Дисертації з теми "Turbocharger control"
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1
Storm, Josefin. "Heat Transfer Modeling for Turbocharger Control." Thesis, Linköpings universitet, Fordonssystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-141949.
Анотація:
Turbocharging is a way to stay competitive on the market where there are increasing demands on fuel consumption and engine performance. Turbocharging lets the engine work closer to its maximum power and thereby reduces the relative losses due to pumping and friction. The turbocharger is exposed to big temperaturedifferences and heat flows will occur both internally between the turbine and the compressor as well as between the turbocharger and its surroundings. Away to get a better understanding of the behaviour of the turbocharger is to understand the heat flows better. This thesis is therefore aimed at investigating theeffect of heat transfer on the turbocharger. In the thesis, different ways of accountfor the heat transfer within the turbocharger is investigated and a heat transfermodel is presented and validated. The model can be used as a tool to estimate theimportance of different heat flows within the turbocharger. A set of heat transfer coefficients are estimated and the heat transfer is modelled with good accuracyfor high engine loads and speeds.
2
Pesiridis, Apostolos. "Turbocharger turbine unsteady aerodynamics with active control." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498148.
3
Carrasco, Mora Enrique. "Variable Stator Nozzle Angle Control in a Turbocharger Inlet." Thesis, KTH, Kraft- och värmeteknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-174345.
Анотація:
Turbochargers are becoming an essential device in internal combustion engines as they boost the intake air with more pressure in order to increase the power output. These devices are normally designed for a single steady design point but the pulsating flow delivered from the internal combustion engine is everything but steady. The efficiency drop experienced in the off-design points by the fixed geometry turbochargers have made some research groups to look into new variable geometry solutions for turbocharging. A nozzle ring is a device which normally achieves a higher performance under design conditions, but the efficiency rapidly drops at off-design conditions. In this paper, a variable angle nozzle ring is designed and implemented in the model of a radial turbine of a turbocharger in order to study its potential when working under real internal combustion engine cycles. To understand the profit margin the turbine performance is compared with two turbines with the same impeller geometry: one without nozzle ring and one with a nozzle ring with a fixed angle. The results show that the maximum efficiency angle function calculated for the variable angle nozzle ring achieves an improvement in the total efficiency of 5 % when comparing with a turbine with a fixed angle and 18 % when comparing with a vaneless turbine. The improved guidance achieved due to the variable blade angle leads to less turbine losses and therefore more mechanical energy can be extracted from the exhaust mass flow throughout all the combustion cycle but a further study should be made in order to match all the engine operations points. Notably, taking the pulsating boundary conditions into consideration, a remarkable improvement is achieved already for the fixed angle nozzle ring.
4
Lindén, Erik, and David Elofsson. "Model-based turbocharger control : A common approach for SI and CI engines." Thesis, Linköpings universitet, Institutionen för systemteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-70288.
Анотація:
In this master’s thesis, a turbine model and a common control structure for theturbocharger for SI and CI-engines is developed. To design the control structure,simulations are done on an existing diesel engine model with VGT. In order tobe able to make simulations for engines with a wastegated turbine, the model isextended to include mass flow and turbine efficiency for that configuration. Thedeveloped model has a mean absolute relative error of 3.6 % for the turbine massflow and 7.4 % for the turbine efficiency. The aim was to control the intake manifoldpressure with good transients and to use the same control structure for VGTand wastegate. By using a common structure, development and calibration timecan be reduced. The non-linearities have been reduced by using an inverted turbinemodel in the control structure, which consists of a PI-controller with feedforward.The controller can be tuned to give a fast response for CI engines and a slowerresponse but with less overshoot for SI engines, which is preferable.
5
Bengtsson, Mikael. "A Control-Oriented 0D Model of a Turbocharger Gas Stand Including Heat Transfer." Thesis, Linköpings universitet, Fordonssystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119837.
Анотація:
A turbocharger’s performance is measured in a gas stand in order to provide information of the components characteristics. The measurement procedure is a very time consuming process and it is thus desired to make it more time-efficient. To allow for development of an enhanced control strategy used during the measurements, a 0D model of a gas stand is developed. The physical gas stand components are modeled and validated against measurements, all showing a reasonable result. Turbocharger heat transfers are investigated and modeled using a lumped capacitance approach. The heat transfer models shows approximative results when comparing with measurements which is explained by the lack of temperature measurement made on the bearing housing. When the complete gas stand model is validated against measurements, an improvement of the measurement procedure is examined. By adding an idealized heat source with the possibility to heat the compressor housing, it is possible to reduce the time it takes to reach an equilibrium when switching between two steady state operating points.
6
Wadner, Martin. "Co-Simulation of Engine Model and Control System with focus on Turbocharger Model." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-81059.
Анотація:
The demands on heavy duty vehicles is constantly raising with government legislations on CO2 emissions becoming stricter and increasing customer demands. A continuous search for new methods and tools is a crucial element in finding more performance and lower emissions, which are prerequisites for heavy duty vehicles of the future. This thesis is conducted at Scania CV AB and aims at proposing a co-simulation setup which implements the engine management system, EMS, for turbocharger control, into engine simulation models that the company uses to simulate the behaviour of their combustion engines. The EMS software for turbocharger control is modelled in a MATLAB Simulink model and the engine simulation model is modelled in GT-SUITE. The thesis is also suggesting improvements to a turbine model that is modelled within the given EMS software. The results suggest a co-simulation setup that enables the engine simulation models to utilize the EMS software for turbocharger control which thereby enhances their ability to predict engine behaviour. The setup can also be used as a tool during the development process for other part of the EMS and could ease the need for physical engine tests in test cell. The suggested improvements to the turbine model revolves around building a model capturing the aspects of a so called twin scroll turbine and also to implement a better estimation of the turbine efficiency. The improvements to the turbine model ultimately leads to improving the response behaviour of the EMS turbocharger control system.
7
Cao, Kun. "The development of a pulse-optimized flow control method for turbocharger turbine performance improvement." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/44972.
Анотація:
A new turbocharger turbine concept that enhances exhaust energy recovery has been developed; it is known as the ‘rotating vane turbine’ (RVT). It aims to address the negative impact of the pulsating exhaust flow on the turbocharger turbine, so that the exhaust energy can be recovered more efficiently compared to the state of art turbocharging technologies. Different from traditional turbine configurations, in which the nozzle is stationary, the RVT incorporates a rotating nozzle ring at a relatively low speed. It thus minimises the deviation of the turbine incidence angle from the optimal design angle on average through a pulse cycle, it as such leads to an improvement of turbine performance. Two control methods are investigated for the rotating nozzle: a passive self-rotation and one that is controlled from the outside with the use of an external driving turbine. The geometry of the rotating nozzle ring is also optimized to reduce the incidence loss on the nozzle blade under unsteady flow. The new RVT is studied through numerical calculation in order to demonstrate that the rotating nozzle ring can adaptively change the flow angle at the turbine inlet through a pulse cycle. As a result, the turbine operating point is pushed to better performance region with higher turbine efficiency and lower pressure ratio, compared to a traditional stationary nozzle ring. The flow analysis shows that the turbine performance improvement is due to the reduction of the flow separation on the turbine blade under sub-optimal operating conditions. Detailed experimental testing is also carried out to further validate the new concept. Two rotating nozzles with different angles are tested under different flow frequencies, turbine speeds, turbine loads and mass flow rates. As comparisons, stationary vane turbine (SVT) and nozzleless turbine are also tested under the same operating conditions as for RVT. The testing results demonstrate that, the rotating nozzle ring can reduce the amplitude of the flow pulses, thereby reducing the unsteadiness level of the turbine operation. Similar to the simulation results, a significant increase in average turbine efficiency as well as a reduction of turbine pressure ratio are observed for RVT, compared to for SVT or nozzleless turbine. A preliminary study of 1D engine simulation is also carried out to investigate the impact of the new RVT on the engine performance. The simulation results show that, the back pressure of the engine with RVT is reduced based on the same engine power output. This indicates the new RVT can effectively reduce the BSFC of an engine, compared to a traditional SVT.
8
Liu, Yuxing. "Systematic Optimization and Control Design for Downsized Boosted Engines with Advanced Turbochargers." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1405764571.
9
Cieslar, Dariusz. "Control for transient response of turbocharged engines." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/244951.
Анотація:
The concepts of engine downsizing and down-speeding offer reductions in CO2 emissions from passenger cars. These reductions are achieved by reducing pumping and friction losses at part-load operation. Conventionally, rated torque and power for downsized units are recovered by means of turbocharging. The transient response of such engines is, however, affected by the static and dynamic characteristics of the turbo-machinery. Recent advances in engine simulation and control tools have been employed for the purpose of the research reported in this thesis to identify and verify possible air-path enhancements. A systematic method for evaluating various turbocharger assistance concepts is proposed and discussed in this thesis. To ensure a fair comparison of selected candidate systems, an easily reconfigurable controller providing a close-to-optimal operation, while satisfying physical limits, is formulated. This controller is based on the Model Predictive Control framework and uses a linearised mean value model to optimise the predicted behaviour of the engine. Initially, the controller was applied to a 1D simulation model of a conventional light-duty Diesel engine, for which the desired closed-loop features were verified. This procedure was subsequently applied to various air-path enhancement systems. In this thesis, a turbocharger electric assistance and various concepts based on compressed gas injection were considered. The capability of these systems to improve engine response during third gear tip-in manoeuvre was quantified. This investigation was also complemented with a parametric study of how effectively each of the considered methods used its available resources. As a result, injecting compressed gas into the exhaust manifold was identified as an effective method, which to date has attracted limited attention from engine research community. The effectiveness of the exhaust manifold assistance was experimentally verified on a light-duty Diesel engine. The sensitivity of the improvements to compressed gas supply parameters was also investigated. This led to the development of the BREES system: a low component count, compressed gas based system for reducing turbo-lag. It was shown that during braking manoeuvres a tank can be charged to the level sufficient for a subsequent boost assistance event. Such a functionality was implemented with a very limited set of additional components and only minor changes to the standard engine control.
10
Mehmood, Adeel. "Modeling, simulation and robust control of an electro-pneumatic actuator for a variable geometry turbocharger." Phd thesis, Université de Technologie de Belfort-Montbeliard, 2012. http://tel.archives-ouvertes.fr/tel-00827445.
Анотація:
The choice of technology for automotive actuators is driven by the need of high power to size ratio. In general, electro-pneumatic actuators are preferred for application around the engine as they are compact, powerful and require simple controlling devices. Specially, Variable Geometry Turbochargers (VGTs) are almost always controlled with electro-pneumatic actuators. This is a challenging application because the VGT is an important part of the engine air path and the latter is responsible for intake and exhaust air quality and exhaust emissions control. With government regulations on vehicle pollutant emissions getting stringent by the year, VGT control requirements have also increased. These regulations and requirements can only be fulfilled with precise dynamic control of the VGT through its actuator. The demands on actuator control include robustness against uncertainty in operating conditions, fast and smooth positioning without vibration, limited number of measurements. Added constraints such as nonlinear dynamic behavior of the actuator, friction and varying aerodynamic forces in the VGT render classical control methods ineffective. These are the main problems that form the core of this thesis.In this work, we have addressed the above mentioned problems, using model based control complemented with robust control methods to overcome operational uncertainties and parametric variations. In the first step, a detailed physical model of an electro-pneumatic actuator has been developed; taking into account the nonlinear characteristics originating from air compressibility and friction. Means to compensate for aerodynamic force have been studied and implemented in the next step. These include model parametric adaptation and one dimensional CFD (Computational Fluid Dynamics) modeling. The complete model has been experimentally validated and a sensitivity analysis has been conducted to identify the parameters which have the greatest impact upon the actuator's behavior. The detailed simulation model has then been simplified to make it suitable for control purposes while keeping its essential behavioral characteristics (i.e. transients and dynamics). Next, robust controllers have been developed around the model for the control objective of accurate actuator positioning in presence of operational uncertainty. An important constraint in commercial actuators is that they provide output feedback only, as they are only equipped with low-cost position sensors. This hurdle has been overcome by introducing observers in the control loop, which estimate other system states from the output feedback. The estimation and control algorithms have been validated in simulation and experimentally on diesel engine test benches.
11
Gustafsson, Jonatan. "Linearization Based Model Predictive Control of a Diesel Engine with Exhaust Gas Recirculation and Variable-Geometry Turbocharger." Thesis, Linköpings universitet, Fordonssystem, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-174829.
Анотація:
Engine control systems aim to ensure satisfactory output performance whilst adhering to requirements on emissions, drivability and fuel efficiency. Model predictive control (MPC) has shown promising results when applied to multivariable and nonlinear systems with operational constraints, such as diesel engines. This report studies the torque generation from a mean-value heavy duty diesel engine with exhaust gas recirculation and variable-geometry turbocharger using state feedback linearization based MPC (LMPC). This is accomplished by first introducing a fuel optimal reference generator that converts demands on torque and engine speed to references on states and control signals for the MPC controller to follow. Three different MPC controllers are considered: a single linearization point LMPC controller and two different successive LMPC (SLMPC) controllers, where the controllers are implemented using the optimization tool CasADi. The MPC controllers are evaluated with the World Harmonized Transient Cycle and the results show promising torque tracking using a SLMPC controller with linearization about reference values.
12
Růsek, Lukáš. "Plnící turbodmychadlo." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228804.
Анотація:
A masters thesis deals with the question of deisel engine boosting by rotary turbochargers. The objective of the thesis is to propose suitable turbocharger´s concept for defined diesel combustion engine with power of 430 [kW]. The air boosting pressure is controlled by exhaust gas flow through the turbine and different EGR regimes, which are considered in the basic and corrected calculations. The final turbocharger´s concept is proposed to satisfy the defined technical requirements. Next technical recommendations are briefly summarized in the thesis conclusion for following turbocharger´s concept application.
13
Hájek, Daniel. "Zvýšení pružnosti zážehového motoru přeplňováním." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-228975.
Анотація:
The master’s thesis deals with the question of petrol engine boosting by rotary turbochargers. The objective of the thesis is to project suitable turbocharger for defined single-cylinder petrol engine. After selecting the suitable turbocharger type it will follow the construction of the computational model of the single-cylinder turbocharged petrol engine in the Lotus Engine Simulation software. In the computational model is boost pressure regulated by the turbine waste gate valve. The result will be the boost pressure values scheme for the highest possible torque so that the maximum combustion pressures will not exceed the value of 9,5 MPa. There are summarized findings and results in the conclusion of the thesis.
14
El, Hadef Jamil. "Approche quasi-systématique du contrôle de la chaîne d’air des moteurs suralimentés, basée sur la commande prédictive non linéaire explicite." Thesis, Orléans, 2014. http://www.theses.fr/2014ORLE2002/document.
Анотація:
Les centaines de millions de véhicules du parc automobile mondial nous rappellent à quel point notre société dépend du moteur à combustion interne. Malgré des progrès significatifs en termes d’émissions polluantes et de consommation, les moteurs à essence et diesel demeurent l’une des principales sources de pollution de l’air des centres urbains modernes. Ce constat motive les autorités à renforcer les normes anti-pollution, qui tendent à complexifier la définition technique des moteurs. En particulier, un nombre croissant d’actionneurs fait aujourd’hui, du contrôle de la chaîne d’air, un challenge majeur. Dans un marché de plus en plus mondialisé et où le temps de développement de moteurs se doit d’être de plus en plus court, ces travaux entendent proposer une solution aux problèmes liés à cette augmentation de la complexité. La proposition repose sur une approche en trois étapes et combine : modélisation physique du moteur, contrôle prédictif non linéaire et programmation multiparamétrique. Le cas du contrôle de la chaîne d’air d’un moteur à essence suralimenté sert de fil conducteur au document. Dans son ensemble, les développements présentés ici fournissent une approche quasi-systématique pour la synthèse du contrôle de la chaîne des moteurs à essence suralimentés. Intuitivement, le raisonnement doit pouvoir être étendu à d’autres boucles de contrôle et au cas des moteurs dieselThe hundreds of millions of passenger cars and other vehicles on our roads emphasize our society’s reliance on internal combustion engines. Despite striking progress in terms of pollutant emissions and fuel consumption, gasoline and diesel engines remain one of the most important sources of air pollution in modern urban areas. This leads the authorities to lay down increasingly drastic pollutant emission standards, which entail ever more complex engine technical definitions. In particular, due to an increasing number of actuators in the past few years, the air path of internal combustion engines represents one of the biggest challenges of engine control design. The present thesis addresses this issue of increasing engine complexity with respect to the continuous reduction in development time, dictated by a more and more competitive globalized market. The proposal consists in a three-step approach that combines physics-based engine modeling, nonlinear model predictive control and multi-parametric nonlinear programming. The latter leads to an explicit piecewise affine feedback control law, compatible with a real-time implementation. The proposed approach is applied to the particular case of the control of the air path of a turbocharged gasoline engine. Overall, the developments presented in this thesis provide a quasi-systematic approach for the synthesis of the control of the air path of turbocharged gasoline engines. Intuitively, this approach can be extended to other control loops in both gasoline and diesel engines
15
Kristoffersson, Ida. "Model Predictive Control of a Turbocharged Engine." Thesis, KTH, Reglerteknik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-107508.
Анотація:
Engine control becomes increasingly important in newer cars. It is therefore interesting to investigate if a relatively new control method as Model Predictive Control (MPC) can be useful in engine control in the future. One of the advantages of MPC is that it can handle contraints explicitly. In this thesis basics on turbocharged engines and the underlying theory of MPC is presented. Based on a nonlinear mean value engine model, linearized at multiple operating points, we then implement both a linear and a nonlinearMPC strategy and highlight implementation issues. The implemented MPC controllers calculate optimal wastegate position in order to track a requested torque curve and still make sure that the constraints on turbocharger speed and minimum and maximum opening of the wastegate are fulfilled.
16
Leufvén, Oskar, and Johan Bergström. "Surge Modeling and Control of Automotive Turbochargers." Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-9616.
Анотація:
Mean Value Engine Modeling (MVEM) is used to make engine control development less expensive. With more and more cars equipped with turbocharged engines good turbo MVEM models are needed. A turbocharger consists of two major parts: turbine and compressor. Whereas the turbine is relatively durable, there exist phenomenons on the compressor that can destroy the turbocharger. One of these is surge.
Several compressor models are developed in this thesis. Methods to determine the compressor model parameters are proposed and discussed both for the stable operating range as well as for the surge region of a compressor map. For the stationary region methods to automatically parameterize the compressor model are developed. For the unstable surge region methods to get good agreement for desired surge properties are discussed. The parameter sensitivity of the different surge properties is also discussed. A validation of the compressor model shows that it gives good agreement to data, both for the stationary region as well as the surge region.
Different open loop and closed loop controllers as well as different performance variables are developed and discussed. A benchmark is developed, based on a measured vehicle acceleration, and the control approaches are compared using this benchmark. The best controller is found to be a open loop controller based on throttle and surge valve mass flow.
17
Plianos, Alexandros. "Nonlinear modelling and control of turbocharged diesel engines." Thesis, University of Sussex, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.496800.
Анотація:
The main focus of this thesis is the investigation of nonlinear control designs on the airpath of a diesel engine equipped with exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT). This problem presents strong couplings between controlled variables and actuators, since both EGR and VGT flows are driven by gases in the exhaust manifold. An additional coupling arises from the common shaft of the compressor and the turbine. The multivariable, highly nonlinear dynamics of the system gives motivation for model-based nonlinear control. Firstly, an eighth order mean-value model of the diesel engine is derived. This is consequently used to perform closed-loop simulations and to tune the controller gains offline. To reduce the complexity of the controllers, a third-order mean-value is used to design the nonlinear controllers.
18
Johansson, Max. "Optimal Control of Heat Transfer Rates in Turbochargers." Thesis, Linköpings universitet, Fordonssystem, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-148734.
Анотація:
The turbocharger is an important component of competitive environmentally friendly vehicles. Mathematical models are needed for controlling turbochargers in modern vehicles. The models are parameterized using data, gathered from turbocharger testing ingas stands (a flow bench for turbocharger, where the engine is replaced with a combustion chamber, so that the exhaust gases going to the turbocharger can be controlled with high accuracy). Collecting the necessary time averaged data is a time-consuming process. It can take more than 24 hours per turbocharger. To achieve a sufficient level of accuracy in the measurements, it is required to let the turbocharger system reach steady state after a change of operating point. The turbocharger material temperatures are especially slow to reach steady state. A hypothesis is that modern methods in control theory, such as numeric optimal control, can drastically reduce the wait time when changing operating point. The purpose of this thesis is to provide a method of time optimal testing of turbo chargers. Models for the turbine, bearing house and compressor are parameterized. Well known models for heat transfer is used to describe the heat flows to and from exhaust gas and charge air, and turbocharger material, as well as internal energy flows between the turbocharger components. The models, mechanical and thermodynamic, are joined to form a complete turbocharger model, which is validated against measured step responses. Numeric optimal control is used to calculate optimal trajectories for the turbo charger input signals, so that steady state is reached as quickly as possible, fora given operating point. Direct collocation is a method where the optimal control problem is discretized, and a non-linear program solver is used. The results show that the wait time between operating points can be reduced by a factor of 23. When optimal trajectories between operating points can be found, the possibility of further gains, if finding an optimal sequence of trajectories, are investigated. The problem is equivalent to the open traveling salesman, a well studied problem, where no optimal solution can be guaranteed. A near optimal solution is found using a genetic algorithm. The developed method requires a turbocharger model to calculate input trajectories. The testing is done to acquire data, so that a model can be created, which is a catch-22 situation. It can be avoided by using system identification techniques. When the gas stand is warming up, the necessary model parameters are estimated, using no prior knowledge of the turbocharger.
19
Novotný, Pavel. "Zážehový motor s Millerovým cyklem optimalizace provozu turbodmychadla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-449786.
Анотація:
The diploma thesis deals with the calculation of thermodynamic parameters of a turbocharged petrol engine with Miller cycle. A drive unit from Volkswagen, the EA211EVO model line, was chosen as the engine. The engine has a displacement of 1498 cm3 and engine power reaches 110kW at 5000 to 6000 RPM. In this work, a basic description of the thermodynamics of cycles of spark ignition engines is performed, then the problem of turbocharging and methods of its control are presented. The following are the created engine models in GTSuite environment in variants with WasteGate and Variable Turbine Geometry. Finally, operation optimizations with various valve timing changes are presented. The individual variants are the compared.
20
Wiklund, Eric, and Claes Forssman. "Bypass Modeling and Surge Control for turbocharged SI engines." Thesis, Linköping University, Department of Electrical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-3594.
Анотація:
Since measurements in engine test cells are closely coupled with high costs it is of interest to use physically interpretable engine models instead of engine maps. Such engine models can also be used to do off-line tests of how new or altered components affects engine performance.
In the thesis an existing mean value engine model will be extended with a model of a compressor bypass valve. A controller for that valve will also be developed. The purpose with that controller is to save torque and boost pressure but at the same time avoid having the compressor entering surge during fast closing transients in the throttle position.
Both the extension and controller is successfully developed and implemented. The extension lowers the pressure after the compressor and increases the pressure before the compressor when the bypass valve is being opened and the controller shows better results in simulations than the controller used in the research lab. By using the proposed controller, as much as 5 percent higher torque can be achieved in simulations.
Finally there is a discussion on wastegate control alternatives and the use of TOMOC for optimization of wastegate control.
21
Leufvén, Oskar. "Compressor Modeling for Control of Automotive Two Stage Turbochargers." Licentiate thesis, Linköpings universitet, Fordonssystem, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-64342.
Анотація:
There is a demand for increasing efficiency of automotive engines, and one way to achieve this is through downsizing and turbocharging. In the design compromises are made, for example the maximum power of the engine determines the size of the compressor, but since the compressor mass flow range is limited, this affects the torque for low engine speeds. A two stage system, with two different sized turbochargers, reduces this compromise, but the system complexity increases. To handle the complexity, models have come to play a central role where they aid engineers in the design. Models are used in simulation, for design optimization and also in the control synthesis. In all applications it is vital that the models have good descriptive capabilities for the entire operating range studied. A novel control oriented compressor model is developed, with good performance in the operating regions relevant for compressors in a two stage system. In addition to the nominal operating regime, also surge, choke and operation at pressure ratios less than unity, are modeled. The model structure can be automatically parametrized using a compressor map, and is based on static functions for low computational cost. A sensitivity analysis, isolating the important characteristics that influence surge transients in an engine is performed, and the gains of a novel surge controller are quantified. A compressor map is usually measured in a gas stand, that has different surrounding systems, compared to the application where the compressor is used. A method to automatically determine a turbo map, when the turbo is installed on an engine in an engine test stand is developed. The map can then be used to parametrize the developed compressor model, and effectively create a model parametrized for its intended application. An experimental analysis of the applicability of the commonly used correction factors, used for estimating compressor performance when the inlet conditions deviate from nominal, is presented. Correction factors are vital, to e.g. estimate turbocharger performance for driving at high altitude or to analyze second stage compressor performance, where the variations in inlet conditions are large. The experimental campaign uses measurements from an engine test cell and from a gas stand, and shows a small, but clearly measurable trend, with decreasing compressor pressure ratio for decreasing compressor inlet pressure, for points with equal corrected shaft speed and corrected mass flow. A method is developed, enabling measurements to be analyzed with modified corrections. An adjusted shaft speed correction quantity is proposed, incorporating also the inlet pressure in the shaft speed correction. A high altitude example is used to quantify the influence of the modified correction.
22
Argolini, Roberto, and Viviana Bloisi. "On optimal control of the wastegate in a turbocharged SI engine." Thesis, KTH, Reglerteknik, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-106241.
Анотація:
The project aims to improve positive torque transient response through more advanced wastegate controllers than what are used today. All controllers are developed for a standard General Motors turbocharged engine. In many turbocharged SI engines, a wastegate is used for preventing the turbine to overrun and to decrease the pumping loss. Today, the wastegate is controlled by a PI controller, which tries to fulfill a compromise between fuel consumption and torque response by regulating the wastegate position. A nonlinear Mean Value Engine Model (MVEM) of this engine, with 13 states and linearized in 45 different working points, is used. The original model, implemented in Matlab/Simulink, has been enriched with new features, like lambda and spark advance efficiencies and the related exhaust temperature correction. The project aims to do a theoretical analysis to find the optimal control of wastegate position, investigating also spark retard and fuel enrichment during a positive torque transient. First a solution for achieving optimal wastegate control is designed, based on Linear Quadratic (LQ) approach. Since the optimal control strategy is expected to vary quite much for different working points, a gain scheduling architecture has been investigated. An independent lambda controller has been developed, in order to maximize the lambda efficiency and quicken the torque response during transient. Since the system operates near a constraint boundary, another solution based on Model Predictive Control (MPC) of the wastegate has been investigated. The MPC design has been extended also to a MIMO formulation, adding the throttle and the air to fuel ratio as control inputs, and the trade off between fast torque response and fuel economy is analyzed. A complete realtime MPC implementation, with the capability for automatic code generation in the dSpace microAutobox environment, requires the model, now with 13 states, to be reduced to a minimum state space order. The extent of model reduction that is required and the possible performance deterioration have been investigated.
23
Thomasson, Andreas. "Modeling and control of actuators and co-surge in turbocharged engines." Doctoral thesis, Linköpings universitet, Fordonssystem, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-105687.
Анотація:
The torque response of the engine is important for the driving experience of a vehicle. In spark ignited engines, torque is proportional to the air flow into the cylinders. Controlling torque therefore implies controlling air flow. In modern turbocharged engines, the driver commands are interpreted by an electronic control unit that controls the engine through electromechanical and pneumatic actuators. Air flow to the intake manifold is controlled by an electronic throttle, and a wastegate controls the energy to the turbine, affecting boost pressure and air flow. These actuators and their dynamics affect the torque response and a lot of time is put into calibration of controllers for these actuators. By modeling and understanding the actuator behavior this dynamics can be compensated for, leaving a reduced control problem, which can shorten the calibration time. Electronic throttle servo control is the first problem studied. By constructing a control oriented model for the throttle servo and inverting that model, the resulting controller becomes two static compensators for friction and limp-home nonlinearities, together with a PD-controller. A gain-scheduled I-part is added for robustness to handle model errors. The sensitivity to model errors is studied and a method for tuning the controller is presented. The performance has been evaluated in simulation, in test vehicle, and in a throttle control benchmark. A model for a pneumatic wastegate actuator and solenoid control valve, used for boost pressure control, is presented. The actuator dynamics is shown to be important for the transient boost pressure response. The model is incorporated in a mean value engine model and shown to give accurate description of the transient response. A tuning method for the feedback (PID) part of a boost controller is proposed, based on step responses in wastegate control signal. Together with static feedforward the controller is shown to achieve the desired boost pressure response. Submodels for an advanced boost control system consisting of several vacuum actuators, solenoid valves, a vacuum tank and a vacuum pump are developed. The submodels and integrated system are evaluated on a two stage series sequential turbo system, and control with system voltage disturbance rejection is demonstrated on an engine in a test cell. Turbocharged V-type engines often have two parallel turbochargers, each powered by one bank of cylinders. When the two air paths are connected before the throttle an unwanted oscillation can occur. When the compressors operate close to the surge line and a disturbance alters the mass flow balance, the compressors can begin to alternately go into surge, this is called co-surge. Measurements on co-surge in parallel turbocharged engines are presented and analyzed. A mean value engine model, augmented with a Moore-Greitzer compressor model to handle surge, is shown to capture the cosurge behavior. A sensitivity analysis shows which model parameters have the largest influence of the phenomena. The compressor operation in the map during co-surge is studied, and the alternating compressor speeds are shown to have a major impact on the continuing oscillation. Based on the analysis, detection methods and a controller are proposed, these detect co-surge and control the turbo speeds to match during co-surge. The controller is evaluated both in simulation and on a test vehicle in a vehicle dynamometer, showing that co-surge can be detected and the oscillations quelled.
24
Zhou, Junqiang. "CONTROL OF OVER-ACTUATED SYSTEMS WITH APPLICATION TO ADVANCED TURBOCHARGED DIESEL ENGINES." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420810533.
25
Löthgren, Svante. "Model-Based Control of Two-Stage Turbochargers for Heavy-Duty Diesel Engines." Thesis, Linköpings universitet, Fordonssystem, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-109351.
Анотація:
The concept of downsizing has proved to be a succesful method to improve engine efficiency. The engine key component is the turbocharging system that use excess energy in the exhaust gases to compress air into the cylinder. There are different types of supercharging systems, in the thesis a serial turbo system is modeled together with a complete six cylinder engine. A model-based controller is developed that regulates the intake pressure to a certain reference. The controller operates in modes that are defined by the engine operating point. To control the turbochargers it is necessary to have knowledge about the energy in the exhaust gases. A dynamic temperature model has therefore been analyzed, which has led to surprising results regarding the temperature measurements made in the test cells. This is analyzed and improvements are suggested.The engine model is validated and the system, including controller, is evaluated in certain simulations. The serial turbo concept is compared to a VGT turbo system, which gives a hint of the possible advantages of serial turbo charging.Konceptet downsizing är bevisligen en mycket kapabel lösning för att höja en motors verkningsgrad. Nyckelkomponenten är turbosystemet som använder överskottsenergi i avgaserna för att komprimera in luft till cylindern. Det finns olika typer av turbosystem, i denna uppsats modelleras en seriell turbostruktur tillsammans med en komplett sexcylindrig motor. En modellbaserad regulator utvecklas för att reglera insugstrycket. Regulatorn arbetar i moder som definieras av motorns arbetspunkt. För att styra turboladdningen på ett bra sätt är det viktigt att ha vetskap om energin i motorns avgaser, varpå mer dynamik har införts i befintlig temperaturmodell. Temperaturmätningar har lett till förvånande och teoretiskt motstridiga resultat. Detta har undersökts och förslag på förbättringar tas fram.Motormodellen har validerats och systemet tillsammans med regulatorn har utvärderats i simuleringsexperiment. Det seriella turbosystemet jämförs med ett VGT-system, varpå potentiella fördelar hos en seriell dubbelturbo diskuteras.
26
Jung, Merten. "Mean-value modelling and robust control of the airpath of a turbocharged diesel engine." Thesis, University of Cambridge, 2003. https://www.repository.cam.ac.uk/handle/1810/265454.
Анотація:
This thesis investigates mean-value modelling and robust control of the airpath of a diesel engine equipped with variable geometry turbocharger (VGT) and exhaust gas recirculation (EGR). Both the EGR and the VGT are driven by the exhaust gas and render the control problem inherently multivariable. In order to allow for model-based control design, a mean-value model of the airpath of the engine is derived with a focus on the parameterisation of the turbocharger. The effect of heat transfer via the turbocharger housing on the efficiencies derived from temperature measurements is identified as being very significant at low speed and load points regularly met on emission drive cycles. A physics-based parameterisation for the turbine efficiency map, which is the most difficult to model, is suggested. Based on experimentally obtained frequency responses, the parameters which are most uncertain in the model, i. e. compressor and turbine efficiency as well as the effective area of the EGR valve, are identified to have the biggest effect on the frequency responses. Different parameterisations of these uncertainties are then used for extended Je00 loopshaping design at a fixed engine operating point. Applying ?, analysis tools, it turns out that the application tailored uncertainties yield a better controller performance, which is confirmed by experimental data. In order to extend the controller operating regime, the nonlinear model is simplified and converted to linear parameter-varying (LPV) form . A robustly gain scheduled LPV controller is synthesised for this model using a gridding approach for the intake manifold pressure as scheduling variable. The designed controller is implemented on the engine in real-time. The experimental results are very promising and indicate that the quasi-LPV model captures the significant nonlinearities and dynamics of the plant.
27
Glenn, Bradley Charles. "Coordinated control of the turbo electrically assisted variable geometry turbocharged diesel engine with exhaust gas recirculation." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1127225590.
28
Cedrone, Kevin David. "Control strategy for hydrocarbon emissions in turbocharged direct injection spark ignition engines during cold-start." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/81693.
Анотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 185-191).
Gasoline consumption and pollutant emissions from transportation are costly and have serious, demonstrated environmental and health impacts. Downsized, turbocharged direct-injection spark ignition (DISI) gasoline engines consume less fuel and achieve superior performance compared with conventional port fuel injected spark ignition (PFI-SI) engines. Although more efficient, turbocharged DISI engines have new emissions challenges during cold start. DISI fuel injection delivers more liquid fuel into the combustion chamber, increasing the emissions of unburned hydrocarbons. The turbocharger slows down activation (warm-up) of the catalytic exhaust after-treatment system. The objective of this research is to find a control strategy that: 1. Accelerates warm-up of the catalyst, and 2. Maintains low emissions of unburned hydrocarbons (UBHCs) during the catalyst warm-up process. This research includes a broad experimental survey of engine behaviour and emission response for a modern turbocharged DISI engine. The study focuses on the idle period during cold-start for which DISI engine emissions are worst. Engine experiments and simulations show that late and slow combustion lead to high exhaust gas temperatures and mass flow rate for fast warm-up. However, late and slow combustion increase the risk of partial-burn misfire. At the misfire limit for each parameter, the following conclusions are drawn: 1. Late ignition timing is the most effective way to increase exhaust enthalpy flow rate for fast catalyst warm-up. 2. By creating a favourable spatial fuel-air mixture stratification, split fuel injection can simultaneously retard and stabilize combustion to improve emissions and prevent partial-burn misfire. 3. Excessive trapped residuals from long valve overlap limit the potential for valve timing to reduce cold-start emissions. 4. Despite their more challenging evaporation characteristics, fuel blends with high ethanol content showed reasonable emissions behaviour and greater tolerance to late combustion than neat gasoline. 5. Higher exhaust back-pressure leads to high exhaust temperature during the exhaust stroke, leading to significantly more post-flame oxidation. 6. Post-flame oxidation in the combustion chamber and exhaust system play a critical role in decreasing the quantity of catalyst-in emissions due to hydrocarbons that escape primary (flame) combustion. A cold start strategy combining late ignition, 15% excess air, and high exhaust backpressure yielded the lowest cumulative hydrocarbon emissions during cold start.
by Kevin David Cedrone.
Ph.D.
29
Glenn, Bradley C. "Coordinated control of the turbo electrically assisted variable geometry turbocharged diesel engine with exhaust gas recirculation." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1127225590.
Анотація:
Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xv, 178 p.; also includes graphics (some col.). Includes bibliographical references (p. 153-158). Available online via OhioLINK's ETD Center
30
Backhouse, R. J. "The dynamic behaviour and feedback control of a turbocharged automotive diesel engine with variable geometry turbine." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375340.
31
Mrosek, Matthias. "Model-based control of a turbocharged diesel engine with high- and low-pressure exhaust gas recirculation." Phd thesis, VDI Verlag, 2017. https://tuprints.ulb.tu-darmstadt.de/6960/1/Dissertation_Mrosek_TUprints.pdf.
Анотація:
Modern Diesel engines fulfil challenging requirements for emission limits, fuel consumption and ride comfort by numerous modular combinable components and mechatronical actuators. These components are utilised for precondition and aftertreatment of air, fuel and exhaust gas, which is involved in the combustion process. In this dissertation a methodology for a model-based function development with semi-physical engine models for control of air path quantities of an exemplary Diesel engine with high-pressure (HP-EGR) and low-pressure exhaust gas recirculation (LP-EGR) is developed. In this framework for function development black-box models for stationary and dynamical emission formation are utilised to optimise reference values for the air path control and to rate the developed control scheme with regard to the cumulated driving cycle emissions of the new European driving cycle (NEDC).
A combination of HP-EGR and LP-EGR represents a novel approach to significantly lower the particulate and NOx emissions of Diesel engines. A semi-physical mean value engine model with lumped parameters is the base to analyse the system properties of the complex air path. In doing so, the additional LP-EGR shows only minor influences to the quantities charge air pressure and HP-EGR, while there are significant influences of these quantities on the LP-EGR mass flow rate. Furthermore, the LP-EGR is characterised by significant gas propagation times in the intake and exhaust system. These delays are modelled by a gas composition model, which is incorporated into the control scheme.
NOx and particulate emissions as well as engine torque are stationary modelled by local polynomial models with input quantities of the combustion process. These quantities are air mass flow rate, charge air pressure, intake temperature and crank angle of 50% mass fraction burned. A bilinear interpolation between engine speed and injection quantity transforms local polynomial models into global models. Models for the dynamical emission formation are given by considering the combustion as a batch process. Consequently all dynamics are included in the quantities of the cylinder charge at intake valve closing and the emission measurement dynamics. Thus, a combination of a dynamical gas composition model, stationary emission models and models for the emission measurement dynamics yield the dynamical course of the engine emissions.
The investigated system properties and the emission models deliver the control variables charge air pressure, air content and intake temperature for the engine with VGT-turbocharger, HP- and LP-EGR. A stationary optimisation with regard to emissions and engine torque delivers reference values for the air path control and further shows the potential of the LP-EGR to lower the emissions. Due to the multi-variable characteristics of the air path with different dynamics, there are increased dynamical emissions at engine transients. These dynamical emissions are lowered by dynamical optimised reference values for the air path control.
Generally, the air path is a strongly nonlinear process and the multitude of engine variants and engine operation modes result in a trade-off between achievable control quality, control robustness and number of control parameter sets. A semi-physical feedforward control, which is based upon parameterised model relationships of the mean value engine model delivers a good response to setpoint changes. Thus, the disturbance rejection can be achieved by relatively simple controllers. This results in an significantly lower application effort of control parameters and allows by its modular structure to exchange engine components without the drawback to completely re-parameterise the control parameters. A reference value transformation with modelled states of the gas composition model compensates long gas propagation times in the intake and exhaust system and delivers an optimal air content in the cylinder charge. All control concepts are validated with measurements at the engine test bench. Finally, the derived control concepts for the LP-EGR are compared to the classical HP-EGR control with regard to the cumulated driving cycle emissions. In this investigation the proportion of stationary and dynamical emissions is clearly quantified.
In a nutshell this dissertation is an important contribution for model-based optimisation and function development for the air path control of Diesel engines. The given combination of models for dynamical emission formation, dynamically optimised reference values for the air path control and semi-physical control design are a holistic framework to master the complexity and variance of future Diesel and gasoline engines.
32
Baranski, Jacob A. "Experimental Investigation of Octane Requirement Relaxation in a Turbocharged Spark-Ignition Engine." University of Dayton / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1375262182.
33
Huška, Lukáš. "Software pro řízení zapalování a vstřikování spalovacích motorů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218797.
Анотація:
This master thesis deals with ignition systems which are used in cars vehicles with gas engines and also with setting of the best moment of ignition of gasoline-air mixture in cylinders of engine. Ways of gas injection at diesel engines and their control systems are also described in this thesis. Next chapter deals with control unit and describes main actions which are necessary for today’s motor vehicles. As illustration is used example of succession of actions which are necessary for calculation and setting regular value of pre-ignition. At the end is shown animation, which can be used for practice lessons in a subject Automobile Electric and Electronic Systems as a example. It will simplify understanding of described activities which are all accomplished by central control unit. For purposes of laboratory lessons is in this thesis also discussed measuring of engine performance with changes of parameter of central control unit.
34
Raimbault, Vincent. "Benefit of air intake optimization for new turbocharged gasoline engine." Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0024.
Анотація:
Ces dernières années les ventes de moteurs à allumage commandé sont croissantes. Pourtant les exigences en termes d’émissions de CO2 et d’émissions polluantes sont devenues plus contraignantes, taxant lourdement les dépassements. De plus le cycle d’homologation a évolué vers un élargissement de la fenêtre d’utilisation du moteur ou les émissions sont réglementées. La réduction de cylindrée « downsizing » opérée ces dernières années a permis de réduire les consommations notamment grâce à la réduction des pertes par pompage. Les performances ont pu être maintenues par l’adoption de système de suralimentation et notamment du turbocompresseur. Celui-ci présente toutefois une lacune à bas régime où il ne peut fournir une réponse instantanée et où la pression desuralimentation est limitée. De même à plus haut régime le fort taux de compression utilisé pour augmenter le rendement du moteur rend difficile le contrôle du cliquetis. Cette thèse s’est focalisée sur l’utilisation des ondes de pression pour améliorer la réponse du moteur à bas régime. Tout d’abord avec des outils de simulation puis en validation sur banc moteur. Une seconde partie a permis de développer une architecture de ligne d’admission d’air permettant de réduire la température d’admission afin d’augmenter la résistance au cliquetis et d’augmenter l’avance à l’allumage. La température d’échappement est ainsi réduite. Celle-ci est un élément dimensionnant de la stratégie moteur qui a maintenu, dans ces travaux, un mélange stoechiométrique afin de limiter les émissions polluantesThe last years have witnessed a strong increase of the sold spark ignition engines. Furthermore the new regulations are formally constraining pollutant emissions and CO2 with high fines. In the same time the new homologation driving cycle extends the engine operating conditions where the emissions need to be controlled. The downsizing has been a strong lever over the last years to improve the fuel consumption with reduction of the throttling and thus the pumping losses. With the downsizing, the turbocharger has been widely adopted to maintain the output performance. The implementation of turbocharger challenges the time to torque and the low end torque at low engine speed. In the same time the increase of boost pressure associated to high compression ratio confront the knock controls at maximum power operating conditions. This thesis focuses on acoustic boosting with volumetric efficiency enhancement to improve the low end torque and the time to torque. Firstly a simulation model allows taking into account the combustion behavior as well as the turbocharger characteristics. The intake geometry has been optimized to enhance the engine response time and low end torque. The second part deals with the pressure wave action used to reduce the intake temperature and thus improve the knock resistance being beneficial for exhaust gas temperature reduction. The interaction between the waves created the different cylinder is demonstrated. The test has confirmed the power increase while maintaining lambda 1 and thus keeping the three way catalyst efficient
35
Pimenta, Luciana Bispo. "Simulação dinâmica de planta de condicionamento de gás natural em plataforma offshore." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266786.
Анотація:
Orientador: Maria Regina Wolf MacielDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
Made available in DSpace on 2018-08-19T10:31:27Z (GMT). No. of bitstreams: 1 Pimenta_LucianaBispo_M.pdf: 3231978 bytes, checksum: c2de8436ce07b62fabe1af47e5020ef1 (MD5) Previous issue date: 2011
Resumo: O comportamento dinâmico em unidades de produção de óleo é muito importante para a operação e projeto de equipamentos. O desenvolvimento da tecnologia no processamento primário de petróleo é caracterizado pela otimização de peso e espaço nas unidades de produção. Estas restrições têm sido diretrizes para pesquisas em desenvolvimento de equipamentos mais eficientes e compactos, como hidrociclones. Porém, esta capacidade de compactar equipamentos resultou em redução na flexibilidade em operar com oscilações de carga (golfadas). Ao longo dos últimos anos, a maturação de campos produtores e o aumento na produção de água e no uso de gás lift associados à produção de óleo em lâminas d'água cada vez mais profundas têm aumentado a freqüência de golfadas. A simulação dinâmica pode ser utilizada para desenvolver estratégias para controlar situações transientes em plataformas offshore. Este trabalho utilizou a simulação dinâmica de uma planta de condicionamento de gás natural em plataforma offshore feita no simulador de processos HYSYS 7.2, como ferramenta para analisar a planta e propor melhores condições de operação. Neste trabalho duas situações serão analisadas. Na primeira, apenas o gás associado passa pelo sistema de compressão e o gás não associado é encaminhado diretamente para desidratação com TEG (situação 1). Na segunda, haverá uma quebra de pressão do gás proveniente dos poços de gás e este deverá ser encaminhado para o sistema de compressão juntamente com o gás proveniente dos poços de óleo (situação 2). Em um primeiro momento, a planta foi analisada em modelo de estado estacionário e foi avaliado o efeito da quebra de pressão na temperatura da tubulação à jusante das válvulas responsáveis pela quebra (situação 2). Em um segundo momento, a planta foi avaliada no estado dinâmico, onde foi possível analisar o efeito que as oscilações de carga têm no sistema de compressão da planta, bem como nas trocas térmicas. Este segundo estudo foi avaliado para as situações 1 e 2. Para o estudo em estado estacionário, foi possível observar que a especificação de temperatura mínima de projeto para a tubulação à jusante das válvulas que efetuam a quebra de pressão não é alcançada, porém, existe uma faixa de ?P ideal para cada válvula a fim de evitar a formação de gelo na parte externa da tubulação. Para o estudo dinâmico foi possível avaliar os efeitos que as oscilações de carga trazem para o sistema de compressão e em que situação (1 ou 2) a planta opera com maior estabilidade. Verificou-se que o trocador da saída do sistema de compressão opera com certa instabilidade na situação 1 devido à baixa vazão de gás a ser resfriado e na situação 2 esta instabilidade é reduzida. As conclusões deste estudo mostram a importância da simulação dinâmica como ferramenta de decisão para o engenheiro de processamento de gás na operação da planta
Abstract: Dynamic behavior in oil production units is vital for equipments project and operation. Technology development in offshore primary processing has traditionally been characterized by optimizing weight and space in their production units. Such restrictions have been the guidelines for researches in developing more efficient and compact equipments, such as hydro cyclones. However, this compactness has resulted, invariably, in reduced capacity to deal with load oscillations, typical in offshore units. Along the last years the maturation of production fields, and the increase of water production and gas lift use, associated to the oil production in larger and larger water depths have been increasing slugs intensity. Dynamic simulation can be used to develop better strategies to control transient situations in offshore units. This study use a dynamic simulation of a natural gas offshore conditioning plant as a tool to analyze the plant and to propose better operational conditions. The process simulator to do dynamic simulation was HYSYS 7.2. In this work two situations were analyzed. In the first one, only the gas from oil wells pass through the gas compression system and the gas from gas wells are forwarded directly to dehydration with TEG (situation 1). In the second situation, there will be a pressure drop of the gas from gas wells and this gas should be forwarded to the compression system along with gas from oil wells (situation 2). At first, the plant was analyzed in steady state model and the effect of pressure drop in pipe temperature downstream of the valves responsible for pressure drop was evaluated (situation 2). In a second stage the plant was evaluated in dynamic state where it was possible to analyze the effect of load oscillations in the compression system, as well as in the heat exchange. This second study was evaluated for situations 1 and 2. For the static study, the specification of minimum project temperature for the pipeline downstream of the valves that perform the pressure drop is not achieved but there is an ideal range pressure drop for each valve to prevent ice formation outside the pipe. In the dynamic study was evaluated the effects of load oscillations in compression system and in what situation (1 or 2) the plant operates with greater stability. It was found that the heat exchange of the output of the compression system operates with instability in the situation 1 due to the low flow of gas to be cooled, and in the situation 2 this instability is reduced. The conclusions of this study show the importance of dynamic simulation as a decision tool for the engineer in the gas processing plant operation
Mestrado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química
36
Silvestri, Nicola. "Development, testing and potential benefits of a closed-loop combustion controller on a turbocharged GDI engine." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/12610/.
Анотація:
Nei motori ad accensione comandata, la fase della combustione rappresenta uno dei principali parametri che influenzano l’efficienza di conversione dell’energia chimica del combustibile in lavoro meccanico.
L’istante in cui viene dato il comando di accensione, detto ‘anticipo’, viene attualmente controllato in catena aperta per mezzo di mappe salvate nella centralina elettronica di controllo motore.
Un’alternativa è costituita da un sistema di controllo dell’anticipo di accensione in catena chiusa su di una misura reale del processo di combustione, in modo da regolare l’anticipo per produrre sempre una corretta fasatura della combustione. Tuttavia, l’implementazione di un sistema basato su di una misura di pressione all’interno del cilindro, a causa di costi elevati e problemi di affidabilità dei sensori, non è per il momento perseguibile nell’ambito di applicazioni industriali. Un’alternativa al segnale di pressione è costituita dalla misura della corrente di ionizzazione, effettuata usando la candela stessa come sensore.
Nell’ambito di questo lavoro di tesi è stata condotta una campagna di misure sperimentali per quantificare il livello di correlazione tra alcune caratteristiche del segnale di corrente di ionizzazione e gli indici impiegati per descrivere la fase di combustione derivati dal segnale di pressione.
La fase di implementazione ha portato allo sviluppo e alla sperimentazione di un innovativo controllo in catena chiusa dell’anticipo di accensione. Il sistema è stato testato tramite un ambiente di simulazione appositamente sviluppato e successivamente implementato e collaudato su di un motore Ferrari sovralimentato, al banco prova ed in vettura. Il risultato principale è quindi un innovativo sistema di controllo dell’anticipo, cilindro per cilindro, che è in grado di adattare continuamente l’attuazione sia alla variazione dei parametri interni di funzionamento del motore, sia a quelli esterni.
37
Mrosek, Matthias Patrick Alexander [Verfasser], Rolf [Akademischer Betreuer] Isermann, and Ulrich [Akademischer Betreuer] Konigorski. "Model-based control of a turbocharged diesel engine with high- and low-pressure exhaust gas recirculation / Matthias Patrick Alexander Mrosek ; Rolf Isermann, Ulrich Konigorski." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2017. http://d-nb.info/1145141935/34.
38
Keller, Martin [Verfasser], Dirk [Akademischer Betreuer] Abel, and Stefan [Akademischer Betreuer] Pischinger. "Two-stage model predictive control for the air path of a turbocharged gasoline engine with exhaust gas recirculation / Martin Gerhard Keller ; Dirk Abel, Stefan Pischinger." Aachen : Universitätsbibliothek der RWTH Aachen, 2021. http://d-nb.info/123852379X/34.
39
Smilek, Lukáš. "Zvýšení výkonových parametrů motoru AR67203." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230128.
Анотація:
The aim of this diploma thesis is supercharging of SI engines and design influence on performance. The main objective of this thesis is to propose appropriate modifications on AR67203 engine of Alfa Romeo 155Q4 personal vehicle in order to achieve significantly better performance parameters and a constant torque in the widest possible speed range. That is why I analyze design and modifications that affect the overall engine performance and their appropriate application to the selected engine. An important point of this thesis is the right choice of turbocharger, in order to have an effective cooperation with a modified engine. The calculation study and the simulation in Lotus Engine Simulation software serve this purpose. I also give information about ECU programming. The results, as well as a practical output in the form of measured performance parameters of modified engine, are evaluated at the end.
40
Jhou, Shunyi, and 周順億. "The Feasibility Analysis of Relief Control for Turbochargers by Installing of Fast Solenoid Valves." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/74474443699899694917.
Анотація:
碩士南開科技大學
車輛與機電產業研究所
100
This paper presents the method of relief control for turbochargers. We install a fast solenoid valve on the piping between the actuator of the turbocharger and the intake manifold of the engine. By changing the period and duty cycle of the power supply, we control the solenoid to open the valve and change the air flow direction. This method only allows part of the compressed air into the actuator. Therefore, before pressure decreases followed by the actuator opening, we allow the pressure in intake manifold to achieve the expectations of boost, which is over the set pressure of the original manufacturer. It can promote supercharged performance of the air aspiration. Under the appropriate conditions of the power period and duty cycle, the results show that this method can effectively lower down outlet pressure of the actuator to the expected pressure range. Furthermore, in the transient response time for depressurizing to the target pressure, the higher input pressure requires the longer reaction time. The longer power period results in the shorter transient response time.