A pigging model incorporating three different regions was developed for predicting the dynamics of the pigging operation in two-phase flow pipelines. The model incorporates a transient two-fluid model.The mixed Eulere...A pigging model incorporating three different regions was developed for predicting the dynamics of the pigging operation in two-phase flow pipelines. The model incorporates a transient two-fluid model.The mixed Eulerean-Lagrangian approach was used to couple the transient model and the pigging model which can predict the pigging time, velocity and the change of pigging parameters. An experimental study was carried out to acquire two-phase transient flow and pigging data on a 380m long,81mm diameter horizontal pipeline. A computer-based data acquisition system was used to obtain detailed information of the flow behavior during experimental runs. The data include pigging time, inlet pressure, accumulated liquid in pipeline, pressure and pigging velocity distribution.The predicted results compared fairy well with the experimental data.展开更多
The conversion of biomass into hydrogen-rich gas provides a competitive means for producing clean energy and chemicals from renewable resources.Based on the principle of Gibbs free energy minimization, a new method wa...The conversion of biomass into hydrogen-rich gas provides a competitive means for producing clean energy and chemicals from renewable resources.Based on the principle of Gibbs free energy minimization, a new method was presented with better effectiveness and simplicity to be used for the prediction of chemical equilibrium composition of hydrogen production by biomass gasification in supercritical water(SCW).Applying this method to analyzing the process of glucose gasification in SCW, it was found that the product gas consisted primarily of hydrogen and carbon dioxide as well as a small amount of methane and carbon monoxide.The gas yield was strongly affected by reaction temperature and feedstock concentration and less affected by reaction pressure in the following range:temperature 623—1073 K,pressure 22.5—35 MPa,and concentration 0.1—0.8 mol·L -1 .The hydrogen production in product gas increased with the increase of temperature and decreased with the increase of concentration.展开更多
针对旋流式催化裂化进料喷嘴进行了实验研究和数值模拟。实验中测量了不同工况下的雾化粒径和喷嘴的雾化角，同时验证了各段的压降分配方案。通过VOF（ volume of fluid）方法对喷嘴气液两相流的流动过程进行了数值模拟，描述了喷嘴中...针对旋流式催化裂化进料喷嘴进行了实验研究和数值模拟。实验中测量了不同工况下的雾化粒径和喷嘴的雾化角，同时验证了各段的压降分配方案。通过VOF（ volume of fluid）方法对喷嘴气液两相流的流动过程进行了数值模拟，描述了喷嘴中两相流的填充过程，得到了喷嘴的压力、速度分布和雾化角，并与实验结果进行了比较，二者吻合较好。对上述结果分析后表明，该型旋流式喷嘴雾化粒径在5360μm，雾化角随气液比或流量的增大而有所增加，采用内外嵌套式旋流器可使射流厚度较为均匀。展开更多
文摘A pigging model incorporating three different regions was developed for predicting the dynamics of the pigging operation in two-phase flow pipelines. The model incorporates a transient two-fluid model.The mixed Eulerean-Lagrangian approach was used to couple the transient model and the pigging model which can predict the pigging time, velocity and the change of pigging parameters. An experimental study was carried out to acquire two-phase transient flow and pigging data on a 380m long,81mm diameter horizontal pipeline. A computer-based data acquisition system was used to obtain detailed information of the flow behavior during experimental runs. The data include pigging time, inlet pressure, accumulated liquid in pipeline, pressure and pigging velocity distribution.The predicted results compared fairy well with the experimental data.
文摘The conversion of biomass into hydrogen-rich gas provides a competitive means for producing clean energy and chemicals from renewable resources.Based on the principle of Gibbs free energy minimization, a new method was presented with better effectiveness and simplicity to be used for the prediction of chemical equilibrium composition of hydrogen production by biomass gasification in supercritical water(SCW).Applying this method to analyzing the process of glucose gasification in SCW, it was found that the product gas consisted primarily of hydrogen and carbon dioxide as well as a small amount of methane and carbon monoxide.The gas yield was strongly affected by reaction temperature and feedstock concentration and less affected by reaction pressure in the following range:temperature 623—1073 K,pressure 22.5—35 MPa,and concentration 0.1—0.8 mol·L -1 .The hydrogen production in product gas increased with the increase of temperature and decreased with the increase of concentration.
文摘针对旋流式催化裂化进料喷嘴进行了实验研究和数值模拟。实验中测量了不同工况下的雾化粒径和喷嘴的雾化角，同时验证了各段的压降分配方案。通过VOF（ volume of fluid）方法对喷嘴气液两相流的流动过程进行了数值模拟，描述了喷嘴中两相流的填充过程，得到了喷嘴的压力、速度分布和雾化角，并与实验结果进行了比较，二者吻合较好。对上述结果分析后表明，该型旋流式喷嘴雾化粒径在5360μm，雾化角随气液比或流量的增大而有所增加，采用内外嵌套式旋流器可使射流厚度较为均匀。
