Abstract: Two cooling fans with 50% capacity for the turbine shell and exhaust frame were designed originally for the 9E gas turbine of Shanghai Fengxian Gas Turbine Power Generation Company Limited. If the frame cooling fans malfunctioned during operation of the gas turbine and caused the cooling air flow lose or decrease suddenly, then the heat conditions of the exhaust frame and the cylinder of the unit will vary, and the service life of the components in the thermal pass will be affected greatly. The cooling system for turbine shell and exhaust frame of the gas turbine and the Mark V control system were studied in depth. An optimization scheme, which is to add a domestic fan with 50% capacity, was adopted, and the hidden trouble of the system was removed.

Key words: 9E gas turbine, cooling system for turbine shell and exhaust frame, fan, Mark V control system, optimization