A Study of the Effects of Radiation on Pollutant Emissions in Direct Injection Engines

Author(s):  
Indranil Brahma ◽  
Xuelei Zhu ◽  
Steven H. Frankel ◽  
Jay P. Gore

Abstract The laminar flamelet combustion model was used to study the effects of radiation on chemistry in a direct injection engine. A two dimensional axisymmetric engine code with a simple mixing length turbulence model was used. Four state relationships for different conditions were obtained from laminar opposed flow diffusion flame calculations by considering gas and soot radiation heat loss using detailed gas and global soot kinetics. The effects of radiation on pollutant emissions were studied by using the four state relationships in the engine calculations.

2019 ◽  
Vol 22 (1) ◽  
pp. 125-139
Author(s):  
Jérôme Hélie ◽  
Nicolas Lamarque ◽  
Jean-Luc Fremaux ◽  
Philippe Serrecchia ◽  
Maziar Khosravi ◽  
...  

Gasoline direct injection engines mainly use multi-hole high-pressure injectors. To respect the current pollutant regulation (particle number and particle mass) and continue to decrease pollutant emissions in the future, it is of outmost importance to identify the various sources of carbon particles. In gasoline direct injection, tip wetting can generate a progressive tip sooting that can be a source of large number of particles especially in hot engine conditions. The different topics related to the tip wetting are investigated here without counterbore after the metering hole in order to have a direct access to the optical visualization. In this article, the different phases of the tip wetting are identified experimentally and phenomenological models are proposed.


2005 ◽  
Vol 128 (2) ◽  
pp. 388-396 ◽  
Author(s):  
Dohoy Jung ◽  
Dennis N. Assanis

In this study we report the development and validation of phenomenological models for predicting direct injection (DI) diesel engine emissions, including nitric oxide (NO), soot, and unburned hydrocarbons (HC), using a full engine cycle simulation. The cycle simulation developed earlier by the authors (D. Jung and D. N. Assanis, 2001, SAE Transactions: Journal of Engines, 2001-01-1246) features a quasidimensional, multizone, spray combustion model to account for transient spray evolution, fuel–air mixing, ignition and combustion. The Zeldovich mechanism is used for predicting NO emissions. Soot formation and oxidation is calculated with a semiempirical, two-rate equation model. Unburned HC emissions models account for three major HC sources in DI diesel engines: (1) leaned-out fuel during the ignition delay, (2) fuel yielded by the sac volume and nozzle hole, and (3) overpenetrated fuel. The emissions models have been validated against experimental data obtained from representative heavy-duty DI diesel engines. It is shown that the models can predict the emissions with reasonable accuracy. Following validation, the usefulness of the cycle simulation as a practical design tool is demonstrated with a case study of the effect of the discharge coefficient of the injector nozzle on pollutant emissions.


2021 ◽  
Vol 286 ◽  
pp. 01006
Author(s):  
Andrei Laurentiu Niculae ◽  
Adnan Kadhim Rashid ◽  
Radu Chiriac

The use of biodiesel-diesel blends is a current solution to some important problems, such as the depletion of oil resources, global warming, and the pollutant emissions of smoke, carbon monoxide, and hydrocarbons of diesel engines. However, the use of this alternative fuel is characterized by a reduction in engine effective power and an increase in brake-specific fuel consumption and nitrogen oxide pollutant emissions. Using the AVL MCC zero-dimensional combustion model of the AVL BOOST simulation program, it was evaluated to what extent split injection strategies can improve the performance and fuel economy of a tractor diesel engine fuelled with biodiesel B20 at maximum brake torque condition considering noise and pollutant emissions limitation. Various pilot – main – post split injection strategies have been studied to establish the optimal injection characteristics in terms of performance and fuel economy. Subsequently, they have been adapted in terms of compliance with current emission standards. In this way, it has been emphasized that the split injection solution is a viable way to improve performance, economy, and pollutant emissions of a tractor diesel engine.


Author(s):  
M. A. Alim ◽  
W. Malalasekera

In this work simulation of a turbulent H2/N2 jet diffusion flame with flamelet modeling has been presented. The favre averaged mixture fraction has been employed to model the combustion. Favre-averaged scalar quantities have been calculated from flamelet libraries by making use of a presumed Probability Density Function (PDF) method. To incorporate the effect of radiation heat transfer the combustion model has been extended using the concept of enthalpy defect. The predicted flame temperature profiles and chemical species concentrations with and without radiation heat loss are compared with experimental data. Predictions considering the radiation heat loss found to be in good agreement with temperature and chemical species measurements whereas the adiabatic model significantly overestimates temperatures in the downstream regions of flames where the significant heat loss occurs. This study shows that the combustion simulation using flamelet models considering radiation heat loss are effective for predicting the flow, temperature and chemical kinetics of H2/N2 jet diffusion flame. To account for fluctuations of mixture fraction, its distribution is presumed to have the shape of a beta-function.


Author(s):  
E. Jimenez ◽  
R. Molina ◽  
V. Andrade

The present work has as main objective the use of a biofuel (Ecopaís) in a direct injection vehicle, it is an option to reduce damage to health and the environment, for this a static thermal simulation will be done in the spark plug, to compare the results of the aforementioned software using On Board tests, in a 1500 cc engine. The measurements of the emission factors of CO, HC and NOx gases will be considered in a route established in the city of Quito from 2399 to 2870 meters above sea level. The interaction of the element is carried out in the ANSYS Academic program which is 14977 nodes and 7523 elements to be studied with automatic meshing, obtaining that the Ecopaís and Ecopaís + Ferox fuels have the highest heat flow with a 5% divergence compared to the Extra fuel + Ferox. There is a significant reduction in pollutant emissions of 3% of CO with the use of Ecopaís in comparison to Extra + Ferox fuel, in the case of HC, Ecopaís and Ecopaís + Ferox fuels with 3% lower emissions compared to Extra fuel + Ferox, and in NOx, fuels that have Extra + Ferox and Ecopaís + Ferox solid additives are 3 and 3.5% lower compared to Ecopaís fuel, respectively. Keywords: biofuel, termal, on board, ferox, emission factors. Resumen El presente trabajo tiene como objetivo fundamental la utilización de un biocombustible (Ecopaís) en un vehículo de inyección directa, es una opción para disminuir daños a la salud y al medio ambiente, para ello se hará una simulación térmica estática en la bujía de encendido, para comparar los resultados del mencionado software mediante pruebas On Board, en un motor de 1500 cc. Las mediciones de los factores de emisión de gases de CO, HC y NOx, se contemplará en una ruta establecida en la ciudad de Quito de 2399 hasta 2870 m.s.n.m. La interacción del elemento se realiza en el programa ANSYS Academic que es de 14977 nodos y 7523 elementos a estudiar con el mallado automático, obteniendo que los combustibles Ecopaís y Ecopaís+Ferox tienen el mayor flujo de calor con una divergencia del 5% en comparación del combustible Extra + Ferox. Se evidencia una reducción significativa de emisiones contaminantes del 2.5% del CO con el uso del Ecopaís en comparación del combustible Extra + Ferox, en el caso de HC los combustibles Ecopaís y Ecopaís + Ferox con un 1% menor en emisiones en comparación al combustible Extra + Ferox, y en el NOx los combustibles que tienen aditivo sólido Extra+Ferox y Ecopaís+Ferox son menores en un 6 y 4% con respecto al combustible Ecopaís respectivamente. Palabras clave: biocombustible, térmica, on board, ferox, factores de emisiones.


2012 ◽  
Vol 78 (794) ◽  
pp. 1860-1869
Author(s):  
Yoshiyuki KOBAYASHI ◽  
Tsuneaki ISHIMA ◽  
Tomio OBOKATA ◽  
Teruyoshi MORITA ◽  
Takuya YAMADA

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.


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