| The permanent magnet eddy current transmission device is a new type of speed control device developed according to the principle of electromagnetic induction,which has the advantages of light load start,energy saving and environmental protection,overload protection and the like.However,it also has the inconvenience that when the stall or overload occurs during the working process,the energy of the prime mover will be completely converted into the thermal energy of the conductor disk resistance,and the heat generated will be transmitted to the permanent magnet through the air gap,so that The magnet temperature rises rapidly and the demagnetization fails,and it cannot work with normal working efficiency.Especially in the flammable and explosive environment such as coal mines,because the underground space is small,the air circulation is not smooth,and the high temperature generated cannot be quickly dissipated and there is a great danger to its production.In this paper,the composition and structure of the disc permanent magnet eddy current transmission device and its working principle are introduced in detail,and the causes of the eddy current loss on the conductor disc and the hazards caused are analyzed.Based on the magnetic circuit method,the eddy loss of the device is theoretically calculated and finite element calculation is carried out by Maxwell.The trend and distribution of induced current density and induced current on the conductor disk are analyzed,and the eddy current loss curve of the device is also obtained.Prepare for the design of the rear cooling system and the study of the temperature field.Based on the air-cooling heat dissipation principle and the analysis of the eddy current loss of the device in the previous chapter,another structure of the heat dissipation system is proposed.The FLUENT fluid simulation software was used to simulate the air flow field of the improved heat dissipation system,and the air flow rate inside the heat dissipation system was obtained.The process of flow field simulation is described and the calculation results are fully explained.The rationality of the designed heat dissipation system is verified by simulation calculation.Based on the condition of the device operating in a flammable and explosive environment,and the hazards arising from the occurrence of stall and overload,the necessity of studying the temperature field is proposed.In this paper,the rated power is 45 kW,and the permanent magnet is used as the 8-pole disc-type permanent magnet eddy current transmission device for temperature field analysis and calculation.According to the operating parameters under normal conditions,the thermal parameter values related to temperature field research are solved.The steady-state temperature field simulation was carried out by ANSYS Workbench to obtain the temperature distribution of each component of the device,and the improved heat dissipation system was once again proved to have better heat dissipation effect.Finally,the optimization analysis of the heat dissipation system is carried out,and the relationship between the input parameters and the output parameters is obtained.Finally,a set of optimal structural parameters and the optimized model are calculated.Figure [52] table [ 7] references [55]... |
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