铁路罐车装运的液体货物易于流动,在运行过程中会对罐壁产生不同于固体货物的动态力,此动态力将对行车安全产生影响。本文采用FLUENT软件对罐车内流体货物的动侧压力进行数值模拟计算,用VOF(vol-ume of fluid)模型模拟罐车受到制动冲击...铁路罐车装运的液体货物易于流动,在运行过程中会对罐壁产生不同于固体货物的动态力,此动态力将对行车安全产生影响。本文采用FLUENT软件对罐车内流体货物的动侧压力进行数值模拟计算,用VOF(vol-ume of fluid)模型模拟罐车受到制动冲击时其内部气液两相流,得到以下结论:(1)罐车运输液体货物受到制动冲击时,在冲击端产生较大压力;(2)罐车内增加挡波板有利于抑制液体晃动;(3)罐车冲击端的受力大小与其制动初始速度有关。展开更多
Improving the flexibility of combined heat and power(CHP)units is an important way to solve the problem of wind power accommodation in northern China.Firstly,this paper analyzes the principle of an extraction-type CHP...Improving the flexibility of combined heat and power(CHP)units is an important way to solve the problem of wind power accommodation in northern China.Firstly,this paper analyzes the principle of an extraction-type CHP unit,calculates its safe operation range,and analyzes its contradiction between heating and peaking.Secondly,the safe operation ranges of the CHP unit with several flexibility modifications are further calculated,which involve two-stage bypass,low-pressure cylinder(LPC)removal,heat storage tank,and electric boiler.Finally,based on the safe operation ranges,their effects on improving the capabilities of deep peak shaving and wind power accommodation are compared,and their adaptabilities to different wind scenarios are analyzed.The results show that:①all flexibility modifications can improve the deep peak shaving capability of the CHP unit,especially for the two-stage bypass and the electric boiler;②LPC removal modification can accommodate wind power to some extent,but most of wind power is still abandoned;③heat storage tank modification is unstable in different wind scenarios,which is determined by the surplus heating capability during the daytime.展开更多
文摘铁路罐车装运的液体货物易于流动,在运行过程中会对罐壁产生不同于固体货物的动态力,此动态力将对行车安全产生影响。本文采用FLUENT软件对罐车内流体货物的动侧压力进行数值模拟计算,用VOF(vol-ume of fluid)模型模拟罐车受到制动冲击时其内部气液两相流,得到以下结论:(1)罐车运输液体货物受到制动冲击时,在冲击端产生较大压力;(2)罐车内增加挡波板有利于抑制液体晃动;(3)罐车冲击端的受力大小与其制动初始速度有关。
基金supported in part by the National Natural Science Foundation of China(No.51806063)。
文摘Improving the flexibility of combined heat and power(CHP)units is an important way to solve the problem of wind power accommodation in northern China.Firstly,this paper analyzes the principle of an extraction-type CHP unit,calculates its safe operation range,and analyzes its contradiction between heating and peaking.Secondly,the safe operation ranges of the CHP unit with several flexibility modifications are further calculated,which involve two-stage bypass,low-pressure cylinder(LPC)removal,heat storage tank,and electric boiler.Finally,based on the safe operation ranges,their effects on improving the capabilities of deep peak shaving and wind power accommodation are compared,and their adaptabilities to different wind scenarios are analyzed.The results show that:①all flexibility modifications can improve the deep peak shaving capability of the CHP unit,especially for the two-stage bypass and the electric boiler;②LPC removal modification can accommodate wind power to some extent,but most of wind power is still abandoned;③heat storage tank modification is unstable in different wind scenarios,which is determined by the surplus heating capability during the daytime.
