Combustion and Emission Characteristics of Direct-Injection Compression Ignition Engines by Means of Two-Stage Split and Early Fuel Injection

2002 ◽  
Vol 124 (3) ◽  
pp. 660-667 ◽  
Author(s):  
K. Yamane ◽  
Y. Shimamoto

The objective of this study was to experimentally clarify the effect of two-stage split and early injection on the combustion and emission characteristics of a direct-injection (DI) diesel engine. Engine tests were carried out using a single-cylinder high-speed DI diesel engine and an injection system, combining an ordinary jerk pump and an electronically controlled high-pressure injection system, KD-3. In these experiments to compare the combustion and exhaust emission characteristics with two-stage split and early injection, a single-stage and early injection was tested. The FT-IR exhaust-gas analyzer simultaneously measured the exhaust emissions of 26 components. The results showed that HCHO, CH3CHO, and CH3COOH were emitted during the very early stage of both single injection and two-stage injection. These concentrations were higher than those from diesel combustion with ordinary fuel injection timings. These exhaust emissions are characteristic components of combustion by premixed compression ignition with extremely early injection. In particular, the HCHO concentration in exhaust was reduced with an increase in the maximum rate of heat release after cool flame due to pre-reaction of pre-mixture. At extremely early injection, the NOx concentration was extremely low; however, the indicated specific fuel consumption (ISFC) was higher than that of ordinary diesel combustion. In the case of two-stage injection, the degree of constant volume is increased, so that ISFC is improved. These results also demonstrated the possibility of reducing HCHO, NOx, and smoke emissions by means of two-stage split and early injection.

2013 ◽  
Vol 388 ◽  
pp. 217-222
Author(s):  
Mohamed Mustafa Ali ◽  
Sabir Mohamed Salih

Compression Ignition Diesel Engine use Diesel as conventional fuel. This has proven to be the most economical source of prime mover in medium and heavy duty loads for both stationary and mobile applications. Performance enhancements have been implemented to optimize fuel consumption and increase thermal efficiency as well as lowering exhaust emissions on these engines. Recently dual fueling of Diesel engines has been found one of the means to achieve these goals. Different types of fuels are tried to displace some of the diesel fuel consumption. This study is made to identify the most favorable conditions for dual fuel mode of operation using Diesel as main fuel and Gasoline as a combustion improver. A single cylinder naturally aspirated air cooled 0.4 liter direct injection diesel engine is used. Diesel is injected by the normal fuel injection system, while Gasoline is carbureted with air using a simple single jet carburetor mounted at the air intake. The engine has been operated at constant speed of 3000 rpm and the load was varied. Different Gasoline to air mixture strengths investigated, and diesel injection timing is also varied. The optimum setting of the engine has been defined which increased the thermal efficiency, reduced the NOx % and HC%.


Author(s):  
D.K. Dond ◽  
N.P. Gulhane

Limited fossil fuel reservoir capacity and pollution caused by them is the big problem in front of researchers. In the present paper, an attempt was made to find a solution to the same. The conventional fuel injection system was retrofitted with a simple version of the common rail direct injection system for the small diesel engine. Further, the effect of injection system parameters was observed on the performance and emission characteristics of the retrofitted common rail direct injection diesel engine. The parameters such as injection pressure, the start of pilot injection timing, the start of main injection timing and quantity of percentage fuel injection during the pilot and main injection period were considered for experimental investigation. It was observed that all the evaluated parameters were found vital for improving the engine’s performance and emission characteristics. The retrofitted common rail direct injection system shows an average 7% rise in brake thermal efficiency with economic, specific fuel consumption. At the same time, much more reduction in hydrocarbon, carbon monoxide and smoke opacity with a penalty of a slight increase in nitrogen oxides.


2011 ◽  
Vol 121-126 ◽  
pp. 2238-2242
Author(s):  
Ming Hai Li ◽  
Feng Jiang ◽  
Biao Liu ◽  
Ming Gao Ouyang

GT-Suite software is used to establish the simulation model of electronic fuel injection system for 16V280ZJ diesel engine. Combustion process simulation calculation is conducted to the direct injection (DI) diesel engine based on a main-post double injection scheme. Simulation parameters are modified based on the comparison with given experimental results. The calculation results effectively reflect the influence of fuel ratio and the interval angle between main and post injection over emission and fuel economy. Finally, in order to improve the engine emissions and reduce the pressure rise rate, we get the optimal injection solution for the main-post injection mode.


Author(s):  
V. Anandram ◽  
S. Ramakrishnan ◽  
J. Karthick ◽  
S. Saravanan ◽  
G. LakshmiNarayanaRao

In the present work, the combustion, performance and emission characteristics of sunflower oil, sunflower methyl ester and its blends were studied and compared with diesel by employing them as fuel in a single cylinder, direct injection, 4.4 KW, air cooled diesel engine. Emission measurements were carried out using five-gas exhaust gas analyzer and smoke meter. The performance characteristics of Sunflower oil, Sunflower methyl ester and its blends were comparable with those of diesel. The components of exhaust such as HC, CO, NOx and soot concentration of the fuels were measured and presented as a function of load and it was observed that the blends had similar performance and emission characteristics as those of diesel. NOx emissions of sunflower oil methyl ester were slightly higher than that of diesel but that of sunflower oil was slightly lower than that of diesel. With respect to the combustion characteristics it was found that the biofuels have lower ignition delay than diesel. The heat release rate was very high for diesel than for the biofuel.


Author(s):  
J A Stephenson ◽  
B A Hood

The paper describes the development of a high-speed direct injection (HSDI) diesel engine suitable for passenger car applications. The evolution from a low emissions medium-speed engine, through a four-cylinder 2.3 litre research engine, into a four-cylinder 2.0 litre production engine is presented. The challenge to the engineer has been to develop the HSDI engine to operate with acceptable noise, emissions, smoke and driveability over the wide speed range (up to 5000 r/min) required for passenger cars. The key element in this task was the optimization of the combustion system and fuel injection equipment. The HSDI is shown to have a significant fuel economy advantage over the prechamber indirect injection (IDI) engine. Future developments of the fuel injection system are described which will further enhance the HSDI engine and provide additional noise and emissions control.


2004 ◽  
Vol 126 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Renshan Liu ◽  
Chao Zhang

A numerical study of NOx reduction for a Direct Injection (DI) Diesel engine with complex geometry, which includes intake/exhaust ports and moving valves, was carried out using the commercial computational fluid dynamics software KIVA-3v. The numerical simulations were conducted to investigate the effects of engine operating and geometrical parameters, including fuel injection timing, fuel injection duration, and piston bowl depth, on the NOx formation and the thermal efficiency of the DI Diesel engine. The tradeoff relationships between the reduction in NOx and the decrease in thermal efficiency were established.


Author(s):  
Donggon Lee ◽  
Kyusoo Jeong ◽  
Hyun Gu Roh ◽  
Chang Sik Lee

This study describes the effects of two-stage combustion (TSC) strategy on combustion and emission characteristics in 4 cylinder common-rail direct injection (CRDI) diesel engine fueled with biodiesel blends. In the present work, to investigate the combustion and emission characteristics, the experiments were performed under various injection pressures, first injection quantity and first injection timing of TSC strategy at constant engine speed and engine load. In addition, conventional diesel fuel (ULSD) was used to compare with biodiesel blends. The experimental results show that combustion of biodiesel blends is stable for various test conditions regardless of blending ratio, and indicated specific fuel consumption (ISFC) was increased as biodiesel blending ratio increased. In the emission characteristics, biodiesel blends generated lower indicated specific nitrogen oxides (IS-NOx) and indicated specific soot (IS-Soot) emissions compared to those of ULSD when the first injection quantity increased.


The purpose of this study is to investigate the effect of fuelinjection pressure onhomogeneous charge formation and performanceand emission characteristics of Homogeneous charge compression ignition engine. The fuel injection pressure isone of the primary parameter for improvingthe homogeneity of the mixture and governing the power output and emission characteristics of HCCI engine. In this investigation, diesel fuelwasinjected at different injection pressuresas 2bar, 3bar, 4bar and 5bar respectively throughbyport fuel injector. The experimental investigationsshow that increasing the fuel injection pressure will promote the fuel to penetrate with air and creates well pre mixedair/fuel charge.The result shows, the specific fuel consumption (SFC) of HCCI engine isslightlyhigherthan the SFC of conventional diesel engine.The HCCI engine with 3bar injection pressure operated engine has lower SFC values compared to other injection pressure operated HCCI engine.The brake thermal efficiency of HCCI engine, operated with 3barinjection pressure has maximum BTE values over the other injection pressure operated engine.From theresult, it is observed that HCCI engine has lower smoke density values compared to conventional diesel engine andfurther reducedby increasing the fuel injection pressure. The 3bar injection pressure operated HCCI engine has emitted lower smoke densitycompared to other injection pressure operated HCCI engine. The 3bar injection pressureoperated HCCIengine hasemittedmaximum oxides of nitrogen (NOx) emissions than the other injection pressure operated HCCI engine. Other exhaust emissions of carbon monoxide (CO) and hydrocarbon (HC)emissions are increased when compared toconvention diesel engine


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