Analysis And Improvement Methods Of Generator Cooling Effect Of Qinshan NPP Phase-? Unit 4

The capacity of generator unit keeps increasing,with the development of installed gross capacity.In order to ensure the efficient operation of the large capacity generator,analysis and improvement methods of generator cooling effect is necessary.Based on the analysis of the effect of the cooling effect of steam turbine generator on the performance and capacity of the generator,this paper introduces the development and characteristics of different cooling ways of steam turbine generator.By taking Qinshan NPP phase-II unit 4 as the research object,this paper analyzes the main functions,operating characteristics and main equipments of GST/GRV and GHE.This paper has further analyzed the two most important factors affecting the cooling effect: purity and humidity of hydrogen.This paper has systematically analyzed the possible causess for the generator hydrogen purity decline and humidity rise,as well as discussed the matching solutions by combining with practice like experiments and checking.This research focuses on those problems which are related to GHE system,such as oil temperature control;air and hydrogen side oil blowby;oil leakage into generator;etc.,and concludes the reason with the balance valve disorder of hydrogen side exciter end of generator and early damage of seal tile of unit 4.Meanwhile,the analysis and discussion in this paper provides reference for dealing with similar problems in the same type unit.