Rotor cooling for double axial flow turbines

摘要

A double axial flow turbine structure having rotor cooling on the upstream side of the turbine's inlet or control stages with lower pressure turbine stages being situated axially downstream from the control stages. Motive fluid flow through the control stages is in opposite axial directions. Apertures in the control stages' rotatable disc portions of the rotor cause motive fluid which has been expanded through the control stages to be pumped into a cooling space formed axially between the control stages and radially between the rotor and a stationary structure which constitutes either one or two nozzle chambers which direct the motive fluid into the control stages. Motive fluid leakage between the stationary structure and the control stage discs is minimized by a first set of seals disposed between each control stage disc and the stationary structure. Motive fluid leakage contact with the rotor is minimized by a second set of seals disposed between each control stage and the stationary structure with a conduit providing fluid communication through the stationary structures for the leakage past the first sets of seals to an area between the stationary structures prior to transmission of such leakage to the exits from the control stages.