某新型空冷汽轮发电机转子通风方式的流场分析

Flow Field Analysis of New Type Ventilation Method in One Air-cooled Turbo-generator Rotor

某空冷汽轮发电机转子冷却风道采用了新型通风方式。为得到该新型通风方式流场特性,建立了该汽轮发电机转子半轴向段单槽通风道整体结构模型;依据计算流体力学(computational fluid dynamics,CFD)原理,采用有限体积法,计算得到转子端部、轴向及副槽通风道内速度、压力与流量分布特点;利用单节距副槽三维温度场模型计算转子温升,计算结果与实验数据相符,验证了模拟计算的准确性。结果表明,弧段风道流动阻力由风扇压头克服,副槽风道流动阻力由旋转科氏力克服,该新型通风方式有利于减小轴向温差。

To obtain the flow field characteristics of a new type ventilation system used in a certain air-cooled turbo-generator rotor,the cooling duct model of half axis length in one slot was established. The physical properties of flow field in rotor cooling duct were simulated by the finite volume method according computational fluid dynamics （CFD） principle. The temperature rise was calculated by the 3D temperature field model of single pitch sub-slot,and the results were well agreement with the measured results. The results show that the flow resistance of arc cooling duct is overcame by fan pressure head,the flow resistance of sub-slot cooling duct is overcame by Coriolis force,and the new type system is beneficial to decrease the temperature difference along axis.