Thermodynamic, thermal and structure calculations of the steam turbine in unsteady states are performed for a turbine heat-up from the cold state. The calculations are made for a given geometry of the turbine outer casing, inner casing, stator blade carriers, rotor and other elements of the turbine heat-up system as well as for given parameters of the steam supplied to turbine inlet/exit pipes and given heat-and-flow balance at crucial turbine flow sections. The objective of these calculations is to determine the maximum unsteady stresses in metal elements as well as temporal expansions (absolute and relative) of the turbine outer casing, inner casing, blade carriers, balance piston glands, outer shaft glands and turbine rotor during the cold start-up. For the first time the heat fluxes at the turbine heat exchange surfaces are calculated using a RANS solver in the code FLUENT. Structure computations are made using a FE model in the code ANSYS (casing) and ABAQUS (shaft), based on the given surface heat fluxes. The investigated 30 MW synchronous (50Hz) turbine was equipped with a measurement system to determine the temperature of the metal at several points and relative displacements of turbine elements at crucial locations during its heat-up. In many cases, the obtained numerical results agree well with available measurement data.

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