Effect of Fuel Injection Timing Relative to Ignition Timing on the Natural-Gas Direct-Injection Combustion

2003 ◽  
Vol 125 (3) ◽  
pp. 783-790 ◽  
Author(s):  
Z. Huang ◽  
S. Shiga ◽  
T. Ueda ◽  
H. Nakamura ◽  
T. Ishima ◽  
...  
Keyword(s):  
Late Stage ◽  
Equivalence Ratio ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection Timing ◽  
Ignition Timing ◽  
Fuel Injection Timing ◽  
Initial Stage ◽  
Wide Range ◽  
Early Injection

The effect of fuel injection timing relative to ignition timing on natural gas direct-injection combustion was studied by using a rapid compression machine (RCM). The ignition timing was fixed at 80 ms after the compression start. When the injection timing was relatively early (injection start at 60 ms), the heat release pattern showed a slower burn in the initial stage and a faster burn in the late stage, which is similar to that of flame propagation of a premixed gas. In contrast to this, when the injection timing was relatively late (injection start at 75 ms), the heat release rate showed a faster burn in the initial stage and a slower burn in the late stage, which is similar to that of diesel combustion. The shortest duration was realized at the injection end timing of 80 ms (the same timing as the ignition timing) over a wide range of equivalence ratio. The degree of charge stratification and the intensity of turbulence generated by the fuel jet are considered to cause this behavior. Early injection leads to longer duration of the initial combustion, whereas late injection leads to a longer duration of the late combustion. Early injection showed relatively lower CO concentration in the combustion products while late injection gave relatively lower NOx. It was suggested that early injection leads to combustion with weaker stratification, and late injection leads to combustion with stronger stratification. Combustion efficiency was kept at a high value over a wide range of equivalence ratio.

Effect of Fuel Injection Timing Relative to Ignition Timing on the Natural-Gas Direct-Injection Combustion

2001 ◽  
Author(s):  
Zuohua Huang ◽  
Seiichi Shiga ◽  
Takamasa Ueda ◽  
Nobuhisa Jingu ◽  
Hisao Nakamura ◽  
...  
Keyword(s):  
Heat Release ◽  
Late Stage ◽  
Equivalence Ratio ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection Timing ◽  
Ignition Timing ◽  
Fuel Injection Timing ◽  
Initial Stage ◽  
Wide Range

Abstract Effect of fuel injection timing relative to ignition timing on natural gas direct-injection combustion was studied by using a rapid compression machine. The ignition timing was fixed at 80 ms from the compression start. When the injection timing was relatively earlier (injection start at 60 ms), the heat release pattern showed slower burn in the initial stage and faster burn in the late stage, which is similar to that of flame propagation of a premixed gas. In contrast to this, when the injection timing was relatively later (injection start at 75 ms), the heat release rate showed faster burn in the initial stage and slower burn in the late stage, which is similar to that of diesel combustion. The shortest duration was realized at the injection end timing of 80 ms (the same timing as the ignition timing) over the wide range of equivalence ratio. The degree of charge stratification and the intensity of turbulence generated by the fuel jet is considered to cause these behaviors. Earlier injection leads to longer duration of the initial combustion, whereas the later injection does longer duration of the late combustion. Earlier injection showed relatively lower CO emission while later injection produces relatively lower NOx emission. It was suggested that earlier injection leads to lower mixture stratification combustion and later injection leads to higher mixture stratification combustion. Combustion efficiency maintained high value over the wide range of equivalence ratio.

Combustion characteristics of natural-gas direct-injection combustion under various fuel injection timings

2003 ◽  
Vol 217 (5) ◽  
pp. 393-401 ◽  
Author(s):  
Z Huang ◽  
S Shiga ◽  
T Ueda ◽  
H Nakamura ◽  
T Ishima ◽  
...  
Keyword(s):  
Natural Gas ◽  
Fuel Injection ◽  
Direct Injection ◽  
Pressure Rise ◽  
Combustion Efficiency ◽  
Time Interval ◽  
Injection Timing ◽  
Ignition Timing ◽  
Fuel Injection Timing ◽  
Wide Range

The characteristics of natural-gas direct-injection combustion under various fuel injection timings were studied by using a rapid compression machine. Results show that natural-gas direct injection can result in combustion that is much faster than homogeneous combustion while shortening the time interval between injection timing and ignition timing can markedly decrease the combustion duration. Unburned hydrocarbon would increase over a wide range of equivalence ratios, shortening the time interval between injection timing and ignition timing can decrease the value to that of homogeneous-mixture combustion. The NOx level is high but the CO level is low over a wide range of equivalence ratios and is little affected by fuel injection timing. High values of pressure rise due to combustion can be realized and it is insensitive to the variation in fuel injection timing. High combustion efficiency can be achieved, which is also independent of injection timing.

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 During Negative Valve Overlap Period on a GDI-HCCI Engine

2018 ◽  
Author(s):  
Sok Ratnak ◽  
Jin Kusaka ◽  
Yasuhiro Daisho ◽  
Kei Yoshimura ◽  
Kenjiro Nakama
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Single Pulse ◽  
Injection Timing ◽  
Pulse Injection ◽  
Hcci Combustion ◽  
Fuel Injection Timing ◽  
Intake Stroke ◽  
Negative Valve Overlap ◽  
Valve Overlap

Gasoline Direct Injection Homogeneous Charge Compression (GDI-HCCI) combustion is achieved by closing early the exhaust valves for trapping hot residual gases combined with direct fuel injection. The combustion is chemically controlled by multi-point auto-ignition which its main combustion phase can be controlled by direct injection timing of fuel. This work investigates the effect of single pulse injection timing on a supercharged GDI-HCCI combustion engine by using a four-stroke single cylinder engine with a side-mounted direct fuel injector. Injection of primary reference fuel PRF90 under the near-stoichiometric-boosted condition is studied. The fuel is injected during negative valve overlap (NVO) or recompression period for fuel reformation under low oxygen concentration and the injection is retarded to intake stroke for the homogeneous mixture. It is found that the early fuel injection in NVO period advances the combustion phasing compared with the retarded injection in the intake stroke. Noticeable slower combustion rate from intake stroke fuel injection is obtained compared with the NVO injection due to charge cooling effect. Zero-dimensional combustion simulations with multiple chemical reaction mechanisms are simulated to provide chemical understanding from the effect of fuel injection timing on intermediate species generations. The species such as C2H4, C3H6, CH4, and H2 are found to be formed during the NVO injection period from the calculations. The effects of single pulse injection timings on combustion characteristics such pressure rise rate, combustion stability, and emissions are also discussed in this study.

Two-Stroke Engine with Fuel Semi-Direct Injection Using FAI System

2011 ◽  
Vol 130-134 ◽  
pp. 796-799
Author(s):  
Ming Ming Wu ◽  
Yan Xiang Yang ◽  
Da Guang Xi ◽  
Ping Zhang ◽  
Zhong Guo Jin
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection System ◽  
Injection Timing ◽  
Fuel System ◽  
Power Performance ◽  
Fuel Injection Timing ◽  
Injection Quantity ◽  
Stroke Engine

This paper presents the feasibility of semi-direct injection on a 50cm3, two-stroke motorcycle gasoline engine, which is applied FAI semi-direct injection fuel system. The structure and fuel injection system is improved based on the original carburetor engine and the FAI injector is easily installed. The results of laboratory and drive test show that, compared with the original carburetor fuel system, through optimization calibration of fuel injection timing and injection quantity can improve power performance and fuel economy.

Experimental and Simulation Study of Fuel Injection Timing, Pressure and EGR for Lower Exhaust Emissions From Diesel HCCI Combustion

2009 ◽  
Author(s):  
S. Juttu ◽  
S. S. Thipse ◽  
N. V. Marathe ◽  
M. K. Gajendra Babu
Keyword(s):  
Simulation Study ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Exhaust Emissions ◽  
Injection Timing ◽  
Nox Emissions ◽  
Hcci Combustion ◽  
Fuel Injection Timing ◽  
Start Of Injection ◽  
Wide Range

The objective of this work is to study the effect of different control parameters viz. EGR, fuel injection pressure and start of injection timing on exhaust emissions from diesel fueled HCCI combustion concept. A 4-cylinder LCV engine has been selected for experiments and FIRE 3D CFD software was used for simulation study. The basic idea of the simulation study is to find the suitable EGR ratio to run the engine on HCCI combustion mode so as to avoid any damage to the engine during testing. From simulation study, it was observed that the minimum EGR required for running the engine at 5.6 bar BMEP @ 2500 rpm in HCCI mode is approximately 45%. The trends of simulation results viz. soot and NOx emissions are closely following the experiments. The experiments were conducted at different loads at 2500 rpm and EGR varied from 0% to 60%. With increased EGR ratio, soot bump was observed at 50%, 75% and 100%. The BTE dropped to 24.5% from 33.5%. The effect of fuel injection pressures (750bar, 1000bar and 1500bar) were studied to improve the BTE and to control soot bump over a wide range injection timings EGR ratio. Detailed experiments were conducted at 2.8 bar BMEP @ 2500 rpm to study simultaneous reduction of NOx, SOOT, UHC and CO emissions from diesel HCCI combustion. At injection pressure (1500 bar), advanced fuel injection timing and high EGR ratio, the soot CO and THC emissions were reduced significantly without penalty on NOx emissions. The BTE was improved from 24.5% to 31% against 33.5% of convention diesel combustion.

Particulate Emission Reduction by Fuel Injection Timing Optimization in a Gasoline Direct Injection Engine

2021 ◽  
pp. 1-19
Author(s):  
Nikhil Sharma ◽  
Avinash Kumar Agarwal
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Superior Performance ◽  
Transport Sector ◽  
Injection Timing ◽  
Particulate Emissions ◽  
Particulate Emission ◽  
Fuel Injection Timing ◽  
Gdi Engine

Abstract Optimized fuel injection timings in internal combustion (IC) engines exhibit superior performance, combustion characteristics, and lower emissions. Particularly, particulate emissions from a gasoline direct injection (GDI) engine are highly dependent on fuel injection timings. GDI engines have emerged as a popular choice of powerplants for automobiles among customers. They are preferred over multiple-port fuel injection (MPFI) engines in the transport sector because of their superior fuel economy and performance characteristics. The main objective of this study was to optimize a GDI engine for the lowest particulate emission at different fuel injection timings. GDI engine was investigated for particulate matter (PM) mass/ particulate number (PN) emissions at five fuel injection timings (230, 250, 270, 290, 310 °btdc), which covered the entire envelope. Once the optimum fuel injection timing was determined, an engine exhaust particle sizer was used to measure the particle size-number distribution. Particulate samples from the engine were also collected on the filter paper for morphological investigations of particulates collected under optimized fuel injection timings. These experiments confirmed the importance and need to optimize the fuel injection timings at every engine operating point to reduce the PM/PN emissions from a GDI engine, which remains one of the biggest challenges to this technology.

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