The evaluation methods of turbine steam seal retrofitting were introduced

which were theoretical calculation method based on measured gap space change

indirectly judging state method and thermal performance test method.This paper focuses on thermal performance test method

and the technical feature and application range were illustrated about condition evaluation for shaft end steam seal

shaft seal condition of coupling HP-IP cylinders

steam seal retrofitted effect and heat rate comprehensive assessment etc.It was concluded that the theoretical calculation method was used for qualitative evaluation of steam seal retrofitting;while indirectly judging state method was offered for field unit operation

while thermal performance test method could specially and economically evaluate the steam seal retrofitting according to test range and location.Further evaluation should take unit overhaul economy and heat rate improvement into consideration.These methods would be helpful in selection of steam seals and estimation of investment recovery efficiency.