Investigation On Forced Cooling Techniques Of The Large Turbine

With the high speed development of electric power industry, the high parameter and big capacity thermal power generator sets have been more and more put into service because of their better economy, and having more and more importance in electric power network. Under the big environment of the current electric power market, each electric power economic has paid great attention to the problem of how to safely shorten the shut down time for large turbine maintenance.According to the actual condition and specifics of turbine system, this article gives the fast cooling program for 2X600MW turbine from Yangzhou No.2 power generation LTD. which is designed and made by Westinghouse Co.. Mainly from the safety angle, the article analyzes and studies lots of examples of domestic and abroad turbine fast cooling systems. The article has made further study on the program using the method of finite element analysis by computer imitation calculation. It calculates the stress field and temperature field of turbine rotor and cylinder for each operation condition, especially the worst extreme limit condition. And it gives the life lose estimation for turbine rotor and cylinder during the fast cooling.On the method of fast cooling control, the article has made detailed estimation calculation on the two control method of isothermal drop rate and isothermal difference respectively which are used currently. And it compares the two control method at the sides of operation and safety. The article points out that the method of isothermal drop rate is obviously better than the method of isothermal difference.According to the actual system condition of Yangzhou No.2 power plant unit, the article puts forward the specific actualizing program of fast cooling system on the basis of theoretical calculation.