On January 6, the National Energy Administration released the operational indices of Chinese power industry in 2009, including total consumption, capital construction investment and the capacity of
The paper reports quality analysis and evaluation at 6 - 10/0.4 kV low-voltage distribution grids in Uzbekistan. Power quality frequently does not correspond to the rated value which is largely due to unbalanced phase...The paper reports quality analysis and evaluation at 6 - 10/0.4 kV low-voltage distribution grids in Uzbekistan. Power quality frequently does not correspond to the rated value which is largely due to unbalanced phase loading in grids and which also results in increased power loss. The study of the asymmetrical operating modes of the rural distribution networks of 0.4 kV was conducted in three steps: measurement, calculations and analysis of relevant data;providing practical guidelines and finally, implementing instruments to normalize grid operation. Measuring was conducted using certified instrumentation analyzer “MALIKA” designed by authors. The study and analysis of additional power losses as the function of indicators of asymmetrical features of voltage and current in operating 0.4 kV grids reveals that, quality of electric power at grids under investigation, merely does not meet the requirements of the Interstate Standard.展开更多
It is well known that injection strategies including the injection timing and pressure play the most important role in determining engine performance,especially in pollutant emissions.However,the injection timing and ...It is well known that injection strategies including the injection timing and pressure play the most important role in determining engine performance,especially in pollutant emissions.However,the injection timing and pressure quantitatively affect the performance of diesel engine with a turbo charger are not well understood.In this paper,the fire computational fluid dynamics(CFD)code with an improved spray model has been used to simulate the spray and combustion processes of diesel with early and late injection timings and six different injection pressure(from 275 bar to 1000 bar).It has been concluded that the use of early injection provides lower soot and higher NOx emissions than the late injection.In this study,it has been tried using the change of fuel injection time at these two next steps:before top dead center(BTDC)and after top dead center(ATDC)in order to achieving optimum emission and power in a specific point.展开更多
In this study,maintaining a constant fuel rate,injection pressure of 275 bar to1000 bar(275 × 10^(2) kPa to 1000× 10^(2) kPa),has been changed.Effect of injection pressure,the pressure inside the cylinder on...In this study,maintaining a constant fuel rate,injection pressure of 275 bar to1000 bar(275 × 10^(2) kPa to 1000× 10^(2) kPa),has been changed.Effect of injection pressure,the pressure inside the cylinder on the free energy,power,engine indicators,particularlyindicators of fuel consumption,pollutants and their effects on parameters affecting the outputof the engine combustion chamber have been studied in droplet diameter.Finally,the effects offuel mixture equivalence,Cantor temperature,soot and NO_(x),due to the increase of injectionpressure,engine efficiency and emissions have been examined.展开更多
Calibration of the relationship between the scattering angle and the CCD pixel is a key part of achieving accurate measurements of rainbow refractometry.A novel self-calibrated global rainbow refractometry system base...Calibration of the relationship between the scattering angle and the CCD pixel is a key part of achieving accurate measurements of rainbow refractometry.A novel self-calibrated global rainbow refractometry system based on illumination by two lasers of different wavelengths is proposed.The angular calibration and refractive index measurement of two wavelengths can be completed simultaneously without extra measurement devices.The numerical and experimental results show the feasibility and high precision of the self-calibration method,which enables the rainbow refractometry to be implemented in a more powerful and convenient way.The self-calibrated rainbow system is successfully applied to measure the refractive indices of ethanol-water solutions with volume concentrations of 10% to 60%.展开更多
文摘On January 6, the National Energy Administration released the operational indices of Chinese power industry in 2009, including total consumption, capital construction investment and the capacity of
文摘The paper reports quality analysis and evaluation at 6 - 10/0.4 kV low-voltage distribution grids in Uzbekistan. Power quality frequently does not correspond to the rated value which is largely due to unbalanced phase loading in grids and which also results in increased power loss. The study of the asymmetrical operating modes of the rural distribution networks of 0.4 kV was conducted in three steps: measurement, calculations and analysis of relevant data;providing practical guidelines and finally, implementing instruments to normalize grid operation. Measuring was conducted using certified instrumentation analyzer “MALIKA” designed by authors. The study and analysis of additional power losses as the function of indicators of asymmetrical features of voltage and current in operating 0.4 kV grids reveals that, quality of electric power at grids under investigation, merely does not meet the requirements of the Interstate Standard.
文摘It is well known that injection strategies including the injection timing and pressure play the most important role in determining engine performance,especially in pollutant emissions.However,the injection timing and pressure quantitatively affect the performance of diesel engine with a turbo charger are not well understood.In this paper,the fire computational fluid dynamics(CFD)code with an improved spray model has been used to simulate the spray and combustion processes of diesel with early and late injection timings and six different injection pressure(from 275 bar to 1000 bar).It has been concluded that the use of early injection provides lower soot and higher NOx emissions than the late injection.In this study,it has been tried using the change of fuel injection time at these two next steps:before top dead center(BTDC)and after top dead center(ATDC)in order to achieving optimum emission and power in a specific point.
文摘In this study,maintaining a constant fuel rate,injection pressure of 275 bar to1000 bar(275 × 10^(2) kPa to 1000× 10^(2) kPa),has been changed.Effect of injection pressure,the pressure inside the cylinder on the free energy,power,engine indicators,particularlyindicators of fuel consumption,pollutants and their effects on parameters affecting the outputof the engine combustion chamber have been studied in droplet diameter.Finally,the effects offuel mixture equivalence,Cantor temperature,soot and NO_(x),due to the increase of injectionpressure,engine efficiency and emissions have been examined.
基金supported by the National Natural Science Foundation of China(No.51576177)the Major Program of the National Natural Science Foundation of China(No.51390491)+1 种基金the National Basic Research Program of China(No.2015CB251501)the Program of Introducing Talents of Discipline to University(No.B08026)
文摘Calibration of the relationship between the scattering angle and the CCD pixel is a key part of achieving accurate measurements of rainbow refractometry.A novel self-calibrated global rainbow refractometry system based on illumination by two lasers of different wavelengths is proposed.The angular calibration and refractive index measurement of two wavelengths can be completed simultaneously without extra measurement devices.The numerical and experimental results show the feasibility and high precision of the self-calibration method,which enables the rainbow refractometry to be implemented in a more powerful and convenient way.The self-calibrated rainbow system is successfully applied to measure the refractive indices of ethanol-water solutions with volume concentrations of 10% to 60%.
