Low lube oil level trip not in Gas Turbines.

It is for some manufacturers, it just depends on the control philosophy the engineers subscribe to. Some steam turbine lube oil reservoirs are smaller than that for a comparably rated gas turbine. Many steam turbines have a MUCH longer coast down time than gas turbine (the axial compressor acts as kind of a break; steam turbines don't have that and condenser vacuum contributes to a longer coast down, also).

This author wishes that turbine manufacturers, in general, would start building some "smarts" into their control systems--they certainly have the compute horsepower these days to do so. Like logic which looks at the rate of increase or decrease in lube oil level and alarms BEFORE the level reaches a low or high setpoint. Same for bearing metal temperatures, vibration, exhaust temperature or exhaust hood temperature, or condenser vacuum, rate of change of cooling water pressure, rate of change of lube oil pressure, rate of change of hydraulic oil pressure--the list could go on and on.

Now, some would say that this is just adding to the alarm "jungle", but this author's experience says that most operators and their supervisors pay little or not attention to any operating conditions UNTIL there's an alarm.

Will building some smarts into the control system avoid any major catastrophes? Probably. Will it cause operators and supervisors to look more closely at operating conditions? Probably. Will it take some tuning to make the monitoring less prone to annunciating nuisance alarms? Probably. Will it save a unit or two? Probably.

Will it happen soon? Probably not. Cost-reduction is the name of the game today; and writing more code costs more money.

markvguy
 
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