Full-Load HCCI Operation with Variable Valve Actuation System in a Heavy-Duty Diesel Engine

2007 ◽  
Author(s):  
Yuuichi Kodama ◽  
Izumi Nishizawa ◽  
Takumi Sugihara ◽  
Norihiko Sato ◽  
Tadashi Iijima ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Heavy Duty ◽  
Full Load ◽  
Variable Valve Actuation ◽  
Actuation System ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel ◽  
Variable Valve ◽  
Valve Actuation

Impact of Geometric Compression Ratio and Variable Valve Actuation on Gasoline Compression Ignition in a Heavy-Duty Diesel Engine

2020 ◽  
Author(s):  
Yu Zhang ◽  
Praveen Kumar ◽  
Meng Tang ◽  
Yuanjiang Pei ◽  
Brock Merritt ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Premixed Combustion ◽  
Compression Ignition ◽  
Heavy Duty ◽  
Variable Valve Actuation ◽  
Partially Premixed Combustion ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel ◽  
Variable Valve ◽  
Valve Actuation

Abstract Gasoline compression ignition (GCI) is a promising powertrain solution to simultaneously address the increasingly stringent regulation of oxides of nitrogen (NOx) and a new focus on greenhouse gases. GCI combustion benefits from extended mixing times due to the low reactivity of gasoline, but only when held beneath the threshold of the high temperature combustion regime. The geometric compression ratio (GCR) of an engine is often chosen to balance the desire for low NOx emissions while maintaining high efficiency. This work explores the relationship between GCR, variable valve actuation (VVA) and emissions when using GCI combustion strategies. The test article was a Cummins ISX15 heavy-duty diesel engine with an unmodified production air and fuel system. The test fuel was an ethanol-free gasoline with a market-representative research octane number (RON) of 91.4–93.2. In the experimental investigation at 1375 rpm/10 bar BMEP, three engine GCRs were studied, including 15.7, 17.3, and 18.9. Across the three GCRs, GCI exhibited a two-stage combustion process enabled through a split injection strategy. When keeping both NOx and CA50 constant, varying GCR from 15.7 to 18.9 showed only a moderate impact on engine brake thermal efficiency (BTE), while its influence on smoke was pronounced. At a lower GCR, a larger fraction of fuel could be introduced during the first injection event due to lower charge reactivity, thereby promoting partially-premixed combustion and reducing smoke. Although increasing GCR increased gross indicated thermal efficiency (ITEg), it was also found to cause higher energy losses in friction and pumping. In contrast, GCI performance showed stronger sensitivity towards EGR rate variation, suggesting that air-handling system development is critical for enabling efficient and clean low NOx GCI combustion. To better utilize gasoline’s lower reactivity, an analysis-led variable valve actuation investigation was performed at 15.7 GCR and 1375 rpm/10 bar BMEP. The analysis was focused on using an early intake valve closing (EIVC) approach by carrying out closed-cycle, 3-D CFD combustion simulations coupled with 1-D engine cycle analysis. EIVC was shown to be an effective means to lengthen ignition delay and promote partially-premixed combustion by lowering the engine effective compression ratio (ECR). By combining EIVC with a tailored fuel injection strategy and properly developed thermal boundary conditions, simulation predicted a 2.3% improvement in ISFC and 47% soot reduction over the baseline IVC case while keeping NOx below the baseline level.

Self-Starting Cogging-Torque-Assisted Motor Drive for Use in a Heavy-Duty Diesel Engine

2019 ◽  
Author(s):  
Devin K. Reinholz ◽  
Bradley A. Reinholz ◽  
Rudolf J. Seethaler
Keyword(s):  
Diesel Engine ◽  
Motor Drive ◽  
Heavy Duty ◽  
Cogging Torque ◽  
Actuation System ◽  
Heavy Duty Diesel Engine ◽  
Simulation Results ◽  
Heavy Duty Diesel ◽  
Damper Windings ◽  
Variable Valve

Abstract This paper describes the design process and simulation results of a variable valve actuation system modeled after the cogging-torque-assisted motor drive (CTAMD) found in literature. Unlike the CTAMD, the new design is capable of handling large exhaust pressures. Furthermore, the new design incorporates damper windings to improve upon the CTAMD by enabling self-starting. The new variable valve actuator is designed for the 6-cylinder Westport 15L diesel engine. The simulated results suggest that the new variation of the CTAMD can be effectively applied to a turbocharged heavy-duty diesel engine. Simulation results show that the designed motor is capable of self-starting, and infinitely variable lifts. The damper windings are shown to be more beneficial at enabling self-starting and infinitely variable lifts than a spring, since they do not impose additional energy requirements during a valve transition. Furthermore, the new design is also shown to be capable of actuating exhaust valves in the presence of cylinder pressures up to 16 bar with similar efficiency to that of a standard camshaft valve train.

Characteristics of Particulate Matter about Emissions in a Heavy-Duty Diesel Engine with Biodiesel Blends

2014 ◽  
Vol 852 ◽  
pp. 802-807
Author(s):  
Di Ming Lou ◽  
Tian Yu Shen ◽  
Yi Zhou ◽  
Zhi Yuan Hu ◽  
Pi Qiang Tan ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Particle Number ◽  
Number Concentration ◽  
Particle Number Concentration ◽  
Heavy Duty ◽  
Full Load ◽  
Nucleation Mode ◽  
Heavy Duty Diesel Engine ◽  
Load Characteristics ◽  
Heavy Duty Diesel

A China-V Heavy-duty diesel engine fueled with blends of 5%, 10%, 20%, 50% waste cooking oil biodiesel and diesel (marked separately BD5, BD10, BD20, BD50), pure biodiesel (BD100) and pure diesel (D100), was tested on full load speed characteristics and 1400 r/min and 2200 r/min load characteristics to study influence of biodiesel fuel and engine conditions on particle size distributions and particle number concentration. The results show that when fueled with blends containing less than 50% biodiesel, the particle number concentrations show single peak distribution curves (nucleation mode), for the pure biodiesel, particle number concentrations show bimodal distribution including nucleation mode and accumulation mode on full load speed characteristics and 1400 r/min and 2200 r/min load characteristics; on full load speed characteristics, for BD100, the peak of particle number concentration of BD100 is lowest, compared with D100, it is about one order of magnitude lower; on 1400r/min load characteristics, with the biodiesel proportion increasing, the number of nucleation mode and accumulation mode particles decreases; on lower than 1800 r/min full load speed characteristics and 1400 r/min and 2200 r/min load characteristics, with the biodiesel proportion increasing, the particle number concentration decreases.

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