为揭示煤液化热高压分离器(简称"热高分")内的煤粉漂移规律,基于热高分的结构特性和多相流物性参数,建立物理模型,并采用VOF(volume of fluid)模型和DPM(discrete phase model)模型,数值分析进口液固两相中固相质量分数、颗...为揭示煤液化热高压分离器(简称"热高分")内的煤粉漂移规律,基于热高分的结构特性和多相流物性参数,建立物理模型,并采用VOF(volume of fluid)模型和DPM(discrete phase model)模型,数值分析进口液固两相中固相质量分数、颗粒粒径对煤粉漂移特性的影响。研究发现:在气液交界面处,煤粉颗粒平均质量浓度最大,并随进口固相质量分数的增加而增大;小颗粒对气流的跟随性好,故气相出口的煤粉漂移率与颗粒粒径呈负相关关系;当进口固相质量分数增大到7%以上时,对应同一颗粒粒径下煤粉漂移率基本不变。通过在热高分上部增加45°倾斜挡板,发现气相出口处煤粉漂移率从2.03%下降到0.88%。展开更多
以煤直接液化工艺过程中热高压分离器(简称"热高分")内的颗粒漂移为研究对象,建立带静态分离挡板的热高分物理模型,并采用VOF(Volume of Fluid)模型和DPM(Discrete Phase Model)模型,数值分析静态分离挡板5种倾斜角度下热高...以煤直接液化工艺过程中热高压分离器(简称"热高分")内的颗粒漂移为研究对象,建立带静态分离挡板的热高分物理模型,并采用VOF(Volume of Fluid)模型和DPM(Discrete Phase Model)模型,数值分析静态分离挡板5种倾斜角度下热高分罐内部速度场、不同液位高度颗粒平均浓度及气相出口煤粉漂移率的分布规律。研究结果表明:静态分离挡板的倾斜角度对速度场的影响明显,在挡板附近区域形成小回流涡旋效应,产生对颗粒随气流夹带提升的抑制作用;颗粒平均浓度在气-液交界面区域最高,随着热高分罐内高度的增加而逐渐降低;与其余倾斜角度相比,α=45°时气相出口的颗粒漂移率达到最小,较未设置分离挡板时,颗粒漂移率降低50%以上。研究有望为热高压分离压力容器的设计和运行优化提供参考。展开更多
A new concept,compound damp drip for absorbing shock wave in oscillatory tube,is developed in the present paper.The main idea of the concept is that the shock wave absorber must has the two functions,that is,it can no...A new concept,compound damp drip for absorbing shock wave in oscillatory tube,is developed in the present paper.The main idea of the concept is that the shock wave absorber must has the two functions,that is,it can not only exhaust the energy of the incident shock wave fully but also transfer the energy out promptly.In the experiment,the compound damp drip is structured with a multi-orifice for intensifying the energy dissipation of the shock wave and an internal cooling system for strengthening the heat transfer.The experimental results show that a strong reflect shock wave,whose strength is 66%of the incident shock wave ,is measured at the position of the relative tube length x/L =0.3 when the oscillatory tube without the compound damp drip.But,after the compound damp drip is amounted at the closed end of the tube,the reflect shock wave is eliminated effectively and the refrigerating efficiency η is increased by 4?%～10?% in case of the L/d ratio is 140 and the expansion ratio ε is changed from 2.0 to 6.0.What is more ,the refrigerating efficiency in case of L/d =140 and the tube is mounted with the compound damp drip is still higher by 2?%～6?% than that the tube without damp drip but L/d =300.The above result means that while the damp drip is used,the refrigerating efficiency can be increased and the size of the refrigerator can be decreased significantly.展开更多
文摘为揭示煤液化热高压分离器(简称"热高分")内的煤粉漂移规律,基于热高分的结构特性和多相流物性参数,建立物理模型,并采用VOF(volume of fluid)模型和DPM(discrete phase model)模型,数值分析进口液固两相中固相质量分数、颗粒粒径对煤粉漂移特性的影响。研究发现:在气液交界面处,煤粉颗粒平均质量浓度最大,并随进口固相质量分数的增加而增大;小颗粒对气流的跟随性好,故气相出口的煤粉漂移率与颗粒粒径呈负相关关系;当进口固相质量分数增大到7%以上时,对应同一颗粒粒径下煤粉漂移率基本不变。通过在热高分上部增加45°倾斜挡板,发现气相出口处煤粉漂移率从2.03%下降到0.88%。
文摘以煤直接液化工艺过程中热高压分离器(简称"热高分")内的颗粒漂移为研究对象,建立带静态分离挡板的热高分物理模型,并采用VOF(Volume of Fluid)模型和DPM(Discrete Phase Model)模型,数值分析静态分离挡板5种倾斜角度下热高分罐内部速度场、不同液位高度颗粒平均浓度及气相出口煤粉漂移率的分布规律。研究结果表明:静态分离挡板的倾斜角度对速度场的影响明显,在挡板附近区域形成小回流涡旋效应,产生对颗粒随气流夹带提升的抑制作用;颗粒平均浓度在气-液交界面区域最高,随着热高分罐内高度的增加而逐渐降低;与其余倾斜角度相比,α=45°时气相出口的颗粒漂移率达到最小,较未设置分离挡板时,颗粒漂移率降低50%以上。研究有望为热高压分离压力容器的设计和运行优化提供参考。
文摘A new concept,compound damp drip for absorbing shock wave in oscillatory tube,is developed in the present paper.The main idea of the concept is that the shock wave absorber must has the two functions,that is,it can not only exhaust the energy of the incident shock wave fully but also transfer the energy out promptly.In the experiment,the compound damp drip is structured with a multi-orifice for intensifying the energy dissipation of the shock wave and an internal cooling system for strengthening the heat transfer.The experimental results show that a strong reflect shock wave,whose strength is 66%of the incident shock wave ,is measured at the position of the relative tube length x/L =0.3 when the oscillatory tube without the compound damp drip.But,after the compound damp drip is amounted at the closed end of the tube,the reflect shock wave is eliminated effectively and the refrigerating efficiency η is increased by 4?%～10?% in case of the L/d ratio is 140 and the expansion ratio ε is changed from 2.0 to 6.0.What is more ,the refrigerating efficiency in case of L/d =140 and the tube is mounted with the compound damp drip is still higher by 2?%～6?% than that the tube without damp drip but L/d =300.The above result means that while the damp drip is used,the refrigerating efficiency can be increased and the size of the refrigerator can be decreased significantly.
