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I desire to calculate the %age droop setting of turbine at our plant but I am having some problems.
Normally 4% droop is claimed by GE manuals. There are two gas turbines at our plant, one operating on Iso and other on part load droop mode. The turbines have design output of 24.5MW at base load and 26.45MW at peak load. Design conditions are 15 deg C ambient temperature and 14.7 PSI atmospheric pressure. It is running on natural gas and has HRSG on exhaust. Since a long time has passed after its manufacturing now we normally get 18MW at base load and 19.2MW at peak load.
Now the question. When we talk about %age droop setting and say that "it is amount of frequency (or speed) drop when the load moves from 0% to 100%", is this 100% load the base load or peak load?
Secondly, when I saw the reference speed of my turbine, it was 101.74% when load was 13.6MW (ambient conditions are 40 deg C temp and 14.3psi atmospheric pressure). Even for design conditions, at peak load and 4% droop, the reference speed should be 102% for 13.2MW (am I right?). How come this reference speed is there? I wanted to know the factors which have decreased (or changed) its droop setting. Shouldn't the droop value increase with the passage of time? Isn't the reference speed setting calculated with help of base load value?
We have one turbine operating with MarkV and other with MarkII control system. To get the exact droop setting, I have seen the control constants in CSP. Somebody on this forum told that it is DWKDG constant that says the droop setting. We have its value 0.05%/MW. Other than this there is also a constant FSKRN2 (called as 'droop speed correction factor') whose value is 7.969%/%. The droop setting calculated on base of DWKDG constant comes out to be very low (1.2%) so there must be some other constant governing the droop setting. Can anybody tell the control constant that shows the droop setting or that leads to calculation of droop setting?
Thanks and Regards.
Normally 4% droop is claimed by GE manuals. There are two gas turbines at our plant, one operating on Iso and other on part load droop mode. The turbines have design output of 24.5MW at base load and 26.45MW at peak load. Design conditions are 15 deg C ambient temperature and 14.7 PSI atmospheric pressure. It is running on natural gas and has HRSG on exhaust. Since a long time has passed after its manufacturing now we normally get 18MW at base load and 19.2MW at peak load.
Now the question. When we talk about %age droop setting and say that "it is amount of frequency (or speed) drop when the load moves from 0% to 100%", is this 100% load the base load or peak load?
Secondly, when I saw the reference speed of my turbine, it was 101.74% when load was 13.6MW (ambient conditions are 40 deg C temp and 14.3psi atmospheric pressure). Even for design conditions, at peak load and 4% droop, the reference speed should be 102% for 13.2MW (am I right?). How come this reference speed is there? I wanted to know the factors which have decreased (or changed) its droop setting. Shouldn't the droop value increase with the passage of time? Isn't the reference speed setting calculated with help of base load value?
We have one turbine operating with MarkV and other with MarkII control system. To get the exact droop setting, I have seen the control constants in CSP. Somebody on this forum told that it is DWKDG constant that says the droop setting. We have its value 0.05%/MW. Other than this there is also a constant FSKRN2 (called as 'droop speed correction factor') whose value is 7.969%/%. The droop setting calculated on base of DWKDG constant comes out to be very low (1.2%) so there must be some other constant governing the droop setting. Can anybody tell the control constant that shows the droop setting or that leads to calculation of droop setting?
Thanks and Regards.