Early Direct-Injection, Low-Temperature Combustion of Diesel Fuel in an Optical Engine Utilizing a 15-Hole, Dual-Row, Narrow-Included-Angle Nozzle

2008 ◽  
Vol 1 (1) ◽  
pp. 1057-1082 ◽  
Author(s):  
Glen C. Martin ◽  
Charles J. Mueller ◽  
David M. Milam ◽  
Michael S. Radovanovic ◽  
Christopher R. Gehrke
Keyword(s):  
Low Temperature ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Low Temperature Combustion ◽  
Included Angle ◽  
Optical Engine ◽  
Temperature Combustion

scholarly journals Simultaneous particulate matter and nitrogen oxide emission reduction through enhanced charge homogenization in diesel engines

2018 ◽  
Vol 22 (5) ◽  
pp. 2039-2052 ◽  
Author(s):  
Urban Zvar-Baskovic ◽  
Rok Vihar ◽  
Samuel Rodman-Opresnik ◽  
Tomaz Katrasnik
Keyword(s):  
Particulate Matter ◽  
Low Temperature ◽  
Diesel Fuel ◽  
Minor Effect ◽  
Exhaust Gas ◽  
Low Temperature Combustion ◽  
Engine Control ◽  
Pyrolysis Oil ◽  
Trade Off ◽  
Temperature Combustion

In the presented study, low temperature combustion was established with a direct injection of diesel fuel being a representative of high reactivity fuels and tire pyrolysis oil being a representative of low reactivity fuels. Tire pyrolysis oil was tested as a potential waste derived fuel for low temperature combustion, as it features diesel-like physical properties and lower cetane number compared to diesel fuel. The goal of this study was determination of suitable injection strategies and exhaust gas re-circulation rates to explore potentials of both fuels in reducing emissions in low temperature combustion modes. It was demonstrated that relatively small changes in the engine control strategy possess the potential to significantly improve NOx/particulate matter trade-off with minor effect on engine efficiency. In addition, low temperature combustion was for the first time successfully demonstrated with tire pyrolysis oil fuel, however, it was shown that lower re-activity of the fuel is by itself not sufficient to improve NOx /soot trade-off compared to the diesel fuel as entire spectra of fuel properties play an important role in improving NOx /soot trade-off. This study thus establishes relations between different engine control strategies, intake manifold pressure and exhaust gas recirculation rate on engine thermodynamic parameters and engine-out emissions while utilizing innovative waste derived fuel that have not yet been analysed in similar combustion concepts.

CFD Analysis of Diesel-Methane Dual Fuel Low Temperature Combustion at Low Load and High Methane Substitution

2018 ◽  
Author(s):  
Andrea Aniello ◽  
Lorenzo Bartolucci ◽  
Stefano Cordiner ◽  
Vincenzo Mulone ◽  
Sundar R. Krishnan ◽  
...  
Keyword(s):  
Low Temperature ◽  
Heat Release ◽  
Diesel Fuel ◽  
Single Stage ◽  
Dual Fuel ◽  
Low Temperature Combustion ◽  
Two Stage ◽  
Low Load ◽  
Temperature Heat ◽  
Temperature Combustion

Over the last few decades, emissions regulations for internal combustion engines have become increasingly restrictive, pushing researchers around the world to exploit innovative propulsion solutions. Among them, the dual fuel low temperature combustion (LTC) strategy has proven capable of reducing fuel consumption and while meeting emissions regulations for oxides of nitrogen (NOx) and particulate matter (PM) without problematic aftertreatment systems. However, further investigations are still needed to reduce engine-out hydrocarbon (HC) and carbon monoxide (CO) emissions as well as to extend the operational range and to further improve the performance and efficiency of dual-fuel engines. In this scenario, the present study focuses on numerical simulation of fumigated methane-diesel dual fuel LTC in a single-cylinder research engine (SCRE) operating at low load and high methane percent energy substitution (PES). Results are validated against experimental cylinder pressure and apparent heat release rate (AHRR) data. A 3D full-cylinder RANS simulation is used to thoroughly understand the influence of the start of injection (SOI) of diesel fuel on the overall combustion behavior, clarifying the causes of AHRR transition from two-stage AHRR at late SOIs to single-stage AHRR at early SOIs, low temperature heat release (LTHR) behavior, as well as high HC production. The numerical campaign shows that it is crucial to reliably represent the interaction between the diesel spray and the in-cylinder charge to match both local and overall methane energy fraction, which in turn, ensures a proper representation of the whole combustion. To that aim, even a slight deviation (∼3%) of the trapped mass or of the thermodynamic conditions would compromise the numerical accuracy, highlighting the importance of properly capturing all the phenomena occurring during the engine cycle. The comparison between numerical and experimental AHRR curves shows the capability of the numerical framework proposed to correctly represent the dual-fuel combustion process, including low temperature heat release (LTHR) and the transition from two-stage to single stage AHRR with advancing SOI. The numerical simulations allow for quantitative evaluation of the residence time of vapor-phase diesel fuel inside the combustion chamber and at the same time tracking the evolution of local diesel mass fraction during ignition delay — showing their influence on the LTHR phenomena. Oxidation regions of diesel and ignition points of methane are also displayed for each case, clarifying the reasons for the observed differences in combustion evolution at different SOIs.

Comparison of Filter Smoke Number and Elemental Carbon Mass From Partially Premixed Low Temperature Combustion in a Direct-Injection Diesel Engine

2011 ◽  
Vol 133 (10) ◽  
Author(s):  
William F. Northrop ◽  
Stanislav V. Bohac ◽  
Jo-Yu Chin ◽  
Dennis N. Assanis
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Elemental Carbon ◽  
Direct Injection ◽  
Low Temperature Combustion ◽  
Soot Mass ◽  
Temperature Combustion ◽  
Carbon Mass ◽  
Partially Premixed ◽  
Premixed Low Temperature Combustion

Partially premixed low temperature combustion (LTC) is an established advanced engine strategy that enables the simultaneous reduction of soot and NOx emissions in diesel engines. Measuring extremely low levels of soot emissions achievable with LTC modes using a filter smoke meter requires large sample volumes and repeated measurements to achieve the desired data precision and accuracy. Even taking such measures, doubt exists as to whether filter smoke number (FSN) accurately represents the actual smoke emissions emitted from such low soot conditions. The use of alternative fuels such as biodiesel also compounds efforts to accurately report soot emissions since the reflectivity of high levels of organic matter found on the particulate matter collected may result in erroneous readings from the optical detector. Using FSN, it is desired to report mass emissions of soot using empirical correlations derived for use with petroleum diesel fuels and conventional modes of combustion. The work presented in this paper compares the experimental results of well known formulas for calculating the mass of soot using FSN and the elemental carbon mass using thermal optical analysis (TOA) over a range of operating conditions and fuels from a four-cylinder direct-injection passenger car diesel engine. The data show that the mass of soot emitted by the engine can be accurately predicted with the smoke meter method utilizing a 3000 ml sample volume over a range of FSN from 0.02 to 1.5. Soot mass exhaust concentration calculated from FSN using the best of the literature expressions and that from TOA taken over all conditions correlated linearly with a slope of 0.99 and R2 value of 0.94. A primary implication of the work is that the level of confidence in reporting the soot mass based on FSN for low soot formation regimes such as LTC is improved for both petroleum diesel and biodiesel fuels.

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.

Effects of Fuel Volatility on Early Direct-Injection, Low-Temperature Combustion in an Optical Diesel Engine

2010 ◽  
Vol 24 (3) ◽  
pp. 1538-1551 ◽  
Author(s):  
A. S. (Ed) Cheng ◽  
Brian T. Fisher ◽  
Glen C. Martin ◽  
Charles J. Mueller
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Direct Injection ◽  
Low Temperature Combustion ◽  
Temperature Combustion
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