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Steam Turbine-Generator for Sale Unit Information

Steam Turbine Solutions, Inc., P.O. 871, Bolton, MA 01740 [email protected], 978-751-1857, www.steamturbinesolutions.com

Submitted by:

Turbine OEM: General Electric Generator OEM: General Electric

Turbine Type: Straight Condensing with 3 Uncontrolled Extractions Turbine-Generator Rating: 66,086 kW’s

e Steam Turbine Solutions, Inc., P.O. Box 871, Bolton, MA 01740

[email protected], 978-751-1857, www.steamturbinesolutions.com

Table of Contents Section Page

Equipment Summary……………………………………………………………………..…………………………...3 Unit Price………………………………………………………………………………………………………………...3 Performance and Value Vs. New Equipment……………………………………………..……………………....4 Unit Life Expectancy and Reliability…………………………………………………..……………………………4

Steam Turbine Design Details and Capabilities………………………………………..…………….…………..5 Steam Turbine Application and Reapplication Summary………………………………..…...……….……….6 Generator Design Details……………………………………………………………………………….…….……...8 Turbine Control System…………………………………………………………………………………….….……..8 Unit Supervisory Instrumentation……………………………………………………………………………..……9 Condition Based Maintenance Provisions……………………………………………………………………..….9 Generator Control System………………………………………………………………………………………..…..9 Auxiliary Systems………………………………………………………………………………………….…….……10 Condenser Systems……………………………...............................................................................................11 Additional Documentation Available……………………..…………………………………………………….....12 Technical Support and Contact Information……………………………………………………………….….....12 Appendix 1- Unit Data………………………………………………………………………………………….….….13 Appendix 2- Unit Pictures………………………………………………………………………………………....…38



Equipment Summary

This unit for sale is a 1991 vintage GE 66,086 kW rated straight condensing steam turbine and an 80,300 kVA rated generator, including its auxiliary systems and the condenser system. The condenser is a Graham water cooled condenser with a duty of 434.83 X 10⁶ btu/lb, exhaust pressure of 2.24” HgA and turbine exhaust flow of 481,020 lb./hr. The unit was shipped from the factory in 1991 and put in service in May 1992. This unit has its original steam path components which are the most modern GE industrial impulse steam turbine designs available. The unit operated base base-loaded until 2015 when it was shut down due to economic reasons. The steam turbine has been stored since the shutdown in 2015 with a dehumidification system on the turbine and the generator heaters operating to reduce the possibility for the intrusion of moisture and to preserve the main components. The unit and its auxiliary systems are designed for outdoor application, so it could be reapplied in an outdoor or indoor application. Auxiliary systems, motors, pumps, oil systems for units designed for indoor applications are not suitable for outdoors application, but outdoors units can serve both services. The unit had a major overhaul in 2013 with significant expenditure, upgrades, parts replacements and repair work to improve unit efficiency and long term reliability. The owner spent in excess of $1.24M on the turbine generator major inspection, parts and repairs during the project. The turbine and generator controls upgrades cost nearly $800,000 and the condenser re-tubing project cost was in excess of $840,000. The total cost of the 2013 major inspection and upgrades was in excess of $2.9M Descriptions of those upgrades are located in this evaluation. All the pertinent thermodynamic, electrical, and mechanical data for assessing the reapplication of the unit is located in Appendix 1 of this report. Pictures of the installed unit are located in Appendix 2 of this report. The following is an assessment of the unit design, potential reapplication scenarios and features and accessories of the unit. Unit Price A unit in this size range would cost approx. $15,000,000 if purchased as new equipment including the condenser system. The delivery would be approximately 14 months ARO. This unit is for sale for an asking price of $3,250,000 as is, where is, is available immediately and



subject to prior sale. The unit is in excellent condition and, due to the major controls and condenser upgrades completed during the 2013 major inspection, has all the modern GE steam path components, systems and features and accessories that would be sold with new equipment if purchased today. Performance and Value Vs. New Equipment Based on the performance table supplied, with the unit new and clean, overall turbine generator efficiency of the unit at its maximum output point of 66,000 kw’s, is calculated to be 85%. This efficiency is what would be expected of any modern condensing steam turbine of this size, energy range, and steam path design. A new unit would not yield any significant performance improvements over this unit design to warrant the huge price increase for new equipment over this used steam turbine generator. For example, if new equipment could get a 1-2% increase in performance over the subject unit (a realistic performance gain over this unit design) that would equate to a gain of 660 kW’s for the same inlet flow. At $.04/kw-hr and 80% availability rate that would equal about $230,000/year at 1% in extra generation from a slightly increased efficiency. The price difference between a new unit and the subject unit is $12,000,000. Therefore, it would take 52 years at 1% performance improvement to recover the extra cost of the new unit just to gain 1%+ in performance from a new unit. Taking into consideration that this unit is available now, rather than 14 months from now (as a new unit), the extra generation over those 14 months is equal to an extra $21,400,000 in revenue over that period. Unit Life Expectancy and Reliability Steam turbines are typically designed for a 30-year life. This is misunderstood in the industry that units only have a 30-year lifespan due to their estimated design life. Steam turbines that operate under 1000F at the inlet are not susceptible to the material stress creep issues that happen on the larger utility units with high temperature inlet conditions, which give them a limited life due to thermo-mechanical cycling stresses. These higher temperature units are also designed for a 30-year life span. Therefore, the components in steam turbines with lower than 1000F inlet steam temps only have the issue of wear of the unit due to operation, but not the material stress creep issues. With the exception of unit wear and steam purity issues, these lower temperature units have a far more extended rotor and casing life span than their perceived design life than a 1000F+ machine. There are still many GE units in baseload operation from the 1920’s, 1930’S and 1940’s. 50+ years of efficient and reliable operation is common in the worldwide steam turbine generator fleet. This unit was base-loaded for its years of operation and has very limited cycling.



Steam Turbine Design Details and Capabilities

Inlet/HP Section The subject steam turbine was designed and built by GE in Schenectady, NY and is a 15 stage impulse condensing steam turbine with 3 uncontrolled extractions for feed water heating. The unit has a single row 1st stage for better performance at above ½ load than a traditional 2 row Curtis wheel that was often used on industrial sized units. The overall turbine generator efficiency based on the provided guarantee point heat balance is calculated to be 85%. The inlet steam conditions are 850psig/825F and the inlet is sized for a guarantee flow of 573,334 pph. The max expected flow (not guaranteed) is 641,446 pph of steam flow. The turbine inlet flange is 12”-900# and is oversized such that it could be upgraded to pass up to 660,000 pph of 850psig/825FF steam or an increase of 15% increase over design, if needed for reapplication. The 641,446 pph “expected” flow rating is at “valves wide open”, it does not mean that the unit can actually pass that flow, its margin put in by the OEM to make sure the unit meets its guaranteed flow passing capability due to the unknowns of variations and tolerances in the manufacturing process. Exhaust Section The exhaust section of this machine has a single flow 23” last stage blade in a GE Model SF66 downward facing exhaust casing. The last stage blades have both over and under blade covers and a mid-span tie wire with a reinforced tie-wire hole boss to reduce tie wire hole stresses from the original design, which is GE’s most modern design for this 23” last stage blade. This was a redesign of an older blade that had some reliability issues and lower performance. This newer design took those issues into consideration to significantly improve upon both the reliability and performance of the last stage. The over and under covers provide 360 degree coupling of the blades along with the improved tie wires which lock the blades together not only at the tip, but also at the mid span to provide improved damping of the system. The blades are shielded on the leading edge with a stellite shield to reduce the chance of moisture erosion of the base metal of the blade. The last 5 stages of this machine have both moisture removal provision built into the diaphragms and casing drains to remove the stage moisture collected during operation. The exhaust hood comes with a hood spray system to keep the exhaust hood below 175F at start-up and in low load situations for alignment purposes.



Steam Turbine Application and Re-Application Summary

HP/Inlet Section The unit can be operated with pressures and temperatures up to 850 psig/825F. The unit could also be operated at lower than these design steam conditions. If the buyer’s needs are lower than these design inlet conditions the unit could be reviewed for this operation. For example, if the buyer’s inlet conditions are 600 psig/750F instead of the design 850 psig/825F conditions, the unit flow passing capability would be reduced to 430,000 pph (guaranteed) or 480,000 pph (expected) without modifications to the steam path. The steam path could easily be modified by low cost and high value methods, such as stage removal and some minor hardware changes, to get up to 495,000 pph of 600 psig/750F flow. The unit could be redesigned to pass as much as 495,000 pph of 600 psig/750F steam before it hits the design limitation of the inlet head to pass any more flow. Based on the calculated efficiency of the original heat balance and assuming the removal of the 3 uncontrolled extractions from service, the unit could potentially put out 54,500 kw’s at 600 psig/750F to 2.5” HgA with 430,000 pph of steam without any major steam path modifications. With minor mods it could pass up to 495,000 pph which would equal approximately 62,500 kW’s. These are just a few examples of how the unit can fit other than design steam conditions and operate both reliably and efficiently. It is very common to reapply steam turbine generators into different cycles with lower than design steam conditions. Significant increases in inlet pressure and temperatures for unit reapplication above 850 psig/825F are limited by casing material and casing design limits. Small increases in inlet pressure and temperature may be able to be accommodated with some engineering evaluation. Some of the increased flows or changed inlet conditions may or may not require unit modifications (not every application change requires hardware changes). A review by an experienced steam turbine engineer can determine the output and suitability at these off design conditions. All potential steam condition changes can be evaluated on a case by case basis. The seller will provide any serious potential buyer with a preliminary evaluation of thermo-mechanical fit to their specific cycle at no charge. Extractions The turbine has 3 uncontrolled extraction pressure levels for feed water heating. Each extraction has 2 separate openings to accommodate the original flow required to the heaters. These extractions can be used for other feed water heater cycles, blanked off for straight through operation or be used for process extraction steam. Another use for these uncontrolled



extractions is to add an admission to the unit where the buyer has excess low pressure steam available to admit back into the unit for increased power. This is also common where the unit is reapplied into a combined cycle application where the HRSG has 2nd pressure level steam flow at a lower pressure to put back into the turbine for increase power generation. This can easily be accommodated on this unit with minor modifications for combined cycle operation. This unit could be a great complement to a multiple LM6000, Frame 6 or Frame 7EA gas turbine combined cycle project. The design pressure levels of the uncontrolled extractions at rated inlet reconditions are approximately 110 psia,44 psia and 12 psia. Any of these extractions could be used to provide process flow in an industrial cycle with steam hosts. These pressures don’t need to match the original design exactly and can range quite a bit from the design and still be used for process needs. A mechanical evaluation can be done to determine the suitable pressures and flows for process steam. These uncontrolled extractions can also be individually blanked off or used depending on the buyer’s requirements. The openings are large for each extraction and could provide significant process flow if required. The extractions have the following flange sizes (2) 10” lines, (2) 12” lines and (2) 14” lines. NEMA SM-23 allows flows from extractions at up to 250’/sec steam exit velocity, but the OEM’s typically design for far less steam velocity by providing larger openings to reduce velocity and small piping losses. The NEMA limit allows increased flow capacity from these extractions, if required for reapplication, while still operating safely and reliably. Exhaust Section The exhaust section of this unit is designed to pass 452,000 pph. The exhaust section of this machine could pass up to 580,000 pph before hitting a mechanical blade stress limit for a 23” last stage blade. The exhaust hood comes with a hood spray system to keep the hood below 175F at start-up and in low load situations. The design exhaust pressure for the unit is 4” HgA due to the location of the unit in the southeastern US and cooling water available for the unit. In a climate with colder cooling water than the southeastern US, the unit is fully capable of running down to a 1.5” HgA backpressure or lower to increase the available energy and power from the unit. The existing condenser can provide a 1.25” HgA backpressure with design exhaust flow of 450,000 pph with 60F cooling water. More detail of the condenser capability is given later in the report.



Generator Design Details The generator is a GE H2 cooled, 80,300 kva, 13,800 v, 2 pole generator with a .85 PF and a .56 short circuit ratio. This rating is based on a 30 psig H2 pressure, with a 115F H2 temperature and a 100F cooling water temperature. Based on the GE generator inspection report from 2013 this generator has modern 18Mn-18Cr retaining ring material to meet the reliability and insurance company requirements. Many used units still have the older (or “outdated”) 18Mn-5Cr rings that won’t meet the reliability or insurance company requirements for long term operation. The cost to replace rings on a reapplied unit without 18Mn-18Cr material rings is roughly $250,000-$400,000 depending on size of the rings. The generator electrical design data and performance information is located in the Appendix 1 of this report. The data provided should be sufficient for any request by your utility for their transmission study. The generator hydrogen control cabinet has been removed from the unit, the buyer can purchase a new modern cabinet with digital controls and monitoring from E-One Corp., the contact info is on their website link as follows: http://www.eone.com/utility-systems/regions/us/generator-systems/hydrogen-control-cabinet-2.html The original H2 control cabinets with these units are obsolete and most likely need to be replaced in any reapplication of this vintage unit.

Turbine Control System/DCS This unit just had a complete controls upgrade in 2013 to GE’s most modern digital control system, the Mark VIe TMR (Triple-Modular Redundant). The system is both a DCS and a turbine controls system integrated into one system. This Mark VIe is essentially three parallel isolated control systems. The system uses two-out-of-three voting to provide high integrity, error-free, uninterrupted process operation with no possibility of a single point of failure. More information on the control system can be found on the following links: http://www.geautomation.com/products/mark-vie http://www.geautomation.com/system/files/files/gea-s1300.pdf If you would like to see all the controls and instrumentation included with this unit, a full bill of materials, electrical outline, complete instruction manuals and P&ID’s are available for the control system.

http://www.eone.com/utility-systems/regions/us/generator-systems/hydrogen-control-cabinet-2.html

http://www.eone.com/utility-systems/regions/us/generator-systems/hydrogen-control-cabinet-2.html

http://www.geautomation.com/products/mark-vie

http://www.geautomation.com/system/files/files/gea-s1300.pdf



Unit Supervisory Instrumentation The set includes full unit supervisory instrumentation using a Bently Nevada 3300 series probes and devices for monitoring alarm and trip functions. The monitoring of these devices is integrated into the Mark VIe control system. There are vibration probes on all bearings, axial position, turbine key phasor and dual element bearing and generator RTD’s for temperature monitoring. Due to it’s larger size, this unit comes with both upper and lower turbine casing thermocouple and differential expansion detectors to aid in the real time evaluation of the start-up conditions of the unit which allows reduced thermal stresses and allows a smoother start-up of the machine. There are also local sight flows and temperature and pressure indicators in the required locations. A list of all supervisory instrumentation and devices included is available upon request. Condition Based Maintenance Provisions The steam turbine is incorporated with 6 locations for borescope access to inspect the condition of the steam path between major inspections and to allow for condition based maintenance and major outage interval extensions based on the borescope inspection of steam path condition. Generator Control System The generator has a new GE EX2100e digital control system that was retrofitted in 2013. The EX2100e Excitation Control is GE’s latest state-of-the-art control for both new and retrofit steam, gas, and hydro generators. The control hardware and software design is closely coordinated between GE’s system and controls engineering to ensure delivery of a true system solution. Integration between the EX2100e control, Mark* VIe control, Mark VI Integrated Control System (ICS), LS2100e Static Starter, and human-machine interface (HMI) is seamless. For stand-alone retrofit applications, integration with customer distributed control systems (DCS) through ModBus® Ethernet is supported. Generator protection devices are included in the EX2100e system. More information can be found at the following website link: http://www.geautomation.com/system/files/files/gea-s1302.pdf

http://www.geautomation.com/system/files/files/gea-s1302.pdf



Auxiliary Systems The following turbine and generator auxiliary systems are included in the price of the STG set: Lube and Seal Oil System The system provides both lube oil to the set and seal oil for the hydrogen cooled generator. It consists of the following items:

2000-gallon oil tank

(2) AC motor driven bearing and seal oil pumps

DC emergency bearing and seal oil pump

DC motor starter with battery bank and charger

Duplex oil coolers

Tank heater

Duplex oil filters

Pump test capability

Alarm and trip devices High Pressure Control Oil System

(2) AC motor driven high pressure hydraulic pumps

Duplex control oil coolers

Tank heater

Duplex oil filters and fluid conditioning system

Duplex accumulators

Pump test capability

Alarm and trip devices Seal Oil System

Seal oil differential pressure regulator

Seal oil filtering system

Piping, drain tanks and devices for seal oil pressure and drain control

Seal and bearing drain tanks

Hydrogen Gas Control System

As stated previously the hydrogen control cabinet has been removed from the unit and is not available

Hydrogen and C02 bottle manifold



Steam Seal Regulator System

Pneumatically operated and controlled Fisher steam seal feed and dump valves

Fisher split range controller

Manual and by pass valving Gland Seal Condenser System

Surface Condenser

AC motor driven blower Non Return Valves

(3) Non return valves for the 3 uncontrolled extraction locations-reverse flow pneumatically tripped and controlled

On line test capability Main Stop Valve

14”-900# partial arc stop valve with integral steam strainer

High pressure actuated

On line test capability Turning Gear

AC motor driven turning gear

Pneumatically actuated remote and automatic engagement Condenser System The condenser and support systems are included in the price of this unit. The condenser was manufactured by Graham Manufacturing Co. in 1990. The unit is rated at the following:

Surface Area: 58,691 sq. ft.

Duty: 434.83 X 10⁶ btu/lb.

Exhaust Pressure: 2.24” HgA

Exhaust Flow: 481,020 lb./hr.

Colling Water Inlet Temp: 80F

Cooling Water Flow: 43,480 GPM

Tube Material: 90/10 CuNi



The items included in the condenser system are the following

Surface condenser

Condensate pumps

Air ejection system with inter and after condenser

Assorted gauges and valves Due to the relatively low exhaust pressure and high cooling water temperature for its duty in the southeastern US, this is a very large condenser to be able to pull 2.25” HgA in such a warm climate. If its reapplied to a location with lower cooling water temperatures the exhaust pressure could be greatly reduced, for a significant gain in available energy and extra power generation over operation in a warm climate. For example, if the condenser is operated at its exhaust pressure rating point of 2.25” HgA and the reapplication was to operate at 1.5” HgA, the gain in kW’s just from a lowering of the backpressure in a cooler climate would equal 500+ kW’s or about 1% in output. It’s a significant gain and could generate an extra $200,000 yearly (estimated based on $.05/kw-hr) for no extra steam flow/fuel for the boiler. The support systems are also included in the scope of supply. The condenser was completely re-tubed in 2013, so it is in “as new” operational condition. The owner has spent in excess of $840,000 to perform this re-tubing of the condenser. The complete condenser data is provided in Appendix 1 below. Additional Documentation Available

Construction Prints

STG Mechanical Outline (larger format than in this report)

Multiple hard copies of GE and Graham Condenser Instruction Manuals

STG Parts Books

Miscellaneous STG component drawings

Multiple copies of GE Mark VIe control system instruction manuals and retrofit data

GE STG training manuals from Training Course



Technical Support and Contact Information The price of the unit includes limited technical support and engineering services to any potential buyer.



Appendix 1

Unit Data



Steam Turbine Generator Nameplate



Steam Turbine Data Sheets

198075

Replaced with GE Mark VIe in 2013

Not Traditional Automatic

Extraction



Steam Turbine Data Sheets



Steam Turbine Cross Section

Insert Here



Steam Turbine Generator Performance



Steam Turbine Generator Performance Guarantee Point- Heat Balance



Steam Turbine Generator Performance OEM Locus of Valve Point Heat Balance



Steam Turbine Generator Mechanical Outline



Generator Data



Condenser Data

Condenser Re-tubed in 2013



Condenser Data



Appendix 2

Unit Pictures

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