Study Of Fluid Flow And Heat Transfer Characteristics In Stator Radial Ventilation Ducts For Helium Fan Drive Motor

The helium fan drive motor of high temperature gas cooled reactor(HTGR)is the only driving device for the heat transfer medium in the first circuit of HTGR and is one of the key factors for the stable operation of HTGR core.Helium is forced into the ventilation structure of the motor for the first time as a heat transfer working medium,which makes the drive motor work under the helium environment of high temperature and high pressure,posing a great challenge to the safe and stable operation of the motor.Therefore,the study of fluid heat transfer law in the motor ventilation structure under high temperature and high pressure helium gas environment is significant to improve the life of the motor and guarantee the steady and safe operation of the HTGR.In this dissertation,some documents about the HTGR,the convection heat transfer coefficient calculation of helium heat transfer working medium,fluid field calculation and temperature field are summarized and analyzed in detail.The research status of this issue at home and abroad are expounded,and the research purpose and significance of this issue are cleared.A fluid-solid coupling model of helium fan drive motor stator radial ventilation ducts was established.According to the theory of fluid dynamics and heat transfer,the fluid field and temperature field in the motor are coupled and use the finite element method to caculate.The distribution law of the fluid field,stator temperature and surface heat transfer coefficient in the radial ventilation ducts under helium environment was studied.The distribution rules of fluid flow velocity,stator temperature and heat transfer coefficient in different directions were revealed,and the corresponding relations between motor temperature rise and fluid flow velocity and heat coefficient were clarified.The influences of medium flow state and medium characteristics on fluid flow,stator temperature and surface heat dissipation coefficient at the inlet of radial ventilation ducts were calculated and analyzed.The distribution rules of fluid flow velocity,stator temperature and surface heat dissipation coefficient in different directions under different inlet flow velocity,different incident angle and different cooling medium were analyzed.It provides a theoretical basis for the design of the ventilating ducts of the helium fan drive motor.The research results of this dissertation make the calculation of fluid heat transfer in the ventilation ducts of the helium fan drive motor more detailed and in-depth,and the calculation and analysis of the convection heat transfer coefficient of the helium heat transfer working medium provide a reference for the calculation of the motor ventilation and cooling under high temperature and high pressure helium environment.