Steam turbine discharge
Steam turbine discharge
(OP)
Hello
We are looking at possibly increasing the steam turbine speed by about a 150 rpm to bring down the discharge temp of the steam for downstream equipment. This is a small single stage turbine. And the plan is to increase the speed at no load condition to drop steam enthaply. The use of desuperheater downstream was addressed and discarded due to certain reasons.
Does this pose any issues I do not see this to have any major implications. Are there other ways to drop steam temp on the discharge without doing any major modifications.
Thank you
We are looking at possibly increasing the steam turbine speed by about a 150 rpm to bring down the discharge temp of the steam for downstream equipment. This is a small single stage turbine. And the plan is to increase the speed at no load condition to drop steam enthaply. The use of desuperheater downstream was addressed and discarded due to certain reasons.
Does this pose any issues I do not see this to have any major implications. Are there other ways to drop steam temp on the discharge without doing any major modifications.
Thank you





RE: Steam turbine discharge
RE: Steam turbine discharge
Johnny Pellin
RE: Steam turbine discharge
RE: Steam turbine discharge
For example, with variable speed turbines API requests to have 5% margin between rated speed and maximum continuous speed and that is to cover the many things that can be deviate from design in real world which needs to be covered with a safety margin.
If you run over speed, means between rated and max continuous speed you will reduce this 5% margin available so this needs to be carefully evaluated from mechanical and rotor-dynamic point of view (check the critical speeds of the turbine for example) assuming the amount of over speed you intend to apply really provide the advantage in terms of temperature drop you are looking for. At no load it is normal that the temperature is high. You could also inject water condensate at no load to reduce the exhaust temperature.
Best advice is to contact manufacturer for feasibility.
You should have given more details on the application/machine type.