scholarly journals The Strategies of NOx Emission Reduction for Diesel Engines

2018 ◽  
Vol 3 (11) ◽  
pp. 32-36 ◽  
Author(s):  
Cao Dao Nam ◽  
Van Vang Le
Keyword(s):  
Diesel Engines ◽  
Combustion Engine ◽  
Control Strategies ◽  
Direct Injection ◽  
Low Temperature Combustion ◽  
Technical Problems ◽  
Direct Injection Engines ◽  
The Road ◽  
Loading Mode ◽  
On The Road

Diesel engines are more efficient than forced ignition engines but due to diffused combustion and work with high air residue levels, burning products contain soot and NOx, pollutants that work Handling it on the road today still has many technical problems. The technology of organizing the combustion of diesel engines directly affects the level of pollution generated. Direct injection diesel engines have a lower fuel consumption than a combustion engine with a separation of about 10% and a lower level of soot emissions when the engine is operating in local loading mode. However, direct injection engines work noisier and generate more pollutants (NOx, HC). Today, this type of combustion chamber is only used for heavy-duty truck engines. Limiting the optimal emission level for diesel engines needs to balance the concentration of the two main pollutants, NOx and soot. Low temperature combustion (LTC) engines need different enabling technologies depending on the fuel and strategy used to achieve combustion of the premixed fuel–air mixture. Controlling the combustion rate is one of the major challenges in LTC engines, particularly in PPCI combustion engine to achieve higher thermal efficiency, the desired phasing of combustion timings is essential even at moderate combustion rates. Present chapter describes the combustion control variables and control strategies used for LTC engines. Various methods demonstrated to control the LTC engines can be categorized in to two main strategies: (i) altering pressure–temperature and (ii) altering fuel reactivity of the charge.

scholarly journals The influence of exhaust system leak on the operating parameters of a turbocharged spark ignition engine

2018 ◽  
Vol 19 (6) ◽  
pp. 468-472
Author(s):  
Krystian Hennek ◽  
Mariusz Graba
Keyword(s):  
Oxygen Sensor ◽  
Combustion Engine ◽  
Exhaust System ◽  
Spark Ignition Engine ◽  
Si Engine ◽  
The Road ◽  
Torque Measurements ◽  
Si Engines ◽  
Common Technique ◽  
On The Road

Turbocharging of an internal combustion engine is the most common technique to improve an engines’ performance. In present it is not hard to meet vehicles on the road with turbocharged SI engines, which have a high mileage, and because of this fact there is a high risk of exhaust systems leak. This might have its influence not only on the emissions, but also on the vehicles performance. Thereby this dissertation shows the comparative analysis of the influence of exhaust system leak in the catalyzer input on the exhaust gasses composition in the catalyzer output and the operation parameters of an turbocharged SI engine. During the research some parameters were recorded and compared, e. g.: the engines power and torque, the injec-tors opening time, the oxygen sensors voltage signals in the input and in the output of the catalyzer, the concentration of harmful gasses in the exhaust tailpipe. The research was conducted with the use of a single roller MAHA MSR 500 chassis dynamometer. A series of torque measurements was performed. Under these measurements a simulation of the exhaust system leakage of a turbocharged SI passenger car engine was made. As a result three variations of the wideband oxygen sensor acting were reached. The wideband sensor is mounted between the turbocharger unit and the input of the catalyzer. In the test the influence of the leakage on the injector’s opening time and the composition of harmful exhaust substances were pointed.

scholarly journals The End of the M.E.?

2005 ◽  
Vol 127 (05) ◽  
pp. 26-29 ◽  
Author(s):  
Peter Huber ◽  
Mark P. Mills
Keyword(s):  
Fuel Cell ◽  
Mechanical Engineering ◽  
Combustion Engine ◽  
Electrical Power ◽  
Single Step ◽  
Second Century ◽  
Basic Operation ◽  
The Road ◽  
Energy Economy ◽  
On The Road

This article highlights that mechanical engineers control most of the rest of our energy economy. The engineering focus will shift inexorably toward finding the most efficient means of generating electricity on-board. Trains and monster trucks both use big diesel generators. Hybrid cars on the road today burn gasoline, but it is the fuel cell that attracts the most attention from visionaries and critics of the internal combustion engine. Remarkably elegant in its basic operation, the fuel cell transforms fuel into electricity in a single step, completely bypassing the furnace, turbine, and generator. In this scenario, mechanical engineering ultimately surrenders its last major under-the-hood citadel to chemical engineers. One might say that the age of mechanical engineering was launched by James Watt's steam engine in 1763, and propelled through its second century by Nikolaus Otto’s 1876 invention of the spark-ignited petroleum engine. We are now at the dawn of the age of electrical engineering, not because we recently learned how to generate light-speed electrical power, but because we have now finally learned how to control it.

Examination of Initialization and Geometric Details on the Results of CFD Simulations of Diesel Engines

2010 ◽  
Vol 133 (4) ◽  
Author(s):  
Michael J. Bergin ◽  
Ettore Musu ◽  
Sage Kokjohn ◽  
Rolf D. Reitz
Keyword(s):  
Diesel Engines ◽  
Cylinder Head ◽  
Fluid Dynamic ◽  
Direct Injection ◽  
Valve Lift ◽  
Low Temperature Combustion ◽  
Swirl Ratio ◽  
Dynamic Simulations ◽  
Temperature Combustion ◽  
Honeycomb Cell

Computational fluid dynamic simulations using the AVL FIRE and KIVA 3V codes were performed to examine commonly accepted techniques and assumptions used when simulating direct injection diesel engines. Simulations of a steady-state impulse swirl meter validated the commonly used practice of evaluating the swirl ratio of diesel engines by integrating the valve flow and torque history over discrete valve lift values. The results indicate the simulations capture the complex interactions occurring in the ports, cylinder, and honeycomb cell impulse swirl meter. Geometric details of engines due to valve recesses in the cylinder head and piston cannot be reproduced axisymmetrically. The commonly adopted axisymmetric assumption for an engine with a centrally located injector was tested by comparing the swirl and emissions history for a noncombusting and a double injection low temperature combustion case with varying geometric fidelity. Consideration of the detailed engine geometry including valve recesses in the piston altered the swirl history such that the peak swirl ratio at TDC decreased by approximately 10% compared with the simplified no-recess geometry. An analog to the detailed geometry of the full 3D geometry was included in the axisymmetric geometry by including a groove in the cylinder head of the mesh. The corresponding emissions predictions of the combusting cases showed greater sensitivity to the altered swirl history as the air-fuel ratio was decreased.

Study of Cylinder Charge Control for Enabling Low Temperature Combustion in Diesel Engines

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Prasad Divekar ◽  
Usman Asad ◽  
Xiaoye Han ◽  
Xiang Chen ◽  
Ming Zheng
Keyword(s):  
Low Temperature ◽  
Diesel Engines ◽  
Direct Injection ◽  
Flame Temperature ◽  
Stable Operation ◽  
Low Temperature Combustion ◽  
Multiple Control ◽  
Engine Load ◽  
Combustion Modes ◽  
Temperature Combustion

Suitable cylinder charge preparation is deemed critical for the attainment of a highly homogeneous, diluted, and lean cylinder charge, which is shown to lower the flame temperature. The resultant low temperature combustion (LTC) can simultaneously reduce the NOx and soot emissions from diesel engines. This requires sophisticated coordination of multiple control systems for controlling the intake boost, exhaust gas recirculation (EGR), and fueling events. Additionally, the cylinder charge modulation becomes more complicated in the novel combustion concepts that apply port injection of low reactivity alcohol fuels to replace the diesel fuel partially or entirely. In this work, experiments have been conducted on a single cylinder research engine with diesel and ethanol fuels. The test platform is capable of independently controlling the intake boost, EGR rates, and fueling events. Effects of these control variables are evaluated with diesel direct injection and a combination of diesel direct injection and ethanol port injection. Data analyses are performed to establish the control requirements for stable operation at different engine load levels with the use of one or two fuels. The sensitivity of the combustion modes is thereby analyzed with regard to the boost, EGR, fuel types, and fueling strategies. Zero-dimensional cycle simulations have been conducted in parallel with the experiments to evaluate the operating requirements and operation zones of the LTC combustion modes. Correlations are generated between air–fuel ratio (λ), EGR rate, boost level, in-cylinder oxygen concentration, and load level using the experimental data and simulation results. Development of a real-time boost-EGR set-point determination to sustain the LTC mode at the varying engine load levels and fueling strategies is proposed.

scholarly journals Particle number measurements in the European legislation and future JRC activities

2018 ◽  
Vol 174 (3) ◽  
pp. 3-16
Author(s):  
Barouch GIECHASKIEL ◽  
Tero LAHDE ◽  
Ricardo SUAREZ-BERTOA ◽  
Michael CLAIROTTE ◽  
Theodoros GRIGORATOS ◽  
...  
Keyword(s):  
Solid Particle ◽  
Particle Number ◽  
Fuel Injection ◽  
Direct Injection ◽  
Special Focus ◽  
The European Union ◽  
Heavy Duty ◽  
Direct Injection Engines ◽  
Light Duty ◽  
On The Road

The solid particle number method was introduced in the European Union (EU) light-duty legislation for diesel vehicles to ensure the installation of the best-available technology for particles (i.e., wall-flow diesel particulate filters) without the uncertainties of the volatile nucleation mode and without the need of large investment for purchasing the equipment. Later it was extended to gasoline vehicles with direct injection engines, heavy-duty engines (both compression ignition and positive ignitions) and non-road mobile machinery engines. Real Driving Emissions (RDE) testing on the road with Portable Emissions Measurement Systems (PEMS) for particle number (and NOx) during type approval and in-service conformity testing was recently (in 2017) introduced for light-duty vehicles, and is under discussion for heavy-duty vehicles in-service conformity testing. This paper will summarize the existing legislation regarding solid particle number and discuss the on-going activities at EU level. The main focus at the moment is on improving the calibration procedures, and extending the lower detection size below 23 nm with inter-laboratory exercises. In parallel, discussions are on-going to introduce testing at low ambient temperature, regeneration emissions in the light-duty regulation, a particle limit for other technologies such as gasoline port-fuel injection vehicles, and the feasibility of particle measurements to L-category vehicles (mopeds, motorcycles, tricycles and minicars). A short overview of periodical technical inspection investigations and the situation regarding non-exhaust traffic related sources with special focus on brakes and tyres will be described.

scholarly journals One-Dimensional Modeling of Mechanical and Friction Losses Distribution in a Four-Stroke Internal Combustion Engine

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Bernardo Tormos ◽  
Jaime Martín ◽  
Diego Blanco-Cavero ◽  
Antonio J. Jiménez-Reyes
Keyword(s):  
Diesel Engine ◽  
Combustion Engine ◽  
Direct Injection ◽  
Mechanical Efficiency ◽  
Road Transport ◽  
The European Union ◽  
The Road ◽  
Ring Assembly ◽  
1D Model ◽  
Mechanical Elements

Abstract As the road transport accounts between 15%–18% of worldwide CO2 emissions, the automotive sector has a deep commitment to mitigate global warming. Consequently, stricter regulations have been adopted by the European Union and worldwide to reduce that big impact. Approximately, 10% of the energy generated by fuel combustion in the engine is destined to the auxiliaries components activation and the movement of mechanical elements with relative motion between themselves. A reduction on that figure or alternatively a mechanical efficiency improvement can be directly translated on target alignment. The aim of this work is developing a model to predict the mechanical and friction losses and its distribution in a four-stroke direct injection-diesel engine and simulating different strategies, which increment the engine efficiency. A 1D model has been developed and fitted in gt-suite based on the experimental results of a 1.6-L diesel engine. Additionally, a description of the tribological performance has been realized in different parts of the engine where friction is present. Finally, the engine friction maps have been broken down in order to quantify the friction losses produced in the piston ring assembly, crankshaft bearings, and valvetrain.

Study of Cylinder Charge Control for Enabling Low Temperature Combustion in Diesel Engines

2013 ◽  
Author(s):  
Prasad Divekar ◽  
Usman Asad ◽  
Xiaoye Han ◽  
Xiang Chen ◽  
Ming Zheng
Keyword(s):  
Low Temperature ◽  
Diesel Engines ◽  
Direct Injection ◽  
Flame Temperature ◽  
Stable Operation ◽  
Low Temperature Combustion ◽  
Multiple Control ◽  
Engine Load ◽  
Combustion Modes ◽  
Temperature Combustion

Suitable cylinder charge preparation is deemed critical for the attainment of a highly homogeneous, diluted, and lean cylinder charge which is shown to lower the flame temperature. The resultant low temperature combustion (LTC) can simultaneously reduce the NOx and soot emissions from diesel engines. This requires sophisticated coordination of multiple control systems for controlling the intake boost, exhaust gas recirculation (EGR), and fueling events. Additionally, the cylinder charge modulation becomes more complicated in the novel combustion concepts that apply port injection of low reactivity alcohol fuels to replace the diesel fuel partially or entirely. In this work, experiments have been conducted on a single cylinder research engine with diesel and ethanol fuels. The test platform is capable of independently controlling the intake boost, EGR rates, and fuelling events. Effects of these control variables are evaluated with diesel direct injection and a combination of diesel direct injection and ethanol port injection. Data analyses are performed to establish the control requirements for stable operation at different engine load levels with the use of one or two fuels. The sensitivity of the combustion modes is thereby analyzed with regard to the boost, EGR, fuel types and fueling strategies. Zero-dimensional cycle simulations have been conducted in parallel with the experiments to evaluate the operating requirements and operation zones of the LTC combustion modes. Correlations are generated between air-fuel ratio (λ), EGR rate, boost level, in-cylinder oxygen concentration and load level using the experimental data and simulation results. Development of a real-time boost-EGR set-point determination to sustain the LTC mode at the varying engine load levels and fueling strategies is proposed.

Examination of Initialization and Geometric Details on the Results of CFD Simulations of Diesel Engines

2009 ◽  
Author(s):  
Mike Bergin ◽  
Ettore Musu ◽  
Sage Kokjohn ◽  
Rolf D. Reitz
Keyword(s):  
Diesel Engines ◽  
Fluid Dynamic ◽  
Direct Injection ◽  
Valve Lift ◽  
Low Temperature Combustion ◽  
Swirl Ratio ◽  
Cfd Simulations ◽  
Complex Interactions ◽  
Temperature Combustion ◽  
Honeycomb Cell

Computational Fluid Dynamic (CFD) simulations using the AVL Fire and Kiva 3v codes were performed to examine commonly accepted techniques and assumptions used when simulating direct injection diesel engines. Simulations of a steady state impulse swirl meter validated the commonly used practice of evaluating the swirl ratio of diesel engines by integrating the valve flow and torque history over discrete valve lift values [1]. The results indicate the simulations capture the complex interactions occurring in the ports, cylinder and honeycomb cell impulse swirl meter. The commonly adopted axisymmetric assumption for an engine with a centrally located injector was tested by comparing the swirl and emissions history for a motored case and a double injection low temperature combustion case. Consideration of the detailed engine geometry including valve recesses in the piston and the head lowered the peak swirl ratio at TDC by approximately 10% compared to the simplified no-recess case. The corresponding combusting cases also had different heat release and emissions predictions but could be partially compensated for by lowering the initial swirl ratio for the axisymmetric case.

scholarly journals A Vehicle Device Tailored for Hybrid Trolleybuses and Overhead Wires Implementation in SUMO

10.29007/6pqr ◽  
2019 ◽  
Author(s):  
Jakub Sevcik ◽  
Jan Prikryl
Keyword(s):  
Public Transport ◽  
Combustion Engine ◽  
Electric Circuit ◽  
The Road ◽  
Interesting Possibility ◽  
Traction Substations ◽  
Kirchhoff’S Laws ◽  
On The Road ◽  
Charging Stations ◽  
Public Transport Service

The electrification of transport is one of the key parts of the present aim to reduce undesirable vehicular emissions in the atmosphere. While the full electrification of personal vehicles is mostly associated with employing a big battery pack on the board and charging on (static) charging stations, another interesting possibility appears in the case of public transport – dynamic drawing of the power from overhead wires. Regarding vehicles moving on the road, this concept is used by trolleybuses or hybrid trolleybuses, i.e. vehicles combining power from the overhead wires and batteries.A replacement of classic buses (with a combustion engine) with (hybrid) trolleybuses is hardly possible without an appropriate adjustment of public transport lines and the necessary infrastructure. For this purpose, a simulation of the adjusted public transport service may be used to identify weaknesses of the proposed solution.This paper presents a new vehicle device and a new additional part of road infrastructure in SUMO. It introduces device.elecHybrid based on existing device.battery, extending its functionality and tailoring it for the needs of hybrid trolleybuses. In addition, overhead wires and traction substations are implemented. As the voltage and electric cur- rents in the overhead wires depend on traffic, the overhead wire parameters are optionally evaluated by a built-in electric circuit solver using Kirchhoff’s laws.The proposed changes allow us to simulate hybrid trolleybus in-motion charging under the overhead wire. The extensions can be immediately used in micro-simulations or even (in a simplified version) in the meso-simulation mode.

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