scholarly journals The Effect of Hydrogen Addition on Low-Temperature Combustion of Light Hydrocarbons and Alcohols

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3808
Author(s):  
Fekadu Mosisa Wako ◽  
Gianmaria Pio ◽  
Ernesto Salzano
Keyword(s):  
Experimental Data ◽  
Burning Velocity ◽  
Engine Performance ◽  
Pollutant Emissions ◽  
Low Temperature Combustion ◽  
Laminar Burning Velocity ◽  
Nox Formation ◽  
Hydrogen Addition ◽  
Temperature Combustion ◽  
Fuel Mixtures

Hydrogen is largely considered as an attractive additive fuel for hydrocarbons and alcohol-fueled engines. Nevertheless, a complete understanding of the interactions between blended fuel mechanisms under oxidative conditions at low initial temperature is still lacking. This study is devoted to the numerical investigation of the laminar burning velocity of hydrogen–hydrocarbon and hydrogen–alcohol fuels under several compositions. Estimations were compared with experimental data reported in the current literature. Additionally, the effects of hydrogen addition on engine performance, NOX, and other pollutant emissions of the mentioned fuels have been thermodynamically analyzed. From the study, it has been observed that the laminar burning velocity of the fuel mixtures increased with increasing hydrogen fractions and the peak value shifted to richer conditions. Besides, hydrogen fraction was found to increase the adiabatic flame temperatures eventually favoring the NOX formation for all fuel blends except the acetylene–hydrogen–air mixture where hydrogen showed a reverse effect. Besides, hydrogen is also found to improve the engine performances and helps to surge thermal efficiency, improve the combustion rate, and lessen other pollutant emissions such as CO, CO2, and unburned hydrocarbons. The model predicted well and in good agreement with the experimental data reported in the recent literature.

Effects of fuel properties on combustion and pollutant emissions of a low temperature combustion mode diesel engine

Fuel ◽  
2020 ◽  
Vol 267 ◽  
pp. 117123 ◽  
Author(s):  
Song Li ◽  
Jinping Liu ◽  
Yu Li ◽  
Mingrui Wei ◽  
Helin Xiao ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Fuel Properties ◽  
Pollutant Emissions ◽  
Low Temperature Combustion ◽  
Combustion Mode ◽  
Temperature Combustion

Numerical study on laminar burning velocity and ignition delay time of ammonia flame with hydrogen addition

Energy ◽  
2017 ◽  
Vol 126 ◽  
pp. 796-809 ◽  
Author(s):  
Jun Li ◽  
Hongyu Huang ◽  
Noriyuki Kobayashi ◽  
Chenguang Wang ◽  
Haoran Yuan
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Numerical Study ◽  
Burning Velocity ◽  
Laminar Burning Velocity ◽  
Hydrogen Addition

A Computational Investigation of the Impact of Multiple Injection Strategies on Combustion Efficiency in Diesel-Natural Gas Dual Fuel Low Temperature Combustion Engine

2019 ◽  
Author(s):  
Lorenzo Bartolucci ◽  
Stefano Cordiner ◽  
Vincenzo Mulone ◽  
Sundar R. Krishnan ◽  
Kalyan K. Srinivasan
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Natural Gas ◽  
Combustion Efficiency ◽  
Dual Fuel ◽  
Pilot Injection ◽  
Low Temperature Combustion ◽  
Single Cylinder ◽  
Temperature Combustion ◽  
The Impact

Abstract Dual fuel diesel-methane low temperature combustion (LTC) has been investigated by various research groups, showing high potential for emissions reduction (especially oxides of nitrogen (NOx) and particulate matter (PM)) without adversely affecting fuel conversion efficiency in comparison with conventional diesel combustion. However, when operated at low load conditions, dual fuel LTC typically exhibit poor combustion efficiencies. This behavior is mainly due to low bulk gas temperatures under lean conditions, resulting in unacceptably high carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions. A feasible and rather innovative solution may be to split the pilot injection of liquid fuel into two injection pulses, with the second pilot injection supporting the methane combustion once the process is initiated by the first one. In this work, diesel-methane dual fuel LTC is investigated numerically in a single-cylinder heavy-duty engine operating at 5 bar brake mean effective pressure (BMEP) at 85% and 75% percentage of energy substitution (PES) by methane (taken as a natural gas surrogate). A multidimensional model is first validated in comparison with experimental data obtained on the same single-cylinder engine for early single pilot diesel injection at 310 CAD and 500 bar rail pressure. With the single pilot injection case as baseline, the effects of multiple pilot injections and different rail pressures on combustion emissions are investigated, again showing good agreement with experimental data. Apparent heat release rate and cylinder pressure histories as well as combustion efficiency trends are correctly captured by the numerical model. Results prove that higher rail pressures yield reductions of HC and CO by 90% and 75%, respectively, at the expense of NOx emissions, which increase by ∼30% from baseline. Furthermore, it is shown that post-injection during the expansion stroke does not support the stable development of the combustion front as the combustion process is confined close to the diesel spray core.

scholarly journals A Review on Homogeneous Charge Compression Ignition and Low Temperature Combustion by Optical Diagnostics

2015 ◽  
Vol 2015 ◽  
pp. 1-23 ◽  
Author(s):  
Chao Jin ◽  
Zunqing Zheng
Keyword(s):  
Low Temperature ◽  
Chemical Reaction ◽  
Homogeneous Charge Compression Ignition ◽  
Optical Diagnostics ◽  
Diagnostic Methods ◽  
Pollutant Emissions ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Temperature Combustion ◽  
Homogeneous Charge

Optical diagnostics is an effective method to understand the physical and chemical reaction processes in homogeneous charge compression ignition (HCCI) and low temperature combustion (LTC) modes. Based on optical diagnostics, the true process on mixing, combustion, and emissions can be seen directly. In this paper, the mixing process by port-injection and direct-injection are reviewed firstly. Then, the combustion chemical reaction mechanism is reviewed based on chemiluminescence, natural-luminosity, and laser diagnostics. After, the evolution of pollutant emissions measured by different laser diagnostic methods is reviewed and the measured species including NO, soot, UHC, and CO. Finally, a summary and the future directions on HCCI and LTC used optical diagnostics are presented.

Low Temperature Combustion Using Nitrogen Enrichment to Mitigate NOx From Large Bore Gas-Fueled Engines

2008 ◽  
Author(s):  
Munidhar S. Biruduganti ◽  
Sreenath B. Gupta ◽  
Raj Sekar
Keyword(s):  
Low Temperature ◽  
Power Density ◽  
Nox Reduction ◽  
Engine Performance ◽  
Air Separation ◽  
Nitrogen Enrichment ◽  
Nox Emissions ◽  
Low Temperature Combustion ◽  
Lean Burn ◽  
Temperature Combustion

Low Temperature Combustion (LTC) is identified as one of the pathways to meet the mandatory ultra low NOx emissions levels set by regulatory agencies. This phenomenon can be realized by utilizing various advanced combustion control strategies. The present work discusses nitrogen enrichment using an Air Separation Membrane (ASM) as a better alternative to the mature Exhaust Gas Re-circulation (EGR) technique currently in use. A 70% NOx reduction was realized with a moderate 2% nitrogen enrichment while maintaining power density and simultaneously improving Fuel Conversion Efficiency (FCE). The maximum acceptable Nitrogen Enriched Air (NEA) in a single cylinder spark ignited natural gas engine was investigated in this paper. Any enrichment beyond this level degraded engine performance both in terms of power density and FCE, and unburned hydrocarbon (UHC) emissions. The effect of ignition timing was also studied with and without N2 enrichment. Finally, lean burn versus stoichiometric operation utilizing NEA was compared. Analysis showed that lean burn operation along with NEA is one of the effective pathways for realizing better FCE and lower NOx emissions.

Experimental Investigation and Thermodynamic Modelling of an RCCI Engine With Gasoline and Ethanol As Pilot Fuels

2019 ◽  
Author(s):  
Chinmaya Mishra ◽  
P. M. V. Subbarao
Keyword(s):  
Experimental Investigation ◽  
Engine Performance ◽  
High Reactivity ◽  
Low Temperature Combustion ◽  
Oxides Of Nitrogen ◽  
Reactivity Controlled Compression Ignition ◽  
Simultaneous Reduction ◽  
Temperature Combustion ◽  
Energy Share ◽  
Reduction Of Oxides

Abstract Reactivity controlled compression ignition (RCCI) is an emerging premix low temperature combustion philosophy. Contemporary understanding suggests that RCCI concept with a premix high octane (low reactivity) fuel and direct injected high cetane (high reactivity) fuel ensures in-cylinder stratification of equivalence ratio as well as fuel reactivity. This stratification of reactivity coupled with partial premixing ensures simultaneous reduction of oxides of nitrogen and smoke. Furthermore, the induced delay in combustion phasing and high compression ratio ensures diffusive flames away from piston surface resulting in higher thermal efficiency. In the present work, an experimental investigation was carried out using port injected gasoline and anhydrous ethanol as low reactivity pilot fuels and direct injected diesel as high reactivity main fuel under various energy share. A comparative study of both the pilot fuels were carried out in terms of engine performance, emission and in-cylinder behavior in both representative and statistical perspective.

The Lean Mixture Operational Limits of a S.I. Engine When Operated on Fuel Mixtures

2005 ◽  
Author(s):  
Hailin Li ◽  
Ghazi A. Karim ◽  
A. Sohrabi
Keyword(s):  
Experimental Data ◽  
Fuel Economy ◽  
Engine Performance ◽  
Nox Emissions ◽  
Lean Mixture ◽  
Turn On ◽  
Unstable Combustion ◽  
Fuel Mixtures ◽  
Traditional Approaches ◽  
Combustion Processes

The operation of S.I. engines on lean mixtures is attractive in principle since it can provide improved fuel economy, reduced tendency to knock and extremely low NOx emissions. However, the associated flame propagation rates become degraded significantly and drop sharply as the operating mixture is made increasingly lean. Consequently, there exist distinct operational lean mixture limits beyond which satisfactory engine performance cannot be maintained due to the resulting prolonged and unstable combustion processes. The paper presents experimental data obtained in a single cylinder, variable compression ratio, S.I., CFR engine when operated in turn on CH4, H2, CO, gasoline, iso-octane and some of their binary mixtures. A quantitative approach for determining the operational limits of S.I. engines is suggested, compared and validated against corresponding experimental results of other traditional approaches. On this basis, the dependence of the values of the lean mixture operational limits on the composition of the fuel mixtures is investigated and discussed. The operational limit for throttled operation with methane as the fuel is also established.

scholarly journals Laminar Burning Velocity Model Based on Deep Neural Network for Hydrogen and Propane with Air

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3381
Author(s):  
Konrad Malik ◽  
Mateusz Żbikowski ◽  
Andrzej Teodorczyk
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Deep Neural Network ◽  
Burning Velocity ◽  
Analytical Models ◽  
Variable Pressure ◽  
Data Generation ◽  
Data Preparation ◽  
Laminar Burning Velocity ◽  
Neural Network Models

The aim of the study was to develop deep neural network models for laminar burning velocity (LBV) calculations. The present study resulted in models for hydrogen–air and propane–air mixtures. An original data-preparation/data-generation algorithm was also developed in order to obtain the datasets sufficient in quality and quantity for models training. The discussion about the current analytical models highlighted issues with both experimental data and methodology of creating those analytical models. It was concluded that there is a need for models that can capture data from multiple experimental techniques with ease and automate the model design and training process. We presented a full machine learning based approach that fulfills these requirements. Not only model development, but also data preparation was described in detail as it is crucial in obtaining good results. Resulting models calculations were compared with popular analytical models and experimental data gathered from literature. The calculations comparison showed that the models developed were characterized by the smallest error with regards to the experiments and behaved equally well for variable pressure, temperature, and equivalence ratio. The source code of ready-to-use models has been provided and can be easily integrated in, for example, CFD software.

A two-eddy theory of premixed turbulent flame propagation

1981 ◽  
Vol 301 (1457) ◽  
pp. 1-25 ◽  
Keyword(s):  
Experimental Data ◽  
Reynolds Number ◽  
Burning Velocity ◽  
Turbulent Flame ◽  
Experimental Measurements ◽  
Laminar Burning Velocity ◽  
Turbulent Reynolds Number ◽  
Theoretical Predictions ◽  
Premixed Turbulent Flame ◽  
Turbulent Burning Velocity

Available experimental data on the turbulent burning velocity of premixed gases are surveyed. There is discussion of the accuracy of experimental measurements and the means of ascertaining relevant turbulent parameters. Results are presented in the form of the variation of the ratio of turbulent to laminar burning velocities with the ratio of r.m.s. turbulent velocity to laminar burning velocity, for different ranges of turbulent Reynolds number. A two-eddy theory of burning is developed and the theoretical predictions of this approach, as well as those of others, are compared with experimentally measured values.

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