Possibilities to Achieve Future Emission Limits for HD DI Diesel Engines Using Internal Measures

2005 ◽  
Author(s):  
D. T. Hountalas ◽  
G. C. Mavropoulos ◽  
T. C. Zannis ◽  
V. Schwarz
Keyword(s):  
Diesel Engines ◽  
Future Emission ◽  
Emission Limits

Modelling of the Selective Catalytic NOx Reduction for Diesel Engine

2011 ◽  
Vol 71-78 ◽  
pp. 2098-2102
Author(s):  
Hang Xu ◽  
Fang Yin Tu ◽  
Zhi Xia He ◽  
Jun Ma ◽  
Qian Wang
Keyword(s):  
Mathematical Model ◽  
Catalytic Reduction ◽  
Catalytic Converter ◽  
Nox Reduction ◽  
Space Velocity ◽  
Reaction Model ◽  
Future Emission ◽  
Emission Limits ◽  
The Impact ◽  
Good Agreement

As Future emission limits of diesel engines is more stringent, model-based control strategy of selective catalytic reduction (SCR) is becoming necessary. Therefore, a catalytic converter mathematical model for simulating selective catalytic deNOx reaction is very important. In this paper, a one dimension catalytic converter mathematical model that consists of thermal energy model, SCR reaction model and NH3storage model for simulating urea-SCR reaction process is presented. Based on this model, the impact of temperature and gas hourly space velocity (GHSV) on NOx conversion efficiency has been researched. According to the results of simulation, it shows good agreement with experimental data.

MAHLE Advanced EGR Systems for Commercial Diesel Engines to Meet Future Emission Demands

2007 ◽  
Author(s):  
Marco Warth ◽  
Boris Lerch ◽  
Adam Loch ◽  
Alfred Elsaesser
Keyword(s):  
Diesel Engines ◽  
Operating Conditions ◽  
Intake Manifold ◽  
Emission Regulations ◽  
Technical Advances ◽  
Future Emission ◽  
Heavy Duty Diesel ◽  
Low Torque ◽  
Key Aspects ◽  
Fast Acting

Given the ever more stringent emission regulations modern diesel engines undergo these days, the need for advanced EGR systems becomes crucial in all major applications, in particular on- & off-road commercial diesel engines. One of the key aspects of these so-called advanced EGR systems thereby is to reliably provide the engine with the appropriate, high amounts of EGR over the entire range of operating conditions. Whereas common systems are either optimized for low-torque/low-speed operating conditions, or a narrow range around one specific engine speed, the advanced systems aim to both cover the entire operating range and significantly increase the current level of EGR. The advanced EGR systems developed at MAHLE make use of two types of fast acting devices in a modular approach. Depending on the engine size/layout and the amount of EGR needed, the devices are either placed directly in the EGR line or the intake manifold. Using the latest technical advances in mechatronics, the oscillating valves can be opened or closed within less than 3ms, which makes it not only possible to accurately control the amount of EGR fed back into the engine, it also allows to boost the amount of EGR using the exhaust pressure oscillations. In addition to these oscillating valves, rotational flaps have been developed to significantly reduce the complexity of the systems, while still offering similar benefits in terms of EGR rates and variability. Shown hereafter are the results from thorough investigations conducted on both European and US heavy-duty diesel engines. Focusing on some of the most common engine characteristics, such as EGR rates, emissions of nitrogen oxide and fuel consumption, significant benefits can be seen using the newly developed technologies. Compared to conventional measures, such as increased exhaust backpressure and/or constant charge-air throttling, the advanced systems prove to be both more efficient and flexible in terms of EGR rates, as well as beneficial regarding some of the most important engine characteristics.

Study of Possible Range Extender Concepts with Respect to Future Emission Limits

2010 ◽  
Author(s):  
Andreas Ebner ◽  
Franz Winkler ◽  
Martin Abart ◽  
Raphael Luz ◽  
Roland Kirchberger ◽  
...  
Keyword(s):  
Range Extender ◽  
Future Emission ◽  
Emission Limits

Flow Analysis of Multiple Injectors in High-Power-Density HSDI CR Diesel Engines

2018 ◽  
Vol 388 ◽  
pp. 1-13
Author(s):  
Luca Piancastelli ◽  
Eugenio Pezzuti ◽  
Stefano Cassani
Keyword(s):  
Fuel Consumption ◽  
Power Density ◽  
Diesel Engines ◽  
High Speed ◽  
Direct Injection ◽  
Flow Analysis ◽  
Boost Pressure ◽  
Closing Time ◽  
Emission Limits ◽  
Opening And Closing

The primary task in DI (Direct Injection) diesel engines design is the fulfilment of the required emission limits. This result should be achieved with acceptable power-to-rpm diagrams, acceptable fuel consumption, acceptable power density and affordable purchase and maintenance expenses. The most common approach to fulfil these requirements is the downsizing. In this case a significant increase in the crankshaft speed and boost pressure is unavoidable. In this way, an improvement in airflow through the redesign of the intake and exhaust geometry is obtained. Unfortunately, duct design is extremely difficult due to “Mach lock”. A further important boundary condition is due the injector inertia. The dynamic response improves with small injectors due to the Newton’s second law. Small injectors designed for unitary power of 15 to 70 HP are extremely common. Therefore, most of the research is centered on these injectors. Furthermore, their small inertia favors better opening and closing time. Nozzles number and position is also greatly influential on combustion performance. The larger surface of the spray reduces the gasification time of the droplets. For these reasons, multiple injectors systems may be used in large high pressure HSDI-CR (High Speed Direct Injection – Common Rail) diesels. Multi injection was commonplace in relatively large old diesels. This paper proposes new intake duct geometries for modern two-injectors-per-cylinder truck-size engines. For this purpose a new promising, patented concept is introduced. The study includes flow simulations during the intake phase. This patented geometry induces the presence of two extremely strong swirls approximately centered to the injectors, with excellent swirl coefficient and high flow rate. The use of swirl generators on the manifolds avoids the necessity to design helical intake ducts. This patented approach simplifies head design. Moreover, using a VG (Variable Geometry) arrangement for the volutes (swirl generators) it is possible to tune the swirl index at the optimum for every crankshaft velocity and every load. In this way, the vehicle fuel consumption is also reduced.

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