The Minimum Entropy Generation Optimization Analysis For Heat Transfer Of Permanent Magnetic Speed Governor

Because of its simple structure,wide speed range,green and environmental protection and many other advantages,permanent magnetic speed regulator is widely used in rotary equipment,such as pumps,centrifuge,and so on.At present,the research on permanent magnetic speed governor is mainly concentrated in the field of electromagnetic field,performance research and application upgrade,etc.And the research on the heat dissipation and energy saving in the field of permanent magnetic speed governor is rarely reported.Heat dissipation structure of the permanent magnet governor based on the theory of entropy production has carried on the simulation analysis,on the basis of the second law of thermodynamics,entropy generation rate control equations for heat transfer and fluid flow in the cooling process of permanent magnetic speed regulator are deduced,mathematical models are developed to describe the temperature field,fluid flow and entropy production;Using computational fluid dynamics software FLUENT to simulate structure parameters of the side blades and the circumferential fins for effect of heat dissipation and energy saving respectively,analyzing the influence on the entropy generation and temperature field of blade angle,blade number,blade height and fin number,fin height,fin spacing.And in order to enhance the convection heat transfer,opening convection holes between the blades and fins respectively.For the purpose of the minimum entropy production and temperature rise to the greatest extent reduced to obtain the optimum parameters of the blades and the fins;The optimum parameters were obtained to establish the overall optimization model,the side blade optimization results,the circumferential fin optimization results and the overall optimization results were compared,the results show the heat dissipation and energy saving effect of the overall optimization model is the best.The irreversible loss of permanent magnetic speed governor is mainly determined by heat transfer entropy production.For heat dissipation and energy saving effect,blades is better than fins.Convection hole plays an important role in the optimization of heat dissipation and energy saving,etc.Combing theoretical method and simulation method to research and analyse the heat dissipation structure of permanent magnet speed governor thoroughly,the influence rules of the structural parameters on the heat dissipation and energy saving of the permanent magnetic speed governor are comparatively comprehensive grasped.The conclusions of this study offer a reference for the optimal design of heat dissipation and energy saving on permanent magnet speed governor.