Flanges, bolting and gaskets for exhaust gas, piping for diesel engines and boiler uptakes

1970 ◽  
Keyword(s):  
Diesel Engines ◽  
Exhaust Gas

THE CHANCES FOR REDUCTION OF VIBRATIONS IN MECHANICAL SYSTEM WITH LOW-EMISSION SHIPS COMBUSTION ENGINES

2021 ◽  
Vol 157 (A4) ◽  
Author(s):  
R Grega ◽  
J Homišin ◽  
M Puškár ◽  
J Kul’ka ◽  
J Petróci ◽  
...  
Keyword(s):  
Mechanical System ◽  
Diesel Engines ◽  
Fuel Mixture ◽  
Adverse Impact ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Low Emission ◽  
Power Outputs ◽  
Exhaust Gas Emissions ◽  
Engine Power

Development of diesel engines is focused on reduction of exhaust gas emissions, increase of efficiency of the fuel mixture combustion and decrease of fuel consumption. Such engines are referred to as low-emission engines. Low- engines trends bring higher engine power outputs, torques and also increase of vibrations and noisiness level. In order to reduce these vibrations of diesel engines, it is necessary to apply different dynamical elements, which are able to increase an adverse impact of exciting amplitudes. One of the results is application of a pneumatic dual-mass flywheel. The pneumatic dual-mass flywheel is a dynamical element that consists of two masses (the primary and the secondary mass), which are jointed together by means of a flexible interconnection. This kind of the flywheel solution enables to change resonance areas of the mechanical system which consequently leads to reduction of vibrations.

scholarly journals Improving Efficiency, Extending the Maximum Load Limit and Characterizing the Control-Related Problems Associated With Higher Loads in a 6-Cylinder Heavy-Duty Natural Gas Engine

2010 ◽  
Author(s):  
Mehrzad Kaiadi ◽  
Per Tunestal ◽  
Bengt Johansson
Keyword(s):  
Natural Gas ◽  
Compression Ratio ◽  
Diesel Engines ◽  
Maximum Load ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Heavy Duty ◽  
Load Limit ◽  
Overall Efficiency ◽  
Exhaust Gas Temperature

High EGR rates combined with turbocharging has been identified as a promising way to increase the maximum load and efficiency of heavy duty spark ignition Natural Gas engines. With stoichiometric conditions a three way catalyst can be used which means that regulated emissions can be kept at very low levels. Most of the heavy duty NG engines are diesel engines which are converted for SI operation. These engine’s components are in common with the diesel-engine which put limits on higher exhaust gas temperature. The engines have lower maximum load level than the corresponding diesel engines. This is mainly due to the lower density of NG, lower compression ratio and limits on knocking and also high exhaust gas temperature. They also have lower efficiency due to mainly the lower compression ratio and the throttling losses. However performing some modifications on the engines such as redesigning the engine’s piston in a way to achieve higher compression ratio and more turbulence, modifying EGR system and optimizing the turbocharging system will result in improving the overall efficiency and the maximum load limit of the engine. This paper presents the detailed information about the engine modifications which result in improving the overall efficiency and extending the maximum load of the engine. Control-related problems associated with the higher loads are also identified and appropriate solutions are suggested.

A new mass and temperature control valve for exhaust gas recirculation in car diesel engines

MTZ worldwide ◽  
2007 ◽  
Vol 68 (12) ◽  
pp. 21-23
Author(s):  
Thomas Holzbaur ◽  
Eike Willers ◽  
Achim Hess ◽  
Hans-Peter Klein ◽  
Markus Schuessler ◽  
...  
Keyword(s):  
Temperature Control ◽  
Diesel Engines ◽  
Control Valve ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Gas Recirculation

Holistic Control of Diesel Engines and Exhaust Gas Aftertreatment

MTZ worldwide ◽  
2019 ◽  
Vol 80 (12) ◽  
pp. 52-59
Author(s):  
Enrico Neumann ◽  
Daniel Eckardt ◽  
Steve Kipping
Keyword(s):  
Diesel Engines ◽  
Exhaust Gas ◽  
Exhaust Gas Aftertreatment

Parametric Study of the Scavenging Process in Marine Two-Stroke Diesel Engines

2015 ◽  
Author(s):  
Fredrik Herland Andersen ◽  
Stefan Mayer
Keyword(s):  
Diesel Engines ◽  
Vortex Breakdown ◽  
Initial Conditions ◽  
Combustion Process ◽  
Operating Conditions ◽  
Exhaust Valve ◽  
Delivery Ratio ◽  
Exhaust Gas ◽  
Scale Production ◽  
Cfd Model

Large commercial ships such as container vessels and bulk carriers are propelled by low-speed, uniflow scavenged two-stroke diesel engines. The integral in-cylinder process in this type of engine is the scavenging process, where the burned gas from the combustion process is evacuated through the exhaust valve and replaced with fresh air for the subsequent compression stroke. The scavenging air enters the cylinder via inlet ports which are uncovered by the piston at bottom dead center (BDC). The exhaust gas is then displaced by the fresh air. The scavenging ports are angled to introduce a swirling component to the flow. The in-cylinder swirl is beneficial for air-fuel mixture, cooling of the cylinder liner and minimizing dead zones where pockets of exhaust gas are trapped. However, a known characteristic of swirling flows is an adverse pressure gradient in the center of the flow, which might lead to a local deficit in axial velocity and the formation of central recirculation zones, known as vortex breakdown. This paper will present a CFD analysis of the scavenging process in a MAN B&W two-stroke diesel engine. The study include a parameter sweep where the operating conditions such as air amount, port timing and scavenging pressure are varied. The CFD model comprise the full geometry from scavenge receiver to exhaust receiver. Asymmetric inlet and outlet conditions is included as well as the dynamics of a moving piston and valve. Time resolved boundary conditions corresponding to measurements from an operating, full scale production, engine as well as realistic initial conditions are used in the simulations. The CFD model provides a detailed description of the in-cylinder flow from exhaust valve opening (EVO) to exhaust valve closing (EVC). The study reveals a close coupling between the volume flow (delivery ratio) and the in-cylinder bulk purity of air which appears to be independent of operating conditions, rpm, scavenge air pressure, BMEP etc. The bulk purity of air in the cylinder shows good agreement with a simple theoretical perfect displacement model.

Diesel Engine Intake Condition Control-Oriented Models for Active Fuel Injection Profile Control

2011 ◽  
Author(s):  
Fengjun Yan ◽  
Junmin Wang
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Exhaust Gas Recirculation ◽  
High Fidelity ◽  
Exhaust Gas ◽  
Engine Model ◽  
Profile Control ◽  
Gas Recirculation

Fueling control in Diesel engines is not only of significance to the combustion process in one particular cycle, but also influences the subsequent dynamics of air-path loop and combustion events, particularly when exhaust gas recirculation (EGR) is employed. To better reveal such inherently interactive relations, this paper presents a physics-based, control-oriented model describing the dynamics of the intake conditions with fuel injection profile being its input for Diesel engines equipped with EGR and turbocharging systems. The effectiveness of this model is validated by comparing the predictive results with those produced by a high-fidelity 1-D computational GT-Power engine model.

Catalytic filters for the simultaneous removal of soot and NOx: Effect of CO2 and steam on the exhaust gas of diesel engines

2011 ◽  
Vol 176 (1) ◽  
pp. 134-138 ◽  
Author(s):  
M.E. Gálvez ◽  
S. Ascaso ◽  
R. Moliner ◽  
R. Jiménez ◽  
X. García ◽  
...  
Keyword(s):  
Diesel Engines ◽  
Simultaneous Removal ◽  
Exhaust Gas

Diesel engines with low-pressure exhaust-gas recirculation

MTZ worldwide ◽  
2008 ◽  
Vol 69 (2) ◽  
pp. 20-26 ◽  
Author(s):  
Stefan Münz ◽  
Christiane Römuss ◽  
Peter Schmidt ◽  
Kai-Henning Brune ◽  
Heinz-Peter Schiffer
Keyword(s):  
Diesel Engines ◽  
Exhaust Gas Recirculation ◽  
Low Pressure ◽  
Exhaust Gas ◽  
Gas Recirculation
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