The Experts below are selected from a list of 171 Experts worldwide ranked by ideXlab platform
Uwe Kiencke - One of the best experts on this subject based on the ideXlab platform.
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Engine modeling and exhaust gas estimation for DI-diesel engines
Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148), 2001Co-Authors: Dara Daniel Torkzadeh, Wolfgang Längst, Uwe KienckeAbstract:Engine models are a basis for better controlling combustion process and the exhaust emissions resulting from it. Currently the zero- and quasi-dimensional models are mostly used. These types of model are also addressed in this article. Zero-dimensional models are computationally efficient but they are not able to describe fuel efficiency or the generation of pollutants. It is therefore necessary to enhance combustion process models with phenomenological fuel spray and vaporization models, with a local resolution of at least two Zones. The chemical model for calculating emissions is based on the two-Zone model. The amount of mass, which is transferred from the unBurned to the Burned Zone, is the input for a chemical model based on the equilibrium for the OCH-system (oxygen/carbon/hydrogen). The nitrogen-oxide emissions are calculated by using the advanced Zeldovich-mechanism which uses the reaction-kinetic approach rather than the less accurate chemical equilibrium assumption. The NO/sub x/-emissions (nitrogen-oxides) can be influenced by changing the exhaust-gas recirculation (EGR) rate.
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Model Based Exhaust Gas Estimation of a Common Rail Diesel Engine
IFAC Proceedings Volumes, 2001Co-Authors: Dara Daniel Torkzadeh, Wolfgang Längst, Uwe KienckeAbstract:Abstract In order to improve fuel economy and the emissions of internal combustion engines, it is necessary to model the combustion process as a basis for control. In this paper, behavioral models are adopted as a compromise between accuracy of description and model complexity. The fuel injection and vaporization process is resolved into three Zones: fluid droplets, vaporized and combusted fuel. The combustion chamber is divided into areas of Burned and unBurned gases, separated by the flame front. The chemical model for calculating emissions is based on the two-Zone model. The amount of mass, which is transferred from the unBurned to the Burned Zone, is the input for a chemical model based on the equilibrium for the OCH -system (oxygen/carbon/hydrogen). The result is the total quantity of masses in the Burned Zone. The nitrogen-oxide emissions are calculated by using the advanced Zeldovichmechanism which uses the reaction-kinetic approach rather than the less accurate chemical equilibrium assumption. The NO x -Emissions (nitrogen-oxides) can be influenced by changing the exhaust-gas recirculation
Lin Tian - One of the best experts on this subject based on the ideXlab platform.
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study on mgo mgo al2o3 bricks used Burned Zone of cement rotary kiln
Advanced Materials Research, 2011Co-Authors: Guo Hua Li, Shu Jiang Chen, Lin TianAbstract:The effects of iron scales and high iron magnesite as well as the content on microstructure and properties of MgO-MgO·Al2O3 bricks used Burned Zone of large cement rotary kilns have been studied. It focuses on testing coating adherence in this paper. The results show that apparent porosity of adding iron scales sample is higher than the sample by adding high iron magnesite, which is increased with increasing of iron scales content; Compression strength is decreased with increasing of iron scales content, The high iron magnesia cause the irregular change of the compression strength, compression strength was maximum when high iron magnesite content of additive was 6%; Coating adherence was optimum adding 3% high iron magnesite, adding 3% iron scales is followed, any other is bad. Over all, the sample adding 3% high iron magnesite is more suitable for large dry method cement kiln Burned Zone．
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Study on MgO-MgO•Al2O3 Bricks Used Burned Zone of Cement Rotary Kiln
Advanced Materials Research, 2011Co-Authors: Guo Hua Li, Shu Jiang Chen, Lin TianAbstract:The effects of iron scales and high iron magnesite as well as the content on microstructure and properties of MgO-MgO·Al2O3 bricks used Burned Zone of large cement rotary kilns have been studied. It focuses on testing coating adherence in this paper. The results show that apparent porosity of adding iron scales sample is higher than the sample by adding high iron magnesite, which is increased with increasing of iron scales content; Compression strength is decreased with increasing of iron scales content, The high iron magnesia cause the irregular change of the compression strength, compression strength was maximum when high iron magnesite content of additive was 6%; Coating adherence was optimum adding 3% high iron magnesite, adding 3% iron scales is followed, any other is bad. Over all, the sample adding 3% high iron magnesite is more suitable for large dry method cement kiln Burned Zone．
Li Guohu - One of the best experts on this subject based on the ideXlab platform.
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Study on MgO-MgO·Al_2O_3 Bricks Used Burned Zone of Cement Kiln
Materials review, 2014Co-Authors: Li GuohuAbstract:The effects of iron scales and high iron magnesia as well as the content on microstructure and properties of MgO-MgO·Al2O3bricks used Burned Zone of large cement rotary kilns were studied.It focuses on testing coating adherence.The results show that the porosity of adding iron scales sample is higher than the sample by adding high iron magnesia,which is increased with increasing of iron scales content;cold crushing strength reduced with content of iron scales.The high iron magnesia cause the irregular change of cold crushing strength,cold crushing strength was maximum when high iron magnesia content was 6%;coating adherence and resistance to cement clinker permeation was optimum when adding 12% high iron magnesia.
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study on mgo mgo al_2o_3 bricks used Burned Zone of cement kiln
Materials review, 2014Co-Authors: Li GuohuAbstract:The effects of iron scales and high iron magnesia as well as the content on microstructure and properties of MgO-MgO·Al2O3bricks used Burned Zone of large cement rotary kilns were studied.It focuses on testing coating adherence.The results show that the porosity of adding iron scales sample is higher than the sample by adding high iron magnesia,which is increased with increasing of iron scales content;cold crushing strength reduced with content of iron scales.The high iron magnesia cause the irregular change of cold crushing strength,cold crushing strength was maximum when high iron magnesia content was 6%;coating adherence and resistance to cement clinker permeation was optimum when adding 12% high iron magnesia.
Dara Daniel Torkzadeh - One of the best experts on this subject based on the ideXlab platform.
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Engine modeling and exhaust gas estimation for DI-diesel engines
Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148), 2001Co-Authors: Dara Daniel Torkzadeh, Wolfgang Längst, Uwe KienckeAbstract:Engine models are a basis for better controlling combustion process and the exhaust emissions resulting from it. Currently the zero- and quasi-dimensional models are mostly used. These types of model are also addressed in this article. Zero-dimensional models are computationally efficient but they are not able to describe fuel efficiency or the generation of pollutants. It is therefore necessary to enhance combustion process models with phenomenological fuel spray and vaporization models, with a local resolution of at least two Zones. The chemical model for calculating emissions is based on the two-Zone model. The amount of mass, which is transferred from the unBurned to the Burned Zone, is the input for a chemical model based on the equilibrium for the OCH-system (oxygen/carbon/hydrogen). The nitrogen-oxide emissions are calculated by using the advanced Zeldovich-mechanism which uses the reaction-kinetic approach rather than the less accurate chemical equilibrium assumption. The NO/sub x/-emissions (nitrogen-oxides) can be influenced by changing the exhaust-gas recirculation (EGR) rate.
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Model Based Exhaust Gas Estimation of a Common Rail Diesel Engine
IFAC Proceedings Volumes, 2001Co-Authors: Dara Daniel Torkzadeh, Wolfgang Längst, Uwe KienckeAbstract:Abstract In order to improve fuel economy and the emissions of internal combustion engines, it is necessary to model the combustion process as a basis for control. In this paper, behavioral models are adopted as a compromise between accuracy of description and model complexity. The fuel injection and vaporization process is resolved into three Zones: fluid droplets, vaporized and combusted fuel. The combustion chamber is divided into areas of Burned and unBurned gases, separated by the flame front. The chemical model for calculating emissions is based on the two-Zone model. The amount of mass, which is transferred from the unBurned to the Burned Zone, is the input for a chemical model based on the equilibrium for the OCH -system (oxygen/carbon/hydrogen). The result is the total quantity of masses in the Burned Zone. The nitrogen-oxide emissions are calculated by using the advanced Zeldovichmechanism which uses the reaction-kinetic approach rather than the less accurate chemical equilibrium assumption. The NO x -Emissions (nitrogen-oxides) can be influenced by changing the exhaust-gas recirculation
Masahiro Ishida - One of the best experts on this subject based on the ideXlab platform.
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diesel combustion analysis based on two Zone model examination of excess air ratio in Burned Zone
Jsme International Journal Series B-fluids and Thermal Engineering, 1996Co-Authors: Masahiro Ishida, Hironobu Ueki, Noboru Matsumura, Zhili ChenAbstract:The Burned Zone excess air ratio λ d in the diffusion combustion process was analyzed using the two-Zone model, and it was compared with the excess air ratio λ f estimated using a steady diffusion flame model of the fuel spray. It is found that λ d is dependent on the fuel spray penetration and ignition delay. If the premixed combustion fraction is less than 50%, the NO formation is minimally influenced by the excess air ratio during premixed combustion and is dependent on the excess air ratio λ d which determines the maximum temperature during diffusion combustion. It is clarified by analysis of the two-Zone model that the large reduction in NO x due to timing retard is mainly caused by decreases in both combustion temperature and combustion pressure, and the small reduction in NO x occurring when the nozzle-hole diameter is decreased, is due to a small decrease in combustion pressure resulting from a decrease in the heat release rate during premixed combustion.
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Diesel Combustion Analysis Based on Two-Zone Model (Comparison between Model Analysis and Experiment)
Jsme International Journal Series B-fluids and Thermal Engineering, 1996Co-Authors: Masahiro Ishida, Hironobu Ueki, Noboru Matsumura, Masanori YamaguchiAbstract:The proposed two-Zone model of diesel combustion consists of a Burned Zone and an unBurned Zone, and the thermodynamic process is independent and adiabatic in each Zone except that the air is entrained from the unBurned Zone to the Burned Zone under a specified condition of the excess air ratio during the combustion period. The excess air ratio in the diffusion combustion period is assumed to be constant in the present model. The calculated time histories of the Burned-Zone gas temperature and the cumulative soot formation were compared with the measured time histories of the flame temperature and the KL value based on the infrared two-color method. The calculated results agree qualitatively and partly quantitatively with the experimental results except for the swirl effect. As a result, it is shown that the present two-Zone model analysis is very useful and effective in evaluating the combustion process in a DI diesel engine.
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An Analysis of the Added Water Effect on NO Formation in D.I. Diesel Engines
SAE Technical Paper Series, 1994Co-Authors: Masahiro Ishida, Zhili ChenAbstract:The effect of water in the suction air and in the emulsified fuel on NO formation was analyzed experimentally and theoretically from the point of view of changes in specific heat and the entrained air rate of the Burned gas in the combustion chamber. The specific heat was calculated accurately through the chemical equilibrium composition analysis considering the absolute humidity of the suction air, the amount of water added in the emulsified fuel as well as the residual gas fraction. In order to estimate the NO formaiton rate, the Burned gas temperature which is dominated by the excess air ratio and the specific heat of the Burned gas was calculated by using the two-Zone combustion model. The effect of absolute humidity of the suction air on NO formation is so large that a change in absolute humidity of 0.01 kg/kg results in about 20% reduction of NOx. This large reduction is based on only about 1% change in specific heat of the Burned Zone gas. With respect to the mechanism of a large NOx reduction due to the water emulsified fuel, it is found by the two-Zone model analysis that the entrained air rate of the Burned gas is hardlymore » changed by the added amount of water. Therefore, the increases in both specific heat and the gas weight due to the added amount of water in the Burned Zone result in a decrease in the Burned gas temperature which reduces NOx largely. 12 refs., 15 figs., 6 tabs.« less
