根据构件最大允许转角限值,验证了挠度曲线近似微分方程求解形状函数在抗爆设计中的适用性;采用《Introduction to Structural Dynamics》中荷载和质量传递系数的计算原理,对两端刚接梁在两个集中载荷对称布置、三个集中载荷均匀布置以...根据构件最大允许转角限值,验证了挠度曲线近似微分方程求解形状函数在抗爆设计中的适用性;采用《Introduction to Structural Dynamics》中荷载和质量传递系数的计算原理,对两端刚接梁在两个集中载荷对称布置、三个集中载荷均匀布置以及对称三角形载荷布置三种不同工况的传递系数进行推导分析,并对GB 50779—2012《石油化工控制室抗爆设计规范》附录B中的部分数据进行纠正和补充。展开更多
Based on analysis of energy dissipation in the core region of gas-solid fluidized bed risers, a simplified model for determination of core-annulus solids mass transfer coefficient was developed according to turbulent ...Based on analysis of energy dissipation in the core region of gas-solid fluidized bed risers, a simplified model for determination of core-annulus solids mass transfer coefficient was developed according to turbulent diffusion mechanism of particles. The simulation results are consistent with published experimental data. Core-annulus solids mass transfer coefficient decreases with increasing particle size, particle density and solids circulation rate,but generally increases with increasing superficial gas velocity and riser diameter. In the upper dilute region of gas-solid fluidized bed risers, core-annulus solids mass transfer coefficient was found to change little with the axial coordinate in the bed.展开更多
Prediction of CO2 leakage into biosphere is very important for risk assessment in geological carbon storage projects. Underground CO2 can be transported into biosphere through short term leakage due to fractures of we...Prediction of CO2 leakage into biosphere is very important for risk assessment in geological carbon storage projects. Underground CO2 can be transported into biosphere through short term leakage due to fractures of wellbores or cap rocks, which has been extensively investigated, and long term leakage due to diffusion, which has few relevant studies. This paper presents a diffusive model for CO2 gradual leakage into biosphere during a long period after CO2 injection. First, the paper describes a general diffusive model with long term secondary trapping effects for CO2 fluxes from underground into biosphere. Secondly, a simplified one-dimensional model is presented and solved for the CO2 concentrations in groundwater. The results show that the groundwater CO2 concentration will reach the maximum value at about 50 th year after CO2 injection and then slowly decrease due to secondary trapping effects.Moreover, the partition coefficient is the dominant parameter for predicting the groundwater CO2 concentration while the convective mass transfer coefficient plays an insignificant role.展开更多
文摘根据构件最大允许转角限值,验证了挠度曲线近似微分方程求解形状函数在抗爆设计中的适用性;采用《Introduction to Structural Dynamics》中荷载和质量传递系数的计算原理,对两端刚接梁在两个集中载荷对称布置、三个集中载荷均匀布置以及对称三角形载荷布置三种不同工况的传递系数进行推导分析,并对GB 50779—2012《石油化工控制室抗爆设计规范》附录B中的部分数据进行纠正和补充。
文摘Based on analysis of energy dissipation in the core region of gas-solid fluidized bed risers, a simplified model for determination of core-annulus solids mass transfer coefficient was developed according to turbulent diffusion mechanism of particles. The simulation results are consistent with published experimental data. Core-annulus solids mass transfer coefficient decreases with increasing particle size, particle density and solids circulation rate,but generally increases with increasing superficial gas velocity and riser diameter. In the upper dilute region of gas-solid fluidized bed risers, core-annulus solids mass transfer coefficient was found to change little with the axial coordinate in the bed.
基金supported by the National Natural Science Foundation of China (51006060, 51136001)the Tsinghua University Initiative Scientific Research Program
文摘Prediction of CO2 leakage into biosphere is very important for risk assessment in geological carbon storage projects. Underground CO2 can be transported into biosphere through short term leakage due to fractures of wellbores or cap rocks, which has been extensively investigated, and long term leakage due to diffusion, which has few relevant studies. This paper presents a diffusive model for CO2 gradual leakage into biosphere during a long period after CO2 injection. First, the paper describes a general diffusive model with long term secondary trapping effects for CO2 fluxes from underground into biosphere. Secondly, a simplified one-dimensional model is presented and solved for the CO2 concentrations in groundwater. The results show that the groundwater CO2 concentration will reach the maximum value at about 50 th year after CO2 injection and then slowly decrease due to secondary trapping effects.Moreover, the partition coefficient is the dominant parameter for predicting the groundwater CO2 concentration while the convective mass transfer coefficient plays an insignificant role.
