scholarly journals Optimal Control of Diesel Engines: Numerical Methods, Applications, and Experimental Validation

2014 ◽  
Vol 2014 ◽  
pp. 1-21 ◽  
Author(s):  
Jonas Asprion ◽  
Oscar Chinellato ◽  
Lino Guzzella
Keyword(s):  
Optimal Control ◽  
Numerical Methods ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Large Scale ◽  
Experimental Validation ◽  
Control Unit ◽  
Pollutant Emissions ◽  
Control Input ◽  
Dynamic Optimisation

In response to the increasingly stringent emission regulations and a demand for ever lower fuel consumption, diesel engines have become complex systems. The exploitation of any leftover potential during transient operation is crucial. However, even an experienced calibration engineer cannot conceive all the dynamic cross couplings between the many actuators. Therefore, a highly iterative procedure is required to obtain a single engine calibration, which in turn causes a high demand for test-bench time. Physics-based mathematical models and a dynamic optimisation are the tools to alleviate this dilemma. This paper presents the methods required to implement such an approach. The optimisation-oriented modelling of diesel engines is summarised, and the numerical methods required to solve the corresponding large-scale optimal control problems are presented. The resulting optimal control input trajectories over long driving profiles are shown to provide enough information to allow conclusions to be drawn for causal control strategies. Ways of utilising this data are illustrated, which indicate that a fully automated dynamic calibration of the engine control unit is conceivable. An experimental validation demonstrates the meaningfulness of these results. The measurement results show that the optimisation predicts the reduction of the fuel consumption and the cumulative pollutant emissions with a relative error of around 10% on highly transient driving cycles.

Optimal control of a turbocharged direct injection diesel engine by direct method optimization

2018 ◽  
Vol 20 (6) ◽  
pp. 640-652 ◽  
Author(s):  
Jose Manuel Luján ◽  
Carlos Guardiola ◽  
Benjamín Pla ◽  
Alberto Reig
Keyword(s):  
Optimal Control ◽  
Fuel Consumption ◽  
Control Strategy ◽  
Fuel Efficiency ◽  
Optimization Method ◽  
Operating Conditions ◽  
Experimental Results ◽  
Pollutant Emissions ◽  
Engine Fuel ◽  
Optimal Control Strategy

This work studies the effect and performance of an optimal control strategy on engine fuel efficiency and pollutant emissions. An accurate mean value control-oriented engine model has been developed and experimental validation on a wide range of operating conditions was carried out. A direct optimization method based on Euler’s collocation scheme is used in combination with the above model in order to address the optimal control of the engine. This optimization method provides the optimal trajectories of engine controls (fueling rate, exhaust gas recirculation valve position, variable turbine geometry position and start of injection) to reproduce a predefined route (speed trajectory including variable road grade), minimizing fuel consumption with limited [Formula: see text] emissions and a low soot stamp. This optimization procedure is performed for a set of different [Formula: see text] emission limits in order to analyze the trade-off between optimal fuel consumption and minimum emissions. Optimal control strategies are validated in an engine test bench and compared against engine factory calibration. Experimental results show that significant improvements in both fuel efficiency and emissions reduction can be achieved with optimal control strategy. Fuel savings at about 4% and less than half of the factory [Formula: see text] emissions were measured in the actual engine, while soot generation was still low. Experimental results and optimal control trajectories are thoroughly analyzed, identifying the different strategies that allowed those performance improvements.

NOx Emissions From Oceangoing Ships: Calculation and Evaluation

2003 ◽  
Author(s):  
Horst W. Koehler
Keyword(s):  
Fuel Consumption ◽  
Diesel Engines ◽  
Atmospheric Chemistry ◽  
Pollutant Emissions ◽  
Nox Emissions ◽  
Consumption Rates ◽  
Type Size ◽  
Mode Of Transportation ◽  
Engine Type ◽  
Bunker Fuel

Currently available global inventories of nitrogen oxides (NOx) and other pollutant emissions from merchant ships are based, at least partly, on data published by international marine bunker fuel suppliers. However, the uncertainty of such data seems to be quite high, because the figures released by bunker fuel companies might be incomplete or based, for example, on data collected from only the largest ports. Besides, all similar other studies conducted so far were based on simplified average emission and fuel consumption characteristics of diesel engines and did not take into account variations with engine type, size, engine load and engine speed, as well as only being valid for new state-of-the-art diesel engines as supplied by the industry today. Furthermore, fuel consumption rates of the auxiliary engine equipment onboard vessels were neglected. The author therefore adopted a different approach by calculating the actual bunker amount and the fleet’s 2001 NOx emissions in order to reduce uncertainty in existing inventories and to assist in achieving a better modeling of the effects of ships’ pollutants on atmospheric chemistry. For this study, all ships of 100 gross tonnage (gt) and above were taken into account. This methodology resulted in a significantly higher world fleet fuel consumption, and, consequently, much higher oceangoing ships’ NOx emissions than known or anticipated so far. In spite of the fleet’s high NOx emission rate in absolute figures this paper shows, that when emissions are based on the annual seaborne trade, merchant shipping is an environmentally efficient mode of transportation of freight.

Effects of triglyceride gasoline blends on combustion and emissions in a common rail direct injection diesel engine

2017 ◽  
Vol 19 (10) ◽  
pp. 1068-1078 ◽  
Author(s):  
Arunachalam Lakshminarayanan ◽  
Daniel B Olsen ◽  
Perry E Cabot
Keyword(s):  
Fuel Consumption ◽  
Vegetable Oils ◽  
Diesel Engines ◽  
Alternative Fuels ◽  
Direct Injection ◽  
Pollutant Emissions ◽  
Compression Ignition Engine ◽  
Unleaded Gasoline ◽  
Particulate Matter Emissions ◽  
Volume Measurements

This study presents the combustion and emission results using a blend of unrefined triglycerides (straight vegetable oils) and regular unleaded gasoline in a compression ignition engine typically used in farming machinery. Most farm equipment is powered by diesel engines. A sizable cost of producing a crop on a farm can be attributed to fuel—diesel in such cases. Farmers and researchers have been interested in the use of alternative fuels, especially triglycerides, which could potentially bring down the fuel cost portion of the farm input costs. One of the major drawbacks of using unrefined triglycerides is poor cold flow properties due to high density and viscosity. To overcome this, the triglycerides can be blended with gasoline to lower the density and viscosity. This blend has been used in existing diesel engines without the need for any modification to the engine or its control system. The experiments were conducted on a 4.5-L Tier 3 engine. The fuel used was a blend of unrefined canola triglyceride and regular unleaded gasoline (10% by volume). Measurements include mass fraction burned combustion pressure, fuel consumption and pollutant emissions. The fuel consumption of TGB10 was lower than most straight vegetable oils found in the literature, but higher than diesel. The peak pressure of TGB10 was slightly higher than diesel and occurred earlier than diesel. The brake-specific NOx was lower than diesel at lower and no load points. Particulate matter emissions of TGB10 were higher than diesel at rated speed. Total hydrocarbon emissions were generally higher than diesel. CO emissions were lower than diesel except at low or no load points where they were significantly higher.

scholarly journals Experimental Assessment of the Performance and Emissions of a Spark-Ignition Engine Using Waste-Derived Biofuels as Additives

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5209
Author(s):  
Joaquim Costa ◽  
Jorge Martins ◽  
Tiago Arantes ◽  
Margarida Gonçalves ◽  
Luis Durão ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Electronic Control Unit ◽  
Engine Performance ◽  
Control Unit ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Pollutant Emissions ◽  
Low Grade ◽  
Performance And Emissions ◽  
Fuel Mixtures

The use of biofuels for spark ignition engines is proposed to diversify fuel sources and reduce fossil fuel consumption, optimize engine performance, and reduce pollutant emissions. Additionally, when these biofuels are produced from low-grade wastes, they constitute valorisation pathways for these otherwise unprofitable wastes. In this study, ethanol and pyrolysis biogasoline made from low-grade wastes were evaluated as additives for commercial gasoline (RON95, RON98) in tests performed in a spark ignition engine. Binary fuel mixtures of ethanol + gasoline or biogasoline + gasoline with biofuel incorporation of 2% (w/w) to 10% (w/w) were evaluated and compared with ternary fuel mixtures of ethanol + biogasoline + gasoline with biofuel incorporation rates from 1% (w/w) to 5% (w/w). The fuel mix performance was assessed by determination of torque and power, fuel consumption and efficiency, and emissions (HC, CO, and NOx). An electronic control unit (ECU) was used to regulate the air–fuel ratio/lambda and the ignition advance for maximum brake torque (MBT), wide-open throttle (WOT)), and two torque loads for different engine speeds representative of typical driving. The additive incorporation up to 10% often improved efficiency and lowered emissions such as CO and HC relative to both straight gasolines, but NOx increased with the addition of a blend.

scholarly journals Factors Affecting the Rate of Fuel Consumption in Aircrafts

2021 ◽  
Vol 13 (14) ◽  
pp. 8066
Author(s):  
Thowayeb H. Hassan ◽  
Abu Elnasr E. Sobaih ◽  
Amany E. Salem
Keyword(s):  
Fuel Consumption ◽  
Positive Association ◽  
Pollutant Emissions ◽  
Aviation Industry ◽  
Factors Affecting ◽  
Fuel Flow ◽  
Homogeneity Of Variance ◽  
Strong Positive Association ◽  
Ground Distance ◽  
The Cost

The cost of fuel and its availability are among the most major concerns for aircrafts and the aviation industry overall. Environmental difficulties with chemical pollutant emissions emitted by aviation machines are also connected to fuel consumption. As a result, it is crucial to examine factors that affect the overall fuel usage and consumption in the airport-based aviation industry. Several variables were investigated related to the total fuel consumed, such as dry operating weight (DOW) (KG), zero-fuel weight (ZFW), take-off weight (TOW), air distance (AIR DIST) (KM), and ground distance (GDN DIST). Analysis of the correlation between total fuel consumed as well as the extra fuel and selected variables was conducted. The results showed that the most positively associated factors with the total used fuel were the air distance (r2 = 0.86, p < 0.01), ground distance (r2 = 0.78, p < 0.01), TOW (r2 = 0.68, p < 0.01), and flight time (r2 = 0.68, p < 0.01). There was also a strong positive association between the average fuel flow (FF) and actual TOW (r2 = 0.74, p < 0.01) as well as ZFW (r2 = 0.61, p < 0.01). The generalized linear model (GLM) was utilized to assess the predictions of total energy usage after evaluating important outliers, stability of the homogeneity of variance, and the normalization of the parameter estimation. The results of multiple linear regression revealed that the most significant predictors of the total consumed fuel were the actual ZFW (p < 0.01), actual TOW (p < 0.01), and actual average FF (p < 0.05). The results interestingly confirmed that wind speed has some consequences and effects on arrival fuel usage. The result reflects that thermal and hydrodynamic economies impact on the flying fuel economy. The research has various implications for both scholars and practitioners of aviation industry.

Sign in / Sign up

Export Citation Format

Share Document