Effect of Two-Stage Injection Timing on a Gas-Jet Ignition CNG Engine

2014 ◽  
Vol 663 ◽  
pp. 342-346
Author(s):  
Mas Fawzi Mohd Ali ◽  
Amir Khalid ◽  
Yoshiyuki Kidoguchi
Keyword(s):  
Fuel Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Gas Jet ◽  
Exhaust Emission ◽  
Injection Technique ◽  
Injection Timing ◽  
Two Stage ◽  
Lean Burn ◽  
Cng Engine

Compressed natural gas (CNG) engines normally operate in lean condition to take the advantage of higher efficiency and better fuel economy. Several studies have shown that gas-jet ignition with two-stage injection technique is effective to extend the lean combustible range of CNG engines. This paper investigates the effectiveness of such technique using a prototype lean burn direct injection CNG engine. The experiment was conducted at speed of 900 rpm, fuel injection pressure of 3 MPa, equivalence ratio φ=0.8, and ignition timing at top dead center. The effect of first injection timing on the test engine performance and exhaust emission was analyzed. The result shows that the first injection timing is crucial in determining the performance of the engine. First injection timings when the piston is near to bottom dead center produced relatively stable combustion. First injection timings when the piston is at midpoint produced misfire. First injection timings near the gas-jet ignition produced unstable combustion except at a certain timings which produced acceptable combustion with low hydrocarbon and carbon monoxide emissions.

Distribution of Two-Stage Direct Injection CNG-Air Mixture near Lean Limit Using CFD

2013 ◽  
Vol 465-466 ◽  
pp. 448-452
Author(s):  
Mas Fawzi ◽  
Bukhari Manshoor ◽  
Yoshiyuki Kidoguchi ◽  
Yuzuru Nada
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Gas Jet ◽  
Exhaust Emission ◽  
Injection Technique ◽  
Injection Timing ◽  
Two Stage ◽  
Lean Burn

Previous work shows that gas-jet ignition with two-stage injection technique is effective to extend lean combustible ranges of CNG engines. In this report, the robustness of the gas-jet ignition with two-stage injection method was investigated purposely to improve the performance of a lean burn direct injection CNG engine. The experiment was conducted using an engine at speed of 900 rpm, fuel-injection-pressure of 3MPa, equivalence ratio at 0.8, and ignition timing at top dead center. The effect of first injection timing on the test engine performance and exhaust emission was analyzed. First injection timings near the gas-jet ignition produced unstable combustion with occurrence of misfires except at a timing which produced distinctively good combustion with low HC and CO emissions. Computational fluid dynamics was used to provide hindsight of the fuel-air mixture distribution that might be the cause of misfires occurrence at certain injection timings.

Experimental and Theoretical Study of Injection Timing on Performance and Exhaust Emissions in a Port-Injected Gasoline Engine

2006 ◽  
Author(s):  
E. Movahednejad ◽  
F. Ommi ◽  
M. Hosseinalipour ◽  
O. Samimi
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Engine Performance ◽  
Fuel Mixture ◽  
Exhaust Emissions ◽  
Operating Conditions ◽  
Exhaust Emission ◽  
Injection Timing ◽  
Intake Port ◽  
One Dimensional

For spark ignition engines, the fuel-air mixture preparation process is known to have a significant influence on engine performance and exhaust emissions. In this paper, an experimental study is made to characterize the spray characteristics of an injector with multi-disc nozzle used in the engine. The distributions of the droplet size and velocity and volume flux were characterized by a PDA system. Also a model of a 4 cylinder multi-point fuel injection engine was prepared using a fluid dynamics code. By this code one-dimensional, unsteady, multiphase flow in the intake port has been modeled to study the mixture formation process in the intake port. Also, one-dimensional air flow and wall fuel film flow and a two-dimensional fuel droplet flow have been modeled, including the effects of in-cylinder mixture back flows into the port. The accuracy of model was verified using experimental results of the engine testing showing good agreement between the model and the real engine. As a result, predictions are obtained that provide a detailed picture of the air-fuel mixture properties along the intake port. A comparison was made on engine performance and exhaust emission in different fuel injection timing for 2600 rpm and different loads. According to the present investigation, optimum injection timing for different engine operating conditions was found.

scholarly journals Theoretical study to determine the proper injection system for upgrading fuel system of diesel engine om357 to common rail system

2018 ◽  
Vol 7 (4) ◽  
pp. 2594
Author(s):  
Razieh Pourdarbani ◽  
Ramin Aminfar
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Common Rail ◽  
Injection System ◽  
Injection Timing ◽  
Common Rail System ◽  
Common Rail Injection System ◽  
Multi Stage

In this research, we tried to investigate all the fuel injection systems of diesel engines in order to select the most suitable fuel injection system for the OM357 diesel engine to achieve the highest efficiency, maximize output torque and reduce emissions and even reduce fuel consumption. The prevailing strategy for this study was to investigate the effect of injection pressure changes, injection timing and multi-stage injection. By comparing the engines equipped with common rail injection system, the proposed injector for engine OM357 is solenoid, due to the cost of this type of injector, MAP and controller (ECU). It is clear that this will not be possible only with the optimization of the injection system, and so other systems that influence engine performance such as the engine's respiratory system and combustion chamber shape, etc. should also be optimized. 

In-Cylinder Injection of Oxygen-Enriched Air to Reduce Diesel Exhaust Emissions

2006 ◽  
Author(s):  
Douglas E. Longman ◽  
Roger L. Cole ◽  
Suresh K. Aggarwal
Keyword(s):  
Fuel Injection ◽  
Engine Performance ◽  
Oxygen Enrichment ◽  
Air Injection ◽  
Injection System ◽  
Injection Technique ◽  
Injection Timing ◽  
Gaseous Emissions ◽  
Scanning Mobility Particle Sizer ◽  
Fuel Injection Timing

The long time challenge for diesel engine manufacturers has been to reduce both particulate matter (PM) and NOx emissions simultaneously without sacrificing engine performance. One technique for reducing PM has been to inject air or oxygen-enriched air directly into the combustion chamber. Previous studies using the KIVA-3V computational fluid dynamics (CFD) model have shown benefits and the importance of the gas injection’s characteristics on the technique’s effectiveness in reducing emissions. Using a Caterpillar 3401E single cylinder engine, an experimental investigation has been conducted to demonstrate the effectiveness of an oxygen-enriched air injection system and fuel injection timing retard in reducing the NOx and the PM emissions in terms of both the particulate size and concentration. The gaseous emissions were measured using a Pierburg AMA 2000 gaseous emissions bench which included a chemiluminescent analyzer for NOx volumetric measurements, non-dispersive infrared (NDIR) analyzer for CO and CO2 measurements, and a parametric fuel cell for O2 measurements. PM emissions (i.e., soot particle concentration and size distribution) were measured using a TSI Model 3936 Scanning Mobility Particle Sizer (SMPS). The experimental observations regarding the effects of oxygen-enriched air injection on NOx and PM emissions were in accord with the previously reported results for late-cycle gas injection from a KIVA-3V model. The air injection technique additionally provided a low level of oxygen-enrichment during the compression cycle, with results similar to previous intake air oxygen-enrichment studies. A simultaneous reduction of NOx and particulates was demonstrated when the fuel injection timing characteristics were optimized in conjunction with the oxygen-enriched air injection. The experimental PM emissions were analyzed for number and size distributions and also found to be consistent with previously reported trends.

Effect of process parameters on the diesel engine performance fuelled with Prosopis juliflora biodiesel response surface methodology approach

2021 ◽  
pp. 095440892110430
Author(s):  
Abhishek Sharma ◽  
Avdhesh Tyagi ◽  
Yashvir Singh ◽  
Nishant K Singh ◽  
Navneet K Pandey
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Fuel Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Prosopis Juliflora ◽  
Injection Timing ◽  
Gas Temperature ◽  
Input Parameters ◽  
Fuel Injection Pressure

The rapid consumption of crude oil and resulting pollution are very severe problems in modern energy sectors. To meet these global problems, biodiesels obtained from non-edible plants can play a very crucial role. Keeping this idea in mind the present study focuses on making some efforts for the best utilization of innovative blends of Prosopis juliflora biodiesel in the operation of diesel engines. Four engine input parameters viz. fuel injection pressure (16–24 MPa), P. Juliflora biodiesel blends (0–10%), shaft loads (20–100%) and injection timing (15–31°bTDC (before top dead centre)) are selected for optimization process. The experiments were executed in accordance with response surface methodology. The results of the experiments revealed that the optimum combination for engine input parameters were at fuel injection timing 30°bTDC, fuel injection pressure 22 MPa, 4% P. juliflora biodiesel blending at 59% of engine load to achieve best performance. The individual desirability of brake thermal efficiency, brake specific fuel consumption, exhaust gas temperature and peak cylinder pressure were found to be 0.888, 0.949, 0.624 and 0.749, respectively, and the composite desirability of engine responses was found to be 0.7923 which makes the results acceptable.

A Simulation Model for the Performance Enhancement of Turbocharged Diesel Engine

2017 ◽  
Author(s):  
Farrukh Ahmad ◽  
Imran Aziz ◽  
Samiur Rahman Shah
Keyword(s):  
Diesel Engine ◽  
Simulation Model ◽  
Performance Enhancement ◽  
Fuel Injection ◽  
Engine Performance ◽  
Industrial Sector ◽  
Injection Technique ◽  
Injection Timing ◽  
Testing Time ◽  
Compression Ignition Engine

Diesel engines are widely used throughout the world in the transportation and industrial sector. Over the years, engineers and researchers have made continuous efforts to maximize the efficiency of the diesel engine, but there is still room for improvement. By maximizing the efficiency we can not only reduce the fuel consumption of engine, but can also add positively to the environment by reducing the emissions from the engine. In the present research a simulation model for the optimization of the performance of a diesel engine’s has been developed using the cylinder to cylinder approach. Physical, empirical and thermodynamic relations are used to setup the model in MATLAB. The model can predict the backflow through the valves based upon pressure difference across the valves. Multi event fuel injection technique is employed using main injection and pilot injection. The turbocharger is investigated with and without intercooler to see the effect on engine performance. The simulated results are in good agreement with already presented experimental results. A study has been performed to analyze the effect of variation of different parameters on the efficiency of the compression ignition engine. The parameters analyzed are bore to stroke ratio, compression ratio, equivalence ratio, injection timing variation (advance, retard), inlet charge heating and turbo-charging. By using the developed technique it is easier to make decisions regarding efficiency optimization in the design phase of the engine. The testing time and cost associated with the engine can also be reduced. The study provides a thorough insight on the effect of parametric variation on engine efficiency.

Correlation of Ignitability with Injection Timing for Direct Injection Combustion Fuelled with Compressed Natural Gas and Gasoline

2003 ◽  
Vol 217 (6) ◽  
pp. 499-506 ◽  
Author(s):  
Z Huang ◽  
S Shiga ◽  
T Ueda ◽  
H Nakamura ◽  
T Ishima ◽  
...  
Keyword(s):  
Natural Gas ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection Pressure ◽  
Gasoline Direct Injection ◽  
Injection Timing ◽  
Electrode Gap ◽  
Lean Burn ◽  
Compressed Natural Gas ◽  
Study Results

A study on the correlation of ignitability with fuel injection timing for direct injection combustion fuelled with natural gas and gasoline was carried out by using a rapid compression machine. The injection pressure of natural gas is 9 MPa and the injection pressure of gasoline is 7 MPa. The study results show that natural gas direct injection possesses higher momentum than that of gasoline, and this is beneficial to the combustion enhancement since a higher intensity of turbulence could be induced. Correlation of ignitability with injection timing shows better behaviour in natural gas direct injection, and this correlation is insensitive to injection modes in the case of natural gas. Thus, natural gas direct injection would have better engine applicability under cold-start conditions. The lean burn limits of natural gas and gasoline direct injection can extend to extremely low equivalence ratio when the ignitable stratified mixture exists around the spark electrode gap by optimizing the injection timing.

Diesel engine performance mapping using a parametrized mixing time model

2017 ◽  
Vol 19 (2) ◽  
pp. 202-213 ◽  
Author(s):  
Michal Pasternak ◽  
Fabian Mauss ◽  
Christian Klauer ◽  
Andrea Matrisciano
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Mixing Time ◽  
Combustion Process ◽  
Engine Performance ◽  
Injection Timing ◽  
Engine Control ◽  
Reactor Model ◽  
Time Model ◽  
Tabulated Chemistry

A numerical platform is presented for diesel engine performance mapping. The platform employs a zero-dimensional stochastic reactor model for the simulation of engine in-cylinder processes. n-Heptane is used as diesel surrogate for the modeling of fuel oxidation and emission formation. The overall simulation process is carried out in an automated manner using a genetic algorithm. The probability density function formulation of the stochastic reactor model enables an insight into the locality of turbulence–chemistry interactions that characterize the combustion process in diesel engines. The interactions are accounted for by the modeling of representative mixing time. The mixing time is parametrized with known engine operating parameters such as load, speed and fuel injection strategy. The detailed chemistry consideration and mixing time parametrization enable the extrapolation of engine performance parameters beyond the operating points used for model training. The results show that the model responds correctly to the changes of engine control parameters such as fuel injection timing and exhaust gas recirculation rate. It is demonstrated that the method developed can be applied to the prediction of engine load–speed maps for exhaust NOx, indicated mean effective pressure and fuel consumption. The maps can be derived from the limited experimental data available for model calibration. Significant speedup of the simulations process can be achieved using tabulated chemistry. Overall, the method presented can be considered as a bridge between the experimental works and the development of mean value engine models for engine control applications.

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