh, Simon. "Neural Network Based Model Predictive Control of Turbulent Gas-Solid Corner Flow." Thesis, Uppsala universitet, Signaler och system, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-420056.
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Over the past decades, attention has been brought to the importance of indoor air quality and the serious threat of bio-aerosol contamination towards human health. A novel idea to transport hazardous particles away from sensitive areas is to automatically control bio-aerosol concentrations, by utilising airflows from ventilation systems. Regarding this, computational fluid dynamics (CFD) may be employed to investigate the dynamical behaviour of airborne particles, and data-driven methods may be used to estimate and control the complex flow simulations. This thesis presents a methodology for machine-learning based control of particle concentrations in turbulent gas-solid flow. The aim is to reduce concentration levels at a 90 degree corner, through systematic manipulation of underlying two-phase flow dynamics, where an energy constrained inlet airflow rate is used as control variable. A CFD experiment of turbulent gas-solid flow in a two-dimensional corner geometry is simulated using the SST k-omega turbulence model for the gas phase, and drag force based discrete random walk for the solid phase. Validation of the two-phase methodology is performed against a backwards facing step experiment, with a 12.2% error correspondence in maximum negative particle velocity downstream the step. Based on simulation data from the CFD experiment, a linear auto-regressive with exogenous inputs (ARX) model and a non-linear ARX based neural network (NN) is used to identify the temporal relationship between inlet flow rate and corner particle concentration. The results suggest that NN is the preferred approach for output predictions of the two-phase system, with roughly four times higher simulation accuracy compared to ARX. The identified NN model is used in a model predictive control (MPC) framework with linearisation in each time step. It is found that the output concentration can be minimised together with the input energy consumption, by means of tracking specified target trajectories. Control signals from NN-MPC also show good performance in controlling the full CFD model, with improved particle removal capabilities, compared to randomly generated signals. In terms of maximal reduction of particle concentration, the NN-MPC scheme is however outperformed by a manually constructed sine signal. In conclusion, CFD based NN-MPC is a feasible methodology for efficient reduction of particle concentrations in a corner area; particularly, a novel application for removal of indoor bio-aerosols is presented. More generally, the results show that NN-MPC may be a promising approach to turbulent multi-phase flow control.
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García, Edith. "Automatic Status Logger for a Gas Turbine." Thesis, Linköping University, Department of Science and Technology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11590.
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<p>The Company Siemens Industrial Turbo Machinery AB manufactures and launches in operation among other things gas turbines, steam turbines, compressors, turn-key power plants and carries out service for components for heat and power production. Siemens also performs research and development, marketing, sales and installations of turbines and completes power plants, service and refurbish.</p><p>Our thesis for the engineering degree is to develop an automatic status log which will be used as a tool to control how the status of the machine is before and after technical service at gas turbines. Operational disturbances will be registered in a structured way in order to get a good possibility to follow up the reliability of the application.</p><p>An automatic log function has been developed and will be activated at start, stop and shutdown of the turbine system. Log files are created automatically and get a name with the event type, the date and the time. The files contain data as timestamp, name, measured values and units of the signals which are going to be analyzed by the support engineers. They can evaluate the cause of the problem using the log files.</p>
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Ludvigsen, Marius, and Christian Wallervand. "Gamifying an Oil-Gas-Water Separation Process in a Process Control System to Improve Operators' Motivation, Skills, and Process Understanding." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for datateknikk og informasjonsvitenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18798.
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Serious games and its related fields have lately received a lot of interest due to their potential for training and education. Serious games can be defined as (digital) games that are used for reasons other than entertainment. Gamification can be related to serious games and can be defined as the process of game-thinking and game mechanics to engage users and solve problems.The initiator of this project was ABB. ABB delivers a process control system used to control the processes of an oil production facility. One of these processes is separating oil and gas from water. A simulator of this separation process was developed and then implemented into HawkEye, a prototype of the existing process control system. We have worked with ABB to gamify the implemented separation process using different game mechanics to discover whether gamification can be used to improve a process operator's skills, understanding, and motivation. In a process control system, the process at hand has the highest priority due to its severity, which means that the gamified elements have to be subtle.The implemented separation process was tested on two groups consisting of ten people each, most of them students. The two groups carried out the separation process twice, one time without the gamified elements and one time with the gamified elements. The difference between the two groups was in which order they did the separation process.After the experiment, data was gathered from the implemented system, and also from a survey, a quiz and interviews that we conducted. These data were analysed to determine if the gamified separation process yielded better results than the non-gamified separation process. Results from the experiments showed that there was no improvement in the participants' skill or understanding because of gamification, but that the gamified elements had a positive effect on both groups' motivation.
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Ghadhban, Zaid T. "Design of a stand alone fully integrated communications, monitoring and control system for a novel remote sub-sea gas facility." Curtin University of Technology, Faculty of Engineering, Department of Chemical Engineering, 2008. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=120520.
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The growing demand for hydrocarbon fluids, and the future expectation of insufficient onshore reserves, is driving the exploration and development of off-shore oil and gas fields. A significantly increasing number of the new fields are situated in deep water, placing significant constraints on the application of conventional platform (sea surface) systems. This has, by necessity, generated the rapid growth of sub-sea processing technology.<br>An integral part of a novel sub-sea natural gas dehydration project is the need to design and develop a communications, monitor and control system that is extremely reliable within a harsh marine environment. The off shore gas gathering and processing facility will be unmanned, therefore the entire ongoing operation of the sub-sea facility, and any sea surface equipment, will be dependent on the proper functioning of the communication system. System redundancy and low power consumption are also important issues.<br>The continuous bi-directional transmission of information between the field and shore-based control centres, together with the complexity of any maintenance / repair missions requires an extremely highly reliable system. The prospect of false alarms must be maintained at an absolute minimum.<br>Within this thesis the history and development of ocean based communications up to current state-of-the art technology is reviewed. Based on the unique and demanding requirements of the sub-sea gas processing facility, detailed recommendations are made for both a primary and back-up communication systems that meet the given criteria of being robust and having very low power requirements.
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Katewa, Luis. "Pre-study and system design of a mobile platform simulator system." Thesis, KTH, Hälsoinformatik och logistik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-288928.
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There are many ways to produce energy, using e.g. gas or hydro turbines. To guarantee a stable power output, it is important to consider components that could control and adjust the output power automatically. The intention of this thesis work is to carry out a pre-study and system design of a mobileplatform simulator system that could be used by companies like Siemens and help them to reduce their OPEX (Operational expenditure) and easily evaluate their AVR (AutomaticVoltage Regulator) solutions and test improvements. In this document, Siemens has decided to call the simulator system, MPSS (Mobile Platform Simulator System). The pre-study includes the theory behind energy production, synchronous generator, simulator system, AVR, control systems and electrical grid. Furthermore, the pre-study includes selection of the proposed components for the simulator system and design of the complete simulator system that will be built by the Siemens R&D engineers at a later stage. The Mobile Platform Simulator System (MPSS) is intended to test the AVR performance, which is a component with its prime purpose being to maintain the output voltage values from the generator at a fixed value, regardless of the current being drawn by the load. It is important that these output values are constantly regulated during the process of producing electricity, so that problems such as overvoltage, overcurrent etc. can be prevented. The MPSS will also be able to simulate real working scenarios e.g. from the different components of an energy production system, such as gas and hydro turbine, synchronous generator, AVR, electrical grid and serve for personnel training. The MPSS will consist of three main components; Simulator, AVR and control system. Therefore, the report will initially provide the background and general theory behind the synchronous generator, AVR and control system used in power generation systems. General information about the electrical grid is also provided. Furthermore, the report suggests the best possible choice for the necessary components to build a MPSS as well instructions on how to perform event simulation. The necessary documentation, including a circuit diagram to support the building of the MPSS by the R&D engineers at late stage, is also provided. Finally, the general analysis of the technical and non-technical aspects related to the choice of components, work process, method and result are discussed in the end of this report.<br>Det finns många sätt att producera energi, genom användning av exempelvis gas- eller hydroturbiner. För att garantera en stabil produktion är det viktigt att noga överväga komponenter, som kan styra och justera uteffekten automatiskt. Avsikten med detta arbete är att göra en förstudie och systemdesign av ett simulatorsystem som kan användas av företag som Siemens, med avsikt att hjälpa dem att minska sin driftskostnad(OPEX), och lättare kunna utvärdera sina AVR-lösningar (Automatic Voltage Regulator)och möjliga testförbättringar. För detta arbete har Siemens bestämt att kalla systemet för ett mobilt simulatorsystem eller MPSS (Mobile Platform Simulator System). Förstudien innehåller teorin bakom energiproduktion, synkrongenerator generator, simulatorsystem, AVR, styrsystem och elnät. Ett urval av de olika komponenterna för simulatorsystemet och en slutgiltig design tas fram. Det kompletta simulatorsystemet kommer i ett senare skede att byggas av forsknings- och utvecklingsingenjörerna på Siemens. Simulatorsystemet är avsett att testa AVR-prestanda, vilket är en komponent vars huvudsakliga syfte är att upprätthålla utspänningsvärdena från en generator inom ett fast intervallvärde, oberoende av vilken effekt som en last drar. Det är viktigt att utgångsvärden ständigt regleras under elproduktionsprocesser så att utgångsvärden hålls inom systemets tillåtna gränser så att problem som över-/underspänning, över-/underström, över-/underfrekvens etc. kan förhindras. Simulatorsystemet kommer också att kunna simulera verkliga arbetsscenarier för olika komponenter i ett energiproduktionssystem, såsom gas- och hydroturbin, synkrongenerator, AVR och laster, exempelvis elnät, samt kunna användas vid personalutbildning. Simulatorsystemet kommer att bestå av tre huvudkomponenter; Simulator, AVR och styrsystem. Inledande beskrivning av arbetets bakgrund och allmän teoretisk kring komponenterna synkrongenerator, AVR och styrsystem, som används vid i kraftgenereringssystem, ges. Även en allmän bakgrund om elnätet och dess funktion presenteras. Därefter presenteras förslag på bästa möjliga val av nödvändiga komponenter för att bygga ett simulatorsystem. Ett förslag om hur händelse simulering görs samt vilken nödvändig dokumentation och kretsdiagram som behövs för att bygga ett simulatorsystem presenteras. I slutet av detta arbete presenteras en allmän analys av de tekniska och icke-tekniska aspekterna kring val av komponenter, arbetsprocess samt metod och resultat.
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Hoang, Thai Minh. "Quantum control of a many-body system in a spin-1 Bose-Einstein condensate." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50358.
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Ultracold atoms provide a powerful tool for studying quantum control of interacting many-body systems with well-characterized and controllable Hamiltonians. In this thesis, we demonstrate quantum control of a many-body system consisting of a ferromagnetic spin-1 Bose-Einstein condensate (BEC). By tuning the Hamiltonian of the system, we can generate either a phase space with an unstable hyperbolic fixed point or a phase space with an elliptical fixed point. A classical pendulum with a stable oscillation about the "down" position and an inverted pendulum with unstable non-equilibrium dynamics about the "up" position are classical analogs of the quantum spin dynamics we investigate in this thesis. In one experiment, we dynamically stabilize the system about an unstable hyperbolic fixed point, which is similar to stabilizing an inverted pendulum. In a second experiment, we parametrically excite the system by modulating the quadratic Zeeman energy. In addition, we demonstrate rectifier phase control as a new method to manipulate the quantum states of the many-body system. This is similar to parametric excitation and manipulation of the oscillation angle of a classical pendulum. These experiments demonstrate the ability to control a quantum system realized in a spinor BEC, and they also can be applied to other quantum systems. In addition, we extend our studies to atoms above the Bose-Einstein transition temperature, and we present results on thermal spin relaxation processes and equilibrium spin populations.
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Yilmaz, Oguz. "Participation Of Combined Cycle Power Plants To Power System Frequency Control: Modeling And Application." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607228/index.pdf.
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This thesis proposes a method and develops a model for the participation of a combined cycle power plant to power system frequency control.
Through the period of integration to the UCTE system, (Union for Coordination of Transmission of Electricity in Europe) frequency behavior of Turkey&rsquo<br>s grid and studies related to its improvement had been a great concern, so is the reason that
main subject of my thesis became as &ldquo<br>Power System Frequency Control&rdquo<br>.
Apart from system-wide global control action (secondary control)<br>load control loops at power plants, reserve power and its provision even at the minimum capacity generation stage, (primary control) are the fundamental concerns of this subject.
The adjustment of proper amount of reserve at the power plants, and correct system response to any kind of disturbance, in the overall, are measured by the quality of the
frequency behaviour of the system.
A simulator that will simulate a dynamic gas turbine and its control system model, together with a combined cycle power plant load controller is the outcome of this thesis.
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Klapdor-Kleingrothaus, Thorwald [Verfasser], and Ulrich [Akademischer Betreuer] Landgraf. "Gas gain studies for MicroMegas detectors and development of the high voltage control system for the detectors of the ATLAS new small wheel upgrade." Freiburg : Universität, 2019. http://d-nb.info/1180285689/34.
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Cabaret, Sébastien. "Algorithmes de contrôles avancés pour les installations à gaz du Large Hadron Collider au CERN suivant le framework et l'approche dirigée par les modèles du projet Gas Control System." Amiens, 2008. http://www.theses.fr/2008AMIE0104.
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Cette thèse présente les résultats obtenus dans le cadre de mes recherches au CERN (Centre Européen pour le Recherche Nucléaire). Elle traite de l’intégration d’algorithmes de contrôles avancés pour les 21 installations à Gaz du nouvel accélérateur de particules, le LHC (Large Hadron Collider). La démarche s’inscrit dans le choix stratégique du projet appelé GCS (Gas Control System) : produire l’ensemble des systèmes de contrôle-commande par des déclinaisons récursives de production automatique des applications. Les équipements de contrôles prévus à cet effet sont des automates programmables industriels et des systèmes de supervisions industrielles. Dans ce contexte, certains algorithmes de contrôles avancés se démarquent par leur capacité à s’adapter à ces exigences : le prédicteur de Smith (compensation des retards), les méthodes prédictives (robustesses et réglages conviviaux), le contrôleur RST (structure ouverte et résolution polynomiale) et les identifications paramétriques en ligne (utilisation des modèles de comportements). Les travaux s’articulent en quatre points. Le premier traite de la synthèse des stratégies d’identification et de régulations avancées dans un automate programmable industriel. Le deuxième exprime la validité d’implémentation. Le troisième développe la systématisation d’utilisation d’algorithmes de régulation, dans un projet empreint de deux méthodologies de réalisations innovantes : un framework de développement et une réalisation dirigée par les modèles. Enfin le quatrième s’attache à fournir aux experts de processus à gaz, une interface standard permettant l’utilisation efficace des algorithmes de régulation avancée<br>This thesis highlights my final research results at CERN (European Nuclear Research Center). It deals with advanced control algorithms integrated for the 21 Gas System installations of the new particles accelerator named LHC (Large Hadron Collider). The process is enclosed into the strategic GCS project (Gas Control System): producing the overall control systems by recursive declinations via an automation production application. The controls equipments engage are industrials Programmable Logic Controllers combine with SCADA systems (System Control And Data Acquisition). In this context some advanced control algorithms are well adapted by its capability to comply with these typical needs: the Smith Predictor (dead time compensation), the predictive methods (robustness and convivial tuning), the RST controller (open structure and polynomial resolution) and the online parametric identification methods. The work presented is structured in four points. First, it deals with the synthesis of advanced control loop and identification methods for an industrial Programmable Logic Controller. Second, it exposes the implementation validity. Third, it develops the systemic use of advanced control loops in a large scale project build with two innovative methodologies: a framework of development and a model driven realization. Fourth, it concludes by providing to the Gas process experts a standard interface allowing an efficient use of advanced control algorithms
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Kleman, Björn, and Henrik Lindgren. "Evaluation of model-based fault diagnosis combining physical insights and neural networks applied to an exhaust gas treatment system case study." Thesis, Linköpings universitet, Fordonssystem, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-176650.
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Fault diagnosis can be used to early detect faults in a technical system, which means that workshop service can be planned before a component is fully degraded. Fault diagnosis helps with avoiding downtime, accidents and can be used to reduce emissions for certain applications. Traditionally, however, diagnosis systems have been designed using ad hoc methods and a lot of system knowledge. Model-based diagnosis is a systematic way of designing diagnosis systems that is modular and offers high performance. A model-based diagnosis system can be designed by making use of mathematical models that are otherwise used for simulation and control applications. A downside of model-based diagnosis is the modeling effort needed when no accurate models are available, which can take a large amount of time. This has motivated the use of data-driven diagnosis. Data-driven methods do not require as much system knowledge and modeling effort though they require large amounts of data and data from faults that can be hard to gather. Hybrid fault diagnosis methods combining models and training data can take advantage of both approaches decreasing the amount of time needed for modeling and does not require data from faults. In this thesis work a combined data-driven and model-based fault diagnosis system has been developed and evaluated for the exhaust treatment system in a heavy-duty diesel engine truck. The diagnosis system combines physical insights and neural networks to detect and isolate faults for the exhaust treatment system. This diagnosis system is compared with another system developed during this thesis using only model-based methods. Experiments have been done by using data from a heavy-duty truck from Scania. The results show the effectiveness of both methods in an industrial setting. It is shown how model-based approaches can be used to improve diagnostic performance. The hybrid method is showed to be an efficient way of developing a diagnosis system. Some downsides are highlighted such as the performance of the system developed using data-driven and model-based methods depending on the quality of the training data. Future work regarding the modularity and transferability of the hybrid method can be done for further evaluation.
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Petr, Vojtěch. "Využití bezpečnostního PLC pro řízení plynových hořáků." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-254466.
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The topic of this diploma thesis is the safety of a gas burner control. The aim is to fully automate the system by using a gas burner safety control system (Fail-Safe PLC) so as to reduce to minimum the risks. Because great emphasis is placed on safety, so Czech standards and what is connected with safety control systems are discussed. This project is implemented in cooperation with industrial automation company ElektroMAR a. s.
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Petipas, Floriane. "Conception et conduite de systèmes d’électrolyse à haute température alimentés par des énergies renouvelables." Thesis, Paris, ENMP, 2013. http://www.theses.fr/2013ENMP0015/document.
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Le « Power-to-Gas » pourrait devenir une solution attractive pour le stockage des énergies renouvelables, pourvu que des électrolyseurs soient capables de fonctionner efficacement dans des conditions intermittentes à un coût abordable. Ce travail a pour objectif d'évaluer la faisabilité technique du fonctionnement intermittent de systèmes d'électrolyse à oxyde solide (SOEC) autour de 1073 K. Des conditions réalistes défavorables sont considérées, consistant en un système autonome sans source externe de chaleur et intégrant une compression d'hydrogène à 3 MPa. La problématique se compose de deux aspects : i) la gamme de fonctionnement du système, limitée à 60-100% en raison de gradients thermiques, est étendue via des stratégies de contrôle efficaces, ii) des procédures sont définies pour minimiser l'impact de l'intermittence sur la durée de vie. Premièrement, une stratégie de contrôle modulaire est proposée, consistant en l'utilisation de plusieurs unités indépendantes qui fonctionnent dans une gamme de puissance tolérable, ou sont arrêtées. La gamme de fonctionnement du système est ainsi étendue à 15-100% dans le cas de quatre unités. Une stratégie de contrôle complémentaire, consistant en un chauffage électrique interne, permet d'étendre la gamme de fonctionnement en réduisant les gradients thermiques, mais elle est susceptible de diminuer la durée de vie. Elle n'est donc appliquée qu'à une unité afin de suivre la courbe de charge et d'étendre la gamme de fonctionnement du système à 3-100%. Deuxièmement, 1800 cycles électriques on-off sont appliqués à une SOEC sans impact sur la dégradation, ce qui montre que des arrêts/démarrages répétés ne diminuent pas la durée de vie. De plus, des procédures de démarrage, standby et arrêt sont définies. Enfin, deux études de systèmes Eolien-SOEC et Solaire-SOEC fonctionnant pendant un an montrent que, avec les stratégies de contrôle implémentées, le système SOEC stocke la puissance appliquée avec un rendement de 91% sur PCS en moyenne, alors que les unités fonctionnent dans des conditions tolérables mis à part une unité qui suit la courbe de charge et est susceptible d'avoir une durée de vie diminuée<br>Power-to-Gas could become an attractive solution for renewable electricity storage, provided that affordable electrolysers are able to operate efficiently under intermittent conditions. This work aims to assess the technical feasibility of operating intermittently a Solid Oxide Electrolysis Cell (SOEC) system around 1073 K. Realistic unfavourable conditions are considered, consisting in a standalone system operated with no external heat source and integrating hydrogen compression to 3 MPa. Two challenges are tackled in this work: i) the system power load range, limited to 60-100% due to thermal gradients, is extended via efficient control strategies, ii) procedures are defined to minimise the impact of the intermittency on the lifetime. First, a modular control strategy is proposed, consisting in the use of several SOEC units which are either operated in a tolerable power load range, or switched off. The system power load range is hence extended to 15-100% in the case of four units. A complementary control strategy, consisting in internal electrical heating, enables to extend the load range by reducing thermal gradients, but it may decrease the lifetime. Thus, it is applied to only one unit for it to follow the load curve and extend the system power load range to 3-100%. Secondly, 1800 on-off electric cycles are applied to an SOEC with no degradation increase, which shows that repeated start/stops do not decrease the lifetime. Start-up, standby and shut-down procedures are also defined. Finally, two case studies of Wind-SOEC and Solar-SOEC systems operated over one year show that, with the implemented control strategies, the SOEC system stores the applied power with an average efficiency of 91% vs. HHV, while units operate under tolerable conditions apart from one unit which follows the load curve and may have a decreased lifetime
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Spindola, Rafael Barbosa. "Controle autom?tico para inje??o otimizada de g?s em po?os de petr?leo equipados para funcionamento com g?s lift cont?nuo." Universidade Federal do Rio Grande do Norte, 2003. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15518.
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Made available in DSpace on 2014-12-17T14:56:21Z (GMT). No. of bitstreams: 1
RafaelBS.pdf: 1607732 bytes, checksum: d5ad875fd4dc09637b9932966f4df8c0 (MD5)
Previous issue date: 2003-07-16<br>The continuous gas lift method is the main artificial lifting method used in the oil industry for submarine wells, due to its robustness and the large range of flow rate that the
well might operate. Nowadays, there is a huge amount of wells producing under this mechanism. This method of elevation has a slow dynamics due to the transients and a
correlation between the injected gas rate and the of produced oil rate. Electronics controllers have been used to adjust many parameters of the oil wells and also to improve the efficiency of the gas lift injection system. This paper presents a intelligent control system applied to continuous gas injection in wells, based in production s rules, that has the target of keeping the wells producing during the maximum period of time, in its best operational condition, and doing automatically all necessary adjustments when occurs some disturbance in the system. The author also describes the application of the intelligent control system as a tool to
control the flow pressure in the botton of the well (Pwf). In this case, the control system actuates in the surface control valve<br>O m?todo de eleva??o por g?s lift cont?nuo ? o principal m?todo de eleva??o artificial utilizado, principalmente, para produ??o em po?os submarinos devido a sua robustez e a larga faixa de vaz?o que o po?o pode produzir. H? um grande percentual de po?os produzindo sob este mecanismo no Brasil. Este tipo de m?todo de eleva??o apresenta algumas caracter?sticas pr?prias, sendo uma delas sua din?mica lenta devido aos transientes e outra ? a exist?ncia de uma correla??o entre a vaz?o de g?s injetado e a vaz?o de ?leo produzido. Controladores eletr?nicos t?m sido utilizados para realizar ajustes em alguns par?metros do po?o e melhorar
a efici?ncia de inje??o de g?s lift. Este trabalho apresenta um sistema inteligente de controle autom?tico da inje??o de
g?s, baseando-se em regras de produ??o, que busca manter os po?os equipados para g?s lift cont?nuo produzindo o maior tempo poss?vel, nas condi??es ?timas de opera??o e que faz os ajustes autom?ticos necess?rios quando ocorre alguma perturba??o no sistema. Mostra-se que ? poss?vel, utilizando o sistema inteligente apresentado, exercer o controle da press?o de fluxo no fundo do po?o (Pwf) atrav?s da manipula??o da abertura da v?lvula de controle de
superf?cie
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Bednář, František. "Analýza možností akumulační tepelné elektrárny v podmínkách ČR." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231650.
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This diploma’s thesis analyzes the possibility of accumulation of thermal power plants in the Czech Republic. The thesis is divided into several parts. The first part describes the different types of storage power plants, the historical development of power storage for compressed air and the appropriateness of their location. The second part is devoted to the design of storage power plant for compressed air in South Moravia. In the next chapter, a calculation is made of all equipment storage power plant, including turbo-compressor, combustion chamber, combustion turbines, the volume of storage tanks and two heat exchangers. The last part is the economic analysis of the return on investment of such a project.
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Chun-Chen, Lin, and 林俊臣. "Control of A Gas Flow Calibration System." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/81003939859308915658.
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碩士<br>中原大學<br>化學工程研究所<br>86<br>The fluid transients caused by the enormous change of flow rate may be harmful to the piping system. The main purpose of this research is to discuss the fluid transients of a gas flow calibration system. Mathematical models of the fluid transients were derived by the principle of mass and momentum balance. The characteristic method was applied for numerical analysis. The simulation studies on the fluid transients of the calibration system were executed by this method. The effects of different operating conditionson the fluid transients were investigated in the simulation studies. PI control law was proposed to implement to the pressure and flow rate control of calibration system. The controller settings were obtained by the continuous cycling method and then fine-tuned using the IAE criterion. Simulation results show that the pressure and flow rate of the system would change enormously by some operating conditions such as the time of valve closing. The changes of the pressure or flow rate during the transient are larger for theshorter closing time. Since the pressure of the system is sensitive to the valve opening , control of pressure would be more difficult than that of flow rate. And the results show that the controlled point nearest to the valve have the best control performance of flow rate in the single pipeline system.
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Hsieh, Wen-Hao, and 謝文豪. "The Intelligent Control of Gas-Assisted Injection Molding System." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/09288108772197083376.
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碩士<br>國立臺北科技大學<br>車輛工程系碩士班<br>91<br>The object of this research is to develop an intelligent controller for controlling the gas-assisted injection molding system. The application of model based classical control theory needs accurate system''s mathematical model for designing controller. However, in tradition injection molding, the macromolecule plastics is unsteady flowing in the process of being stuffing, so it''s difficult to establish or estimate its mathematic model. In this research, the model-free intelligent control strategy was employed to control the gas-assisted injection molding system. In this study, three control strategies were pro-posed: (1) PID controller, (2) fuzzy controller, and (3) self-organizing fuzzy controller (SOFC) to control the gas-assisted injection molding system. The intelligent controls of the gas-assisted injection molding system control performances were satisfactory by using these control strategies from experimental results shown.
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張明詔. "Investigation of Gas Pressure Regulation and Injection Control System." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/77275599615750454311.
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碩士<br>中原大學<br>機械工程學系<br>85<br>Gas injection molding process, being an innovative technology, has advantages of saving material, reducing warpage, shrinkage and cycling time, etc. To achieve these advantages, gas injection control system play an important key.
In this paper, experiments have been conducted to characterize the existing gas injection system. Then a PC based computer control system was then developed with man／machine control interface panel to conduct the closed-loop pressure control.
Currently, there are two kinds of pressure regulation. One is gas volume control system and the other is gas pressure regulating control system. Gas volume control system is simply a boost pressure control. The pressure during packing stage is not easy to hold and multiple stages of pressure settings are not easy to achieve either. Compared to the gas volume control system, pressure regulating control system could more precisely control the pressure even for multiple gas injection points. As present implementation, these two control systems are all integrated with programmable controller. The systems are lack of flexibility for multiple control purpose.
To improve the control capabilities of programmable controller based, a PC based control system is designed and characterized. To facilitate operating the machine, we designed multiple editing screens for the man／machine interface control. Except the main menu, sub-menus are modularized to simplify the operation for users. It is not only easy to operate and easy to learn for users, but also easy to maintain and revise.
From the experiment results, system show 0∼5 bars error to the set values (in the range of 150 bar) under the closed-loop pressure control. Consider the deviations base on the error of the pilot-pressure, the error will be 0.725％. This is comparative small. If the error for the gas penetration length is limited to 6％ all parts full fill the error criteria. This is another performance index which show the repeatability of the process.
Compared the pressure rise time with the Airmold system, pressure will rise to its set-value within 0.2 to 0.4 seconds. In addition to the pressure control system test, gas volume control system was also tested. Pressure rise time to the set-value at first stage is approximately 0.3 to 0.5 seconds, the rise time for the second stage depends on the flow rate of the booster.
The developed system and the Airmold system are all available to control the pressure under different set-values. Base on the experiments, it is found that the developed system has better performance than the Airmold system. As we mention previously, gas volume control system has poor performance when controlling pressure at different set-values.
Controller for the presently develop system and Airmold system are all PID structures. Cinpres system is purely a logic process controller controlled system which has limited applications. The developed system has better performance and flexible structure for the future applications.
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Tsai, Tsung-Hsien, and 蔡宗憲. "Application of the Gas-Assisted Injection Molding Control System." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/6trqs6.
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碩士<br>國立臺北科技大學<br>車輛工程系所<br>93<br>Traditional injection molding machine (TIMM) generally employs an open-loop control strategy for performing injection molding of plastic products.However, such control strategy cannot satisfy for injection molding requirement in complicated geometric shape with large size or hollow plastic products.Therefore, this work developed a closed-loop control strategy to control the TIMM during the filling and holding phases of injection molding;then the high-pressure gas of the gas assisted injection molding system was applied in holding phase of the post-filling process for achieving injection molding of plastic products.
The TIMM incorporated the gas-assisted injection molding system that was called gas-assisted injection molding control system (GAIMCS).The GAIMCS is clearly a nonlinear with uncertain system; hence, designing a model-based controller to control it is difficult because its mathematical model is hard to establish accurately.This work proposes model-free intelligent control strategies: (1) traditional fuzzy controller (TFC), (2) grey prediction fuzzy controller (GPFC), and (3) new modifying self-organizing fuzzy controller (NMSOFC),to control the GAIMCS for evaluating control performance of the system. The GPFC and NMSOFC have better control performance in quickening the rise time and reducing the steady-state error than does TFC,as verified by experimental results.
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Wang, Chia-Chuan, and 王嘉傳. "A gas flow control system integrating MEMS flow sensor." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/17698419680003583299.
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碩士<br>國立交通大學<br>工學院半導體材料與製程設備學程<br>101<br>Gas control in the electronics industry and the semiconductor manufacturing are very important key process. Commonly in gas flow control system the key product is use mass flow controller to control flow rate generally called MFC (Mass Flow controller).Mass flow controller is combined the flow sensor, proportional valve, PID controller device, but when any device needs to re-calibration or maintenance and change the specifications in the production line or re-design will cause a trouble and inconvenience.
This thesis focused on use new generation of MEMS fabrication process flow sensor to replace the traditional thermal flow sensor, and introduce how to combine independent proportional valve, PID controller, PLC and HMI to do a like MFC function flow control system. Because each component are independent modular system, so not only more convenient to maintenance and calibration, and via the independent modular components can be separately applied to various gas flow control system, and can be effectively used in industrial equipment.
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Ebrahimi, Kambiz M., and R. Whalley. "Automotive gas turbine regulation." 2004. http://hdl.handle.net/10454/2636.
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No<br>A multivariable model of an automotive gas turbine, obtained from the linearized system equations is investigated. To facilitate vehicle speed changes, whilst protecting the system against thermal damage, control of the power turbine inlet gas temperature and gas generator speed is proposed by feedback regulation. Fuel flow and the power turbine nozzle area variations are the selected, manipulatable inputs. Owing to the limited control energy available for regulation purposes a multivariable, optimum, minimum control effort strategy is employed in the inner loop controller design study. Simulated, open and closed loop system responses are presented for purposes of comparison. Significant improvements in the transient response interaction reaction times and low steady state output interaction achieved using passive compensation and output feedback alone. Simplification of the closed loop configuration is proposed in the final implementation without performance penalties.