WANG Kuan-hua，PAN Zhi-xian，ZHENG Fei-yi，LAI Hui-jian，CHEN Jin-quan

（Hangzhou Steam Turbine Co. Ltd.，Hangzhou 310012，China）

Abstract：Aiming at the common problem with the water treatment for boiler，turbine scaling itself was analyzed. The thermal calculation result of blade was checked，and the intension calculation on the 5th stage blade at normal condition and choked condition was reviewed. After the broken turbine blade for one garbage plant was analyzed in detail，it was found that the extra force on blade was caused by the flow path reduced that is from the scaling and the extra force cause the blade broken finally. The study results show that，the turbinegenerator set could be run stablity with the follow improvement：optimization on the water treatment performance and attention on the

steam quality change if any with continue checking on steam turbine operation data.

Key words：steam quality；blade fracture；deposit；enthalpy drop