A good understanding of the detailed temperature distribution in the furnace plays an important role in the implementation of operation optimization and design improvement of ethylene pyrolyzer. Numerical simulation o...A good understanding of the detailed temperature distribution in the furnace plays an important role in the implementation of operation optimization and design improvement of ethylene pyrolyzer. Numerical simulation of the turbulent flow, combustion and heat transfer was carried out to investigate the temperature distribution in industrial furnace. Inhomogeneities of the flue-gas temperature distribution were observed in X, Y, and Z direction of the furnace from the simulated results. Along the height of the furnace, the average flue-gas temperature increased initially and decreased afterward, and reached its peak at the height of 5 m. The reactor tube skin temperature varied not only along the height of the furnace, but also around the circumference of the tube. The heat flux profiles from the furnace towards the reactor tubes followed the shape of the average flue-gas temperature profile. The heat flux of the inlet tubes was constantly higher than that of the outlet tubes at the same height in the furnace.展开更多
The main objectives of this study are to identify and analyze variables which have impact on export performances of seven East Africa countries and suggest possible solutions to improve export performance in East Afri...The main objectives of this study are to identify and analyze variables which have impact on export performances of seven East Africa countries and suggest possible solutions to improve export performance in East Africa. Usingdata from World Development Indicators database we conducted panel data analysis for the period of 1990-2014.Empirical results show that labor force, industrialization, foreign direct investment, and exchange rate have positiveimpact on export value. On the other hand, inflation has negative impact on export performance while GDP growthis the only variable that does not affect the export value of East Africa countries. Finally, we suggest somerecommendations, including the need of replacing agricultural exports by the industrial export, improving infrastructural facility as well as the quality of human capital and the need of policies for attracting internationalinvestors.展开更多
文摘A good understanding of the detailed temperature distribution in the furnace plays an important role in the implementation of operation optimization and design improvement of ethylene pyrolyzer. Numerical simulation of the turbulent flow, combustion and heat transfer was carried out to investigate the temperature distribution in industrial furnace. Inhomogeneities of the flue-gas temperature distribution were observed in X, Y, and Z direction of the furnace from the simulated results. Along the height of the furnace, the average flue-gas temperature increased initially and decreased afterward, and reached its peak at the height of 5 m. The reactor tube skin temperature varied not only along the height of the furnace, but also around the circumference of the tube. The heat flux profiles from the furnace towards the reactor tubes followed the shape of the average flue-gas temperature profile. The heat flux of the inlet tubes was constantly higher than that of the outlet tubes at the same height in the furnace.
文摘The main objectives of this study are to identify and analyze variables which have impact on export performances of seven East Africa countries and suggest possible solutions to improve export performance in East Africa. Usingdata from World Development Indicators database we conducted panel data analysis for the period of 1990-2014.Empirical results show that labor force, industrialization, foreign direct investment, and exchange rate have positiveimpact on export value. On the other hand, inflation has negative impact on export performance while GDP growthis the only variable that does not affect the export value of East Africa countries. Finally, we suggest somerecommendations, including the need of replacing agricultural exports by the industrial export, improving infrastructural facility as well as the quality of human capital and the need of policies for attracting internationalinvestors.
