Background
Under settlement agreement, GMG are responsible to rectify 5 problems highlighted by us. Upon completion of each rectification, it will enter into 6 months defect liability period. If no problem arises within defect liability period, the rectification considered successful.
5 Rectifications are:
1. Turbine #1 rectification – after overspeed, Turbine #1 only can run up to 4MW. It cannot goes for higher loading due to thrust bearing temperature too high. This task is to rectify Turbine #1 to enable it run at 6MW without any problem.
2. Turbine #1 & #2 oil line modification – due to oil line mistake installation, we face turbine #1 overspeed problem. This task is to rectify the oil line mistake and ensure tripping mechanism function as it is desired.
3. Boiler #1 superheater hopper rectification – due to “forget install screw” at the hopper causing hopper falling down and castable inside hopper cracked. This task is to rectify the hopper back to its original position and fix back castable in the hopper.
4. Boiler #2 superheater screw conveyor rectification – due to “forget install screw” at the hoper causing castable inside hopper cracked and falling down. It chocked the screw conveyor from discharging ash. This task is to replace the screw conveyor with a hopper to prevent chock-up due to falling castable.
5. DCS system reinstatement – 3 control PC had been faulty. This task is to replace 3 faulty PC fully installed with necessary control software.
Progress Status
Up to today, item 2 & 5 had been completed and we had granted GMG preliminary acceptance on these two item. Thus, item 2 & 5 had enter into defect liability period.
Item 1: Turbine #1 rectification
GMG had sent 5 technicians from QingDao (OEM) to rectify turbine thrust bearing pad high temperature problem. The rectification job had been considered finished but unsuccessful. However, Turbine #1 output had been significantly improve from 4MW to 5.3MW now. Besides, there is no vibration problem been observe up to this stage.
Since the rectification was considered unsuccessful, GMG will need to move into next agreed action plan as per required in Settlement Agreement. They will need to supply and replace full set of turbine rotor for Turbine #1 and rectify the turbine thrust bearing pad temperature at the same time. Turbine rotor expected to arrive by mid or end of November 2014. Upon arrival of turbine rotor, GMG will dispatch their team to site for replacement, then follow by testing and commissioning of Turbine #1 again.
Item 3: Boiler #1 superheater hopper rectification
GMG had completed the hopper repositioning. The castable within hopper had not been fixed as the material prepared was not sufficient at this time. GMG will ship more castable material to site, then follow by fixing castable. This job target to start during the same time with Turbine #1 rotor replacement.
In the mean time, we are operating Boiler #1 in full swing condition as the castable in hopper does not impact the operation. It just reduce some efficiency of boiler.
Item 4: Boiler #2 superheater screw conveyor rectification
GMG had start rectification job on Boiler #2 superheater screw conveyor since last Sunday (24th Aug 2014). They expect to complete the rectification job by this Sunday (31st Aug 2014).
After completion of Boiler #2, we expect to run two boilers and two turbine in full swing condition (as of next week onward).
Regarding the corrosion issue, we had done the below:
1. Water source – We do not use treated water from municipal treatment plant for boiler consumption. In fact we buy fresh city water every day for boiler consumption since Turbine #1 overspeed happen. With cleaner city water, we ensure corrosion in the boiler, turbine and auxiliary equipment to be reduced.
2. Operation improvement – We had signed operation and maintenance contract (on 19th Aug 2014) with SanFeng Covanta who is the major incineration power plant operator in China to come and operate our plant. They will implement more comprehensive maintenance plan to improve plant performance, reliability and safety. SanFeng Covanta dispatch their first team to site on 2nd Sep 2014.
3. Chemical dosing – In order to ensure no residual oxygen after Deaerator, we had added hydrazine dosing to down stream of Deaerator. Hydrazine dosing will kill off residual oxygen which is not been remove during deaeration process. Without oxygen in the water, corrosion rate been minimized.
Finally, I would like to emphasize again (which in fact I talk about this many times), corrosion rate in Turbine #1 was not common. However, I doubt it was fully due to water issue. My suspect is the delay in opening turbine cover after shutdown. The 1 month delay in the duration will cause corrosion in turbine itself.
This hypothesis can be justify when we open Turbine #2 later.
Should you have any doubt on the above, please feel to contact me.
Background
Under settlement agreement, GMG are responsible to rectify 5 problems highlighted by us. Upon completion of each rectification, it will enter into 6 months defect liability period. If no problem arises within defect liability period, the rectification considered successful.
5 Rectifications are:
1. Turbine #1 rectification – after overspeed, Turbine #1 only can run up to 4MW. It cannot goes for higher loading due to thrust bearing temperature too high. This task is to rectify Turbine #1 to enable it run at 6MW without any problem.
2. Turbine #1 & #2 oil line modification – due to oil line mistake installation, we face turbine #1 overspeed problem. This task is to rectify the oil line mistake and ensure tripping mechanism function as it is desired.
3. Boiler #1 superheater hopper rectification – due to “forget install screw” at the hopper causing hopper falling down and castable inside hopper cracked. This task is to rectify the hopper back to its original position and fix back castable in the hopper.
4. Boiler #2 superheater screw conveyor rectification – due to “forget install screw” at the hoper causing castable inside hopper cracked and falling down. It chocked the screw conveyor from discharging ash. This task is to replace the screw conveyor with a hopper to prevent chock-up due to falling castable.
5. DCS system reinstatement – 3 control PC had been faulty. This task is to replace 3 faulty PC fully installed with necessary control software.
Progress Status
Up to today, item 2 & 5 had been completed and we had granted GMG preliminary acceptance on these two item. Thus, item 2 & 5 had enter into defect liability period.
Item 1: Turbine #1 rectification
GMG had sent 5 technicians from QingDao (OEM) to rectify turbine thrust bearing pad high temperature problem. The rectification job had been considered finished but unsuccessful. However, Turbine #1 output had been significantly improve from 4MW to 5.3MW now. Besides, there is no vibration problem been observe up to this stage.
Since the rectification was considered unsuccessful, GMG will need to move into next agreed action plan as per required in Settlement Agreement. They will need to supply and replace full set of turbine rotor for Turbine #1 and rectify the turbine thrust bearing pad temperature at the same time. Turbine rotor expected to arrive by mid or end of November 2014. Upon arrival of turbine rotor, GMG will dispatch their team to site for replacement, then follow by testing and commissioning of Turbine #1 again.
Item 3: Boiler #1 superheater hopper rectification
GMG had completed the hopper repositioning. The castable within hopper had not been fixed as the material prepared was not sufficient at this time. GMG will ship more castable material to site, then follow by fixing castable. This job target to start during the same time with Turbine #1 rotor replacement.
In the mean time, we are operating Boiler #1 in full swing condition as the castable in hopper does not impact the operation. It just reduce some efficiency of boiler.
Item 4: Boiler #2 superheater screw conveyor rectification
GMG had start rectification job on Boiler #2 superheater screw conveyor since last Sunday (24th Aug 2014). They expect to complete the rectification job by this Sunday (31st Aug 2014).
After completion of Boiler #2, we expect to run two boilers and two turbine in full swing condition (as of next week onward).
Regarding the corrosion issue, we had done the below:
1. Water source – We do not use treated water from municipal treatment plant for boiler consumption. In fact we buy fresh city water every day for boiler consumption since Turbine #1 overspeed happen. With cleaner city water, we ensure corrosion in the boiler, turbine and auxiliary equipment to be reduced.
2. Operation improvement – We had signed operation and maintenance contract (on 19th Aug 2014) with SanFeng Covanta who is the major incineration power plant operator in China to come and operate our plant. They will implement more comprehensive maintenance plan to improve plant performance, reliability and safety. SanFeng Covanta dispatch their first team to site on 2nd Sep 2014.
3. Chemical dosing – In order to ensure no residual oxygen after Deaerator, we had added hydrazine dosing to down stream of Deaerator. Hydrazine dosing will kill off residual oxygen which is not been remove during deaeration process. Without oxygen in the water, corrosion rate been minimized.
Finally, I would like to emphasize again (which in fact I talk about this many times), corrosion rate in Turbine #1 was not common. However, I doubt it was fully due to water issue. My suspect is the delay in opening turbine cover after shutdown. The 1 month delay in the duration will cause corrosion in turbine itself.
This hypothesis can be justify when we open Turbine #2 later.
Should you have any doubt on the above, please feel to contact me.
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