Please excuse not providing the daily report for yesterday’s activities. The reason for that is that we very late received the information from our engineering that the reassembly of the bearing may proceed. Please find below some technical explanation why this decision has been taken:
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Our field service engineers have during the yesterday tried to rectify the issue with the axial gap between the turbine bearing casing and outlet casing. The removal of the residues that has been found was successful, however it was not possible to completely remove the gap even when the bearing casing was torqued with a higher torque in accordance with Siemens standard instructions.
Siemens considers it unlikely that the screws will lose tension again based on the fact that the increased torque of the bearing casing will ensure that all possible residues that still remains between the flanges has compressed and will remain compressed and in position even during operation of the engine.
There is a very small angle deviation of the position of turbine bearing due to the gap between the turbine bearing casing and outlet casing, but the small angle deviation is considered irrelevant for the further operation and serviceability of the unit.
Siemens is confident that the gap between the flanges of the turbine bearing casing and outlet casing is the root cause of the increased vibration behavior that has been noticed on Bangpoo 1:1. Further Siemens are confident that the possible residues that still remains between the flanges will remain in position and with the increased torque no further loss of tension on the screws will occur.
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Regarding guide vane #1 there seems to be some miscommunication. We have found no issue regarding guide vane #1 which means it is our intention to reassemble it to the machine and not to replace it. In order to shorten the overall reassembly time this work needs to be done tomorrow.
On the other hand it is Siemens intention to replace guide vane #2 which was damaged. We presently have sourced all materials for this step except the stator ring no 2. There is currently some internal clarification on going to borrow this ring from another project. It is whatsoever is a complex process to figure that out because the lead delivery time for a new stator ring is quite long (100 days).
We hope to be able to have a decision on that beginning of next week.
If the decision is positive we might be able to have all materials for further reassembly steps available during next week. Depending on if we get a positive decision beginning of next week the remaining time needed for reassembly could be estimated with 2 weeks counting from next week. This would mean if all goes well GT11 might be ready for operation by first week of November.
So after the bearing and guide vane no 1 reassembly is completed our site activities will be limited to further checks on the available spare parts and consumables and other preparation activities. Further assembly steps may commence as soon as we get the needed parts from Sweden.
We will send a compiled daily report including the activities from yesterday & today later this evening.