The key to performance monitoring and deterioration diagnosing technologies of gas turbine lies in accurate identifications of the efficiencies of compressor

combustor

and turbine

as well as combustor outlet temperature

which cannot be directly measured but are particularly important. Based on thermodynamic principles

the energy efficiency soft-sensing model for critical components of gas turbine is established

and the accuracy of the model is verified

to realize accurate soft measurement of the above-mentioned comprehensive indicators or parameters. On this basis

according to the historical operation data of an F-class gas turbine

the performance parameters of the key components are identified and the deterioration degrees are analyzed. The results demonstrated that

for gas turbines with peak-clipping operations and frequent start-ups and shutdowns

the deterioration degrees of high-temperature components

such as turbine

are more serious than those of lowtemperature ones

such as the compressor. Therefore

the health status of high-temperature components require careful attention during shutdown maintenances. The proposed model and method can provide theoretical references and effective recommendations for timely condition maintenances of heavy-duty gas turbines.