Simulation Of Heat Flow Field Inside Rotor Of Large Air-cooled Turbine-generator Under Fault Ventilation Conditions

The safety of air-cooled turbo-generator attracts more and more attention.The electrical safety performance is restricted by ventilation failure to some extent,and then ventilation failure causes the motor temperature rise,thus the temperature field of research has practical significance.Most previous studies used equivalent air path method,finite volume method.Some made a study to the flow field of the rotor body,and some carry out the study to a vice slot ventilation section.To get the detail temperature distribution of 150 MW air-cooled turbogenerator rotor and ensure its safe and stable operation.This study from the following aspects: 1.Use Gambit software to build the physical model of the No.8 slot,the longest wind road,of half of the rotor whole tooth of the generator,and mesh.Use Fluent software to get the three-dimensional flow field and temperature field coupled numerical simulation under two operating conditions of 1300 A,1413.6A.Analyze air flow and temperature distribution of the slot wedges outlet of the rotor,and the features of the temperature distribution of each section and the top turn coil of the rotor.The results show that: the maximum temperature of the rotor focused on the vice slot ventilation section which is near the entrance of vice slot.And compare the data of the average temperature rise of the rotor with manufacturers test results within the error of 3%.Calculation method is reliable and results can provide a reference for the design and optimization of the motor ventilation.2.when duct plug 1/2,duct blockage 3/4,full duct blockage and normal duck,compare and analyze air flow,temperature of the wedge outlet and maximum temperature of the rotor windings under the rated conditions.The following conclusions are obtained: when duct is completely blocked,which has greate effect on the maximum temperature rise of the rotor.3.Simulate the flow field of the four slots and 7th and 8th slot blocked.Analyze the distribution of air volume flow,turbulent kinetic energy,velocity and pressure of each slot outlet.The following conclusions are obtained: air flow of the 8th slot,the longest wind road,is the minimum,and reduce more when two slots are blocked.The methods and conclusions of this study provide a theoretical support and guidance for motor fault diagnosis and prediction.