Cooling fluid flow control system for steam turbine system and program product

A cooling fluid flow control system 100 for a turbine section of a steam turbine system 10 and a related program product are provided. In one embodiment, a system includes at least one computing device 204 operably connected to a cooling system. The computing device may be configured to control a flow rate of cooling fluid supplied to a steam turbine system by the cooling system by performing actions including modeling a sensitivity of a wheel space temperature to a change in the flow rate in the form of a piecewise linear relationship, the piecewise linear relationship including a flooded flow rate above which the wheel space temperature becomes insensitive to increased flow rate. The computing device also periodically modifies the flow rate of the cooling fluid supplied to the wheel space of the turbine section to approximate a minimum flooded flow rate based on the measured flow rate and the modeling.