scholarly journals Effects of Gasoline-Diesel Ratio on Combustion and Emission Characteristics of a Dual-Fuel CI Engine: A CFD Simulation

2021 ◽  
Author(s):  
Kazi Mostafijur Rahman ◽  
Md. Habibur Rahaman
Keyword(s):  
Internal Combustion Engines ◽  
Cfd Simulation ◽  
Dual Fuel ◽  
Ignition Process ◽  
Unburned Hydrocarbon ◽  
Auto Ignition ◽  
Combustion Duration ◽  
Pilot Fuel ◽  
Dual Fuel Engines ◽  
Rate Of Heat Release

Recently, considerable efforts are made by the engine researches all over the world, focusing primarily on achieving ultra-low emissions of NOx (nitrogen oxides) and soot without any compromise to high thermal efficiency from dual-fuel engine. In this study, combustion performance and engine-out emission of a single cylinder gasoline-diesel dual-fuel engine are numerically investigated by employing a commercial computation fluid dynamics (CFD) software, especially developed for internal combustion engines modeling. Here, gasoline-diesel relative ratio has been varied to find its impacts on performance of a dual-fuel engine. The results show that, in-cylinder pressure, in-cylinder temperature and rate of heat release (ROHR) are increased with gradual increment in diesel relative to gasoline. Injecting higher amount of diesel directly inside the combustion chamber as pilot fuel might have facilitated the auto-ignition process by reducing the ignition delay and accelerated the premixed gasoline-air flame propagation. These led to shorter main combustion duration which is quite desirable to suppress the knock in dual-fuel engines. In addition, NOx emission is found to decrease with relatively higher percentage of diesel. On the other hand, with increasing gasoline ratio relative to diesel, combustion duration is prolonged significantly and led to incomplete combustion, thereby increasing unburned hydrocarbon (UHC) and carbon monoxide (CO).

Development of a Numerical Model for Ignition Phenomena in a Micro Pilot Ignited Dual Fuel Engine With External Mixture Formation

2017 ◽  
Author(s):  
Michael Schiffner ◽  
Marcus Grochowina ◽  
Thomas Sattelmayer
Keyword(s):  
Flame Propagation ◽  
Ignition Delay ◽  
Cfd Simulation ◽  
Injection Pressure ◽  
Optical Measurements ◽  
Effect Of Temperature ◽  
Dual Fuel ◽  
Ignition Process ◽  
Fuel Blend ◽  
Auto Ignition

In this paper, a numerical investigation of the ignition process of dual fuel engines is presented. Optical measurements revealed that a homogeneous natural gas charge ignited by a small diesel pilot comprises the combustion phenomena of compression ignition of the pilot fuel as well as premixed flame propagation. The 3-Zones Extended Coherent Flame Model (ECFM3Z) was selected, since it can treat auto-ignition, pre-mixed flame propagation and diffusion flame aspects. Usually combustion models in multi-dimensional computational fluid dynamics (CFD) software packages are designed to handle only one reactive species representing the fuel concentration. In the context of the ECFM3Z model the concept of a multi-component fuel is applied to dual fuel operation. Since the available ignition models were not able to accurately describe the ignition characteristics of the investigated setup, a new dual fuel auto-ignition model was developed. Ignition delay times of the fuel blend are tabulated using a detailed reaction mechanism for n-heptane. Thereby, the local progress of pre-ignition reactions in the CFD simulation can be calculated. The ignition model is validated against experiments conducted with a periodically chargeable constant volume combustion chamber. The proposed model is capable to reproduce the ignition delay as well as the location of the flame kernels. The CFD simulations show the effect of temperature stratification and variations in the injection pressure on the apparent ignition delay of the micro pilot.

Combustion Performance and Unburned Hydrocarbon Emissions of a Natural Gas–Diesel Dual Fuel Engine at a Low Load Condition

2017 ◽  
Author(s):  
Hongsheng Guo ◽  
Brian Liko ◽  
Luis Luque ◽  
Jennifer Littlejohns
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Load Condition ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Injection Timing ◽  
Unburned Hydrocarbon ◽  
Diesel Injection ◽  
Dual Fuel Engines ◽  
Dual Fuel Combustion

The combustion of natural gas reduces fuel cost and generates less emissions of carbon dioxide and particulate matter than diesel and gasoline. Replacing diesel by natural gas in internal combustion engines is of great interest for transportation and stationary power generation. Dual fuel combustion is an efficient way to burn natural gas in internal combustion engines. In natural gas–diesel dual fuel engines, unburned hydrocarbon emissions increase with increasing natural gas fraction. Many studies have been conducted to improve the performance of natural gas–diesel dual fuel engines and reported the performance of combustion and emissions of regulated pollutants and total unburned hydrocarbon at various engine operating strategies. However, little has been reported on the emissions of different unburned hydrocarbon components. In this paper, an experimental investigation was conducted to investigate the combustion performance and emissions of various unburned hydrocarbon components, including methane, ethane, ethylene, acetylene, propylene, formaldehyde, acetaldehyde and benzaldehyde, at a low engine load condition. The operating conditions, such as engine speed, load, intake temperature and pressure, were well controlled during the experiment. The combustion and emissions performance of pure diesel and natural gas–diesel dual fuel combustion were compared. The effect of diesel injection timing was analyzed. The results show that appropriately advancing diesel injection timing to form a homogeneous charge compression ignition-like combustion is beneficial to natural gas–diesel dual fuel combustion at low load conditions. The emissions of different unburned hydrocarbon components changed in dual fuel combustion, with emissions of some unburned hydrocarbon components being primarily due to the combustion of natural gas, while those of others being more related to diesel combustion.

scholarly journals Applying detailed chemistry for the dual-fuel engine combustion process simulation using CFD approach

2021 ◽  
Vol 2061 (1) ◽  
pp. 012063
Author(s):  
V N Grinev ◽  
A V Kozlov ◽  
N S Zuev
Keyword(s):  
Experimental Data ◽  
Internal Combustion Engines ◽  
Fuel Efficiency ◽  
Combustion Process ◽  
Propagation Speed ◽  
Fuel Mixture ◽  
Dual Fuel ◽  
Detailed Chemistry ◽  
Pilot Fuel ◽  
Dual Fuel Engines

Abstract Modern research in the area of internal combustion engines is focused on searching and investigating the technologies that will improve fuel efficiency and decrease emissions. The application of dual-fuel engines is considered a potential solution to these problems. In the dual-fuel engine, the natural gas-air mixture is ignited by a small amount of diesel fuel directly injected into a combustion chamber. This paper aims to develop a detailed chemistry mechanism for 3D simulation of the combustion process of a dual-fuel engine, providing sufficient convergence with the experimental data. It should be noted that sufficient convergence must also be provided in terms of such parameters as pilot fuel ignition delay and premixed air-fuel mixture flame propagation speed. In the course of the research, the analysis of the most commonly used detailed chemistry mechanisms for calculation of the combustion process and mechanisms’ disadvantages was performed. The results obtained with the use of the detailed mechanisms were compared with the results obtained without using detailed chemistry and with the experimental data as well.

scholarly journals Effect of methane on pilot-fuel auto-ignition in dual-fuel engines

2019 ◽  
Vol 37 (4) ◽  
pp. 4741-4749 ◽  
Author(s):  
Aleš Srna ◽  
Michele Bolla ◽  
Yuri M. Wright ◽  
Kai Herrmann ◽  
Rolf Bombach ◽  
...  
Keyword(s):  
Dual Fuel ◽  
Auto Ignition ◽  
Pilot Fuel ◽  
Dual Fuel Engines

Combustion Performance and Unburned Hydrocarbon Emissions of a Natural Gas–Diesel Dual Fuel Engine at a Low Load Condition

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Hongsheng Guo ◽  
Brian Liko ◽  
Luis Luque ◽  
Jennifer Littlejohns
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Load Condition ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Injection Timing ◽  
Unburned Hydrocarbon ◽  
Diesel Injection ◽  
Dual Fuel Engines ◽  
Dual Fuel Combustion

The combustion of natural gas reduces fuel cost and generates less emissions of carbon dioxide and particulate matter (PM) than diesel and gasoline. Replacing diesel by natural gas in internal combustion engines is of great interest for transportation and stationary power generation. Dual fuel combustion is an efficient way to burn natural gas in internal combustion engines. In natural gas–diesel dual fuel engines, unburned hydrocarbon emissions increase with increasing natural gas fraction. Many studies have been conducted to improve the performance of natural gas–diesel dual fuel engines and reported the performance of combustion and emissions of regulated pollutants and total unburned hydrocarbon at various engine operating strategies. However, little has been reported on the emissions of different unburned hydrocarbon components. In this paper, an experimental investigation was conducted to investigate the combustion performance and emissions of various unburned hydrocarbon components, including methane, ethane, ethylene, acetylene, propylene, formaldehyde, acetaldehyde, and benzaldehyde, at a low engine load condition. The operating conditions, such as engine speed, load, intake temperature, and pressure, were well controlled during the experiment. The combustion and emissions performance of pure diesel and natural gas–diesel dual fuel combustion were compared. The effect of diesel injection timing was analyzed. The results show that appropriately advancing diesel injection timing to form a homogeneous charge compression ignition (HCCI)-like combustion is beneficial to natural gas–diesel dual fuel combustion at low load conditions. The emissions of different unburned hydrocarbon components changed in dual fuel combustion, with emissions of some unburned hydrocarbon components being primarily due to the combustion of natural gas, while those of others being more related to diesel combustion.

Influence of Injection Parameters and Operating Conditions on Ignition and Combustion in Dual-Fuel Engines

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Marcus Grochowina ◽  
Michael Schiffner ◽  
Simon Tartsch ◽  
Thomas Sattelmayer
Keyword(s):  
Natural Gas ◽  
High Speed ◽  
Measurement Techniques ◽  
Injection Pressure ◽  
Operating Conditions ◽  
Liquid Fuels ◽  
Dual Fuel ◽  
Injection Parameters ◽  
Auto Ignition ◽  
Pilot Fuel

Dual-fuel (DF) engines offer great fuel flexibility since they can either run on gaseous or liquid fuels. In the case of diesel pilot-ignited DF engines, the main source of energy is provided by gaseous fuel, whereas the diesel fuel acts only as an ignition source. Therefore, a proper auto-ignition of the pilot fuel is of utmost importance for combustion in DF engines. However, auto-ignition of the pilot fuel suffers from lower compression temperatures of Miller or Atkinson valve timings. These valve timings are applied to increase efficiency and lower nitrogen oxide (NOx) engine emissions. In order to improve the ignition, it is necessary to understand which parameters influence the ignition in DF engines. For this purpose, experiments were conducted and the influence of parameters, such as injection pressure, pilot fuel quantity, compression temperature, and air–fuel (A/F) equivalence ratio of the homogenous natural gas–air mixture were investigated. The experiments were performed on a periodically chargeable combustion cell using optical high-speed recordings and thermodynamic measurement techniques for pressure and temperature. The study reveals that the quality of the diesel pilot ignition in terms of short ignition delay and a high number of ignited sprays significantly depends on the injection parameters and operating conditions. In most cases, the pilot fuel suffers from too high dilution due to its small quantity and long ignition delays. This results in a small number of ignited sprays and consequently leads to longer combustion durations. Furthermore, the experiments confirm that the natural gas of the background mixture influences the auto-ignition of the diesel pilot oil.

Paper 1: Critical Factors in the Application of Dual-Fuel Engines

1969 ◽  
Vol 184 (16) ◽  
pp. 1-9
Author(s):  
P. W. A. Eke ◽  
J. H. Walker ◽  
M. A. Williams
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Fuel Oil ◽  
Dual Fuel ◽  
Combustion Engines ◽  
Critical Factors ◽  
Liquid Form ◽  
Compression Ignition Engine ◽  
Dual Fuel Engines ◽  
Further Development

A dual-fuel engine may be defined as a compression-ignition engine using mainly gaseous fuel but with a small quantity of fuel oil injected as an ignition source; the engine can be changed over instantaneously and under load to operate on liquid fuel alone. The recent availability of natural gas in this country once again attracts the attention of engineers towards gas as a fuel for internal-combustion engines. This paper traces the development of dual-fuel engines, originally using sewage gas and more recently using natural gas, and considers their advantages, both technical and economic, compared with spark-ignited and diesel engines. The dual-fuel engines within the authors' experience are described. The critical factors in handling natural gas in its liquid form are considered, and the extended scope of dual-fuel engines and alternative fuel engines in mobile applications is briefly reviewed. Finally, the paper examines the future for dual-fuel engines and suggests directions in which further development is required.

scholarly journals A Review on Liquefied Natural Gas as Fuels for Dual Fuel Engines: Opportunities, Challenges and Responses

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6127
Author(s):  
Md Arman Arefin ◽  
Md Nurun Nabi ◽  
Md Washim Akram ◽  
Mohammad Towhidul Islam ◽  
Md Wahid Chowdhury
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Ghg Emissions ◽  
Liquefied Natural Gas ◽  
Future Research ◽  
Dual Fuel ◽  
Combustion Engines ◽  
Emission Regulations ◽  
Dual Fuel Engines ◽  
Sustainable Fuels

Climate change and severe emission regulations in many countries demand fuel and engine researchers to explore sustainable fuels for internal combustion engines. Natural gas could be a source of sustainable fuels, which can be produced from renewable sources. This article presents a complete overview of the liquefied natural gas (LNG) as a potential fuel for diesel engines. An interesting finding from this review is that engine modification and proper utilization of LNG significantly improve system efficiency and reduce greenhouse gas (GHG) emissions, which is extremely helpful to sustainable development. Moreover, some major recent researches are also analyzed to find out drawbacks, advancement and future research potential of the technology. One of the major challenges of LNG is its higher flammability that causes different fatal hazards and when using in dual-fuel engine causes knock. Though researchers have been successful to find out some ways to overcome some challenges, further research is necessary to reduce the hazards and make the fuel more effective and environment-friendly when using as a fuel for a diesel engine.

Single Cylinder Testing of a High-Pressure Electronic Pilot Fuel Injector for Low NOx Emission Dual Fuel Engines: Part I—Baseline, Feasibility, and Comparative Testing

1990 ◽  
Vol 112 (3) ◽  
pp. 413-421 ◽  
Author(s):  
J. Workman ◽  
G. M. Beshouri
Keyword(s):  
Fuel Injection ◽  
Waste Water Treatment ◽  
Injection System ◽  
Dual Fuel ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Pilot Fuel ◽  
Dual Fuel Engines ◽  
Current Minimum ◽  
Feasibility Test

Current dual fuel engines utilizing standard mechanical (Bosch type) fuel injection systems set to 5–6 percent pilot delivery do not appear capable of reducing NOx emissions much below the current minimum of 4 g/bhp-h without incurring substantial penalties in efficiency and operability. A prototype Electronic Pilot Fuel Injector (EPFI) was designed that overcomes the shortcomings of the mechanical injection system, consistently delivering 3 percent or less pilot at pressures as high as 20,000 psi. The EPFI was installed and tested in one cylinder of a standard production dual fuel engine operating at a waste water treatment facility. A feasibility test confirmed that the engine would indeed operate satisfactorily at 2.9 percent pilot. Comparisons with baseline data revealed the EPFI yielded a 45 percent reduction in NOx emissions with a 3 percent or greater improvement in efficiency. Further optimization of the system, discussed in Part II, indicates that even greater reductions in NOx emissions can be obtained without incurring a penalty in fuel consumption.

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