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New Rolls-Royce Retrofit

Rolls-Royce has released the RB211-Gzero, a retrofit upgrade that provides RB211 aeroderivative users with the potential for a 10% power increase. First introduced in 1974 with the RB211-22, there are now over 700 units sold. Combined, they have recorded over 30 million operating hours. The RB211 operates in the power range of 29 to 44 MW.

According to Scott DeWolfe, RB211 Product Director for Rolls-Royce, it has a modular design to make maintenance easier.

“The RB211-Gzero will specifically benefit operators of the 440-plus worldwide installed fleet of RB211-C and RB211-G variant gas generators that feature RT-56 or RT-62 power turbines,” said DeWolfe.

The power increase comes from upgrade features that improve air flow into the engine. At ISO conditions, this serves up a 10% power boost for RB211-G users and as much as 31% for the -C model. Efficiency levels remain unchanged.

“The retrofit only takes two or three days, requires minimal modification to the turbine and takes up no more space,” said DeWolfe.”We raise mass flow into the power turbine without any increase in firing temperature.”

The upgrade should be done as part of the next maintenance overhaul. A few modifications to the package are made onsite such as adjustments to the Inlet Guide Vane (IGV) to let more air through, a modified thrust bearing and some minor changes to the bleed ducting. This will increase the weight slightly, according to DeWolfe.

The RB211-Gzero upgrade focuses on two of the five RB211 modules: air intake and intermediate pressure (IP) compressor. DeWolfe makes it clear that the remaining three modules remain unchanged including the hot section.

The air intake casing has been shortened to ensure identical engine interface length is maintained, compensating for the increased length of the IP compressor. A redesigned elliptically profiled nose bullet extends further forward in the air stream and achieves better airflow entry to the compressor.

The compressor receives most of upgrade attention. Rolls-Royce has added a zero stage to the compressor in order to compress more air. The existing stage one disc and blade row is removed and replaced with a new stage zero and stage one discs and blade assembly to mate with the existing stage two-to-five drum assembly.

“As we have added a stage, we had to increase the length of Intermediate Pressure (IP) compressor casing,” said DeWolfe. “We have also upgraded the early stages of the compressor from stainless steel to titanium.”

Blades on the new discs feature an elliptical leading edge for improved efficiency. Elliptical Leading Edge (ELE) vane technology from the Rolls-Royce Trent aero family contributes to improved compressor efficiency across the widest operating range. The total number of variable-geometry stages increases from one on the RB211-G to three: one row of variable inlet guide vanes and two stages of variable stator vanes.

High-speed gearbox

David Brown has released an adaptable high-speed gearbox range known as the HX series. These gearboxes are designed for critical pump, compressor and generator applications in the oil & gas and power industries.

The core platform has a flexible case design to minimize package pipe runs, multiple oil inlet and outlet positions, an optimized oil flow, and is compliant with API613 and AGMA standards. Various case material and bearing options are available to suit specific temperature and environmental requirements.

Profile grinding is done to ensure optimal tooth contact for long gear life (20 years or more), minimal vibration and quiet running. Technical support is available across the globe in key oil and gas regions.

“The HX series represents the best optimized capacities for high speed gearboxes on the market today,” said John McCarthy, Director or Energy at David Brown. “Our gearboxes can run at pitch line speeds of up to 150 meters per second in line with API613. Two case widths are available and gear ratios up to 8.5:1.

He added that the gear case has been optimized for low ratio pump as well as higher ratio compressor applications. While double helical gears are provided as standard, there is a single helical option available on a designed to order basis.

Tilt pad thrust bearing are utilized in the external housing, as well as rolling element bearings being available for API677 or AGMA-compliant applications.

Turbodesign Suite 5.2

The Turbodesign Suite by Advanced Design Technology is software for the design, analysis and optimization of all types of turbomachinery, such as axial, mixed-flow or centrifugal pumps, compressors, fans, turbines and torque converters. The company has released version 5.2 of this suite. Starting from nominal stage requirements, designers can evaluate turbomachinery package size and performance predictions, perform 3D blade design with 3D inverse design capabilities, analyze flow information per component and stage performances with 3D CFD and automate design.


Bolting security

Joints increasingly have to withstand stresses from multiple fronts, including vibration, dynamic loads, settlement and relaxation. No solution has previously been designed to secure bolts from all of these at once.

This has left designers with the difficulty of figuring out which issue — spontaneous bolt loosening or slackening — will have the biggest effect on the joint, and choosing a solution to handle that problem.

The Nord-Lock X-series washer combines wedge-locking protection against spontaneous bolt loosening (due to vibration and dynamic loads) with a spring effect that protects against slackening due to settlement and relaxation.

Each washer pair has cams on one side and radial teeth on the opposite side to secure the bolted joint with tension instead of friction. The Nord-Lock X-series washers’ conical shape also creates an elastic reserve in the bolted joint to compensate for the loss of preload and prevent slackening.

Roots Turbo Blower

GE Oil & Gas has released the Roots Turbo Blower, an integrated blower package that features a high-speed Permanent Magnet Synchronous Motor (PMSM), a bump-type air foil bearing design and an integral airend. The PMSM allows for high efficiency characteristics at design speeds and turndown speeds as compared to a traditional induction motor. The bump-type air foil bearing provides stability.

Wireless condition monitoring

Vibconnect RF is a wireless condition monitoring systemformachine components. The sensor unit monitors machine vibration, bearing condition and temperature and transmits data to the bridge where it is evaluated.

It monitors the condition of roller bearings and other rotating components, as well as detecting damage caused by cavitation. The bridge acts as the central receiver. It processes the data from the sensor units and transmits it through the operator's network for visualization and archiving.

GT enclosure doors

Consolidated Fabricators, a division of Braden Manufacturing, has announced an approach to the design and manufacture of replacement doors and panels for gas turbine enclosures. GT Smartdoor products are employed to replace leaking, worn-out, corroded or damaged gas turbine access doors.

They feature bolted, formed plate exteriors, eliminating problems associated with the typical welded construction of OEM doors. Previous welded designs created unprotected perimeter surfaces, making thema source of corrosion and climate exposure. Additionally, welded designs limited drainage and allowed greater thermal transfer, leading to higher surface temperatures.

GE Frame 6B improvements

The GE Frame 6B heavy duty gas turbine now has a simplified layout for easier installation, as well as the latest combustion system and turbine hot gas path for reduced maintenance.As a result, it can be ready for first fire within 10 months and can provide up to four years of continuous operation on various gases with no scheduled maintenance.

New features for the Frame 6B include pre-installed packages for easier transport and reduced site installation time and simplified layout for ease of operation and maintenance. This provides 43 MW of output, single-digit NOx emissions, and restart capability during blackouts. More than 1,200 6B gas turbines have been sold since 1980, and more than 170 units have been installed since 2006.

Subsea Pump

FMC Technologies and Sulzer Pumps are collaborating on subsea applications. They have developed a multiphase pump system optimized for harsh subsea environments. The system leverages Sulzer Pumps’ pump hydraulics with FMC Technologies’ high-speed permanent magnet motor technology as well as a subsea system design.

The helico-axial type pump is powered by a 3.2MWpermanent magnet motor and is capable of withstanding pressures up to 5,000 psi. By using permanent magnet motor technology, less maintenance is required and greater speed, efficiency and power can be achieved.

Energy intelligence tools

Rockwell Automation has added new energy intelligence capabilities to its software applications. The new tools — the FactoryTalkVantagePoint Energy bundle, FactoryTalk EnergyMetrix software, and Allen-Bradley IntelliCENTER Energy software — help plant managers view resource consumption in relation to specific units, lines and machines, so they can make more informed energy decisions.

The FactoryTalk VantagePoint Energy bundle allows users to aggregate metered energy-consumption data with production assets to monitor energy use.

The Factory Talk EnergyMetrix software collects, records and stores energy data from Allen-Bradley or thirdpart power meters. The software can capture information on energy use, flow, temperature, and pressure from controllers, third-party devices or manual entries. Users can also set parameters that create alarms, and send human-machine interface and email alerts.

IntelliCENTER software offers a preconfigured setup for intelligent motor control devices, including variable speed drives, overload relays, and sliding-mode controllers.

GT Exhaust system

Universal Acoustic & Emission Technologies designed and manufactured the exhaust system for a Westinghouse 501D5 gas turbine installation at Puget Sound Energy, Fredonia Station in Mount Vernon, WA. The scope included expansion joints, transitions, silencers and stacks, as well as demolition and installation for each system.