Selection of steam cooling technology for high-temperature rotor areas at T-250-240 cogeneration steam turbine

The authors of the paper propose a way for automation of start-up and transient modes of the power units completed with Т-250/300-240 steam turbines based on control of thermal stresses within the HPC body because temperature-profiling rotors being critical turbine elements cannot be ensured with available methods. At this, the forced-steam cooling system of high and intermediate pressure rotors shall be implemented for all operation modes to reduce temperature differences, thus, their criticality. The paper provides a review of patents received for schemes and methods of preparation of cooling steam for the forced cooling system of high-temperature rotors of powerful steam turbines with reheat. It also specifies the best of them. The methods of the passive steam cooling of rotors and the limits of their application are discussed too. These schemes and solutions are estimated.