We have Alstom Steam Turbine capacity 400MW equipped with 02EA GE 9HA turbines in CCPP of capacity 1223MW commissioned in 2018. Steam turbine generator is H2 cooled.
There are leakages from STG bearing oil seals and we are searching for a root cause. Following are my questions
1. What is recommended Vacuum pressure inside lube oil tank as it is not mentioned in OEM manuals
2. Similar issue was reported at a similar site with same machine and configuration and was resolved by adding another line on return to increase the flow back to lube oil tank. It was done by OEM under warranty.
3. GE has not installed any vacuum gauge on lube oil tank? Is it part of their design or its does not has any influence that is why was not installed.
4. Vacuum was not adjusted since commissioning and this leakage issue was raised last year in Sep 2019. (one of the reason vacuum was not adjusted as it considered similar issue as on similar site which was rectified by adding an additional return line)
Kindly provide any technical detail to cater this issue.
There are leakages from STG bearing oil seals and we are searching for a root cause. Following are my questions
1. What is recommended Vacuum pressure inside lube oil tank as it is not mentioned in OEM manuals
2. Similar issue was reported at a similar site with same machine and configuration and was resolved by adding another line on return to increase the flow back to lube oil tank. It was done by OEM under warranty.
3. GE has not installed any vacuum gauge on lube oil tank? Is it part of their design or its does not has any influence that is why was not installed.
4. Vacuum was not adjusted since commissioning and this leakage issue was raised last year in Sep 2019. (one of the reason vacuum was not adjusted as it considered similar issue as on similar site which was rectified by adding an additional return line)
Kindly provide any technical detail to cater this issue.