hi.

do you know any triple shaft turbines (esp. as power turbine) that have load rejection mode? If any, please send me the specific model and manufacturer name and the cause/effects specified for this mode in those turbines.

thanks.

 

hi,

What kind of turbine--gas or steam, or ???

Any turbine used to drive a load (generator; compressor; pump; etc.) must be able to deal with a sudden/complete loss of load in order to prevent over-speeding. The way each type of turbine does so can be very different, and can even depend on the type of load (generator; compressor; pump; etc.).

Any loss of load can be called a load rejection, from full loss of load to partial loss of load. Most turbines will either sense a speed increase and limit the energy flow-rate into the turbine or some will just shut the stop valve(s) preventing any further energy from flowing into the turbine. Again, the type of turbine and the size of the turbine and even the type of load may have some effect on the way a loss of load (load rejection) can be handled.

As for causes of loss of load (load rejection), well they can be many also--and will depend on the type of load. A generator breaker might be opened on some fault, or a compressor might have a failure of a recycle valve or loss of seal oil, etc.

I know of some aero-derivative gas turbines manufactured by GE which have three shafts, and I know of some large steam turbines manufactured by GE, Westinghouse and Allis Chalmers (there are probably others manufactured by Siemens and other European companies) which have multiple shafts. The gas turbine usually have only one output shaft; the other two are strictly related to producing hot combustion gases for the power turbine (connected to the load--be it a generator or a compressor). The multi-shaft steam turbines usually have two or more generators and the shafts may be independent of each other, and they may not.

So, it would be helpful if you would tell us what kind of turbine you are referring to, and what type of load the turbine will be driving. And, if you have more specific questions, we'd be happy to try to answer them.