Combustion and Emission Characteristics of Dual Fuel Engine for Different Parameters

The effects of compression ratio and fuel delivery advance angle on the combustion and emission characteristics of premixed methanol charge induced ignition by Fischer Tropsch diesel engine were investigated using a CY25TQ diesel engine. In the process of reducing the compression ratio from 16.9 to 15.4, the starting point of combustion is fluctuating, the peak of in-cylinder pressure and the maximum pressure increase rate decrease by 44.5% and 37.7% respectively. The peak instantaneous heat release rate increases by 54.4%. HC and CO emissions are on a rising trend. NOx and soot emissions were greatly decreased. The soot emission has the biggest drop of 50%. Reducing the fuel delivery advance angle will make the peak of in-cylinder pressure and the peak of pressure rise rate increase while the peak of heat release rate decreases. The soot emission is negatively correlated with the fuel delivery advance angle. When the fuel delivery advance angle is 16° CA, the soot emissions increased the most by 130%.

Numerical investigation of soot emission sources in a direct-injection spark-ignition engine based on comprehensive breakup model validation

Direct injection system is widely adopted in spark-ignition engines to achieve higher thermal efficiency, but it accompanies a penalty in particulate emission, especially when engine is not fully warmed-up. Split injection strategy is known to be an effective measure to reduce engine-out particulate emissions. To better understand the role of split injections, this study aims to analyze the effect of split injection strategy on the sources of soot formation using computational fluid dynamics simulation. To accurately predict changes in particulate mass and number associated with split injection strategy, it is vital that spray models be carefully validated against the experimental data since spray dynamics govern the formation of soot emission sources, such as local fuel-rich mixtures and wall-deposited fuel-films. To this end, a set of spray experiments for free sprays is performed to measure liquid penetration length and droplet size distribution, and hence a comprehensive validation is conducted for spray breakup models. Then, engine simulations are carried out to predict the change in soot sources according to split injection, and the trend of simulation results is compared against the measured engine-out particulate mass and number. Simulation results indicate that breakup model validation using both penetration length and droplet size data is critical for predicting fuel spray dynamics and formation of sources of soot emission. It is also revealed that the piston wetting decreases as the number of injections increases because less amount of fuel is injected when piston is closer to the injector. Lastly, the late evaporation of heavy gasoline components from fuel-film appears to be a significant contributor to soot precursors formation.

Design And Development Of A Multi-Color Soot Emission Diagnostics To Measure Soot Temperature And Concentration

<div>In this paper, temperature of the soot particles from the flame was determined using line of sight attenuation setup. The emission from the soot particles of the flame will be filtered using a three color pyrometry, in which three slits of different wavelengths will be placed in front of the AP-3200T-USB camera. The author did not use spectrometer to filter the wavelengths because, a spectrometer would give a spectrum consisting of 15 different colors, which is not required in this experiment, since calculation of temperature of the soot only requires two colors to be filtered from the soot. Each wavelength corresponds to RED, BLUE and GREEN color respectively. After the soot emission images are captured in all the three wavelengths, three images will be obtained from the camera. For reading these images, MATLAB code was used, and the pixel intensity values were read from which temperature could be calculated.</div>

Design And Development Of A Multi-Color Soot Emission Diagnostics To Measure Soot Temperature And Concentration

<div>In this paper, temperature of the soot particles from the flame was determined using line of sight attenuation setup. The emission from the soot particles of the flame will be filtered using a three color pyrometry, in which three slits of different wavelengths will be placed in front of the AP-3200T-USB camera. The author did not use spectrometer to filter the wavelengths because, a spectrometer would give a spectrum consisting of 15 different colors, which is not required in this experiment, since calculation of temperature of the soot only requires two colors to be filtered from the soot. Each wavelength corresponds to RED, BLUE and GREEN color respectively. After the soot emission images are captured in all the three wavelengths, three images will be obtained from the camera. For reading these images, MATLAB code was used, and the pixel intensity values were read from which temperature could be calculated.</div>