Spectral IR Images of Direct-Injection Diesel Combustion by High-Pressure Fuel Injection

1995 ◽  
Author(s):  
E. Clasen ◽  
S. Campbell ◽  
K. T. Rhee
2000 ◽  
Vol 123 (3) ◽  
pp. 413-424 ◽  
Author(s):  
M. J. van Nieuwstadt ◽  
I. V. Kolmanovsky

Modern direct injection engines feature high pressure fuel injection systems that are required to control the fuel quantity very accurately. Due to limited manufacturing accuracy these systems can benefit from an on-line adaptation scheme that compensates for injector variability. Since cylinder imbalance affects many measurable signals, different sensors and algorithms can be used to equalize torque production by the cylinders. This paper compares several adaptation schemes that use different sensors. The algorithms are evaluated on a cylinder-by-cylinder simulation model of a direct injection high speed diesel engine. A proof of stability and experimental results are reported as well.


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.


Author(s):  
Jim Cowart ◽  
Len Hamilton ◽  
Dianne Luning Prak

A broadly ranging single injection event was used in a Waukesha diesel CFR engine in order to explore various conventional and alternative combustion modes at light load (2 bar GMEP) using n-heptane fuel. Start of injection (SOI) was varied from the start of the intake valve open (IVO) event all the way past TDC at the end of the compression stroke. Emissions, including detailed particulate, were collected at all of the operating points. Additionally, further experiments were performed with port fuel injection in order to create a homogeneous charge compression ignition (HCCI) combustion mode as well as partially premixed combustion (PPC) using both port and direct fuel injection. HCCI and PPC combustion modes were achieved with the characteristic rise in carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions with however, a corresponding decrease in NOx emissions as compared to conventional direct (into cylinder) injection combustion modes. For conventional diesel operation with progressive advancement of SOI it was seen that start of combustion (SOC) advanced and then retarded slightly before stabilizing. This was associated with a general lengthening of ignition delay (IGD) with progressive SOI advancement. Even with very early intake valve open (IVO) injection events, the emissions behavior did not approach HCCI or PPC, suggesting that the charge mixture homogeneity of companion port injection could not be achieved in this engine using direct injection alone. High speed optical natural light filming of the combustion events through a large quartz window showed conventional diesel combustion with strong diffusion flames, reducing in intensity with PPC operation, and then no visible combustion with HCCI.


Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 277
Author(s):  
Wen-Chang Tsai

The fuel injection system is one of the key components of an in-cylinder direct injection engine. Its performance directly affects the economy, power and emission of the engine. Previous research found that the Taguchi method can be used to optimize the fuel injection map and operation parameters of the injection system. The electronic control injector was able to steadily control the operation performance of a high-pressure fuel injection system, but its control was not accurate enough. This paper conducts an experimental analysis for the fuel injection quantity of DI injectors using the Taguchi-Regression approach, and provides a decision-making analysis to improve the design of electronic elements for the driving circuit. In order to develop a more stable and energy-saving driver, a functional experiment was carried out. The hybrid Taguchi-regression algorithm for injection quantity of a direct injection injector was examined to verify the feasibility of the proposed algorithm. This paper also introduces the development of a high-pressure fuel injection system and provides a new theoretical basis for optimizing the performance of an in-cylinder gasoline direct injection engine. Finally, a simulation study for the fuel injection control system was carried out under the environment of MATLAB/Simulink to validate the theoretical concepts.


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