Ventilation system with skewed rotor cooling ducts of 40-MW synchronous machine: a case study

This paper describes modified ventilation system and thermal analysis of low-power 40-MW turbo generator. The study compares thermal behaviour of the machine for three different arrangements of the rotor ventilation ducts. Variations of both the sub-slot and the radial ducts are analysed. The described work follows up on the ventilation calculation done in past. In particular, there are several options tested to figure out the behaviour of the numerical model. The original design ventilation part of the numerical model was tuned according to measurement. The results show advantages and disadvantages of those options and also show the way how to improve the cooling system of a turbo generator. All given theoretical results are commented and properly concluded.