| The switch is an important part of the railway line.The switch in place is the key to ensure the safe and efficient operation of the train.Winter snow will cause switch failure,sharp rail can not close to the fault,clearing the switch snow has become one of the key work of railway Bureau Group Co.,LTD.Electric heating switch snow melting equipment is one of the important equipment of railway signal system,with high degree of automation,high safety and easy installation and other advantages,has been widely installed and used on railway lines,but in practical application also exposed the inadequate snow melting,low energy utilization,maintenance workload and other problems,so optimize and improve the electric heating switch snow melting system equipment.It is of great significance to the snow melting work of the switch.From the point of view of heat transfer of switch structure,this thesis improves the energy transfer efficiency of switch structure by improving the installation position and power configuration of electric heating element of switch snowmelt system,reduces the workload of maintenance,and achieves the ideal snowmelt effect.Specific research contents are as follows:(1)Heat transfer analysis is conducted on the process of snowmelt and ice melting of the switch structure.Taking the 60kg/m rail No.12 switch as an example,the fluid-thermal coupling physical model of "heat source-rail-snow" of the switch structure is established based on the finite element analysis software COMSOL Multiphysics.Aiming at the problem that the snow melting effect of the pointed rail structure is not ideal during the field snow melting work,combining with the field meteorological data and the installation position of the electric heating element,the installation scheme of the electric heating element installed on both sides of the slide table is proposed,and the field experiment is carried out to confirm the feasibility.(2)The accuracy of the finite element model is verified by simulation test and field test,and the finite element analysis is carried out on the pointed rail structure,movable rail structure and traction point external locking device according to the established model.The results show that the best snow melting effect is obtained by using the sliding table heating method in the pointed rail structure.The movable rail structure can achieve good snow melting effect by heating the inner side of the wing rail.The electric heating element and heat transfer plate shall be installed in the groove of the traction point outside the locking device to ensure that the locking rod and the locking iron are not frozen.(3)In order to get a reasonable power allocation scheme for turnout structure,the experimental algorithm is used to calculate the influence law of environmental temperature,snow thickness and wind speed on heating power.According to the climate characteristics of our country,the thesis divided into severe cold region,cold region and other region.The meteorological data of cities and stations north of Qinling-Huai River are set.The power configuration scheme of electric heating element of switch structure in cold region and cold region is calculated.The results show that the heating power of the switch structure is linearly correlated with the ambient temperature and snow thickness.The relationship between wind speed and heating power is a power function.When wind speed is greater than 1m/s,the heating power growth rate slows down significantly.The calculation results can provide theoretical support for the engineering application of snowmelt system of electric heating switch. |
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