Lifetime of Gas Turbines Hot Section Parts in an O&G Environment

TutorialThe main driver to define the time between overhauls of a gas turbine is the life of the hot components. For an Oil&Gas operator, a turbine overhaul represents a major cost and therefore is a key point for performance improvement. This paper reviews the main damaging mechanisms of the hot sections of gas turbines, the available models, and provides orders of magnitudes of the impact of the different factors in the life of components. It also presents the operational experience of Total through cases for which the time between overhauls was successfully extended

Lifetime of Gas Turbines Hot Section Parts in an O&G Environment

TutorialThe main driver to define the time between overhauls of a gas turbine is the life of the hot components. For an Oil&Gas operator, a turbine overhaul represents a major cost and therefore is a key point for performance improvement. This paper reviews the main damaging mechanisms of the hot sections of gas turbines, the available models, and provides orders of magnitudes of the impact of the different factors in the life of components. It also presents the operational experience of Total through cases for which the time between overhauls was successfully extended

Subsynchronous Vibrations On Turboexpanders Equipped With Magnetic Bearings Assessment, Understanding And Solutions

LectureIn most natural gas applications, turboexpanders are operating close to or on the dew point line and a mixture entering the turboexpander impeller is a combination of liquid and gas phases of the natural gas. The presence of the liquid phase may induce rotordynamic instabilities during operation. Special care should be taken in the case of magnetic bearings. This paper will present a revamp of two turboexpander-compressors equipped with active magnetic bearings (AMB). The application is liquid natural gas (LNG) rejection and gas injection on a Floating Production, Storage and Offloading (FPSO) barge. Prior to upgrade, the turboexpanders had accumulated more than 250 thousand hours in operation. The objective of the upgrade was to adapt to new process conditions and to increase the power of the turboexpanders. After the re-wheeling of turboexpanders, numerous trips due to violent subsynchronous vibrations were experienced. The root-cause analysis revealed that the presence of liquids in the front wheel labyrinth seals caused fluid-induced non-synchronous vibrations (NSV). Methods used in the redesign of the impellers and labyrinth seals that allowed the problem to be solved will be described in detail

Dry Gas Seals

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High Performance Bearing Comparison

LectureWith the increasing demand for high performance gearboxes, larger, faster, more highly loaded bearings are requiring more oil and creating more heat than ever before. This means the lubrication systems must be larger to handle the increasing heat loads and oil demands. Offshore applications, in particular, are greatly affected due to space constraints and increased lubrication system size and cost. In an effort to reduce the oil flow and heat load requirements for the gearbox, experimental tests and field tests were performed with three different bearing designs. The designs were pressure dam, offset half, and tilting pad journal bearings. Data was acquired using a dedicated test rig that allows operation at and beyond design speeds and loads. Field test data was also collected from a full speed, full load string test of a turbo compressor drivetrain. This paper will present results of the experimental test data from these three bearings to assist in the selection of a design that will provide optimum performance for given operation conditions

Dry Gas Seals for Compressors

Discussion GroupHow to specify an integrally geared compressor Typical process applications Controlling an integral gear compressor - IGV, VFD Rotordynamic consideration

Dry Gas Seals for Compressors and Pumps

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Dry Gas Seals for Compressors

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