Air- and fuel-path coordinated control for advanced combustion mode transitions in Diesel engines

2012 ◽  
Author(s):  
Fengjun Yan ◽  
Junmin Wang
Keyword(s):  
Diesel Engines ◽  
Coordinated Control ◽  
Combustion Mode ◽  
Advanced Combustion ◽  
Mode Transitions

Flatness-Based Control of Mode Transitions Between Conventional and Premixed Charge Compression Ignition on a Modern Diesel Engine With Variable Valve Actuation

2013 ◽  
Author(s):  
Carrie M. Hall ◽  
Dan Van Alstine ◽  
Gregory M. Shaver
Keyword(s):  
Diesel Engine ◽  
Gas Exchange ◽  
Diesel Combustion ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Variable Valve Actuation ◽  
Advanced Combustion ◽  
Combustion Modes ◽  
Mode Transitions ◽  
Variable Valve

Energy needs in the transportation sector and strict emissions regulations have caused a growing focus on increasing engine efficiency while simultaneously minimizing engine out emissions. One method for accomplishing this is to leverage advanced combustion strategies which are efficient yet very clean. One such combustion mode is premixed charge compression ignition (PCCI). PCCI can lead to drastically lower emissions than conventional diesel combustion while still maintaining engine efficiencies; however, the engine operation region over which it can be utilized is limited. In order to take advantage of this advanced combustion mode, engines must be designed to move between conventional diesel combustion and PCCI. To achieve transitions between different combustion modes, a control strategy was developed which utilizes a extensively validated gas exchange model and flatness-based methods for trajectory planning and trajectory tracking to enable smooth transitions between different combustion modes on a modern diesel engine with variable valve actuation. Since the engine considered here has the ability to alter valve timings, the control method exploits both capabilities to control the gas exchange process as well as the effective compression ratio of the engine. Simulation results indicate that this flatness-based approach is effective in enabling mode transitions.

A Control-Oriented Model for Dynamics From Fuel Injection Profile to Intake Gas Conditions in Diesel Engines

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Fengjun Yan ◽  
Junmin Wang
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Critical Role ◽  
High Fidelity ◽  
Combustion Mode ◽  
Engine Model ◽  
Advanced Combustion ◽  
Path Control ◽  
Simulation Results ◽  
Transient Operations

Fuel injection profile variations play a critical role in advanced combustion mode control for diesel engines and also possess control authorities on engine in-cylinder conditions (ICCs). In order to systematically utilize the active fueling control, in conjunction with air-path control, for transient operations of advanced multimode combustion diesel engines, this paper presents a physics-based, control-oriented model that describes the inherent dynamics from fuel injection profile variations to the intake gas conditions. To show the effectiveness of the developed control-oriented model, comparisons were made with the simulation results from a high-fidelity GT-Power computational engine model as well as the experimental data acquired on a medium-duty diesel engine during transient operations.

Effect of EGR in a Gasoline Operated Diesel Engine in LTC Mode

2012 ◽  
Author(s):  
Stephen Ciatti ◽  
Swami Nathan Subramanian ◽  
Alison Ferris
Keyword(s):  
Power Density ◽  
Diesel Engines ◽  
High Efficiency ◽  
Cetane Number ◽  
Reference Points ◽  
Experimental Investigations ◽  
Boost Pressure ◽  
Oxides Of Nitrogen ◽  
Advanced Combustion ◽  
Combustion Technology

Conventional combustion techniques struggle to meet the current emissions’ regulations while retaining high engine efficiency. Specifically in automotive diesel engines, oxides of nitrogen (NOx) and particulate matter (PM) emissions have limited the utilization of diesel fuel in compression ignition engines. By comparison, throttled, knock-limited conventional gasoline operated SI engines tend not to be fuel efficient. Advanced combustion systems that simultaneously address PM and NOx while retaining the high efficiency of modern diesel engines, are being developed around the globe [1]. One of the most difficult problems in the area of advanced combustion technology development is the control of combustion initiation [2] and retaining power density [3]. During the past several years, significant progress has been accomplished in reducing emissions of NOx and PM through strategies such as LTC/HCCI/PCCI/PPCI and other advanced combustion processes; however control of ignition and improving power density has suffered to some degree — advanced combustion engines tend to be limited to the 10 bar BMEP range and under [4]. Experimental investigations have been carried out on a light duty, DI, multi cylinder, diesel automotive engine. The engine is operated in low temperature combustion technology with 87 RON (Research Octane Number) fuel [7]. Using an Ignition Quality Test (IQT) device, the equivalent Cetane Number (CN) was measured to be 25. In the present work, various EGR rates are examined to determine the effect on the combustion, emissions and performance. Experiments were conducted at three different engine load/speed combinations that are part of General Motors’ reference points for vehicle operation. To reduce the complexity, boost pressure and injection pressure and timing were kept constant while EGR percentage and intake temperature were used as parameters in this study. The intake temperature was not truly independent, as it trended with EGR level, but based upon the boost level and the available EGR cooling, Intake Air Temperature (IAT) was kept in the range of 40–80 deg C. Additional cooling capacity will be added in future work in an effort to keep IAT more consistent. EGR rates have a detrimental effect on engine efficiencies at lower load while it appears to have little effect on efficiency at higher loads. A more significant effect at very low load appears to be higher intake temperatures (hot EGR) as opposed to the very slight decrease in oxygen concentration.

Dynamic Characteristics of Combustion Mode Transitions in a Strut-Based Scramjet Combustor Model

2013 ◽  
Vol 29 (5) ◽  
pp. 1244-1248 ◽  
Author(s):  
Wen Bao ◽  
Qingchun Yang ◽  
Juntao Chang ◽  
Youhai Zong ◽  
Jichao Hu
Keyword(s):  
Dynamic Characteristics ◽  
Combustion Mode ◽  
Scramjet Combustor ◽  
Mode Transitions
Sign in / Sign up

Export Citation Format

Share Document