To reduce the influence of thermal effects during discharge process for natural gas applications as vehicular fuel,the authors established a mathematical model of methane storage tank system during discharge process a...To reduce the influence of thermal effects during discharge process for natural gas applications as vehicular fuel,the authors established a mathematical model of methane storage tank system during discharge process and solved the equations by method of Newton-Raphson and iterative algorithm. The results reveal that the lowest temperature occurs in the center of tank with temperature drop of 49. 14 ℃,the average temperature drop of system is 42. 78 ℃,and the discharge amount is 2. 733 kg,with a performance loss approaching 24. 5% at the discharge rate of 1. 315 g/s. The inner temperature and discharge amounts can be changed by heating the wall of tank and increasing the thermal conductivity coefficient of adsorbents. Average temperature drop of system is about 20. 1 ℃ and discharge amount is up to 3. 2065 kg,corresponding to discharge efficiency loss of 11. 47% by changing the thermal conductivity from 0. 2 to 0. 5 and the wall temperature from 20 ℃ to 50 ℃. The research on discharge dynamic performance at different discharge rates indicates that the heat supplied by tank wall is larger than natural convection does.展开更多
A novel type of Ti decorating benzene grafted tetrahydrido-silsequioxane struc-tures was designed and investigated using density functional theory（DFT）.The hydrogen adsorption properties of this new material were in...A novel type of Ti decorating benzene grafted tetrahydrido-silsequioxane struc-tures was designed and investigated using density functional theory（DFT）.The hydrogen adsorption properties of this new material were investigated at the same level of theory.The results reveal that up to four hydrogen molecules（with the restrict of 18 electrons rule） can be adsorbed on each Ti atom of（TiC6H5）m-H4-mSi4O6（m = 1-4） molecular systems with the average binding energies of 0.691,0.692,0.693 and 0.695 eV for m = 1-4,respectively.The variations of HOMO- LUMO energy gaps verify that the host structures with four H2 molecules adsorbed own the best kinetics stability.The interaction mechanism of H2 molecules with the host materials mainly attributes to the well-known ＂kubas interactions＂.All the results indicate that the complex structures designed here may be used as hydrogen storage materials at ambient conditions.展开更多
基金Sponsored by the Innovation Program of Chinese Academy of Sciences(Grant No.0907r7,0907z1)
文摘To reduce the influence of thermal effects during discharge process for natural gas applications as vehicular fuel,the authors established a mathematical model of methane storage tank system during discharge process and solved the equations by method of Newton-Raphson and iterative algorithm. The results reveal that the lowest temperature occurs in the center of tank with temperature drop of 49. 14 ℃,the average temperature drop of system is 42. 78 ℃,and the discharge amount is 2. 733 kg,with a performance loss approaching 24. 5% at the discharge rate of 1. 315 g/s. The inner temperature and discharge amounts can be changed by heating the wall of tank and increasing the thermal conductivity coefficient of adsorbents. Average temperature drop of system is about 20. 1 ℃ and discharge amount is up to 3. 2065 kg,corresponding to discharge efficiency loss of 11. 47% by changing the thermal conductivity from 0. 2 to 0. 5 and the wall temperature from 20 ℃ to 50 ℃. The research on discharge dynamic performance at different discharge rates indicates that the heat supplied by tank wall is larger than natural convection does.
基金Supported by the National Natural Science Foundation of China (NSFC Grant No.11074176 and NSAF Grant No.10976019)Doctoral Program of Higher Education of China (No.20100181110080)
文摘A novel type of Ti decorating benzene grafted tetrahydrido-silsequioxane struc-tures was designed and investigated using density functional theory（DFT）.The hydrogen adsorption properties of this new material were investigated at the same level of theory.The results reveal that up to four hydrogen molecules（with the restrict of 18 electrons rule） can be adsorbed on each Ti atom of（TiC6H5）m-H4-mSi4O6（m = 1-4） molecular systems with the average binding energies of 0.691,0.692,0.693 and 0.695 eV for m = 1-4,respectively.The variations of HOMO- LUMO energy gaps verify that the host structures with four H2 molecules adsorbed own the best kinetics stability.The interaction mechanism of H2 molecules with the host materials mainly attributes to the well-known ＂kubas interactions＂.All the results indicate that the complex structures designed here may be used as hydrogen storage materials at ambient conditions.
