NUMERICAL STUDY OF HYDROGEN FUEL COMBUSTION IN COMPRESSION IGNITION ENGINE UNDER ARGON-OXYGEN ATMOSPHERE

2016 ◽  
Vol 78 (6-10) ◽  
Author(s):  
Nik Muhammad Hafiz ◽  
Mohd Radzi Abu Mansor ◽  
Wan Mohd Faizal Wan Mahmood ◽  
Fadzli Ibrahim ◽  
Shahrir Abdullah ◽  
...  
Keyword(s):  
Numerical Study ◽  
High Volume ◽  
Compression Ignition ◽  
Hydrogen Fuel ◽  
Compression Ignition Engine ◽  
Complete Combustion ◽  
Start Of Injection ◽  
Auto Ignition ◽  
Oxygen Medium ◽  
Carbon Dioxide Co2

Gas emissions from automobiles are one of the major causes of air pollution in our environment today. In fact, emissions of carbon dioxide (CO2), a product of complete combustion, has become a significant factor of the global warming effect. Hydrogen, which is a renewable energy, is regarded as a promising energy to solve this problem since the final product of hydrogen (H2) combustion, is water (H2O). However, the reaction of hydrogen fuels in the air under high temperature conditions produces a high volume of harmful nitrogen oxide (NOx). Furthermore, the high auto-ignition temperature of H2 makes it difficult to ignite in a compression ignition engine in normal air. In this research, argon (Ar) is used to replace nitrogen (N2), in order to eliminate NOx and enhance combustion. Simulation for this research was conducted using Converge, computational fluid dynamics software that is based on Yanmar TF90M compression ignition engine parameters. The simulation process was initially conducted with normal air (N2-O2) as the medium of combustion; but later it was replaced with an argon-oxygen (Ar-O2) atmosphere to investigate the ignition possibility of hydrogen fuel. Hydrogen was injected at 9.95 MPa at the start of injection (SOI) at 18º BTDC. The results show that, by employing the same parameters for both simulations in normal air and argon-oxygen mediums, the combustion of hydrogen only occurred in the argon-oxygen medium. However, no combustion took place in normal air. It is therefore concluded that an argon-oxygen medium is applicable for direct hydrogen injection in a compression ignition engine.

scholarly journals Implementing Natural Gas in a Compression Ignition Cycle Using Noble Gas Addition

2019 ◽  
Author(s):  
Martia Shahsavan ◽  
Mohammadrasool Morovatiyan ◽  
Mammadbaghir Baghirzade ◽  
John Hunter Mack
Keyword(s):  
Natural Gas ◽  
Numerical Study ◽  
Noble Gas ◽  
Cetane Number ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Low Carbon ◽  
Compression Ignition Engine ◽  
Optimal Operating ◽  
Auto Ignition

Natural gas is known as a relatively clean fossil fuel due to its low carbon to hydrogen ratio compared to other transportation fuels, which yields a reduction of carbon monoxide, carbon dioxide, and unburned hydrocarbons emissions. However, it has a low cetane number, which makes it a difficult fuel for use in compression ignition engines. A potential solution for this issue can be adding small amounts of argon, as a noble gas with a low specific heat to modify the intake conditions. In this numerical study, a commercial compression ignition engine has been modeled to evaluate the auto-ignition of natural gas with the modified intake conditions. Different amounts of argon added to the intake air are examined in order to attain the optimal operating conditions. A detailed chemistry solver is implemented on a 53-species chemical kinetics mechanism to calculate the rate constants. The results show that compression ignition of natural gas can be achieved by adding small amounts of argon to the intake air. It drastically increases the in-cylinder temperature and pressure near TDC, which enables the auto-ignition of the injected natural gas. Moreover, it leads to the reduction in ignition delay and heat release rate, and expands the combustion duration. Emissions analysis indicates that NOx and CO2 can be significantly diminished by increasing the amount of argon in the intake composition. This study introduces an efficient and clean compression ignition engine fueled with natural gas running in optimal operating conditions using argon addition to the intake.

Numerical study of the combustion mechanism of a homogeneous charge compression ignition engine fuelled with dimethyl ether and methane, with a detailed kinetics model

2005 ◽  
Vol 219 (10) ◽  
pp. 1213-1223 ◽  
Author(s):  
M Yao ◽  
J Qin ◽  
Z Zheng
Keyword(s):  
Heat Release ◽  
Dimethyl Ether ◽  
Homogeneous Charge Compression Ignition ◽  
Numerical Study ◽  
Kinetics Model ◽  
Compression Ignition ◽  
Temperature Reaction ◽  
Compression Ignition Engine ◽  
Auto Ignition ◽  
Homogeneous Charge

The auto-ignition and combustion mechanisms of dimethyl ether (DME) in a fourstroke homogeneous charge compression ignition (HCCI) engine were investigated using a zero-dimensional thermodynamic model coupled with a detailed chemical kinetics model. The results indicate that DME displays two-stage auto-ignition, and heat release with a low-temperature reaction and a high-temperature reaction (HTR). Heat release with the HTR can be separated into two stages: blue flame and hot flame. HCCI ignition is controlled by hydrogen peroxide (H2O2) decomposition, and OH plays a very important role in HCCI combustion. Formaldehyde (CH2O) is the main source of H2O2. Based on the sensitivity analysis of chemical reactions, the major paths of the DME reaction occurring in the engine cylinder are clarified. The major paths of the DME reaction is H-atom abstraction from DME, followed by the first addition of O2 and second addition of O2, and then oxidation to formaldehyde (CH2O), the formyl radical (HCO), and finally carbon monoxide (CO). CO oxidation occurs at the hot flame by the elementary reaction CO + OH = CO2 + H. At leaner DME concentrations, CO cannot be completely converted to carbon dioxide (CO2), and the process will result in high CO emissions.

scholarly journals Study of Knocking Effect in Compression Ignition Engine with Hydrogen as a Secondary Fuel

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
R. Sivabalakrishnan ◽  
C. Jegadheesan
Keyword(s):  
Compression Ignition ◽  
Hydrogen Fuel ◽  
Compression Ignition Engine ◽  
Complete Combustion ◽  
Pressure Signal ◽  
Alternate Fuel ◽  
Measurement And Analysis ◽  
Fuel Mixtures ◽  
Quenching Distance ◽  
Free Environment

The aim of this project is detecting knock during combustion of biodiesel-hydrogen fuel and also the knock is suppressed by timed injection of diethyl ether (DEE) with biodiesel-hydrogen fuel for different loads. Hydrogen fuel is an effective alternate fuel in making a pollution-free environment with higher efficiency. The usage of hydrogen in compression ignition engine leads to production of knocking or detonation because of its lower ignition energy, wider flammability range, and shorter quenching distance. Knocking combustion causes major engine damage, and also reduces the efficiency. The method uses the measurement and analysis of cylinder pressure signal for various loads. The pressure signal is to be converted into frequency domain that shows the accurate knocking combustion of fuel mixtures. The variation of pressure signal is gradually increased and smoothly reduced to minimum during normal combustion. The rapid rise of pressure signal has occurred during knocking combustion. The experimental setup was mainly available for evaluating the feasibility of normal combustion by comparing with the signals from both fuel mixtures in compression ignition engine. This method provides better results in predicting the knocking feature of biodiesel-hydrogen fuel and the usage of DEE provides complete combustion of fuels with higher performance, and lower emission.

scholarly journals Implementing Natural Gas in a Compression Ignition Cycle Using Noble Gas Addition

2019 ◽  
Author(s):  
Martia Shahsavan ◽  
Mohammadrasool Morovatiyan ◽  
Mammadbaghir Baghirzade ◽  
J. Hunter Mack
Keyword(s):  
Natural Gas ◽  
Numerical Study ◽  
Noble Gas ◽  
Cetane Number ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Low Carbon ◽  
Compression Ignition Engine ◽  
Optimal Operating ◽  
Auto Ignition

Abstract Natural gas is known as a relatively clean fossil fuel due to its low carbon to hydrogen ratio compared to other transportation fuels, which yields a reduction of carbon monoxide, carbon dioxide, and unburned hydrocarbons emissions. However, it has a low cetane number, which makes it a difficult fuel for use in compression ignition engines. A potential solution for this issue can be adding small amounts of argon, as a noble gas with a low specific heat to modify the intake conditions. In this numerical study, a commercial compression ignition engine has been modeled to evaluate the auto-ignition of natural gas with the modified intake conditions. Different amounts of argon added to the intake air are examined in order to attain the optimal operating conditions. A detailed chemistry solver is implemented on a 53-species chemical kinetics mechanism to calculate the rate constants. The results show that compression ignition of natural gas can be achieved by adding small amounts of argon to the intake air. It drastically increases the in-cylinder temperature and pressure near TDC, which enables the auto-ignition of the injected natural gas. Moreover, it leads to the reduction in ignition delay and heat release rate, and expands the combustion duration. Emissions analysis indicates that NOx and CO2 can be significantly diminished by increasing the amount of argon in the intake composition. This study introduces an efficient and clean compression ignition engine fueled with natural gas running in optimal operating conditions using argon addition to the intake.

Numerical study on combustion characteristics of six-stroke-cycle gasoline compression ignition engine with continuously variable valve duration valve technology

2019 ◽  
Vol 22 (1) ◽  
pp. 165-183 ◽  
Author(s):  
Oudumbar Rajput ◽  
Youngchul Ra ◽  
Kyoung-Pyo Ha ◽  
You-Sang Son
Keyword(s):  
Numerical Study ◽  
Power Stroke ◽  
Compression Ignition ◽  
Ignition Timing ◽  
Compression Ignition Engine ◽  
Engine Operation ◽  
Wide Range ◽  
Negative Valve Overlap ◽  
Variable Valve ◽  
Valve Overlap

Engine performance and emissions of a six-stroke gasoline compression ignition engine with a wide range of continuously variable valve duration control were numerically investigated at low engine load conditions. For the simulations, an in-house three-dimensional computational fluid dynamics code with high-fidelity physical sub-models was used, and the combustion and emission kinetics were computed using a reduced kinetics mechanism for a 14-component gasoline surrogate fuel. Variation of valve timing and duration was considered under both positive valve overlap and negative valve overlap including the rebreathing of intake valves via continuously variable valve duration control. Close attention was paid to understand the effects of two additional strokes of the engine cycle on the thermal and chemical conditions of charge mixtures that alter ignition, combustion and energy recovery processes. Double injections were found to be necessary to effectively utilize the additional two strokes for the combustion of overly mixed lean charge mixtures during the second power stroke. It was found that combustion phasing in both power strokes is effectively controlled by the intake valve closure timing. Engine operation under negative valve overlap condition tends to advance the ignition timing of the first power stroke but has minimal effect on the ignition timing of second power stroke. Re-breathing was found to be an effective way to control the ignition timing in second power stroke at a slight expense of the combustion efficiency. The operation of a six-stroke gasoline compression ignition engine could be successfully simulated. In addition, the operability range of the six-stroke gasoline compression ignition engine could be substantially extended by employing the continuously variable valve duration technique.

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