Key Structure Analysis And Optimization Of Throwing Snow Removal Device

The Snow collection spiral and snow blowers are the key structures of throwing snow removal devices.In order to improve the working performance of snow removal devices,improve the working efficiency of snow removal devices,and reduce energy consumption,the paper studied the key structures of the snow collection spiral and the snow blower fan based on the self-developed snow removal truck for public railways.China is relatively backward in the research and development of snow removal machinery,and most of its core technologies are in the hands of other countries.Therefore,the research results of the dissertation have important practical significance and practical value for improving the research and development level of snow removal machinery in China and producing more efficient and practical snow removal machinery.The thesis firstly studies the physical and mechanical properties of the snow under different conditions and conditions,which lays the foundation for the further simulation of the snow removal device.Secondly,a three-dimensional dynamic finite element model of spiral-snow interaction is established.Through simulation,the time-domain stress curve and force-time curve of the spiral-snow model interaction process are obtained.The rules of the interaction between the snow-collecting spiral and snow during snow removal are explored;three sets of snow-cutting models with different pitches are set up.Analysis of the effect of pitch change on the spiral-snow interaction law.Thirdly,discrete element method is used to establish a discrete snow element model of spiral snow gathering.The efficiency and energy consumption of spiral snow collection are analyzed under different rotational speeds,and the optimal economic speed range under certain working conditions is explored.Then,in order to study the dynamic characteristics of the spiral,it is verified whether the spiral has resonance in the normal speed range.The modal analysis of the spiral is performed to obtain its natural frequency and mode shape.Finally,a CFD model was established for the snow throwing process of the snow blower.The simulation of the gas-solid two-phase flow field inside the snow blower was carried out to investigate the pressure distribution inside the fan and the distribution of snow velocity.According to the simulation results,the fan casing was,fan blade pitch and number of fan blades for structural optimization.Studies have shown that proper reduction of the pitch is conducive to the smooth operation of the spiral state,reduce the impact on its own structure and power system,and enhance the axial transport capacity of snow,it will slightly reduce the spiral cutting ability of snow and ice.Increasing the speed can speed up the axial transport speed of snow and improve snow transportation efficiency.When the speed is increased,the energy required for the spiral to complete the delivery of a certain amount of snow particles will be reduced first and then increased,and in a certain speed range,the energy consumption is the lowest.Under normal operating conditions,the spiral will not resonate.The structure of the fan casing,the installation angle of the fan blades and the number of fan blades all have a great influence on the gas-solid two-phase flow field inside the fan.Optimizing the design of these structures can increase the snow throwing speed and reduce the unhealthy turbulence and backflow.The phenomenon of flow will reduce the waste of energy and at the same time make the volume concentration distribution of snow more reasonable.