PDVSA El Tejero Report

8/13/2019 PDVSA El Tejero Report

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Site ReportPDVSA-Planta El Tejero

Dates 10/26-11/01/2005

CSA-R8368

Unit No.4 Mars 100

Package-CT89456

Engine SN- 1741C41

Summary

The current operating Mars 100 was recently overhauled and installed by PDVSA in package

No.4 however was impacted by low performance that ultimately was affecting the trough put. Myoverall time on site and the length of stay in Maturin does not reflect the actual work performeddue the plant process and of course the Xmas season. The initial issue regarding the engine

performance was only a matter of the engine test setup Mars 100 verses the current control setupMars 90, nothing more.

Performance

Upon arriving on site the engine was operating at 92.5% Ngp and temp topping T5-1360F withboth the LP and IP recycle valves cycling due to the low output power. The T5 delta across the

thermocouple was high however not a concern at this junction relative to the way the engine wasoperating.

IGV

The as tested guide vane angle stops on the open side were set at 4 max, this was changed to 0and the speed increased to 97.5% Ngp @ T5-1360, hp-normalized. However within an hour of

operation the engine speed had dropped down to 96% Ngp @ T5-1360 and was due to the T5spread along with losing thermocouple (No.4 and No.10).

T5

Performed a few simple tests on the T5 control and found it tracking correctly with zerocompensation however the Isothermo Board has a number of terminals were the threads and

screws are not making good contact. When using wire terminals the standard screws are not longenough causing them to strip out. Any lose connection on either the thermocouples or theinterconnect junction point is going to cause erroneous data within the control system and affectthe overall performance of the engine.

Was able to make some temporary changes to the T5 connections and isothermo board in order tobring the performance back to normal. However due to the T5 spread the IGVs were adjusted asecond time -1 and I clamped down on the T5_Base (1310-1280) in order to limit the overall Hpuntil the isothermal board is changed. Once the isothermal board has been changed the customeris going to send me the running T5 data points at full load (1-17) and based on that Ill reevaluate

the T5_Base.

Air LeakageOn a secondary note the engine has an air leak located at the GP-PT matting flange that istypically associated with poor fit at the 4thstage support plate. My understanding is the GP and

PT were matted on site and it could be that the two sections sagged during the torque process.

As listed in highlight Ive asked PDVSA to shutdown the engine and attempt a re-torque of theflange in an attempt to avoid pulling back the PT to refit the joint. If re-torqing does not correctthe problem I dont think the issue should be left unresolved for a long period of time since it will

affect the performance long term.


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REDUCED SHANK

NORMAL SHANK

97-ft lbs

110-ft lbs

DUE TO AIR LEAKAGE THE GP/PT FLANGE WILL NEED TO BE

TORQUE, THIS WILL BE PERFORMED IN A NORMAL STAR PATTERN.

DO NOT LOOSEN ALL THE BOLTS OR THE ENGINE COULD SAGE.

THE ENGINE WILL NEED TO BE SHUTDOWN AND COOL BEFORE

PROCEEDING.

TORQUE PATTERN

VERIFY THE TYPE OF BOLT USED

IN ENGINE PRIOR TO VERIFYING

TORQUE

GP - PT FLANGE TORQUE

Garry A. Hansen


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Enclosure Temperatures

Noted that the enclosure temperatures are elevated partly due to the inadequacies of the fan, this

can be verified by measuring the motor current relative to the service factor of the motor.However a lot can be done within the package to eliminate most of the heat being dissipated

around the engine hot section.

Oil Leaks-Coupling CoversNoted several leaks from the coupling covers and RTV is still being utilized as the preferredsealant by the customer. Theres nothing wrong with using RTV however in my opinion the

technicians would be better served using a PTFE product that would offer an enhanced sealingcapacity along with easy clean up. For use with the type of coupling covers on the Mars I would

recommend using 1/8 or 3/16 rope packing, which is excellent for sealing rough and irregularsurfaces.


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Conclusion

The engine is operational however I would appreciate the customer looking into the twooutstanding issues, isothermo board and the air leakage. With respect to the overall

performance the steps taken to allow the engine to operate as a Mars 90 was the best course ofaction. Even prior to implementing any control changes that would allow the engine to operate as

a Mars 100 it would have still need to be setup as a Mars 90 for verification purposes. Once theT5 profile can be verified after the isothermo board change out we will schedule a time toimplement the Mars 100 control with the current Moog actuators.

I appreciated all the support given during my stay on sight and please forward any questionsregarding this report to [email protected] or contact me via my cell 0412-313-

4166.

Garry A. HansenRegional Engineer

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PDVSA El Tejero Report