Combustion Characteristics of Methane Direct Injection Engine Under Various Injection Timings and Injection Pressures

2016 ◽  
Author(s):  
Jingeun Song ◽  
Mingi Choi ◽  
Daesik Kim ◽  
Sungwook Park
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Injection Pressure ◽  
Combustion Characteristics ◽  
Injection Timing ◽  
Direct Injection Engine ◽  
Optical Engine ◽  
Start Of Injection ◽  
Crank Angle ◽  
Injection Pressures

The performance of a methane direct injection engine was investigated under various fuel injection timings and injection pressures. A single-cylinder optical engine was used to acquire in-cylinder pressure data and flame images. An outward-opening injector was installed at the center of the cylinder head. Experimental results showed that the combustion characteristics were strongly influenced by the end of injection timing rather than the start of injection timing. Late injection enhanced the combustion speed because the short duration between the end of injection and the spark induced strong turbulence. The flame propagation speeds under various injection timings were directly compared using crank-angle-resolved sequential flame images. The injection pressure was not an important factor in the combustion; the three injection pressure cases of 0.5, 0.8, and 1.1 MPa yielded similar combustion trends. In the cases of late injection, the injection timings of which were near the Intake Valve Closing (IVC) timing, the volumetric efficiency was higher (by 4%) than in the earlier injection cases. This result implies that the methane direct injection engine can achieve higher torque by means of the late injection strategy.

Combustion Characteristics of Methane Direct Injection Engine Under Various Injection Timings and Injection Pressures

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Jingeun Song ◽  
Mingi Choi ◽  
Daesik Kim ◽  
Sungwook Park
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Injection Pressure ◽  
Combustion Characteristics ◽  
Direct Injection Engine ◽  
Optical Engine ◽  
Start Of Injection ◽  
Crank Angle ◽  
Combustion Speed ◽  
Injection Pressures

The performance of a methane direct injection engine was investigated under various fuel injection timings and injection pressures. A single-cylinder optical engine was used to acquire in-cylinder pressure data and flame images. An outward-opening injector was installed at the center of the cylinder head. Experimental results showed that the combustion characteristics were strongly influenced by the end of injection (EOI) timing rather than the start of injection (SOI) timing. Late injection enhanced the combustion speed because the short duration between the end of injection and the spark-induced strong turbulence. The flame propagation speeds under various injection timings were directly compared using crank-angle-resolved sequential flame images. The injection pressure was not an important factor in the combustion; the three injection pressure cases of 0.5, 0.8, and 1.1 MPa yielded similar combustion trends. In the cases of late injection, the injection timings of which were near the intake valve closing (IVC) timing, the volumetric efficiency was higher (by 4%) than in the earlier injection cases. This result implies that the methane direct injection engine can achieve higher torque by means of the late injection strategy.

Characteristics of Lean and Stoichiometric Combustion of Compressed Natural Gas in a Direct Injection Engine

2011 ◽  
Vol 110-116 ◽  
pp. 357-369 ◽  
Author(s):  
Raja Shahzad ◽  
P. Naveenchandran ◽  
A. Rashid ◽  
Amir Aziz
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Engine Performance ◽  
Initial Mixture ◽  
Combustion Characteristics ◽  
Injection Timing ◽  
Direct Injection Engine ◽  
Fuel Injection Timing ◽  
Initial Stage ◽  
Air Mixing

This paper discusses the combustion characteristics of CNG under lean and stochiometric conditions in a direct injection engine. The experiments were carried out on a dedicated CNG-Direct Injection engine with 14:1 compression ratio. Combustion characteristics of CNG have been investigated on various injection timings. Injection timing of the fuel injection timing had significant effects on the engine performance, combustion and emissions. The effects became more significant when injection timing was retarded. Injection timing was set after the closing of intake valve and experiments are conducted at 0% and 50% load conditions. Lean stratified operation experiences faster combustion compared to that of stochiometric. In lean stratified operation, there were fast burn rates at the initial stage and slower burning at the later stage. Whereas in stochiometric conditions there is a slightly slower burn at the initial stage and a moderately faster burn at the later stage. The faster initial combustion in lean stratified operation might be due to rapid burn of the initial mixture due to higher turbulence, while a slower burn in the later stage due to diffusion. In contrary to that in stochiometric operations the initial burn is slightly slower, due to moderately strong turbulence and a faster burn due to moderately proceeding mixture. Thus the main effect of fuel injection timing can be explained by the fuel air mixing and the turbulence produced.

Effect of Fuel Injection Timing and Injection Pressure on Combustion and Odorous Emissions in DI Diesel Engines

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Murari Mohon Roy
Keyword(s):  
Ignition Delay ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection Pressure ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Warm Up ◽  
Fuel Injection Timing ◽  
Peak Cylinder Pressure ◽  
Injection Pressures

This study investigated the effect of fuel injection timing and injection pressure on combustion and odorous emissions in a direct injection diesel engine. Injection timings from 15 deg before top dead center (BTDC) to top dead center (TDC) and injection pressures from 20 MPa to 120 MPa were tested. In emissions, exhaust odor, irritation, aldehydes, total hydrocarbon, and hydrocarbon components are compared in different injection timings and injection pressures condition. Injection timings where main combustion takes place very close to TDC are found to show minimum odorous emissions. Moderate injection pressures (60–80 MPa) showed lower emissions including odor and irritation due to proper mixture formation. Below the injection pressure of 40 MPa, and over 80 MPa, emissions become worse. Combustion analysis is performed by taking cylinder pressures after engine warm-up for different injection timings and injection pressures and analyzing cylinder temperatures and heat release rates. Cylinder pressures and temperatures are gradually decreased when injection timings are retarded. Ignition delay becomes shortest at 5–10 deg BTDC injection timings. The peak cylinder pressure and temperature are increased with higher injection pressures. The shortest ignition delay and minimum emissions is found at around 60 MPa of injection pressure.

Effect of Injection Timing on Combustion Characteristics of a DI Diesel Engine Fuelled with Pistacia chinensis Bunge Seed Biodiesel

2012 ◽  
Vol 614-615 ◽  
pp. 337-342
Author(s):  
Li Luo ◽  
Bin Xu ◽  
Zhi Hao Ma ◽  
Jian Wu ◽  
Ming Li
Keyword(s):  
Combustion Temperature ◽  
Fuel Injection ◽  
Direct Injection ◽  
Combustion Characteristics ◽  
Injection Timing ◽  
Brake Specific Fuel Consumption ◽  
Cylinder Pressure ◽  
Combustion Duration ◽  
Di Diesel Engine ◽  
Maximum Combustion Temperature

In this study, the effect of injection timing on combustion characteristics of a direct injection, electronically controlled, high pressure, common rail, turbocharged and intercooled engine fuelled with different pistacia chinensis bunge seed biodiesel/diesel blends has been experimentally investigated. The results indicated that brake specific fuel consumption reduces with the increasing of fuel injection advance angle and enhances with the increasing of biodiesel content in the blends. The peak of cylinder pressure and maximum combustion temperature increase evidently with the increment of fuel injection advance angle. However, the combustion of biodiesel blends starts earlier than diesel at the same fuel injection advance angle. At both conditions, the combustion duration and the peak of heat release rate are insensitive to the changing of injection timing.

Experimental and Numerical Analysis on the Influence of Direct Fuel Injection Into O2-Depleted Environment of a GDI-HCCI Engine

2020 ◽  
Author(s):  
Ratnak Sok ◽  
Jin Kusaka
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Injection Pressure ◽  
Single Pulse ◽  
Gasoline Direct Injection ◽  
Injection Timing ◽  
Rich Mixture ◽  
Intake Stroke ◽  
Shift Reaction ◽  
Direct Fuel Injection

Abstract Injected gasoline into the O2-depleted environment in the recompression stroke can be converted into light hydrocarbons due to thermal cracking, partial oxidation, and water-gas shift reaction. These reformate species influence the combustion phenomena of gasoline direct injection homogeneous charge compression ignition (GDI-HCCI) engines. In this work, a production-based single-cylinder research engine was boosted to reach IMEPn = 0.55 MPa in which its indicated efficiency peaks at 40–41%. Experimentally, the main combustion phases are advanced under single-pulse direct fuel injection into the negative valve overlap (NVO) compared with that of the intake stroke. NVO peak in-cylinder pressures are lower than that of motoring, which emphasizes that endothermic reaction occurs during the interval. Low O2 concentration could play a role in this evaporative charge cooling effect. This phenomenon limits the oxidation reaction, and the thermal effect is not pronounced. For understanding the recompression reaction phenomena, 0D simulation with three different chemical reaction mechanisms is studied to clarify that influences of direct injection timing in NVO on combustion advancements are kinetically limited by reforming. The 0D results show the same increasing tendencies of classical reformed species of rich-mixture such as C3H6, C2H4, CH4, CO, and H2 as functions of injection timings. By combining these reformed species into the main fuel-air mixture, predicted ignition delays are shortened. The effects of the reformed species on the main combustion are confirmed by 3D-CFD calculation, and the results show that OH radical generation is advanced under NVO fuel injection compared with that of intake stroke conditions thus earlier heat release and cylinder pressure are noticeable. Also, parametric studies on injection pressure and double-pulse injections on engine combustion are performed experimentally.

Influence of fuel injection strategies on efficiency and particulate emissions of gasoline and ethanol blends in a turbocharged multi-cylinder direct injection engine

2019 ◽  
Vol 22 (1) ◽  
pp. 152-164 ◽  
Author(s):  
Ripudaman Singh ◽  
Taehoon Han ◽  
Mohammad Fatouraie ◽  
Andrew Mansfield ◽  
Margaret Wooldridge ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection Timing ◽  
Multiple Injection ◽  
Fuel Mass ◽  
Direct Injection Engine ◽  
Fuel Blends ◽  
Ethanol Blends ◽  
Injection Strategies

The effects of a broad range of fuel injection strategies on thermal efficiency and engine-out emissions (CO, total hydrocarbons, NOx and particulate number) were studied for gasoline and ethanol fuel blends. A state-of-the-art production multi-cylinder turbocharged gasoline direct injection engine equipped with piezoelectric injectors was used to study fuels and fueling strategies not previously considered in the literature. A large parametric space was considered including up to four fuel injection events with variable injection timing and variable fuel mass in each injection event. Fuel blends of E30 (30% by volume ethanol) and E85 (85% by volume ethanol) were compared with baseline E0 (reference grade gasoline). The engine was operated over a range of loads with intake manifold absolute pressure from 800 to 1200 mbar. A combined application of ethanol blends with a multiple injection strategy yielded considerable improvement in engine-out particulate and gaseous emissions while maintaining or slightly improving engine brake thermal efficiency. The weighted injection spread parameter defined in this study, combined with the weighted center of injection timing defined in the previous literature, was found well suited to characterize multiple injection strategies, including the effects of the number of injections, fuel mass in each injection and the dwell time between injections.

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.

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