What purpose does the third bearing serve in some power generators?
- Thread starter Emar
- Start date
Emar,
Happy you've found Control.com.
H- and HA-class machines are relatively new, and while the number if installed units is growing very fast they are still a relatively small percantage of the fleet of GE-design heavy duty gas turbines around the world. These machines were more or less new designs of gas turbines for GE; in the past when they built larger machines (or in a couple of cases, smaller machines) they usually just scaled up (or down) existing designs and re-used a lot of existing technology. H- and HA-class machines were designed with a very different set of operating characteristics from past GE heavy duty gas turbines. Primarily they were designed for high reliability and availability under a wide range of operating conditions: load following (frequency loading and unloading); unstable grid frequency applications; fast start-up; combined cycle operation; fuel flexibility (including future plans for hydrogen fuel); maintenance (to the extent possible); etc. In the past, most GE-design heavy duty gas turbines were designed for two basic purposes: peaking (peak-shaving) applications (simple cycle), and Base Load applications (start them up, load them to full load (Base Load), and let them run for weeks or months) (both simple- and combined cycle applications). So, these machines were quite a departure from decades of designs and machines. And, as such, required a big change in components and operational and protection philosophies.
Now, to your question about the third bearing in some power generators. H- and HA-class machines are big machines (how electrical power outputs). As such, the collector (slip rings and brushes) for the synchronous generator are large and heavy and apparently the designers of the synchronous generators for H- and HA-class machines felt it was prudent to use a third bearing to support the weight of the assembly and reduce possible vibration of such a large assembly. It may also be safer for inspection and maintenance when the machine is running (allowing for a larger enclosure and easier access).
You seem to have some access to lots of drawings and pictures so one would presume you have access to training materials which were provided for operations and maintenance personnel at the site--if not the actual training. So, you have a wealth of material to read and study. I always recommend sitting down with a pad of "Post-It Notes" (small note papers with a band of very slightly sticky adhesive on the edge of one side of each note paper). Start at the beginning of each manual (there are probably LOTS of them) and page through them one page at a time. You will be AMAZED at the information you find--and when you find something you want to return to and study and read in greater detail, put one of these note-papers on the page. But, don't stop to read every time you find something interesting or you'll never get through the process of familiarizing yourself with the manuals and the information contained in them. Just put a note paper to come back to. I also suggest having a notepad to write down most, if not all, of the topics you find of interest, noting the section/tab of the manual where the topic is located. (You can use this to prioritize the topics when you want to read for more detail!)
The Operation & Maintenance Manuals have a LOT of good information, but to really make use of the manuals one needs to familiarize themself with how the manuals are organized and the information contained in them. Without taking the time to page through them in the beginning finding information is going to be difficult and frustrating in the future. Even if you have to do this "on your own time" (when you're not on shift and getting paid to be on site) it is a GREAT investment in your job and possibly your career.
In this modern day and age, the manuals are also usually available in .pdf electronic format, which can make searching a little easier. And, by using the bookmark feature of the pdf reader you can do the electronic equivalent of "Post-It Notes." But, I still recommend making a list of the bookmarks you place and using them to prioritize your future detailed reading. And, I STILL recommend paging through the manuals, one page at a time, even if you use the electronic version because otherwise how are you going to visually see all the information available there?
AND, if you don't already have your own personal copies of the P&IDs provided with the machine I STRONGLY recommend you make the largest copies of them you can and use a pencil to make notes on them as you study them. Which implies that you WILL study them, read the NOTES section of each P&ID, and familiarize yourself with the symbols used on them. THIS IS THE MOST IMPORTANT THING YOU CAN DO TO BECOME A BETTER OPERATOR AND TECHNICIAN! (A good technician is also a good operator--because a good operator knows sequences and knows what's supposed to happen when and what's NOT supposed to happen when...! And a good operator ALSO needs to know this information when helping to troubleshoot alarms and solve problems; just "knowing" the control system isn't enough--one needs to know how the machine operates and is supposed to operate.)
That's about it!
Happy you've found Control.com.
H- and HA-class machines are relatively new, and while the number if installed units is growing very fast they are still a relatively small percantage of the fleet of GE-design heavy duty gas turbines around the world. These machines were more or less new designs of gas turbines for GE; in the past when they built larger machines (or in a couple of cases, smaller machines) they usually just scaled up (or down) existing designs and re-used a lot of existing technology. H- and HA-class machines were designed with a very different set of operating characteristics from past GE heavy duty gas turbines. Primarily they were designed for high reliability and availability under a wide range of operating conditions: load following (frequency loading and unloading); unstable grid frequency applications; fast start-up; combined cycle operation; fuel flexibility (including future plans for hydrogen fuel); maintenance (to the extent possible); etc. In the past, most GE-design heavy duty gas turbines were designed for two basic purposes: peaking (peak-shaving) applications (simple cycle), and Base Load applications (start them up, load them to full load (Base Load), and let them run for weeks or months) (both simple- and combined cycle applications). So, these machines were quite a departure from decades of designs and machines. And, as such, required a big change in components and operational and protection philosophies.
Now, to your question about the third bearing in some power generators. H- and HA-class machines are big machines (how electrical power outputs). As such, the collector (slip rings and brushes) for the synchronous generator are large and heavy and apparently the designers of the synchronous generators for H- and HA-class machines felt it was prudent to use a third bearing to support the weight of the assembly and reduce possible vibration of such a large assembly. It may also be safer for inspection and maintenance when the machine is running (allowing for a larger enclosure and easier access).
You seem to have some access to lots of drawings and pictures so one would presume you have access to training materials which were provided for operations and maintenance personnel at the site--if not the actual training. So, you have a wealth of material to read and study. I always recommend sitting down with a pad of "Post-It Notes" (small note papers with a band of very slightly sticky adhesive on the edge of one side of each note paper). Start at the beginning of each manual (there are probably LOTS of them) and page through them one page at a time. You will be AMAZED at the information you find--and when you find something you want to return to and study and read in greater detail, put one of these note-papers on the page. But, don't stop to read every time you find something interesting or you'll never get through the process of familiarizing yourself with the manuals and the information contained in them. Just put a note paper to come back to. I also suggest having a notepad to write down most, if not all, of the topics you find of interest, noting the section/tab of the manual where the topic is located. (You can use this to prioritize the topics when you want to read for more detail!)
The Operation & Maintenance Manuals have a LOT of good information, but to really make use of the manuals one needs to familiarize themself with how the manuals are organized and the information contained in them. Without taking the time to page through them in the beginning finding information is going to be difficult and frustrating in the future. Even if you have to do this "on your own time" (when you're not on shift and getting paid to be on site) it is a GREAT investment in your job and possibly your career.
In this modern day and age, the manuals are also usually available in .pdf electronic format, which can make searching a little easier. And, by using the bookmark feature of the pdf reader you can do the electronic equivalent of "Post-It Notes." But, I still recommend making a list of the bookmarks you place and using them to prioritize your future detailed reading. And, I STILL recommend paging through the manuals, one page at a time, even if you use the electronic version because otherwise how are you going to visually see all the information available there?
AND, if you don't already have your own personal copies of the P&IDs provided with the machine I STRONGLY recommend you make the largest copies of them you can and use a pencil to make notes on them as you study them. Which implies that you WILL study them, read the NOTES section of each P&ID, and familiarize yourself with the symbols used on them. THIS IS THE MOST IMPORTANT THING YOU CAN DO TO BECOME A BETTER OPERATOR AND TECHNICIAN! (A good technician is also a good operator--because a good operator knows sequences and knows what's supposed to happen when and what's NOT supposed to happen when...! And a good operator ALSO needs to know this information when helping to troubleshoot alarms and solve problems; just "knowing" the control system isn't enough--one needs to know how the machine operates and is supposed to operate.)
That's about it!
