scholarly journals System for Increasing Exhaust Gas Temperature for Catalyst Activation at Light Load Condition in Diesel Engines

2005 ◽  
Vol 71 (705) ◽  
pp. 1453-1458 ◽  
Author(s):  
Hiromi ISHITANI ◽  
Hiroyuki OONISHI ◽  
Hideyuki TSUNEMOTO ◽  
Takanobu YAMADA
Keyword(s):  
Diesel Engines ◽  
Load Condition ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Catalyst Activation ◽  
Light Load ◽  
Exhaust Gas Temperature

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.

Materials Selection for Variable Geometry Turbine Nozzle for Gasoline Engine Application

2014 ◽  
Author(s):  
Vivek O. Shettigar ◽  
Apostolos Pesiridis
Keyword(s):  
Diesel Engines ◽  
Internal Combustion Engines ◽  
Gasoline Engine ◽  
Load Condition ◽  
Working Environment ◽  
Exhaust Gas ◽  
Variable Geometry ◽  
Gas Temperature ◽  
Performance Indices ◽  
Gasoline Engines

Turbocharging is a key technology for reducing emissions in modern automotive internal combustion engines. The application of turbochargers has been regarded as the next step in the downsizing I.C. Engines. The technology has demonstrated its ability to increase the power of small engines by over 30%. This technology had a few drawbacks such as selection of appropriate air-fuel ratio which could either provide better transient response at low load condition or provide increased power at full load condition. In the quest to obtain the benefits of the both conditions, Variable Geometry Turbochargers (VGTs) were introduced. They account for a significant share of the market in mechanical turbocharging for diesel engines. The most common and efficient type of flow control device in use in VGT is the pivoting vane array located at the inlet of the turbocharger. The technology has been effectively applied over the past 20 years in diesel engines due to their relatively lower exhaust gas temperature (compared to gasoline engines) which has allowed inexpensive materials to be used. This isn’t the case for gasoline engines due to their high exhaust gas temperatures. In light of this technical challenge, the current paper discusses the attempts at application of VGTs in gasoline engines and evaluates further material options which can be considered as appropriate candidates for use in the movable nozzle section of a VGT. Exhaust gases temperatures of up to 1050°C with the working pressures reaching in excess of 2 bar is the working environment of a typical VGT. A CFD analysis of appropriately selected materials is presented in this paper and was applied to a generic pivoting vane mechanism, producing results for the stresses and deformations experienced by the selected materials. This paper also includes cost and manufacturability discussion of requirements which will eventually dictate the choice of any given material for mass production. The material is chosen with the help of an in-depth selection processes such as the Paul and Beitz method which includes weighing factors and performance indices. Performance indices can be considered as groups of material properties which represent few important aspect of the performance of the component.

scholarly journals A Three-Zone Scavenging Model for Large Two-Stroke Uniflow Marine Engines Using Results from CFD Scavenging Simulations

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1719 ◽  
Author(s):  
Michael I. Foteinos ◽  
Alexandros Papazoglou ◽  
Nikolaos P. Kyrtatos ◽  
Anastassios Stamatelos ◽  
Olympia Zogou ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Diesel Engines ◽  
Zone Model ◽  
Exhaust Gas ◽  
Mixing Zone ◽  
Gas Temperature ◽  
Cfd Simulations ◽  
Mixing Coefficients ◽  
Marine Diesel ◽  
Exhaust Gas Temperature

The introduction of modern aftertreatment systems in marine diesel engines call for accurate prediction of exhaust gas temperature, since it significantly affects the performance of the aftertreatment system. The scavenging process establishes the initial conditions for combustion, directly affecting exhaust gas temperature, fuel economy, and emissions. In this paper, a semi-empirical zero-dimensional three zone scavenging model applicable to two-stroke uniflow scavenged diesel engines is updated using the results of CFD (computational fluid dynamics) simulations. In this 0-D model, the engine cylinders are divided in three zones (thermodynamic control volumes) namely, the pure air zone, mixing zone, and pure exhaust gas zone. The entrainment of air and exhaust gas in the mixing zone is specified by time varying mixing coefficients. The mixing coefficients were updated using results from CFD simulations based on the geometry of a modern 50 cm bore large two-stroke marine diesel engine. This increased the model’s accuracy by taking into account 2-D fluid dynamics phenomena in the cylinder ports and exhaust valve. Thus, the effect of engine load, inlet port swirl angle and partial covering of inlet ports on engine scavenging were investigated. The three-zone model was then updated and the findings of CFD simulations were reflected accordingly in the updated mixing coefficients of the scavenging model.

Advanced Thermal Management for Modern Diesel Engines: Optimized Synergy Between Engine Hardware and Software Intelligence

2012 ◽  
Author(s):  
Thomas Körfer ◽  
Hartwig Busch ◽  
Andreas Kolbeck ◽  
Christopher Severin ◽  
Thorsten Schnorbus ◽  
...  
Keyword(s):  
Thermal Management ◽  
Diesel Engines ◽  
The Other ◽  
Valve Train ◽  
Oxidation Catalyst ◽  
Temperature Management ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Conversion Rates ◽  
Exhaust Gas Temperature

Both, the continuous tightening of the exhaust emission standards and the global efforts for a significant lowering of CO2 output in public traffic display significant developments for future diesel engines. These engines will utilize not only the mandatory Diesel oxidation catalyst (DOC) and particulate trap (DPF), but also a DeNOx aftertreatment system as well — at least for heavier vehicles. The DOC as well as actually available sophisticated DeNOx aftertreatment technologies, i.e. LNT and SCR, depends on proper exhaust gas temperatures to achieve a high conversion rates. This aspect becomes continuously critical due to intensified measures for CO2 reduction, which will conclude in a drop of exhaust gas temperatures. Furthermore, this trend has to be taken into account regarding future electrification and hybridization scenarios. In order to ensure the high NOx conversion rates in the EAS intelligent temperature management strategies will be required, not only based on conventional calibration measures, but also a further upgrade of the engine hardware. Advanced split-cooling and similar thermal management technologies offer the merit to lower CO2 emissions on one hand and increase exhaust gas temperature at cold start and warm-up simultaneously on the other hand. Besides this, also variable valve train functionalities deliver a substantial potential of active thermal management. In the context of this paper various concepts for exhaust gas temperature management are investigated and compared. The final judgment will focus on the effectiveness concerning real exhaust temperature increase vs. corresponding fuel economy penalty. Further factors, like operational robustness, consequences on operational strategies and related software algorithms as well as cost are assessed. The utilized reference engine in this advanced program is represented by a refined I-4 research engine to achieve best combustion efficiency at minimal engine-out emissions. The detailed studies were performed with an injection strategy, featuring one pilot injection and one main injection event, and an active, advanced closed-loop combustion control. The engine used in this study allows fulfillment of Euro 6 and Tier 2 Bin 5 emissions standards, while offering high power densities above 80 kW/ltr. As a résumé, it can be stated, that with all accomplished variations a significant increase in temperature downstream low pressure turbine can be achieved. The PI and PoI quantities define dominant parameters for emission formation under cold and warm conditions. By using an exhaust cam-phaser CO-, HC- and NOx emissions can be significantly lowered, separating VVT functions from the other investigated strategies.

Increasing Method of Exhaust Gas Temperature at Idling Condition in DI Diesel Engines

2002 ◽  
Vol 2002.4 (0) ◽  
pp. 107-108
Author(s):  
Hiroyuki OONISHI ◽  
Hideyuki TSUNEMOTO ◽  
Hiromi ISHITANI
Keyword(s):  
Diesel Engines ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Exhaust Gas Temperature

Lime kiln conversion from coke to natural gas operation – an option in direction of sustainable energy

2020 ◽  
pp. 431-434
Author(s):  
Oliver Arndt
Keyword(s):  
Natural Gas ◽  
New Technology ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Gaseous Fuels ◽  
Lime Kiln ◽  
Lime Kilns ◽  
Co2 Balance ◽  
Exhaust Gas Temperature

This paper deals with the conversion of coke fired lime kilns to gas and the conclusions drawn from the completed projects. The paper presents (1) the decision process associated with the adoption of the new technology, (2) the necessary steps of the conversion, (3) the experiences and issues which occurred during the first campaign, (4) the impacts on the beet sugar factory (i.e. on the CO2 balance and exhaust gas temperature), (5) the long term impressions and capabilities of several campaigns of operation, (6) the details of available technologies and (7) additional benefits that would justify a conversion from coke to natural gas operation on existing lime kilns. (8) Forecast view to develop systems usable for alternative gaseous fuels (e.g. biogas).

scholarly journals Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part I Standard Measurements

2015 ◽  
Vol 22 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Zbigniew Korczewski
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Technical Condition ◽  
Temperature Measurements ◽  
Injection System ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Gas Temperature ◽  
Measuring Signal ◽  
Exhaust Gas Temperature

Abstract The article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard online measurements of the exhaust gas temperature. A proposal is made to extend the parametric methods of diagnosing workspaces in turbocharged marine engines by analysing time-histories of enthalpy changes of the exhaust gas flowing to the turbocompressor turbine. Such a time-history can be worked out based on dynamic measurements of the exhaust gas temperature, performed using a specially designed sheathed thermocouple. The first part of the article discusses possibilities to perform diagnostic inference about technical condition of a marine engine with pulse turbocharging system based on standard measurements of exhaust gas temperature in characteristic control cross-sections of its thermal and flow system. Selected metrological issues of online exhaust gas temperature measurements in those engines are discusses in detail, with special attention being focused on the observed disturbances and thermodynamic interpretation of the recorded measuring signal. Diagnostic informativeness of the exhaust gas temperature measurements performed in steady-state conditions of engine operation is analysed in the context of possible evaluations of technical condition of the engine workspaces, the injection system, and the fuel delivery process.

Energetic Based Organic Fluid Selection for a Solid Oxide Fuel Cell-Organic Rankine Cycle Combined System

2012 ◽  
Vol 622-623 ◽  
pp. 1162-1167
Author(s):  
Han Fei Tuo
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Heat Recovery ◽  
Waste Heat ◽  
Solid Oxide ◽  
Exhaust Gas ◽  
Oxide Fuel ◽  
Gas Temperature ◽  
Selection For ◽  
Exhaust Gas Temperature

In this study, energetic based fluid selection for a solid oxide fuel cell-organic rankine combined power system is investigated. 9 dry organic fluids with varied critical temperatures are chosen and their corresponding ORC cycle performances are evaluated at different turbine inlet temperatures and exhaust gas temperature (waste heat source) from the upper cycle. It is found that actual ORC cycle efficiency for each fluid strongly depends on the waste heat recovery performance of the heat recovery vapor generator. Exhaust gas temperature determines the optimal fluid which yields the highest efficiency.

Experimental Study of Natural Gas Fuel Temperature Influence on Radiation Enhancement and Emission

2010 ◽  
Author(s):  
S. Mohammad Javadi ◽  
Pourya Nikoueeyan ◽  
Mohammad Moghiman ◽  
M. Ebrahim Feyz
Keyword(s):  
Radiation Intensity ◽  
Flame Temperature ◽  
Photovoltaic Module ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Fuel Temperature ◽  
Flame Radiation ◽  
Exhaust Gases ◽  
No Formation ◽  
Exhaust Gas Temperature

The enhancement of the flame radiation in gas fueled burners not only improves the thermal efficiency, but also can suppress the rate of NO emission due to reducing the flame temperature. In this experimental investigation, the effect of inlet gas temperature on the flame radiation intensity and the rate of NO formation are studied. To serve this aim, with increasing the temperature of inlet methane to the burner up to 310°C, the variations of CO and NO level in exhaust gases and also the exhaust gas temperature are recorded by gas analyzer device. In each case, the flame radiation intensity was also measured by a photovoltaic module. The results revealed that by increasing the inlet gas temperature up to 250°C, the NO concentration and the exhaust gases temperature are raising. But when the inlet gas temperature exceeds from 250°C and reaches to 310°C, the flame luminosity gradually increases which results in 70 percent growth in flame radiation and 10 percent drop in exhaust gas temperature. The results of the preheating of inlet air also show the same behavior.

Sign in / Sign up

Export Citation Format

Share Document