Author: Markus HehnPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Optimizing Diesel Engine Operation Strategy During Transient Operation
Author: Markus HehnModel-based Diesel Engine Management System Optimization
Author: Markus GrahnPublisher:
ISBN: 9789173859097
Category :
Languages : en
Pages :
Book Description
Diesel Engine Transient Operation
Author: Constantine D. RakopoulosPublisher: Springer Science & Business Media
ISBN: 1848823754
Category : Technology & Engineering
Languages : en
Pages : 408
Book Description
Traditionally, the study of internal combustion engines operation has focused on the steady-state performance. However, the daily driving schedule of automotive and truck engines is inherently related to unsteady conditions. In fact, only a very small portion of a vehicle’s operating pattern is true steady-state, e. g. , when cruising on a motorway. Moreover, the most critical conditions encountered by industrial or marine engines are met during transients too. Unfortunately, the transient operation of turbocharged diesel engines has been associated with slow acceleration rate, hence poor driveability, and overshoot in particulate, gaseous and noise emissions. Despite the relatively large number of published papers, this very important subject has been treated in the past scarcely and only segmentally as regards reference books. Merely two chapters, one in the book Turbocharging the Internal Combustion Engine by N. Watson and M. S. Janota (McMillan Press, 1982) and another one written by D. E. Winterbone in the book The Thermodynamics and Gas Dynamics of Internal Combustion Engines, Vol. II edited by J. H. Horlock and D. E. Winterbone (Clarendon Press, 1986) are dedicated to transient operation. Both books, now out of print, were published a long time ago. Then, it seems reasonable to try to expand on these pioneering works, taking into account the recent technological advances and particularly the global concern about environmental pollution, which has intensified the research on transient (diesel) engine operation, typically through the Transient Cycles certification of new vehicles.
Transient Optimization of a Medium Duty Diesel Engine Equipped with a High Pressure EGR and Variable Nozzle Turbocharger
Author: Justin Brett PenningtonPublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 286
Book Description
A medium-duty diesel engine is equipped with a High Pressure EGR (Exhaust Gas Recirculation) and a VNT (Variable Nozzle Turbine) and coupled to an AC Dynamometer. The control of the HPEGR and VNT will be optimized during steady state and transient engine operation to lower nitric oxide and particulate matter production as well as fuel consumption. Brake specific particulate matter, nitric oxide, and fuel consumption will be recorded with fast measurement systems capable of capturing results of transient events. A steady state map of engine speed and load will be used to calibrate initial VNT and EGR control. The calibration will be optimized with a defined formula using emissions production and fuel consumption. After a steady state VNT and HPEGR map is created, the map will be used as a baseline in transient engine operation. The dissertation will contain three parts. Firstly, VNT and HPEGR control assigned via the steady state table will be used during transient events, which will then be increased in speed from a 10 second to a 2 second event. Secondly, the VNT and EGR control will be manually configured in attempt to improve engine performance throughout the transient. Finally, the VNT and EGR control will be applied before the transient event to inspect the effect on engine performance.
Experimental Investigation of Transient Operation and Low Temperature Combustion in a Light Duty Diesel Engine
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 416
Book Description
Detailed and highly time resolved experimental measurements were used to characterize the effects of transient operation on the performance of a light duty diesel engine, and to identify the physical processes responsible for transient-specific combustion behavior. The engine response to transient events varied with the size and type of transition and the combustion strategy used, but the underlying processes were similar in all cases. Differences in the response rate of the fuel and air systems caused large variations in the equivalence ratio of the combustion charge during transient events. For moderate to low load conditions, this was primarily due to the discrepancy between the instantaneous intake air flow rate and the composition of the intake charge caused by storage of exhaust gas in the EGR system. This effect was particularly significant for early injection LTC operation due to higher EGR rates and greater dependence of combustion phasing on intake charge composition. Individual combustion cycles during transient events were compared to steady state operation at the same speed and load to quantify the differences in physical conditions. The greatest effect on combustion and emissions was due to differences in intake charge composition, which varied significantly between transient and steady state operation. The response time of the common rail pressure also contributed to transient behavior in situations where the target pressure varied with changes in speed or load. During larger load transitions, thermal inertia of the engine system had a significant effect on emissions, particularly UHC, but did not influence the combustion phasing or heat release rate. The characteristic rates of change of the charge gas, fluid, and physical component temperatures in response to speed or load transitions were much slower than those of other variables such as pressures or flow rates, and were consistent with concurrent variations in engine-out emissions levels. Numerous mechanisms by which thermal inertia could affect emissions formation were identified, including variation of the intake manifold charge gas temperature, in-cylinder heat transfer, and changing physical properties of the fuel.
Modeling and Optimal Control of Heavy-Duty Powertrains
Author: Vaheed NezhadaliPublisher: Linköping University Electronic Press
ISBN: 9176857484
Category :
Languages : en
Pages : 52
Book Description
Heavy duty powertrains are complex systems with components from various domains, different response times during transient operations and different efficient operating ranges. To ensure efficient transient operation of a powertrain, e.g. with low fuel consumption or short transient duration, it is important to come up with proper control strategies. In this dissertation, optimal control theory is used to calculate and analyze efficient heavy duty powertrain controls during transient operations in different applications. This is enabled by first developing control ready models, usable for multi-phase optimal control problem formulations, and then using numerical optimal control methods to calculate the optimal transients. Optimal control analysis of a wheel loader operating in a repetitive loading cycle is the first studied application. Increasing fuel efficiency or reducing the operation time in such repetitive loading cycles sums up to large savings over longer periods of time. Load lifting and vehicle traction consume almost all of the power produced by a diesel engine during wheel loader operation. Physical models are developed for these subsystems where the dynamics are described by differential equations. The model parameters are tuned and fuel consumption estimation is validated against measured values from real wheel loader operation. The sensitivity of wheel loader trajectory with respect to constrains such as the angle at which the wheel loader reaches the unloading position is also analyzed. A time and fuel optimal trajectory map is calculated for various unloading positions. Moreover, the importance of simultaneous optimization of wheel loader trajectory and the component transients is shown via a side to side comparison between measured fuel consumption and trajectories versus optimal control results. In another application, optimal control is used to calculate efficient gear shift controls for a heavy duty Automatic Transmission system. A modeling and optimal control framework is developed for a nine speed automatic transmission. Solving optimal control problems using the developed model, time and jerk efficient transient for simultaneous disengagement of off-going and engagement of in-coming shift actuators are obtained and the results are analyzed. Optimal controls of a diesel-electric powertrain during a gear shift in an Automated Manual Transmission system are calculated and analyzed in another application of optimal control. The powertrain model is extended by including driveline backlash angle as an extra state in the system. This is enabled by implementation of smoothing techniques in order to describe backlash dynamics as a single continuous function during all gear shift phases. Optimal controls are also calculated for a diesel-electric powertrain corresponding to a hybrid bus during a tip-in maneuver. It is shown that for optimal control analysis of complex powertrain systems, minimizing only one property such as time pushes the system transients into extreme operating conditions far from what is achievable in real applications. Multi-objective optimal control problem formulations are suggested in order to obtain a compromise between various objectives when analyzing such complex powertrain systems.
Parametric Study and Optimization of Diesel Engine Operation for Low Emissions Using Different Injectors
Author: Prashanth Kumar KarraPublisher:
ISBN:
Category :
Languages : en
Pages : 140
Book Description
Transient Diesel Emissions: Analysis of Engine Operation During a Tip-In
Author: Jonathan R. HagenaMeasurement of Diesel Engine Emissions During Transient Operation
Author: Diesel Engine System Design
Author: Qianfan XinPublisher: Elsevier
ISBN: 0857090836
Category : Technology & Engineering
Languages : en
Pages : 1087
Book Description
Diesel Engine System Design links everything diesel engineers need to know about engine performance and system design in order for them to master all the essential topics quickly and to solve practical design problems. Based on the author's unique experience in the field, it enables engineers to come up with an appropriate specification at an early stage in the product development cycle. Links everything diesel engineers need to know about engine performance and system design featuring essential topics and techniques to solve practical design problems Focuses on engine performance and system integration including important approaches for modelling and analysis Explores fundamental concepts and generic techniques in diesel engine system design incorporating durability, reliability and optimization theories