Gas Turbine Generator

When running lube oil pump motor and this time hunting IGV not controlling by Auto and Manual (in Auto to opening set point 5% and actually opened 28%-61% . in Manual set point 5% actually opened with hunting 36%-18% ) After hunting IGV, came to signal IGV Over temp, could you please help to us how to find reason hunting IGV?.
Hi, Akhmed,

My watch isn't working. Can you help me? I tried shaking it, but it didn't help. What could be the problem?

Would you need to know if the watch was mechanical or digital? Does the watch have a mechanical mechanism, or a battery-operated mechanism? Would it be helpful to know if the hands of the analog watch are moving or stopped? Or, if it's a digital watch, if the display shows time at all? Would it be helpful to know if it's a mechanical watch with a mechanical mechanism if it was recently wound or not? Or, if it's a digital watch, or an analog watch with a battery-operated mechanism, if the battery has been replaced recently or not?

We are not standing by your side next to the HMI or the turbine at your site. We cannot see what you can see. We only know what you told us, which isn't very much. It would be helpful to know the manufacturer of the turbine you are having a problem with, the model of the turbine you are having a problem with, the type of actuator used on the IGVs, and if this problem is only happening when testing (when the unit is not producing power), or when it's producing power AND when it's not producing power).

We also can't see the P&IDs for the IGV system, so we don't know a LOT about the IGVs on the unknown turbine at your site.

Help us to help you. (My watch is an analog watch with a battery-operated mechanism. The second hand moves, but the minute and hour hand do not. I can move the hour and minute hands with the watch stem. The watch is manufactured by Dakota. What could be the problem? See? Information can be very useful. On this site, most gas turbine questions are primarily about GE-design heavy duty gas turbines and their control systems. There doesn't seem to be many people willing to share their experiences with other heavy duty gas turbines--and we also don't know if your turbine is a heavy duty turbine, or an aero-derivative gas turbine...)

Again, help us to help you--you will probably like the results very much (especially if your turbine is a GE-design heavy duty gas turbine.)
Hello forum
Good morning everyone.
Please mine question is how long can a gas turbine will be on cool down before start up.
Most sites seem to want to take the unit off cooldown as soon as possible--in an effort to conserve energy (which costs money) and reduce wear on the turbine and auxiliaries..

Most sites seem to think a unit must he on cooldown a minimum of four hours before starting--thinking that will prevent or reduce vibration spikes during starting and acceleration (not bad thinking).

Many sites have found that leaving a unit on ”turning gear” style of cooldown for days or weeks even will cause a phomenon known as ”bucket rock” which results in the roots of the turbine blades (usually the last stage turbine blades) getting very worn as they rock back and forth as the shaft spins slowly. This also causes turbine wheel dovetail (which the turbine blades are slotted into) to experience accelerated wear.

Some manufacturers require a unit be on cooldown to start it--whether it be for one minute, or three minutes, or four hours.

It really depends on how the unit is operated, meaning is it absolutely required the unit be as reliable as possible, not tripping on high vibration, for example, and must be ready to start any time of the day or night? Does it have to be on cooldown (turning gear) prior to starting and high starting reliability is required? If so, then leaving the unit on cooldown continuously may be a good idea, and the potential for increased wear must be monitored regularly to determine the best practice for the turbine at that site given the economics involved.

Most units can be started from zero speed (some can't as noted above), but if the unit has been at zero speed and not on cooldown at all for many days or weeks or even months and is started without being on cooldown for any period (one hour or four hours) it's highly likely there will be high vibrations during starting and acceleration, especially if the lubricating oil is cold (less than approximately 80 degrees F). Some sites will put the unit on cooldown once per day for an hour or two just to prevent rotor sag and to keep the lubricating oil warm if the unit isn't started very often, instead of keeping the unit on cooldown continuously (again to save money on electricity and reduce wear on the turbine and auxiliaries).

I hope this answers your question, because as worded it was a little vague. We don't know if you're asking if the unit has to be on cooldown before every start for some period of time (a couple of hours or more), or if it can be left on cooldown continuously (we don't know what kind of cooldown system the turbine at your has), and we don't know how your turbine is operated and what the starting reliability requirement is. If you need more information please tell us more about the conditions at your site, what kind of turbine you are operating or working on and precisely what your question is and we can try to provide a more concise answer.

It's really not the simple question it might seem to be...!
Yeah, well, Nanjing Gas Turbines are "based on" GE-design heavy duty gas turbines, and the designs are very similar, and the concepts of cooldown are very similar for many heavy duty gas turbines or many different manufacturers.

I believe GE and Nanjing were engaged--and might still be--in some kind of joint venture or technology "sharing" program. And, that's all I'm going to say about that, except it's usually pretty one-sided.

Oh, and if you think the manufacturer of the gas turbine is important to the answer to your question(s) or would require specific information in the answer--then list the manufacturer in your original post in each thread you open. This site doesn't use avatars which would be very helpful at times, so it's necessary to help us by providing the information multiple times, unfortunately, until we get to know you and your site better if you post frequently.