The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Dimitrios T. Hountalas - One of the best experts on this subject based on the ideXlab platform.
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Combustion and exhaust emission characteristics of a dual fuel compression ignition engine operated with pilot Diesel fuel and natural gas
Energy Conversion and Management, 2004Co-Authors: R.g Papagiannakis, Dimitrios T. HountalasAbstract:Abstract Towards the effort of reducing pollutant emissions, especially soot and nitrogen oxides, from direct injection Diesel engines, engineers have proposed various solutions, one of which is the use of a gaseous fuel as a partial supplement for liquid Diesel fuel. These engines are known as dual fuel combustion engines, i.e. they use conventional Diesel fuel and a gaseous fuel as well. This technology is currently reintroduced, associated with efforts to overcome various difficulties of HCCI engines, using various fuels. The use of natural gas as an alternative fuel is a promising solution. The potential benefits of using natural gas in Diesel engines are both economical and environmental. The high Autoignition Temperature of natural gas is a serious advantage since the compression ratio of conventional Diesel engines can be maintained. The present contribution describes an experimental investigation conducted on a single cylinder DI Diesel engine, which has been properly modified to operate under dual fuel conditions. The primary amount of fuel is the gaseous one, which is ignited by a pilot Diesel liquid injection. Comparative results are given for various engine speeds and loads for conventional Diesel and dual fuel operation, revealing the effect of dual fuel combustion on engine performance and exhaust emissions.
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Combustion and exhaust emission characteristics of a dual fuel compression ignition engine operated with pilot Diesel fuel and natural gas
Energy Conversion and Management, 2004Co-Authors: R.g Papagiannakis, Dimitrios T. HountalasAbstract:Towards the effort of reducing pollutant emissions, especially soot and nitrogen oxides, from direct injection Diesel engines, engineers have proposed various solutions, one of which is the use of a gaseous fuel as a partial supplement for liquid Diesel fuel. These engines are known as dual fuel combustion engines, i.e. they use conventional Diesel fuel and a gaseous fuel as well. This technology is currently reintroduced, associated with efforts to overcome various difficulties of HCCI engines, using various fuels. The use of natural gas as an alternative fuel is a promising solution. The potential benefits of using natural gas in Diesel engines are both economical and environmental. The high Autoignition Temperature of natural gas is a serious advantage since the compression ratio of conventional Diesel engines can be maintained. The present contribution describes an experimental investigation conducted on a single cylinder DI Diesel engine, which has been properly modified to operate under dual fuel conditions. The primary amount of fuel is the gaseous one, which is ignited by a pilot Diesel liquid injection. Comparative results are given for various engine speeds and loads for conventional Diesel and dual fuel operation, revealing the effect of dual fuel combustion on engine performance and exhaust emissions. (C) 2004 Elsevier Ltd. All rights reserved
J.f. Griffiths - One of the best experts on this subject based on the ideXlab platform.
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pressure and concentration dependences of the Autoignition Temperature for normal butane air mixtures in a closed vessel
Combustion and Flame, 1994Co-Authors: M.r. Chandraratna, J.f. GriffithsAbstract:The conditions at which Autoignition occurs in lean premixed n-butane + air mixtures over the composition range 0.2%-2.5% n-butane by volume (0.06 < φ < 0.66) were investigated experimentally. Total reactant pressure from 0.1 to 0.6 MPa (1-6 atm) were studied in a spherical, stainless-steel, closed vessel (0.5 dm 3 ). There is a critical transition from nonignition to ignition, at pressures above 0.1 MPa, as the mixture is enriched in the vicinity of 1% fuel vapor by volume. There is also a region of multiplicity, which exhibits three critical Temperatures at a given composition. Chemical analyses of the molecular products of low-Temperature combustion are presented. The analyses show that partially oxygenated components, including many o-heterocyclic compounds, are important products of the lean combustion of butane at Temperatures up to 800 K. The critical conditions for Autoignition are discussed with regard to industrial ignition hazards, especially in the context of the «Autoignition Temperature» of alkanes given by ASTM or BS tests. The differences between the behavior of n-butane and the higher n-alkanes are explained. The experimental results are also used as a basis for testing a reduced kinetic model to represent the oxidation and Autoignition of n-butane or other alkanes
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Pressure and concentration dependences of the Autoignition Temperature for normal butane + air mixtures in a closed vessel
Combustion and Flame, 1994Co-Authors: M.r. Chandraratna, J.f. GriffithsAbstract:The conditions at which Autoignition occurs in lean premixed n-butane + air mixtures over the composition range 0.2%-2.5% n-butane by volume (0.06 < φ < 0.66) were investigated experimentally. Total reactant pressure from 0.1 to 0.6 MPa (1-6 atm) were studied in a spherical, stainless-steel, closed vessel (0.5 dm 3 ). There is a critical transition from nonignition to ignition, at pressures above 0.1 MPa, as the mixture is enriched in the vicinity of 1% fuel vapor by volume. There is also a region of multiplicity, which exhibits three critical Temperatures at a given composition. Chemical analyses of the molecular products of low-Temperature combustion are presented. The analyses show that partially oxygenated components, including many o-heterocyclic compounds, are important products of the lean combustion of butane at Temperatures up to 800 K. The critical conditions for Autoignition are discussed with regard to industrial ignition hazards, especially in the context of the «Autoignition Temperature» of alkanes given by ASTM or BS tests. The differences between the behavior of n-butane and the higher n-alkanes are explained. The experimental results are also used as a basis for testing a reduced kinetic model to represent the oxidation and Autoignition of n-butane or other alkanes
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Auto-ignition Temperatures of binary mixtures of alkanes in a closed vessel: Comparisons between experimental measurements and numerical predictions
Symposium (International) on Combustion, 1991Co-Authors: J.f. Griffiths, D. Coppersthwaite, C.h. Phillips, Charles K. Westbrook, William J. PitzAbstract:Autoignition Temperatures of the binary mixtures methane+ethane and methane+n-butane in air were measured at atmospheric pressure in a 0.56 dm3 spherical reaction vessel. The method followed that for standard ASTM and BS tests for gaseous fuels. Fixed proportions by volume of the total fuel in air were studied, which corresponded at the extreme of each composition range for methane, ethane and butane to the equivalence ratios of =0.93, 1.63 and 3.04 respectively. Supplementary experiments were carried out on n-butane alone in air in the range 0 The Autoignition Temperature (Ta,cr) in binary mixtures was reduced by 40 K from that for pure methane (Ta,cr=900 K) when ethane was present at up to 10% of the total fuel. Similar proportions of butane added to methane caused Ta,cr to be decreased by 90 K. The effects were not linearly dependent on the proportion of additive. There was an additional sensitive region when n-butane was present in the proportion 50–70% of the methane/butane mixture. The Autoignition Temperatures of mixtures containing n-butane alone matched very closely the Autoignition Temperatures of the equivalent methane/butane compositions except at the leanest mixtures (butane Numerical simulations of spontaneous ignition based on a comprehensive kinetic model yielded predicted Autoignition Temperatures that were in very satisfactory agreement with the measured values throughout all ranges of composition. The same regions of high sensitivity to composition change were distinguished. Alkylperoxy isomerisation and decomposition reactions were found to control the reactivity of butane at the lowest Temperatures. Reactions of dialkylperoxy radicals seemed not to be especially important. The rates of H atom abstraction by OH governed the relative reactivity of methane to that of butane. The competition by methane for OH radicals caused a small retarding effect on the overall rate of butane oxidation.
R.g Papagiannakis - One of the best experts on this subject based on the ideXlab platform.
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Combustion and exhaust emission characteristics of a dual fuel compression ignition engine operated with pilot Diesel fuel and natural gas
Energy Conversion and Management, 2004Co-Authors: R.g Papagiannakis, Dimitrios T. HountalasAbstract:Abstract Towards the effort of reducing pollutant emissions, especially soot and nitrogen oxides, from direct injection Diesel engines, engineers have proposed various solutions, one of which is the use of a gaseous fuel as a partial supplement for liquid Diesel fuel. These engines are known as dual fuel combustion engines, i.e. they use conventional Diesel fuel and a gaseous fuel as well. This technology is currently reintroduced, associated with efforts to overcome various difficulties of HCCI engines, using various fuels. The use of natural gas as an alternative fuel is a promising solution. The potential benefits of using natural gas in Diesel engines are both economical and environmental. The high Autoignition Temperature of natural gas is a serious advantage since the compression ratio of conventional Diesel engines can be maintained. The present contribution describes an experimental investigation conducted on a single cylinder DI Diesel engine, which has been properly modified to operate under dual fuel conditions. The primary amount of fuel is the gaseous one, which is ignited by a pilot Diesel liquid injection. Comparative results are given for various engine speeds and loads for conventional Diesel and dual fuel operation, revealing the effect of dual fuel combustion on engine performance and exhaust emissions.
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Combustion and exhaust emission characteristics of a dual fuel compression ignition engine operated with pilot Diesel fuel and natural gas
Energy Conversion and Management, 2004Co-Authors: R.g Papagiannakis, Dimitrios T. HountalasAbstract:Towards the effort of reducing pollutant emissions, especially soot and nitrogen oxides, from direct injection Diesel engines, engineers have proposed various solutions, one of which is the use of a gaseous fuel as a partial supplement for liquid Diesel fuel. These engines are known as dual fuel combustion engines, i.e. they use conventional Diesel fuel and a gaseous fuel as well. This technology is currently reintroduced, associated with efforts to overcome various difficulties of HCCI engines, using various fuels. The use of natural gas as an alternative fuel is a promising solution. The potential benefits of using natural gas in Diesel engines are both economical and environmental. The high Autoignition Temperature of natural gas is a serious advantage since the compression ratio of conventional Diesel engines can be maintained. The present contribution describes an experimental investigation conducted on a single cylinder DI Diesel engine, which has been properly modified to operate under dual fuel conditions. The primary amount of fuel is the gaseous one, which is ignited by a pilot Diesel liquid injection. Comparative results are given for various engine speeds and loads for conventional Diesel and dual fuel operation, revealing the effect of dual fuel combustion on engine performance and exhaust emissions. (C) 2004 Elsevier Ltd. All rights reserved
Jiajia Jiang - One of the best experts on this subject based on the ideXlab platform.
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Prediction of flammability characteristics of pure hydrocarbons from molecular structures
Aiche Journal, 2009Co-Authors: Yong Pan, Juncheng Jiang, Xiaoye Ding, Rui Wang, Jiajia JiangAbstract:A quantitative structure-property relationship study is performed to develop mathematical models for predicting the flammability characteristics of pure hydrocarbons. The molecular structures of the compounds are numerically represented by various kinds of molecular descriptors. Genetic algorithm based multiple linear regression is used to select most statistically effective descriptors on the flash point, the Autoignition Temperature, and the lower and upper flammability limits of hydrocarbons, respectively. The resulted models are four multilinear equations. These models are very simple and can predict the flash point, the Autoignition Temperature, and the lower and upper flammability limits for the test set with average absolute errors of 5.41 K, 28.00 K, 0.044 vol %, and 0.503 vol %, respectively. The models are further compared with other published method and are shown to be more superior. The proposed method can be used to predict the flammability characteristics of hydrocarbons from the knowledge of only the molecular structures. © 2009 American Institute of Chemical Engineers AIChE J, 2010
M.r. Chandraratna - One of the best experts on this subject based on the ideXlab platform.
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pressure and concentration dependences of the Autoignition Temperature for normal butane air mixtures in a closed vessel
Combustion and Flame, 1994Co-Authors: M.r. Chandraratna, J.f. GriffithsAbstract:The conditions at which Autoignition occurs in lean premixed n-butane + air mixtures over the composition range 0.2%-2.5% n-butane by volume (0.06 < φ < 0.66) were investigated experimentally. Total reactant pressure from 0.1 to 0.6 MPa (1-6 atm) were studied in a spherical, stainless-steel, closed vessel (0.5 dm 3 ). There is a critical transition from nonignition to ignition, at pressures above 0.1 MPa, as the mixture is enriched in the vicinity of 1% fuel vapor by volume. There is also a region of multiplicity, which exhibits three critical Temperatures at a given composition. Chemical analyses of the molecular products of low-Temperature combustion are presented. The analyses show that partially oxygenated components, including many o-heterocyclic compounds, are important products of the lean combustion of butane at Temperatures up to 800 K. The critical conditions for Autoignition are discussed with regard to industrial ignition hazards, especially in the context of the «Autoignition Temperature» of alkanes given by ASTM or BS tests. The differences between the behavior of n-butane and the higher n-alkanes are explained. The experimental results are also used as a basis for testing a reduced kinetic model to represent the oxidation and Autoignition of n-butane or other alkanes
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Pressure and concentration dependences of the Autoignition Temperature for normal butane + air mixtures in a closed vessel
Combustion and Flame, 1994Co-Authors: M.r. Chandraratna, J.f. GriffithsAbstract:The conditions at which Autoignition occurs in lean premixed n-butane + air mixtures over the composition range 0.2%-2.5% n-butane by volume (0.06 < φ < 0.66) were investigated experimentally. Total reactant pressure from 0.1 to 0.6 MPa (1-6 atm) were studied in a spherical, stainless-steel, closed vessel (0.5 dm 3 ). There is a critical transition from nonignition to ignition, at pressures above 0.1 MPa, as the mixture is enriched in the vicinity of 1% fuel vapor by volume. There is also a region of multiplicity, which exhibits three critical Temperatures at a given composition. Chemical analyses of the molecular products of low-Temperature combustion are presented. The analyses show that partially oxygenated components, including many o-heterocyclic compounds, are important products of the lean combustion of butane at Temperatures up to 800 K. The critical conditions for Autoignition are discussed with regard to industrial ignition hazards, especially in the context of the «Autoignition Temperature» of alkanes given by ASTM or BS tests. The differences between the behavior of n-butane and the higher n-alkanes are explained. The experimental results are also used as a basis for testing a reduced kinetic model to represent the oxidation and Autoignition of n-butane or other alkanes
