Browse Publications Technical Papers 2013-01-0279

RCCI Engine Operation Towards 60% Thermal Efficiency 2013-01-0279

The present experimental study explored methods to obtain the maximum practical cycle efficiency with Reactivity Controlled Compression Ignition (RCCI). The study used both zero-dimensional computational cycle simulations and engine experiments. The experiments were conducted using a single-cylinder heavy-duty research diesel engine adapted for dual fuel operation, with and without piston oil gallery cooling. In previous studies, RCCI combustion with in-cylinder fuel blending using port-fuel-injection of a low reactivity fuel and optimized direct-injections of higher reactivity fuels was demonstrated to permit near-zero levels of NOx and PM emissions in-cylinder, while simultaneously realizing gross indicated thermal efficiencies in excess of 56%.
The present study considered RCCI operation at a fixed load condition of 6.5 bar IMEP an engine speed of 1,300 [r/min]. The experiments used a piston with a flat profile with 18.7:1 compression ratio. The results demonstrated that the indicated gross thermal efficiency could be increased by not cooling the piston, by using high dilution, and by optimizing in-cylinder fuel stratification with two fuels of large reactivity differences. The best results achieved gross indicated thermal efficiencies near 60%. By further analyzing the results with zero-dimensional engine cycle simulations, the limits of cycle efficiency were investigated. The simulations demonstrated that the RCCI operation without piston oil cooling rejected less heat, and that ~94% of the maximum cycle efficiency could be achieved while simultaneously obtaining ultra-low NOx and PM emissions.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 17% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

Development of a New 2.0-Liter Fuel-Efficient Diesel Engine


View Details


Effect of Compression Ratio and Piston Geometry on RCCI Load Limits and Efficiency


View Details


Measurement of the Oil Film Thickness Between the Cylinder Liner and the Piston Rings in a Heavy Duty Directly Injected Diesel Engine


View Details