Conceptual models for partially premixed low-temperature diesel combustion

Experimental study of n-butanol additive and multi-injection on HD diesel engine performance and emissions

This paper is the follow up of a previous work and its target is to demonstrate that the best fuel for a Compression Ignition engine has to be with high Octane Number. An advanced injection strategy was designed in order to run Gasoline in a CI engine. At high load it consisted in injecting 54 % of the fuel very early in the pilot and the remaining around TDC; the second injection is used as ignition trigger and an appropriate amount of cool EGR has to be used in order to avoid pre-ignition of the pilot. Substantially lower NOx, soot and specific fuel consumption were achieved at 16.56 bar gross IMEP as compared to Diesel. The pressure rise rate did not constitute any problem thanks to the stratification created by the main injection and a partial overlap between start of the combustion and main injection. Ethanol gave excellent results too; with this fuel the maximum load was limited at 14.80 bar gross IMEP because of hardware issues. Applying the commonly used PPC injection strategies to Gasoline resulted in higher pressure oscillations after combustion and the heat transfer was enhanced. It was shown that this problem can be somehow solved by employing a late pilot injection, unfortunately the combustion is diffusion controlled and there is an increase in fuel consumption as compared to the strategy previously described. The viability of having low fuel consumption, NOx, soot and pressure rise rate using high ON fuels in a CI engine was demonstrated using a Scania single cylinder truck engine with 2 liters displacement volume running at 1100 rpm. (Less)

Partially Premixed Combustion at High Load using Gasoline and Ethanol, a Comparison with Diesel

The call for reduction in pollution has been mandated by government′s policies worldwide. This challenges the engine manufacturer to strike an optimum between engine performance and emissions. However with growing technology in the field of fuel injection equipment, the task has become realizable. For past few years it has been the hot topic to improve combustion and emissions of compression ignition engines through optimizing the fuel injection strategies. Choosing between various injection strategies are potentially effective techniques to reduce emission from engines as injection characteristics have great influences on the process of combustion. For example, increasing the fuel injection pressure can improve the fuel atomization and subsequently improve the combustion process, resulting in a higher brake thermal efficiency, producing less HC, CO, PM emissions, but more NOx emission. Pilot injection help in reducing combustion noise and NOx emissions and immediate post injection may help in soot oxidation and late post injection helps in regeneration of diesel particulate filter. This article aims at a comprehensive review of various fuel injection strategies viz varying injection pressure, injection rate shapes, injection timing and split/multiple injections for engine performance improvement and emissions control. Although every strategy has its own merits and demerits, they are explained in detail, in view of helping researchers to choose the better strategy or combination for their applications.

Fuel injection strategies for performance improvement and emissions reduction in compression ignition engines—A review

Effect of two-stage injection on combustion and emissions under high EGR rate on a diesel engine by fueling blends of diesel/gasoline, diesel/n-butanol, diesel/gasoline/n-butanol and pure diesel

The effects of multiple-injection on exhaust emissions and performance in a small HSDI (High Speed Direct Injection) Diesel engine were examined The causes for the improvement were investigated using both in-cylinder observation and three-dimensional numerical analysis methods It is possible to increase the maximum torque, which is limited by the exhaust smoke number, while decreasing the combustion noise under low speed and full load conditions by advancing the timing of the pilot injection Dividing this early-timed pilot injection into two with a small fuel amount is effective for further decreasing the noise while suppressing the increase in HC emission and fuel consumption This is realized by the reduced amount of adhered fuel to the cylinder wall At light loads, the amount of pilot injection fuel must be reduced, and the injection must be timed just prior to the main injection in order to suppress a possible increase in smoke and HC After-injection, which injects a small amount of fuel immediately after the end of the main injection, reduces smoke, HC and fuel consumption This is because the jet flame of the after-injection carries the remaining soot of the main injection to the squish area, and then oxidizes that together with the soot which previously existed in the squish area by promoted atmospheric temperature and enhanced mixing with fresh air

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Achieving Lower Exhaust Emissions and Better Performance in an HSDI Diesel Engine with Multiple Injection

Reduction of Heat Loss and Improvement of Thermal Efficiency by Application of “Temperature Swing” Insulation to Direct-Injection Diesel Engines

A direct injection type internal combustion engine capable of controlling the status of combustion by stratifying an intake in a combustion chamber, reducing harmful substances contained in exhaust gases, and injecting fuel into the combustion chamber, wherein intakes with different compositions are disposed at the center part (13) containing the fuel injection position of the combustion chamber (1) and the peripheral parts thereof, respectively, at the start of the combustion of fuel near the end of a compression stroke, the intakes with different compositions being those containing specified components different in density such as exhaust gases and fuel

Minaji Inayoshi

Papers

Achieving Lower Exhaust Emissions and Better Performance in an HSDI Diesel Engine with Multiple Injection

Reduction of Heat Loss and Improvement of Thermal Efficiency by Application of “Temperature Swing” Insulation to Direct-Injection Diesel Engines

Direct injection type internal combustion engine

Emissions Reduction Potential of Extremely High Boost and High EGR Rate for an HSDI Diesel Engine and the Reduction Mechanisms of Exhaust Emissions

Cause of Exhaust Smoke and Its Reduction Methods in an HSDI Diesel Engine Under High-Speed and High-Load Conditions