A New Approach to Reduce Engine-Out Emissions Enabled by Trajectory-Based Combustion Control

2015 ◽  
Author(s):  
Chen Zhang ◽  
Zongxuan Sun
Keyword(s):  
Internal Combustion Engines ◽  
Control Method ◽  
Nox Emissions ◽  
Combustion Engines ◽  
Combustion Control ◽  
Ignition Timing ◽  
Free Piston ◽  
New Approach ◽  
Convective Heat Loss ◽  
Simulation Results

Previously, the authors have proposed the concept of piston trajectory-based combustion control enabled by free piston engines (FPE). With this novel control method, the FPE realizes in-cycle real-time combustion control, in terms of adjusting the ignition timing and manipulating the in-cylinder temperature trace, through various piston trajectories and achieves higher thermal efficiency compared to the conventional internal combustion engines. In this paper, the effects of this new combustion control on engine-out emissions are studied. First, a model is developed that includes different piston trajectories in the FPE, a convective heat loss sub model and a reduced n-heptane reaction mechanism with major emissions species from diesel engines. Afterwards, a new approach which reduces the engine-out emissions by employing novel piston trajectories is described. At last, analyses of the simulation results demonstrating the variable piston trajectories’ effects on CO and NOx emissions are presented, which further reveal the advantages of the trajectory-based combustion control.

scholarly journals Sustainability Investigation of Vehicles’ CO2 Emission in Hungary

2021 ◽  
Vol 13 (15) ◽  
pp. 8237
Author(s):  
István Árpád ◽  
Judit T. Kiss ◽  
Gábor Bellér ◽  
Dénes Kocsis
Keyword(s):  
Energy Efficiency ◽  
Co2 Emissions ◽  
Energy Supply ◽  
Internal Combustion Engines ◽  
Combustion Engines ◽  
The European Union ◽  
New Approach ◽  
Technology System ◽  
Low Co2

The regulation of vehicular CO2 emissions determines the permissible emissions of vehicles in units of g CO2/km. However, these values only partially provide adequate information because they characterize only the vehicle but not the emission of the associated energy supply technology system. The energy needed for the motion of vehicles is generated in several ways by the energy industry, depending on how the vehicles are driven. These methods of energy generation consist of different series of energy source conversions, where the last technological step is the vehicle itself, and the result is the motion. In addition, sustainability characterization of vehicles cannot be determined by the vehicle’s CO2 emissions alone because it is a more complex notion. The new approach investigates the entire energy technology system associated with the generation of motion, which of course includes the vehicle. The total CO2 emissions and the resulting energy efficiency have been determined. For this, it was necessary to systematize (collect) the energy supply technology lines of the vehicles. The emission results are not given in g CO2/km but in g CO2/J, which is defined in the paper. This new method is complementary to the European Union regulative one, but it allows more complex evaluations of sustainability. The calculations were performed based on Hungarian data. Finally, using the resulting energy efficiency values, the emission results were evaluated by constructing a sustainability matrix similar to the risk matrix. If only the vehicle is investigated, low CO2 emissions can be achieved with vehicles using internal combustion engines. However, taking into consideration present technologies, in terms of sustainability, the spread of electric-only vehicles using renewable energies can result in improvement in the future. This proposal was supported by the combined analysis of the energy-specific CO2 emissions and the energy efficiency of vehicles with different power-driven systems.

scholarly journals The Effect of Pure Oxygenated Biofuels on Efficiency and Emissions in a Gasoline Optimised DISI Engine

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3908
Author(s):  
Tara Larsson ◽  
Senthil Krishnan Mahendar ◽  
Anders Christiansen-Erlandsson ◽  
Ulf Olofsson
Keyword(s):  
Internal Combustion Engines ◽  
Negative Impact ◽  
The Other ◽  
Nox Emissions ◽  
Combustion Engines ◽  
Engine Efficiency ◽  
Spark Timing ◽  
Low Load ◽  
Oxygenated Fuels ◽  
Load Conditions

The negative impact of transport on climate has led to incentives to increase the amount of renewable fuels used in internal combustion engines (ICEs). Oxygenated, liquid biofuels are promising alternatives, as they exhibit similar combustion behaviour to gasoline. In this article, the effect of the different biofuels on engine efficiency, combustion propagation and emissions of a gasoline-optimised direct injected spark ignited (DISI) engine were evaluated through engine experiments. The experiments were performed without any engine hardware modifications. The investigated fuels are gasoline, four alcohols (methanol, ethanol, n-butanol and iso-butanol) and one ether (MTBE). All fuels were tested at two speed sweeps at low and mid load conditions, and a spark timing sweep at low load conditions. The oxygenated biofuels exhibit increased efficiencies, even at non-knock-limited conditions. At lower loads, the oxygenated fuels decrease CO, HC and NOx emissions. However, at mid load conditions, decreased volatility of the alcohols leads to increased emissions due to fuel impingement effects. Methanol exhibited the highest efficiencies and significantly increased burn rates compared to the other fuels. Gasoline exhibited the lowest level of PN and PM emissions. N-butanol and iso-butanol show significantly increased levels of particle emissions compared to the other fuels.

A Virtual-Cam Control Methodology for Free-Piston Engines

2011 ◽  
Author(s):  
Chao Yong ◽  
Eric J. Barth
Keyword(s):  
Internal Combustion Engines ◽  
Control Method ◽  
Piston Engine ◽  
Piston Motion ◽  
Stroke Length ◽  
Free Piston ◽  
Physical Context ◽  
Spark Timing ◽  
Free Piston Engine ◽  
Timing Belt

In conventional internal combustion engines, valves are opened and closed using a cam surface. The cam is kinematically related to the piston positions through the crankshaft and timing belt. In contrast, there is no crankshaft or kinematic cam surface in a free-piston engine to physically realize this mechanism. As a consequence, a free-piston engine has variable stroke lengths, which presents a challenge for active piston motion and precise stroke length control. This paper presents a virtual-cam based approach to relate free-piston motion to actuated engine valve control within a clear and familiar intuitive physical context. The primary functionality of the virtual cam control framework is to create a variable index, which is adjustable from cycle to cycle, for the exhaust/injection valves and spark timing similar to the function of physical cams in conventional engines. Since the cam is virtually created, it can be dynamically rebuilt to comply with cycle-to-cycle variations such as amount of the air/fuel supply, engine load and stroke length. This index rebuilding process is based on a cycle-to-cycle adaptive control method that uses the knowledge obtained from previous cycles to adjust the cam parameters. Preliminary experimental results are presented for a novel liquid-piston free-piston engine intended as a compact and efficient energy source for untethered power dense pneumatic systems such as untethered robots.

scholarly journals Model Based Control Method for Diesel Engine Combustion

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6046
Author(s):  
Hu Wang ◽  
Xin Zhong ◽  
Tianyu Ma ◽  
Zunqing Zheng ◽  
Mingfa Yao
Keyword(s):  
Internal Combustion Engines ◽  
Closed Loop ◽  
Control Method ◽  
Engine Performance ◽  
Quadratic Function ◽  
Combustion Control ◽  
Information Processing Speed ◽  
Loop Control ◽  
Pressure Trace ◽  
Artificial Neural Network Ann

With the increase of information processing speed, more and more engine optimization work can be processed automatically. The quick-response closed-loop control method is becoming an urgent demand for the combustion control of modern internal combustion engines. In this paper, artificial neural network (ANN) and polynomial functions are used to predict the emission and engine performance based on seven parameters extracted from the in-cylinder pressure trace information of over 3000 cases. Based on the prediction model, the optimal combustion parameters are found with two different intelligent algorithms, including genetical algorithm and fish swarm algorithm. The results show that combination of quadratic function with genetical algorithm is able to obtain the appropriate combustion control parameters. Both engine emissions and thermal efficiency can be virtually predicted in a much faster way, such that enables a promising way to achieve fast and reliable closed-loop combustion control.

scholarly journals Study on Zero-Doppler Centroid Control for GEO SAR Ground Observation

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yicheng Jiang ◽  
Bin Hu ◽  
Yun Zhang ◽  
Meng Lian ◽  
Zhuoqun Wang
Keyword(s):  
Control Method ◽  
Elliptical Orbit ◽  
Earth Orbit ◽  
New Approach ◽  
Orbital Parameters ◽  
Ground Observation ◽  
The Earth ◽  
Satellite Platform ◽  
Simulation Results ◽  
The Look

In geosynchronous Earth orbit SAR (GEO SAR), Doppler centroid compensation is a key step for imaging process, which could be performed by the attitude steering of a satellite platform. However, this zero-Doppler centroid control method does not work well when the look angle of radar is out of an expected range. This paper primarily analyzes the Doppler properties of GEO SAR in the Earth rectangular coordinate. Then, according to the actual conditions of the GEO SAR ground observation, the effective range is presented by the minimum and maximum possible look angles which are directly related to the orbital parameters. Based on the vector analysis, a new approach for zero-Doppler centroid control in GEO SAR, performing the attitude steering by a combination of pitch and roll rotation, is put forward. This approach, considering the Earth’s rotation and elliptical orbit effects, can accurately reduce the residual Doppler centroid. All the simulation results verify the correctness of the range of look angle and the proposed steering method.

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