In this work,a six-bed pressure swing adsorption(PSA)process was investigated to produce medical oxygen from air,which uses the combination of six-way rotating distribution valve and PSA and has the main advantage of ...In this work,a six-bed pressure swing adsorption(PSA)process was investigated to produce medical oxygen from air,which uses the combination of six-way rotating distribution valve and PSA and has the main advantage of effectively saving space compared to the traditional two-bed or four-bed PSA process and can obtain greater productivity.The mathematical model of adsorption beds was developed based on the separation mechanism and the interaction among different equipment.Moreover,a pilot-scale device has been constructed to verify the accuracy of mathematical model by experiment.The oxygen product conformed to the medical standard(>93%(vol))with a recovery of over 57%.Some related parameters were also discussed in detail,such as step time,ratio of length to the diameter,flow rate of product.展开更多
The effects of implantation angles of Bileaflet Mechanical Heart Valves （BMHVs） on the blood flow and the leaflet motion are investigated in this paper. The physiological blood flow interacting with the moving leafl...The effects of implantation angles of Bileaflet Mechanical Heart Valves （BMHVs） on the blood flow and the leaflet motion are investigated in this paper. The physiological blood flow interacting with the moving leaflets of a BMHV is simulated with a strongly coupled implicit Fluid-Structure Interaction （FSI） method based on the Arbitrary-Lagrangian-Eulerian （ALE） approach and the dynamic mesh method （remeshing） in Fluent. BMHVs are widely used to be implanted to replace the diseased heart valves, but the patients would suffer from some complications such as hemolysis, platelet activation, tissue overgrowth and device failure. These complications are closely related to both the flow characteristics near the valves and the leaflet dynamics. The current numerical model is validated against a previous experimental study. The numerical results show that as the rotation angle of BMHV is increased the degree of asymmetry of the blood flow and the leaflet motion is increased, which may lead to an unbalanced force acting on the BMHVs. This study shows the applicability of the FSI model for the interaction between the blood flow and the leaflet motion in BMHVs.展开更多
基金supported by Major military logistics research pro-jects(AWS13Z006)National Key Research and Development program of China(2017YFC0806404).
文摘In this work,a six-bed pressure swing adsorption(PSA)process was investigated to produce medical oxygen from air,which uses the combination of six-way rotating distribution valve and PSA and has the main advantage of effectively saving space compared to the traditional two-bed or four-bed PSA process and can obtain greater productivity.The mathematical model of adsorption beds was developed based on the separation mechanism and the interaction among different equipment.Moreover,a pilot-scale device has been constructed to verify the accuracy of mathematical model by experiment.The oxygen product conformed to the medical standard(>93%(vol))with a recovery of over 57%.Some related parameters were also discussed in detail,such as step time,ratio of length to the diameter,flow rate of product.
文摘The effects of implantation angles of Bileaflet Mechanical Heart Valves （BMHVs） on the blood flow and the leaflet motion are investigated in this paper. The physiological blood flow interacting with the moving leaflets of a BMHV is simulated with a strongly coupled implicit Fluid-Structure Interaction （FSI） method based on the Arbitrary-Lagrangian-Eulerian （ALE） approach and the dynamic mesh method （remeshing） in Fluent. BMHVs are widely used to be implanted to replace the diseased heart valves, but the patients would suffer from some complications such as hemolysis, platelet activation, tissue overgrowth and device failure. These complications are closely related to both the flow characteristics near the valves and the leaflet dynamics. The current numerical model is validated against a previous experimental study. The numerical results show that as the rotation angle of BMHV is increased the degree of asymmetry of the blood flow and the leaflet motion is increased, which may lead to an unbalanced force acting on the BMHVs. This study shows the applicability of the FSI model for the interaction between the blood flow and the leaflet motion in BMHVs.
