介绍了一种UNIX环境下基于GIS的在线电网参数可视化管理系统的实现方法.这套基于GIS(Geographic Information System)的电网参数管理系统是在美国ESRI公司的ARC/INFO平台上采用AML(Arc Macro Language)开发而成的,与原有的EMS(Energy Ma...介绍了一种UNIX环境下基于GIS的在线电网参数可视化管理系统的实现方法.这套基于GIS(Geographic Information System)的电网参数管理系统是在美国ESRI公司的ARC/INFO平台上采用AML(Arc Macro Language)开发而成的,与原有的EMS(Energy Management System)集成良好,实现了电网参数的在线显示,并建立了基于CIM(Common Information Model)的参数数据库.展开更多
Combustion noise takes large proportion in diesel engine noise and the studies of its influence factors play an important role in noise reduction. Engine noise and cylinder pressure measurement experiments were carrie...Combustion noise takes large proportion in diesel engine noise and the studies of its influence factors play an important role in noise reduction. Engine noise and cylinder pressure measurement experiments were carried out. And the improved attenuation curves were obtained, by which the engine noise was predicted. The effect of fuel injection parameters in combustion noise was investigated during the combustion process. At last, the method combining single variable optimization and multivariate combination was introduced to online optimize the combustion noise. The results show that injection parameters can affect the cylinder pressure rise rate and heat release rate, and consequently affect the cylinder pressure load and pressure oscillation to influence the combustion noise. Among these parameters, main injection advance angle has the greatest influence on the combustion noise, while the pilot injection interval time takes the second place, and the pilot injection quantity is of minimal impact. After the optimal design of the combustion noise, the average sound pressure level of the engine is distinctly reduced by 1.0 d B(A) generally. Meanwhile, the power, emission and economy performances are ensured.展开更多
文摘介绍了一种UNIX环境下基于GIS的在线电网参数可视化管理系统的实现方法.这套基于GIS(Geographic Information System)的电网参数管理系统是在美国ESRI公司的ARC/INFO平台上采用AML(Arc Macro Language)开发而成的,与原有的EMS(Energy Management System)集成良好,实现了电网参数的在线显示,并建立了基于CIM(Common Information Model)的参数数据库.
基金Project(2011BAE22B05)supported by the National Science and Technology Pillar Program during the 12th Five-year Plan of China
文摘Combustion noise takes large proportion in diesel engine noise and the studies of its influence factors play an important role in noise reduction. Engine noise and cylinder pressure measurement experiments were carried out. And the improved attenuation curves were obtained, by which the engine noise was predicted. The effect of fuel injection parameters in combustion noise was investigated during the combustion process. At last, the method combining single variable optimization and multivariate combination was introduced to online optimize the combustion noise. The results show that injection parameters can affect the cylinder pressure rise rate and heat release rate, and consequently affect the cylinder pressure load and pressure oscillation to influence the combustion noise. Among these parameters, main injection advance angle has the greatest influence on the combustion noise, while the pilot injection interval time takes the second place, and the pilot injection quantity is of minimal impact. After the optimal design of the combustion noise, the average sound pressure level of the engine is distinctly reduced by 1.0 d B(A) generally. Meanwhile, the power, emission and economy performances are ensured.