| Mining cable winding device is an important power supply equipment of electric shovel in open-pit coal mine.At present,the power supply equipment of electric shovel is manually operated traditional plough truck,and the winding length is only 300 meters,which seriously affects the coal mining efficiency and endangers the life safety of cable workers.Our research group cooperates with Haerwusu open-pit coal mine of national energy group to develop the first kilometer level cable winding truck in China,so as to greatly improve the mining efficiency of open-pit coal mine.However,a large increase in the length of the 6.3k V live cable will bring serious temperature rise problems to the core of the equipment,namely the drum part.In this paper,aiming at the reasonable design of the drum,the serious temperature rise caused by the large increase of the cable length of the mine kilometer cable winding truck was studied.Firstly,according to the actual working conditions of the cable winding truck,the heat source of the temperature rise of the cable winding truck was determined,the heat balance equation was established,the three heat transfer modes of conduction,convection and radiation were analyzed,and the electromagnetic fluid temperature multi-physical field coupling theoretical model was established.Secondly,according to the drum structure characteristics,two-dimensional axisymmetric electromagnetic-fluid-temperature multi-physical field coupling numerical model was established by COMSOL software,and grid partition and boundary conditions were applied.By combining theoretical analysis with numerical simulation,the resistance,capacitance and inductance values of multi-layer cable on drum during live operation were obtained.Then,taking the sum of the losses of each part of the cable as the heat source,considering three kinds of natural heat dissipation factors,the influence of the drum material,the number of cable winding layers and the drum structure on the temperature distribution and heat dissipation characteristics was studied.Based on the above rules,the cable winding scheme with the lowest temperature rise was determined.Thirdly,combined with the best cable winding scheme proposed in this paper,the forced air cooling method of cable and reel was determined,the forced convection mathematical model was established,and the air cooling scheme suitable for reel and cable model was designed by using multi-physical field coupling analysis method.Finally,the simulation analysis of the cooling effect of the cable and the drum under different wind speeds was carried out,and the experimental comparison was carried out.The results showed that the forced air cooling mode at the best wind speed could significantly reduce the temperature rise of the cable drum,which verified the effectiveness of the design method in this paper.In this paper,the design scheme of kilometer cable reel solved the problem of serious temperature rise caused by the substantial increase of cable length,greatly improved the mining efficiency of open-pit coal mine,and eliminated the potential safety hazard of excessive temperature rise caused by the accumulation of heat of cable and reel.The experimental results showed that the design scheme was effective,and it completed an important part for the research and development of mine kilometer cable winding truck.There are 49 figures,12 tables and 55 references in this paper. |
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