Effects of low temp steam to a turbine generator 1

[crawfishdaddi]

Due to recently increased production rates at the cogen plant that i work at, we have been sending low superheated steam to one of our Turbine generators. The design parameters for the inlet steam to this GE turbine are 540PSIG at 750F. Steam as low as 680F is regularly sent now to the T.G. and i was wondering if this has any negative internal implications such as blade pitting/ corrosion or possible failure.

Thanks,
CFD

 

[ApC2Kp]

crawfishdaddi,
Studying a Mollier steam chart, the back end of steam turbine could be seeing some 95-90% quality wet steam. That could result in abrasion from moisture particles. Somebody with experience on that particular model turbine might be able to advise you more about expected wear on blades.
The 90% steam quality assumes a vacuum condenser on the steam turbine. If it is a back pressure turbine, such that the exhaust steam at a positive pressure is being exported from the cogen unit, then the exhaust steam is still dry, and no abrasion wear problem occurs.