Based on Bingham rheological model,a three-dimensional numerical simulation model for long-distance pipeline transportation is established by computational fluid dynamics(CFD)to study the pipeline transportationproper...Based on Bingham rheological model,a three-dimensional numerical simulation model for long-distance pipeline transportation is established by computational fluid dynamics(CFD)to study the pipeline transportationproperties of high sliming paste from a copper mine in China.Based on the rheological properties test,the pressure and velocity of pipeline and elbow are simulated by CFD under different mass concentrations and different stowing capacities.The results show that the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with high sliming and pumping agent at the same mass concentration,and the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with low sliming while without pumping agent.It is very important to add pumping agent to whole-tailings paste with high sliming,and the resistance changes with mass concentration and stowing capacity at the same cement-to-sand ratio of1:5and tailings-to-waste ratio of6:1.However,the change is just limited,that is to say,the paste transportation system is of good stability.Furthermore,at the elbow,the maximum pressure and velocity transfer to the outside of the pipe from the inside.However,lubricating layer is formed at the pipe wall because of high content of fine particles in whole-tailings paste,which will protect the elbow from abrasion.CFD provides an intuitive and accurate basis for pipeline transportation study,and would have a wider application space in the study of paste rheological properties and resistance reduction methods.展开更多
An armored face conveyor(AFC) is a key piece of equipment for a fully mechanized long-wall mining system and is currently the only means for transporting bulk material in hard coal mines. To date, the AFC power train ...An armored face conveyor(AFC) is a key piece of equipment for a fully mechanized long-wall mining system and is currently the only means for transporting bulk material in hard coal mines. To date, the AFC power train design has mainly been based on heuristics obtained via experience, coupled with simple calculations, which cannot take the dynamic behaviors and coupling effects of the components into consideration. Therefore, model-based and simulation-driven design is preferred. In this paper, a new design and analysis methodology for an AFC power train is presented to achieve the optimal dynamic characteristics and transmission performance. A preliminary design procedure for a power train is first introduced. Then, a system-level hydro-mechatronic model of the power train is built to evaluate and optimize the preliminary scheme. Sub-models, including those for the motors, fluid couplers, gearboxes, and chain, are obtained according to their individual disciplines and assembled to form the system-level model. The chain sub-system is discretized into multiple finite elements. Governing equations are established for each element based on the Newton Euler approach and assembled according to the topological structure of the chain system. In order to make the new approach applicable for engineers, a design and analysis software is developed, with a graphical user interface that involves the whole design process. MATLAB/SIMULINK is used as the computational engine, and Visual C++ is adopted to develop the interactive software framework. Simulations for the SGZ1000/2000 type AFC are provided as an illustrative case study to validate the effectiveness and practicality of the model and software package.展开更多
基金Project(2016YFC0600709)supported by the National Key R&D Program of ChinaProject(51574013)supported by the National Natural Science Foundation of ChinaProject(FRF-TP-17-024A1)supported by the Fundamental Research Funds for the Central Universities,China
文摘Based on Bingham rheological model,a three-dimensional numerical simulation model for long-distance pipeline transportation is established by computational fluid dynamics(CFD)to study the pipeline transportationproperties of high sliming paste from a copper mine in China.Based on the rheological properties test,the pressure and velocity of pipeline and elbow are simulated by CFD under different mass concentrations and different stowing capacities.The results show that the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with high sliming and pumping agent at the same mass concentration,and the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with low sliming while without pumping agent.It is very important to add pumping agent to whole-tailings paste with high sliming,and the resistance changes with mass concentration and stowing capacity at the same cement-to-sand ratio of1:5and tailings-to-waste ratio of6:1.However,the change is just limited,that is to say,the paste transportation system is of good stability.Furthermore,at the elbow,the maximum pressure and velocity transfer to the outside of the pipe from the inside.However,lubricating layer is formed at the pipe wall because of high content of fine particles in whole-tailings paste,which will protect the elbow from abrasion.CFD provides an intuitive and accurate basis for pipeline transportation study,and would have a wider application space in the study of paste rheological properties and resistance reduction methods.
基金supported by the National Natural Science Foundation of China(Grant No.51375330)the Leading Talent Project of Guangdong Province
文摘An armored face conveyor(AFC) is a key piece of equipment for a fully mechanized long-wall mining system and is currently the only means for transporting bulk material in hard coal mines. To date, the AFC power train design has mainly been based on heuristics obtained via experience, coupled with simple calculations, which cannot take the dynamic behaviors and coupling effects of the components into consideration. Therefore, model-based and simulation-driven design is preferred. In this paper, a new design and analysis methodology for an AFC power train is presented to achieve the optimal dynamic characteristics and transmission performance. A preliminary design procedure for a power train is first introduced. Then, a system-level hydro-mechatronic model of the power train is built to evaluate and optimize the preliminary scheme. Sub-models, including those for the motors, fluid couplers, gearboxes, and chain, are obtained according to their individual disciplines and assembled to form the system-level model. The chain sub-system is discretized into multiple finite elements. Governing equations are established for each element based on the Newton Euler approach and assembled according to the topological structure of the chain system. In order to make the new approach applicable for engineers, a design and analysis software is developed, with a graphical user interface that involves the whole design process. MATLAB/SIMULINK is used as the computational engine, and Visual C++ is adopted to develop the interactive software framework. Simulations for the SGZ1000/2000 type AFC are provided as an illustrative case study to validate the effectiveness and practicality of the model and software package.
