More and more class F gas turbine combined cycle unit was constructed in China.Combined with function of startup steam and status of startup boiler in combined cycle units

the feasibility of equipping no startup boilers for class F combined cycle unit was investigated.The results showed that

for the class F combined cycle units with common configuration of single shaft and multiple-shaft

the one with generator middle-set can be operated without the startup boiler

while the one with generator end-set must equip startup boiler.According to the configuration features

the multiple-shaft combined cycle units which consist of the M701Fturbines should set the startup boiler;while that consist of the SGT5-4000Fturbines manufactured by Siemens company and 9Fturbines manufactured by GE company can start without startup boiler.Using the steam generated from waste heat boiler as the startup steam will prolong the unit startup time

increase the fuel consumption and complexity of dispatching with the power grid during unit starting.So it suggested that the combined cycle unit should be equipped with startup boiler.