Quench chamber is the most important component in the coal gasifier,and is easy to break.In order to find the pattern of turbulent flow and heat transfer of synthetic gas in the Vertical downward pipe,a numerical mode...Quench chamber is the most important component in the coal gasifier,and is easy to break.In order to find the pattern of turbulent flow and heat transfer of synthetic gas in the Vertical downward pipe,a numerical model based on analyzing the flow and heat transfer features of the vertical pipe in quench chamber is first presented.The variations of temperature,velocity of synthetic gas with the change in length and radius of the vertical pipe and the velocity of the gas are obtained,and the effect of radiation is found. The pattern of turbulent flow and heat transfer of synthetic gas in the vertical pipe is further revealed.展开更多
Suitable microstructures required for semisolid casting were formed by using a vertical pipe.Different lengths of vertical pipe,slug dimensions and pouring time were used to investigate their influence on the microstr...Suitable microstructures required for semisolid casting were formed by using a vertical pipe.Different lengths of vertical pipe,slug dimensions and pouring time were used to investigate their influence on the microstructure of A356 alloy.The results indicate that at the same length of the vertical pipe,the morphology of the primary α(Al)gradually deteriorates by the enlargement in the slug size,but the deteriorating speed slows down with increasing pipe length.They also reveal that the increase in the pipe length improves the microstructure,whereas no further improvement appears when the pipe length reaches a certain value.The optimum length of the pipe obtained in the present work is 430 mm.The microstructure of larger slug poured at higher pouring temperature gets worse and it can be improved by moderately elongating pouring time.The relative mechanisms were also discussed.展开更多
文摘Quench chamber is the most important component in the coal gasifier,and is easy to break.In order to find the pattern of turbulent flow and heat transfer of synthetic gas in the Vertical downward pipe,a numerical model based on analyzing the flow and heat transfer features of the vertical pipe in quench chamber is first presented.The variations of temperature,velocity of synthetic gas with the change in length and radius of the vertical pipe and the velocity of the gas are obtained,and the effect of radiation is found. The pattern of turbulent flow and heat transfer of synthetic gas in the vertical pipe is further revealed.
基金Project(2006AA03Z115)supported by the National Hi-tech Research and Development Program of ChinaProject(2006CB605203)supported by the National Basic Research Program of ChinaProject(50374012)supported by the National Natural Science Foundation of China
文摘Suitable microstructures required for semisolid casting were formed by using a vertical pipe.Different lengths of vertical pipe,slug dimensions and pouring time were used to investigate their influence on the microstructure of A356 alloy.The results indicate that at the same length of the vertical pipe,the morphology of the primary α(Al)gradually deteriorates by the enlargement in the slug size,but the deteriorating speed slows down with increasing pipe length.They also reveal that the increase in the pipe length improves the microstructure,whereas no further improvement appears when the pipe length reaches a certain value.The optimum length of the pipe obtained in the present work is 430 mm.The microstructure of larger slug poured at higher pouring temperature gets worse and it can be improved by moderately elongating pouring time.The relative mechanisms were also discussed.
