Auto-ignition and detonation of n-butanol and toluene reference fuel blends (TRF)

2021 ◽  
Vol 229 ◽  
pp. 111378
Author(s):  
Inna Gorbatenko ◽  
Derek Bradley ◽  
Alison S. Tomlin
Keyword(s):  
Fuel Blends ◽  
Auto Ignition

An Investigation of Various Chemical Kinetic Models for the Prediction of Autoignition in HCCI Engine

2012 ◽  
Author(s):  
A. F. Khan ◽  
A. A. Burluka
Keyword(s):  
Kinetic Models ◽  
Chemical Kinetic ◽  
Compression Ignition Engine ◽  
Engine Model ◽  
Fuel Blends ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Delay Times ◽  
Weak Points ◽  
Different Levels

Diverse kinetic models for iso-octane, n-heptane, toluene and ethanol i.e. main gasoline surrogates, have been investigated. The models have different levels of complexity and strong and weak points. Firstly, ignition delay times for various fuel blends have been calculated and compared with published shock tube measurements. Kinetic models which are capable of distinguishing between Primary and Toluene Reference Fuels have been used further on in a zero-dimensional Homogeneous Charge Compression Ignition engine model to predict auto-ignition. The modelling results have been compared to the experimental results obtained in a single cylinder research engine. A discussion has been made on the ability of these models to predict autoignition.

Auto Ignition Study of Methane and Bio Alcohol Fuel Blends

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Xuan Zheng ◽  
Shirin Jouzdani ◽  
Benjamin Akih-Kumgeh
Keyword(s):  
Experimental Data ◽  
Kinetic Models ◽  
Ignition Delay ◽  
Chemical Kinetic ◽  
Dual Fuel ◽  
Fuel Blends ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Alcohol Fuel ◽  
Delay Times

Abstract Methane (CH4) and bio alcohols have different ignition properties. These have been extensively studied and the resulting experimental data have been used to validate chemical kinetic models. Methane is the main component of natural gas, which is of interest because of its relative availability and lower emissions compared to other hydrocarbon fuels. Given growing interest in fuel-flexible systems, there can be situations in which the combustion properties of natural gas need to be modified by adding biofuels such as bio alcohols. This can occur in dual-fuel internal combustion engines or gas turbines with dual-fuel capabilities. The combustion behavior of such blends can be understood by studying the auto ignition properties in fundamental combustion experiments. Studies of the ignition of such blends are very limited in the literature. In this work, the auto ignition of methane and bio alcohol fuel blends is investigated using a shock tube facility. The chosen bio alcohols are ethanol (C2H5OH) and n-propanol (NC3H7OH). Experiments are carried out at 3 atm and 10 atm for stoichiometric and lean mixtures of fuel, oxygen, and argon. The ignition delay times of the pure fuels are first established at conditions of constant oxygen concentration and comparable pressures. The ignition delay times of blends with 50% methane are then measured. The pyrolysis kinetics of the blends is further explored by measuring CO formation during pyrolysis of the alcohol and methane–alcohol blends. The resulting experimental data are compared with the predictions of selected chemical kinetic models to establish the ability of these models to predict the disproportionate enhancement of methane ignition by the added alcohol.

Auto Ignition Study of Methane and Bio Alcohol Fuel Blends

2019 ◽  
Author(s):  
Xuan Zheng ◽  
Shirin Jouzdani ◽  
Benjamin Akih-Kumgeh
Keyword(s):  
Experimental Data ◽  
Kinetic Models ◽  
Ignition Delay ◽  
Chemical Kinetic ◽  
Dual Fuel ◽  
Fuel Blends ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Alcohol Fuel ◽  
Delay Times

Abstract Methane (CH4) and bio alcohols have different ignition properties. These have been extensively studied and the resulting experimental data have been used to validate chemical kinetic models. Methane is the main component of natural gas, which is of interest because of its relative availability and lower emissions compared to other hydrocarbon fuels. Given growing interest in fuel-flexible systems, there can be situations in which the combustion properties of natural gas need to be modified by adding biofuels, such as bio alcohols. This can occur in dual fuel internal combustion engines or gas turbines with dual fuel capabilities. The combustion behavior of such blends can be understood by studying the auto ignition properties in fundamental combustion experiments. Studies of the ignition of such blends are very limited in the literature. In this work, the auto ignition of methane and bio alcohol fuel blends is investigated using a shock tube facility. The chosen bio alcohols are ethanol (C2H5OH) and n-propanol (NC3H7OH). Experiments are carried out at 3 atm and 10 atm for stoichiometric and lean mixtures of fuel, oxygen, and argon. The ignition delay times of the pure fuels are first established at conditions of constant oxygen concentration and comparable pressures. The ignition delay times of blends with 50% methane are then measured. The pyrolysis kinetics of the blends is further explored by measuring CO formation during pyrolysis of the alcohol and methane-alcohol blends. The resulting experimental data are compared with the predictions of selected chemical kinetic models to establish the ability of these models to predict the disproportionate enhancement of methane ignition by the added alcohol.

Co-Firing of Hydrogen and Natural Gases in Lean Premixed Conventional and Reheat Burners (Alstom GT26)

2014 ◽  
Author(s):  
Torsten Wind ◽  
Felix Güthe ◽  
Khawar Syed
Keyword(s):  
Natural Gas ◽  
Ignition Delay ◽  
Flame Temperature ◽  
Nox Emissions ◽  
Natural Gases ◽  
Fuel Blends ◽  
Auto Ignition ◽  
Fuel Flexibility ◽  
Higher Hydrocarbons ◽  
The Impact

Addition of hydrogen (H2), produced from excess renewable electricity, to natural gas has become a new fuel type of interest for gas turbines. The addition of hydrogen extends the existing requirements to widen the fuel flexibility of gas turbine combustion systems to accommodate natural gases of varying content of higher hydrocarbons (C2+). The present paper examines the performance of the EV and SEV burners used in the sequential combustion system of Alstom’s reheat engines, which are fired with natural gas containing varying amounts of hydrogen and higher hydrocarbons. The performance is evaluated by means of single burner high pressure testing at full scale and at engine-relevant conditions. The fuel blends studied introduce variations in Wobbe index and reactivity. The latter influences, for example, laminar and turbulent burning velocities, which are significant parameters for conventional lean premixed burners such as the EV, and auto-ignition delay times, which is a significant parameter for reheat burners, such as the SEV. An increase in fuel reactivity can lead to increased NOx emissions, flashback sensitivity and flame dynamics. The impact of the fuel blends and operating parameters, such as flame temperature, on the combustion performance is studied. Results indicate that variation of flame temperature of the first burner is an effective parameter to maintain low NOx emissions as well as offsetting the impact of fuel reactivity on the auto-ignition delay time of the downstream reheat burner. The relative impact of hydrogen and higher hydrocarbons is in agreement with results from simple reactor and 1D flame analyses. The changes in combustion behaviour can be compensated by a slightly extended operation concept of the engine following the guidelines of the existing C2+ operation concept and will lead to a widened, safe operational range of Alstom reheat engines with respect to fuel flexibility without hardware modifications.

The Influence of New-Typed Oxygenated Fuel Blends on Combustion and Emission Performance for Diesel Engine

2010 ◽  
Vol 113-116 ◽  
pp. 1679-1683 ◽  
Author(s):  
Jin Rui Zhao ◽  
Yan Ping Cai ◽  
Yan Ping He ◽  
Li Mei Li
Keyword(s):  
Diesel Engine ◽  
Nox Emission ◽  
Smoke Emission ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Auto Ignition ◽  
Oxygenated Fuel ◽  
Di Diesel Engine ◽  
Blended Fuel ◽  
Engine Dynamic

A new type of oxygenated fuel blend was designed, it was diesel-fuel mixed with 15%、25% n-butoxyether(NBE) in volume. The experiments were conducted on a TY1100 single cylinder DI diesel engine. When the diesel engine rotational speed was 1400r/min and 2000r/min，the effects of the oxygenated fuel blends on engine Combustion and emission characteristics were studied. Results of experiment show that NBE has good solubility in diesel. When the diesel engine without any modification fueled with 15% ~ 25% NBE-diesel blended fuel，in comparison to original diesel engine, the diesel engine dynamic changes little, auto-ignition period is delay, and the premix combustion period increases, while the diffusive combustion period and combustion duration decreases. At high load, the peak values of cylinder pressure, pressure increase rate decrease strongly, but at low load, the peak values decrease slightly. In the same operating condition, the diesel engine fueled with 15% ~ 25% NBE-diesel blended fuel, its smoke, CO, HC and NOx emission decreases with the increasing content of NBE, can significantly reduce the smoke emission and reduce CO、HC and NOx emissions in some extent. For the largest decline amplitude, smoke emission decreases to 75%, CO emission decreases to 56%, HC emission decreases to 76.9%, and NOx emission decreases slightly, it decreases 13.1%.

Influences of isomeric butanol addition on anti-knock tendency of primary reference fuel and toluene primary reference fuel gasoline surrogates

2019 ◽  
Vol 22 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Yunchu Fan ◽  
Yaozong Duan ◽  
Dong Han ◽  
Xinqi Qiao ◽  
Zhen Huang
Keyword(s):  
Combustion Kinetics ◽  
Molar Percentage ◽  
Research Octane Number ◽  
Fuel Blends ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Delay Times ◽  
Primary Reference ◽  
Primary Reference Fuels

The anti-knock tendency of blends of butanol isomers and two gasoline surrogates (primary reference fuels and toluene primary reference fuels) was studied on a single-cylinder cooperative fuel research engine. The effects of butanol molecular structure (n-butanol, i-butanol, s-butanol and t-butanol) and butanol addition percentage on fuel research octane numbers were investigated. The experimental results revealed that butanol addition to either PRF80 or TPRF80 increased research octane numbers, and the research octane numbers of fuel blends showed higher linearity with the molar percentage than with the volumetric percentage of butanol addition. Furthermore, the research octane number boosting effects of butanol isomers were observed to change with the fuel compositions, that is, i-butanol >s-butanol >n-butanol >t-butanol for primary reference fuels and i-butanol >s-butanol >t-butanol >n-butanol for toluene primary reference fuels. In addition, butanol/primary reference fuel blends exhibited higher research octane numbers than butanol/toluene primary reference fuel blends. We thereafter tried to elucidate the underlying fuel combustion kinetics for the observed anti-knock quality of different butanol/gasoline surrogate blends. It was found that the measured research octane numbers of fuel blends showed the best correlation with the calculated ignition delay times at the thermodynamic condition of 770 K and 2 MPa, and the reaction sensitivity analysis in auto-ignition at this condition revealed that the H-abstraction reactions of butanol isomers by OH radical suppressed fuel reactivity, thus elevating the fuel research octane numbers when butanol was added to the gasoline surrogates. Compared with the butanol/primary reference fuel blends, the positive sensitive reactions related to n-heptane were of higher importance, while the inhibitive effects of sensitive reactions related to butanol and iso-octane decreased for the toluene primary reference fuel/butanol blends, thus leading to lower research octane numbers of the toluene primary reference fuel/butanol blends than those of the butanol/primary reference fuel blends.

Effects of branch structure of alkylbenzenes on spray auto-ignition of n-decane and alkylbenzenes blends

2020 ◽  
pp. 146808742091471 ◽  
Author(s):  
Yaozong Duan ◽  
Wang Liu ◽  
Xin Liang ◽  
Dong Han
Keyword(s):  
Ignition Delay ◽  
Cetane Number ◽  
Methyl Groups ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Combustion Duration ◽  
Ignition Characteristics ◽  
Ignition Propensity

Spray auto-ignition characteristics of the blends of n-decane and several alkylbenzenes were carried out on a heated constant-volume spray combustion chamber. The derived cetane numbers of the fuel blends were determined, and the temperature-dependent ignition delay times and combustion durations were measured across a range of temperatures from 808 to 911 K. The results reveal that blending alkylbenzene to n-decane inhibits fuel spray auto-ignition propensity. For mono-alkylbenzenes, the fuel blend containing toluene has a higher derived cetane number than those with ethylbenzene and n-propylbenzene, but has a lower derived cetane number than the fuel blend containing n-butylbenzene. For those binary fuels containing ethylbenzene, n-propylbenzene and n-butylbenzene, their derived cetane numbers increase with the side alkyl chain length. The derived cetane numbers of the fuel blends with C8H10 isomers follow the trend of n-decane/ o-xylene >  n-decane/ethylbenzene >  n-decane/ m-xylene ∼ n-decane/ p-xylene, given the alkylbenzene blending fraction. For the blends with C9H12 isomers, those containing 1,2,3-trimethylbenzene and 1,3,5-trimethylbenzene have the highest and lowest derived cetane numbers, respectively, while the fuel blends containing 1,2,4-trimethylbenzene, n-propylbenzene and i-propylbenzene have comparatively intermediate derived cetane numbers. The blending effects of alkylbenzenes on ignition delay time are consistent with the observation on fuel derived cetane numbers. Both the number and proximity of substituted methyl groups significantly affect fuel auto-ignition propensity, and the adjacent methyl groups could increase the auto-ignition propensity. The combustion duration for the test fuels, except for n-decane and the n-decane/ n-butylbenzene blend, monotonically decreases with increased temperature. The non-monotonic dependence of combustion duration on temperature, for neat n-decane and the n-decane/ n-butylbenzene blend, may result from the increased diffusive burnt fraction. Finally, the comparison between gas-phase and spray auto-ignition reactivity of the test fuels highlights the contribution of both fuel physics and chemistry in spray auto-ignition.

Influences of C5 esters addition on anti-knock and auto-ignition tendency of a gasoline surrogate fuel

2021 ◽  
pp. 146808742110308
Author(s):  
Xin Liang ◽  
Yaozong Duan ◽  
Yunchu Fan ◽  
Zhen Huang ◽  
Dong Han
Keyword(s):  
Fuel Blends ◽  
Molar Basis ◽  
Auto Ignition ◽  
Lower Reactivity ◽  
Methyl Butanoate ◽  
Octane Rating ◽  
Constant Volume Combustion Chamber ◽  
Primary Reference ◽  
Ignition Characteristics ◽  
Surrogate Fuel

The research octane numbers and auto-ignition characteristics of a toluene primary reference fuel (TPRF), when blended with three C5 esters, γ-valerolactone (GVL), methyl butanoate (MB), and methyl crotonate (MC), were investigated on a cooperative fuel research (CFR) engine and a constant volume combustion chamber (CVCC). In fuel preparation, ethanol was used to improve the miscibility, and the total additive comprised 1/3 ethanol and 2/3 GVL/MB/MC on a molar basis. The experimental results first reveal that the addition of the three series of additives boost fuel octane rating, and their boosting effects rank as MB > GVL ∼ MC when fuels are blended on a molar basis. In contrast, the auto-ignition tendency of the three series of fuel blends, when blended on the molar basis, ranks as the MC blends > the GVL blends> the MB blends. Different from the similar reactivities observed for the MC blends and the GVL blends in the RON tests, the MC blends exhibit higher auto-ignition propensity than the GVL blends, probably because the higher enthalpy of vaporization of GVL causes a more significant cooling effect. Finally, different from the literature studies that reported similar reactivities for pure MB and MC, in this study MB shows lower reactivity than MC when blending with the TPRF gasoline surrogate.

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