RESULTS OF THE GT PRIME PROGRAM …proceedings.asmedigitalcollection.asme.org/data/Conferences/ASMEP/... · Houston Industries Energy, Inc. ... eight General Electric MS7001 gas turbines

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Copyright 0 1998 by ASME

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RESULTS OF THE GT PRIME PROGRAM IMPROVEMENTS TO GENERAL ELECTRIC MS7001B GAS TURBINES AT THE

HOUSTON LIGHT AND POWER Ti!. WHARTON SITE

111111111111,111111111111

Jerome Svatek Houston Industries Energy, Inc.

Michael Elliott Houston Light and Power

Paul Crabtree Gerald E. Jurczynski

John R. (Bob) Johnston General Electric Company

ABSTRACT At the time of the start of the GT PRIME upgrade project, the

eight General Electric MS7001 gas turbines in combined cycle service at the Wharton Station of Houston lighting and Power each had 85,000 hours of operation with 2000 starts. The units were ready for their second major overhaul. A number of hot gas path components required replacement at that time. Rather than replacing components one by one, the user devised a Program for Reliability, Improved Maintenance, and Efficiency (GT PRIME). We will discuss turbine condition, design changes, reduced emissions, and increased output in the paper.

Actual user experience on maintenance and operating costs resulted in some special requirements to be satisfied in addition to the expected parts replacement General Electric had developed many improved parts for newer units, all of which could be easily applied to older machines. The use of these newer production MS700 1 EA parts increase component life, parts availability, . inspection intervals, system reliability and performance. These will be described in the paper.

These 1972 vintage turbines achieved a 5OPPM NOx level by injecting water at a high rate of flow which resulted in the need for more frequent combustion inspection intervals. The development of a dry low NOx system for the unit allowed the combustion inspection interval to double while reducing NOx to 25PPM.

The improvement in cO111 17.12.frOt efficiencies in the gas path resulted in increased output and improved the ht.!? rate. These changes had a significant impact on customer operating costs whieli resulted in a very attractive payback period. We will discuss expected versus actual output, heat rate and emissions results for all eight units. The upgrade of the first unit started in 1992 and the

last unit was completed in 1996. A detailed listing of uprate program schedule by unit is listed in Figure #1.

MAJOR MAINTENANCE CONCERNS The T.H. Wharton combined cycle gas turbines were in base

load continuous duty service from 1975 to 1985. Since then, they have been in mid range peaking service. This service is defined as one start for each twelve to sixteen hours of operation, 150 to 200 starts per year. The user's gas turbines are at base load when running and all fired hours are on temperature control. System spinning reserve and load control is done with large steam turbine generators.

The gas turbines began to require maintenance based on number of starts. At the same time, several major components were reaching the end of their life. The user desired a program to restore the units for another twenty years operation, make improvements for dailycycling, and utilize current production hardware. A plan to accomplish this was developed jointly by the user and the manufacturer. The program WRS broadened by the user to include other items that they felt required replacement to meet their operational objectives. The reason for replacement and a description of how the item was improved will be given for each item changed.

CT PRIME PROGRAM UPGRADE COMPONENTS A cieLiiietd fisting of all GT Prime Program design

improvements is includal in Figure #2. A detailed description of each design change is included in the following patagzphs. As the

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program took four years to complete, many additional design improvements were incorporated into later units, as they became available. Figure #3 provides a detailed matrix of these additional design improvements. In some cases this caused different drawing numbers for later vintage upgrades, but in all cases the actual parts are interchangeable.

Gas Turbine Flange-to-Flange Components

Turbine Nozzles (Three Stages). The first stage turbine nozzles were mostly the original nozzles supplied when the units were delivered in 1972-1974 (four spares had been purchased through the years and nozzles were exchanged in and out of machines as needed). Several of the first stage nozzles had been through four to six repair cycles. The four vane per segment stage one nozzles distorted and cracked in service. Hot gas inspections were becoming more frequent and often occurred as extensions to what was originally planned as a combustion inspection. The new component has improved film cooling, minimizes distortion and cracking by using only two nozzle partitions per segment, and is made of FSX414A material, The nozzle is a readily available production 7001EA nozzle, designed for 2020F turbine inlet temperature, and will be run in these units at 1965F. It will not require inspection before 24,000 hours of nmning or 1200 starts.

The original second and third stage nozzles, made of a cobalt alloy, creep downstream due to their cantilever design. The deflection of second stage nozzles on the units has been higher than average for the fleet, perhaps as a consequence of the turbines cyclical duty. The replacement nozzles are of a substantially more creep resistance nickel alloy, GTD222, and the stage two has film cooled vanes (per Figure #4). Repair for deflection will not be needed prior to 24,000 hours of operation. Due to the significant improvement in creep resistance for GTD222 material for stage two nozzles, air through stage one shroud to stage two nozzle was incorporated into the third uprate by using smaller diameter holes in the shroud as detailed in Figure #3.

Turbine Case Including Shroud Blocks. Some of the turbine cases have cracks at the forward four way joints due to cyclic operation. The gas turbine stator tube has shown internal misalignment and the turbine casing vertical flanges were no longer perpendicular to the machine axis. Thus, a decision was made to provide new MS7001EA style turbine casings. The new cases incorporate improved casting techniques providing a refined grain structure. Shroud blocks are changed from a 400 series stainless steel to type 310 stainless for better corrosion life. In addition, the first stage design is changed to provide more structural stability, while the third stage shroud is changed to be compatible with the 7001E stage three buckets.

Turbine Rotor. The turbine wheels were replaced due to dovetail wear. The new wheels were coated with GECC-1 (a GE proprietary coating) in the dovetail as well as the web areas. The aft turbine stub shaft is replaced because the number three bearing is thirteen inches in diameter (original MS7001B design was eleven inches in diameter) to increase torque capability. The forward

turbine stub shaft was lengthened to move the mating flange with the compressor forward of the number two bearing seals (to make it identical to the highly successful MS7001E design). The stage one to stage two spacer was changed to reroute coning air to the stage two bucket while the stage two to stage three spacer was replaced so a complete new rotor could be provided. Due to the many turbine rotor design changes, it was decided to replace the entire turbine rotor with new M57001E turbine rotors for all eight units.

Turbine Buckets. The first stage buckets had been repaired and recoated two or three times. Metallurgical examination showed voids due to creep and a reduction in properties. There were also buckets found with cracks propagating from the internal cooling holes. The second and third stage buckets had high hours and were also changed. All replacements were to the latest 700 lEA design and suitable for the increase in firing temperature from 1840F to 1965F. (All three stages of turbine buckets are actually suitable for operation at the standard MS700 IRA firing temperature of 2020F.) The buckets were upgraded from 1738 to GTD111 on stage one, from 0500 to 1N738 on stage two with film cooling, and to an improved design still using 1.1500 on stage three. The last several units were also provided with the improved directionally solidified GID111 metallurgy as a thither product improvement Buckets will not require inspection before 24,000 hours or 1200 starts.

Bearings. The number two bearing was changed to incorporate design refinements and to move the forward seal This is desirable to do with the required seventeenth stage wheel, compressor stub shaft change. The number three bearing is a larger diameter to match the shaft which was increased to thirteen inch diameter for torque capability. Both bearings are the latest MS700 lEA configuration for leak resistance.

Exhaust Frame and Exhaust Diffuser. The exhaust frame and diffuser sheet metal had numerous cracks and been repaired many times. With the exception of axial struts, the replacement was to the latest 7EA configuration established after many design iterations. It incorporates an improved cooling system for not only the exhaust struts but also the turbine case. The aft diffuser and turning vane assembly is a non-split design (no horizontal joint) for less leakage and distortion.

Load Coupling. The solid load coupling was replaced because the turbine output flange diameter is a larger diameter for high load capacity.

Compressor Wheel Assembly (Stage l7). The original sevaneenth stage compressor wheel had straight radial vanes to duct turbine cooling air inward. Wheel replacement had been recommended in 1974 to a wheel with involute vanes to reduce flow disturbances believed to cause fretting of the compressor rotor tau bolt and nut threads. The replacement wheel hai the latest involute vanes and also incorptvaies a shorter stub shaft to permit change to the number two bearing seals.

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Compressor Inlet Guide Vanes Olin Flow). New inlet guide vanes of 011)450 material with a reduced camber were retrofitted to increase compressor air flow and output by about 4.4%. Figure #5 shows design changes.

Compressor Stator Vanes (Stage 17 and EGV). Exit guide vanes and seventeenth stage stator vanes were replaced because the higher pressure ratio in the retrofitted unit when run with the inlet guide vanes closed down, to insure maximum exhaust temperature to the boiler at low loads, could cause stall on these stages resulting in blade failure during low ambient operation. The new blade designs incorporate shrouds on the blade tips for improved strength Refer to Figure #6.

Combustion System. The combustion liners and transition pieces required inspection intervals of 4000 hours with water injection according to the schedule for NOx control. This period would be substantially increased to 8000 hours when retrofitting with a Dry Low NOx combustion system. The dry system eliminated the need for water injection when operating on gas fuel. The liners are of Hastalloy X material with thermal barrier coating. Transition pieces were upgraded to the latest heavy wall design and are of HTP784 (Nimonic) material with thermal barrier coating. Figure #7 compares the original combustor vs. the new DLN system.

Gas Turbine Support Equipment

Cooling Water System (Off Base). The old on base cooling water module was marginal at high ambient temperatures. The radiator plenum also reduced the headroom in the accessory compartment The cooling system was completely replaced with a conventional off base system equipped with redundant pumps and two large cooling fans. Availability of space around the units was limited. This required location of the complete cooling skid at some distance from the unit. The roof of the accessory compartment was replaced when the water cooling module was removed so the compartment now has full stand-up headroom.

Lube 011 Pump (Gear Driven). The main lube oil pump was replaced with a pump of larger capacity. This was required to satisfy the flow requirements of the large number three bearing.

Lube 011 Mist Eliminator (Demister). The electrostatic precipitators initially . provided to eliminate the lube oil mist discharge were located on the roof of the accessory compartment between the inlet silencers. This made the frequent access required for maintenance for satisfactory operation difficult They were changed to mechanical lube oil mist eliminators and relocated beside the units. This, along with the cooling water change, also cleared the accessory roof areas for future user replacement of the dual inlet silencers with a single silencer.

Turning Gear Including autch The turning gear located at the generator end of the train was subject to high vibration and required frequent maintenance as did the jaw clutch linking the starting motor to the accessory gear. Both were replaced by a single combined turning gear and SSS clutch located at the accessory end of the turbine in the accessory compartment Figure #8 compares the original starting system arrangement with the new starting system arrangement

Turbine Compartment The original turbine compartment was made to be rail shippable when fully assembled. This places some panels and doors in close proximity to hot turbine casings. Station personnel cut the structure off the base to facilitate major turbine maintenance. The original enclosure after a number of rebuilds was no longer leak tight for proper ventilation or fire protection. A new turbine compartment was designed. It is supported off base and is significantly wider. The roof is higher and readily removable in two pieces. A rail is located inside to easily handle combustion components for improved maintenance during combustion inspections.

Improved Cooling. The turbine compartment and the load tunnel operated at barely acceptable temperature limits. Large, 103HP, exhaust frame blowers were added to positively cool the turbine case, provide balanced exhaust strut cooling, and also provide ventilation to the exhaust tunnel around the number three bearing. A new load compartment roof was provided with the present MS700 lEA production fan system incorporated. A larger replacement fan was added to the turbine compartment roof and the system revised to pull air both from the accessory compartment as well as through four gravity dampers located low in the turbine compartment base

Water Wash Manifolds (On and Off Line). Problems had been encountered with fouled compressors particularly during nearby highway construction. Water wash nozzles and manifolding were added for both on line and off line water washing of the compressor.

GENERATOR UPGRADES

Generator Stator Insulation Upgrade Some of the generator stator coils were replaced in the past 10

years with Class F insulation, which is rated at a higher operating temperature than the original Class B insulation. The original Class B insulation was rated at 100 degrees C operating temperature, measured by RTD. The replacement coils are rated at 120 degrees C. All of the units that had not been fitted with the new coils were uprated accordingly. One unit that had been previously rewound with new F class coils required replacement with new coils during the outage. This unit had some installation problems during the original retrofit that resulted in a number of coil failures while being inspected during the GT PRIME outage. The additional cooling provided by the improved generator ducting and filtering should provide additional reliability.

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Self Cleaning Filter for the Generator

The gas turbine generators are open ventilated design with direct use of ambient air for generator cooling. A self-cleaning type filter with replaceable cartridges was provided for the generator. This was desired because dirt ingestion had been sufficient to require rewinding. The new arrangement also relocated the generator cooling air intake to eliminate ingestion of warm air (due to the close proximity of the exhaust duct) which reduced generator capacity.

Generator Inlet The original installation had the turbine exhaust duct along side

the inlet to one side of the generator. Consequently, the inlet air to one side of the generator was about 10°F higher than ambient temperature. The combined effect of the new generator inlet filter house design and the installation of an air deflector resulted in now having ambient temperature to the generator for cooling.

CONTROL AND INSTRUMENTATION

Mark V SPEEDIRONIC" . Simplex Control System As part of the Dry Low NOx combustion system retrofit the MK-

I SPEEDTRONIC1I4 control system was replaced with a non-redundant MK-V/Simplex SPEEDIRONICTm. One of the considerations for the selection of the MK-V/Simplex over the ME-V11MR (Triple Modular Redundant) system was the physical dimensions of the panel. The MK-V/Simplex panel is 36" wide, the same width as the MK-I panel, while the MK-V/TMR panel is 54" wide. The MK-V Operator Interface PC, the <I>, processor was located in the Main Control Room, remote from the control panel.

New Sensors and Rewiring As part of the control system replacement the turbine wiring was

also replaced to satisfy the Houston Light and Power maintenance concerns. Some devices were also replaced to minimize control problems due to aging instrumentation. In addition, bearing metal thermocouples and vibration proximity probes were added as required by Houston Light and Power. Special probes were provided to allow the removal of the probes without the disassembly of the number three bearing.

Historian A MK-V/Historian, <H> PC, was used to provide data logging

capability of the turbine operation. The data logged by the Historian can be accessed by the <I> processors for display and trending. One historian provides data logging capability for each group of four MK-V/Simplex systems.

Gas Selection Skid

As part of the Dry Low NOx hardware, a fuel gas selection skid was provided and located off-base from the gas turbine. The function of the equipment of the skid was to distribute the fuel gas between the primary and secondary combustion zones of the Dry Low Nat combustor.

SUMMARY OF PERFORMANCE AND EMISSION UP-GRADES

There are numerous performance changes as a result of removal of the water injection system, the increase in turbine firing temperature, and the numerous design improvements. Figure 019 shows a comparison of the uprated gas turbine vs. the generator at various system power factors. Since HL8cP typically operates at electrical system power factors in excess of 0.95, there is sufficient generator capability to handle the increased turbine output

Figure 810 is a detailed matrix of all turbine performance related design changes showing the output and efficiency related performance improvements.

Figure a 1 1 shows the actual improvements in output and heat rate for each unit based on actual performance tests after the completion of the uprate.

The gas turbine performance improvement was guaranteed. On natural gas at 100F ambient with the Dry Low NOx combustion, the output was guaranteed to increase by 9.9 percent while heat rate would be reduced by 3.2 percent over the present water injected turbine performance. As a reference, the 1972 performance was guaranteed to 100°F as 50,100 kilowatts and 12,920 BTU per kWh for each turbine alone.

When adjusted for no water injection, the output guarantee increases to 12.1 percent and the heat rate guarantee decreased to 2.6 percent on a new and clean basis. Actual test results adjusted to 100°F ambient with no water injection show an increase in output of 17.3 percent and a decrease in heat rate of 6.3 percent over that of the unit as tested prior to teardown. This extremely large improvement reflects the recovery of performance degradation included in the before test.

On an expected basis, the overall plant combined cycle output increased by more than 8.0 percent while overall plant heat rate decreased by 3.6 percent at 100F Based on a boiler design revised in 1984, the baseline plant performance per four unit block was 298,370 kilowatts with an overall heat rate of 8090 BM per kWh (LIN). The combined cycle performance increase was not guaranteed.

COMBINED CYCLE/PLANT IMPACT OF THE CT PRIME PROGRAM

It was also necessary to evaluate the impact of the gas turbine upgrade on the steam turbine, heat recovery steam generator, and the steam turbine driven generator.

Steam Turbine When developing performance initially, the cycle was

constrained so as not to exceed steam turbine guaranteed steam flow passing capability. This was sufficiently restrictive to prevent any other steam turbine limits from coming into play. Thus, the steam turbines were within allowable design limits on steam chest pressure and temperature. After a review of the combined cycle performance, it was jointly agreed to use the expected flow passing capability of the steam turbine as a more representative measure of the true cycle limitations. Figure #13 shows both of these limits along with the theoretical steam generated by the boiler on a new and clean basis Note that this limit would only be reached when all four gas turbines in the block with that steam turbine wee operating at full load.


With the flow increased, a second limitation was found. This was steam turbine throttle temperature at part load at high ambient gas turbine inlet temperatures. This was resolved by limiting the gas turbine operating envelope at temperatures above 65°F as shown in Figure #12. Also, to handle the increased steam flow, the first stage nozzle area was increased by 4%, the second stage buckets and diapluam were removed and the bucket notch groups were modified for stages 4 thru 7.

Heat Recovery Steam Generator A plan was developed to modify the superheaters due to inlet

steam temperature limits on the steam turbine. On the lint unit, surface area was removed from the last pass (IffitSG inlet) of the superheater by replacing finned tubes with bare tubes. The HRSG's are General Eleatic horizontal tube forced circulation units supplied to Houston Light and Power in 1975. They had previously been modified by replacing the economizer and adding surface to the evaporator. For this unit, eleven of the thirty-three finned tubes were removed and replaced with bare tubes. Preliminary results indicate a superheater outlet temperature equal to the unmodified units with the gas turbine exhaust temperature increased from 975F (524C) to 1030F (555C). The steam flow increase is approximately twenty percent over an unmodified unit. A portion of the increased steam production is also due to replacement of the exhaust duct bypass dampers, which had been leaking.

providers. PGS provided overall project management, engineering support for the mechanical, electrical and controls, along with on-site engineering of the electrical cabling and junction box interconnections. Additional support was provided by the GE Houston Apparatus Service Center for the turbine and compressor rotors along with the on-site machining.

Pint:: Management The project management phase of this project encompassed all

phases of the project PGS had responsibility of initially identifying all of the work items and then coordinating these items to a master schedule. In addition to the scheduling aspects of the project, the on-site team had the responsibility of materials procurement and budgetary costing. The overall coordination of the execution of the field modification instruction with Schenectady Engineering was provided by the on-site project team.

Another aspect of the project was the cooniination.of the various labor sources. The project utilized Houston Lighting & Power as a labor source for the turbine base, turbine components and associated DLN manifolds. HL&P support was also used in the start-up and checkout of the controls and electrical systems. ADA Construction was used as the craft labor support for the turbine mechanical auxiliaries. Additional work was performed utilizing a local electrical contractor for the installation of new cabling, cable hays, conduit and junction boxes.

Steam Turbine Generators It was also necessary to review the capability of the steam

turbine generator to make sure it could handle the additional output from the steam turbine. Figure #14 shows that there is considerable extra capability in the existing generator (line #2) at 0.95 system power factor to handle the increased steam turbine output (line #5). Thus, it was not necessary to uprate this generator as proposed by lines #3 and #4.

Emissions These units were initially permitted with a NOx emissions

requirement of 0.2 lb/mm Btu of heat input for natural gas. This was achieved by injection of 34 GPM water at ISO conditions to produce a level of 52 PPM NOx at 15 percent oxygen. As this was the first application of the GE Dry Low NOx technology to MS7001B units, the initial requirement for the first few units was more liberal than the final contract requirements. Interim emission levels for the first three units to be modified required that the units could not exceed the "current permitted emission limitations" with retrofit to meet the contractual requirement of 25 PPM NOx at 15 percent oxygen. A new limitation on CO was also applied. The contractual requirement was set at 25 PPM. All eight units met or exceeded the emission reduction requirements of the contract

POWER GENERATION SERVICES SUPPORT THE GT PRIME PROJECT

The role that GE POWC Generation Services (PGS) played in the GT PRIME Project was as unique as the initial concept of such a large scale upgrade. The project required a number of on-site engineering support functions along with a variety of craft labor

Site Engineering Support The on-site support was broken down into turbine mechanical,

auxiliary support modifications, electrical, and controls start-up functions. Each of these areas were supported with field engineers out of the local power generation services office. The mechanical installation of the turbine was composed of the turbine base modifications, turbine component assembly, DLN piping installation, and the installation of a larger turbine enclosure. This work was done with an on-site mechanical field engineer supervising the installation of the equipment and coordinating the HL&P provided labor.

The auxiliaries being composed of all the turbine support functions were coordinated with a designated field engineer which directed the job activities and coordinated the ADA Construction provided craft labor. The auxiliary installation included the installation of a new generator inlet filter, cooling water skid installation, and accessory base modifications. All of the cooling water and fire protection piping installations were also done using GE supplied labor.

The electrical requirements of the project were more detailed than a normal installation in that the customer requested a number of revisions in the junction box and cabling layouts. All of the wiring termination points and cable runs were redesigned per HL&P's plant requirements. The cabling and junction box layouts were revised in a manner which would allow easier accessibility and maintenance for the life extension of the plant.

The Mark V controls installation and unit start-up were a shared task between GE and HIS?. The project provided a start-up controls engineer and HIAF provided all of the instrument and controls craft labor. Additional support was provided in the review of the Mark V programming to the old elementary drawings to ensure that all of the control functions and interconnections were

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correct Site Mark V control loop drawings were developed on site for easier trouble shooting capabilities.

An integral part of the project was the role played by the Houston Service Center. The Service Center provided all of the modifications to the compressor and turbine rotors. The on-site machining and doweling activities were also provided by the Houston Center.

SUMMARY The component changes replaced worn out parts with parts

designed for longer life and longer periods of operation before requiring inspection. Combustion inspection intervals were doubled to 8000 hours, while the hot gas path components (nozzles, buckets and shrouds) shall not require inspection before 24,000 hours or 1200 fired starts. Creep deflection repair of nozzles is not required prior to 24,000 hours operation. Compartment and load tunnel temperatures meet specific temperature guarantees. The support equipment changes facilitate maintenance. The use of the Mark V has improved control reliability.

The units have been upgraded to reflect improvements in technology made in the last two decades. A significantly more reliable an easily maintained unit has been provided. In addition, these changes are guaranteed to provide almost a 10 percent increase in turbine output while reducing heat rate by 3.2 percent while NOx emissions have been reduced from 50 PPM to 25 PPM

Additionally, and most importantly, the significant improvements in technology in the hot gas path area should extend the expected plant life for beyond the intended 20 year extension of the life of the plant

REFERENCES 1. JR Johnston - "Performance and Reliability Improvements for

Heavy Duty Gas Turbines" ASME Paper No. 87-GT-23, 1987 2. DK Prugger and WI McDermott - "Modification of a General

Electric 7001B Turbine for Increased Reliability by Using 7001E Parts" ASME Paper No. 90-GT-284, 1990

3. LA Kelly and HP Leussen - "Upmte Options for the MS7001 and MS9001 Gas Turbines" General Electric Paper GER3667, 1991

4. JR Johnston - "Performance and Reliability Improvements for Heavy Duty Gas Turbines" General Electric Paper GER3571G, 19%

5. RL Gessner - "Various Memos on Houston Lighting and Power Performance Improvement" 1991, 1992

6. DK Prugger and FM Fuseiler - "Planned OT Prime Improvements to General Electric MS7001B Gas Turbines" ASME Paper No. 94-GT-123, 1994

7. RA Kuelinle, Jr. And MA Reed of HIM - "GT PRIME Status on Performance Improvements", 94-JPGC-GT-3


Figure 1

CT PRIME Upgrade Program Project Dates Houston Light and Power

T.H. Wharton Site

TB S/N Unit # Begin Outage Date

Complete Outage Date

217792 43 11130/92 5/27/93

217793 44 9/13/93 2/28/94

217761 42 1/17/94 7118//94

217759 41 9/12/94 2/20/95

217760 32 1/16/95 6/26/95

217758 33 9/11/95 2/19/96

217757 34 1/15/96 6/24/96

217756 31 9/9/96 2/24197

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fmr_e #2 List of Replacement Components for CT Prime Prouram

Flange to Flange Components Turbine nozzles (three stages) Turbine Case including shroud blocks Turbine Rotor

- Buckets (three stages) - Wheels (three stages) - Forward stub shaft - Aft stub shaft - Wheelspacers

Number two bearing complete and compressor discharge case Number three bearing complete Exhaust frame Exhaust diffuser Load coupling Compressor wheel assembly (stage 17) Compressor inlet guide vanes (high flow) Compressor stator vanes (stage 17 and EGV) Dry Low NOx combustion system Transition pieces

Support Equipment Cooling water system (off base) Lube oil pump (gear driven) Lube oil mist eliminator (demister) Turning gear Starting clutch Turbine compartment lagging Improved cooling

- Exhaust frame blowers - Ventilation fans

Wash water manifolds (on and off line)

Generator Upgrades Rotor slip plane modification Partial discharge monitor Generator filtration modifications Generator inlet air deflector

Controls and Instrumentation Mark V SPEEDTRONIC Simplex Control System New sensors and rewiring Historian Performance monitor Gas selection skid Proximity probes (externally removable)

Each item on the replacement list will be discussed. The reason for concern about the item and the nature of the improvement will be given.


JaL&P. T.H. Wharton Plant - MS 7001WE Turbine Parts Matrix

Unit t/-

SIN

Stage 1

Shrouds

Stage 1

Nozzle

Nozzle

Sup't. Ring

Stage 2 Nozzle Air

Stage 1

Bucket Kit.

Rotor Asm.

2-3 Spacer

Cprsr

Discharge Casing

Combustion Wrapper

Turbine Shell Arrangement

Outer Case Assembly,

Combustion

Rotor Assembly,

Compressor

43 -217792 339A99646005 932E01990007 178C65360003 103E55710007 3141371656009 132D3185P005 1811390990001 18113908701301 103E30206009 110E11016001 (Scheduled)

44-217793 339A99640002 103E55710001 185D38250001 103E82010001 109E31360002 209C493I0001

42-217761 339A9964G004 " " " Existing 105E88796002 103E30200013

32-217760 " .. .. "

31-217756 " 109E37350001 103E55710007

33-217758 . 178C65360005 103E55710008 3141371656013 "

41-217759 " .. 103E55710008

34-217757 " " " ii979E0358G003 ,. reiSEE;NOT13,3 ,

Notes: 1. The above matrix represents turbine parts unique to a specified gas turbine tint If not listed in the above matrix, the OT parts associated with GTPRIME are identical for all units. Uni N43 (SIN 217792) is

the only unit with original, but modified Turbine Shell, Compressor Discharge Casing and Combustion Wrapper. All other units employed these new casings to reduce field cycle time and on-site labor cost. 2. Verbal description of each assembly noted above is as follows:

vel

ML 0705, First Stage Shround:

ML 1401, First Stage Nozzle Art:

339A99640002 - .812" dia. cooling holes for stg2 nozzle cooling. 339A99640004 - .469" dia. cooling holes for stg2 nozzle cooling. 339A99646005 - Field modified .812" dia. to .469" dia cooling holes for stg2 nozzle cooling. 932E01990007 - MS7001EA Advance tech WTI 2 vane per segment nozzle 109E37356001 - MT nozzle w/ Cords! Hinge design and improved side wall cooling.

ML 1403, Nozzle Support Ring: I 78C65360003 - Compatable design for new stgl nozzle. I 78C65360005 - Compatable design for new stgl nozzle with improved locking hardware design.

ML 1402, 2nd Stage Nozzle Arr: 979E03586003 - G1'D-222 nozzle, uncoated material. 103E55710001 - GTD-222 nozzle w/ improved cooling design. 103E55716007 - GTD-222 nozzle w/ improved cooling, thicker seal segments between diaphragm sets.

ML 1305, 1st Stage Bucket Kit: 3141371656009 - 6TD-1 I I blunt leading edge equiaxed bucket design. This kit # breaksdown to bucket 103E5592 3141171656013 - 0113-111 blunt leading edge directionally solidified (DS) bucket design. This kit if breaksdown to bucket 109E3203

2-3 Spacer: 132D3185P005 - New AO, current production spacer. Used initially in the CT PRIME project to facilitate rotor upgrade program.

Existing. - Reusing 2-3 spacer from customer's model "B" rotor. ML 0805, Cprsr Discharge Case:

181D90990001 - Modification drawing for machining existing model "B" case, 813E04320003. 185D3825G001 - New special design CDC casing for B to E conversion.

ML 0712, Comb Outer Wrapper:

181D9087G001 - Modification drawing for machining existing model "B" Wrapper, 813E02310007. 103E82010001 - New current design AO combustion wrapper 105E88790002 - Different paint process otherwise same as 103E82016001.

ML 0705, Turbine Shell:

103E30200009 - New turbine shell with full size orifice arrangement in stage 1 shrouds for stg2 nozzle cooling. Casing .100" longer than standard. 103E30200013 - New turbine shell with reduced nozzle cooling passages for stg2 nozzle cooling.

ML 0719, Comb Outer Case Assy:

110E11016001 - Key hole pattern is can positions 2 & 9. 109E31366002 - Key Hole Pattern in can positions 2,4, 7, & 9.

ML 1303, Compressor Rotor Asm. Scheduled Dwg - New standard production 16th & 17th stage wheels/stub shaft 209C4931G001 - 16th stg wheel machined to 1811396890001 and Special thicker 17th stg wheel and stub shaft.

3. This nozzle is a used GTD-222 Nozzle from unit 443 which was referbished and coated.

Figure 3


Performance Improvement

Output Heat Rate

MS6001B +1.0% -0.4% MS7001E/EA +0.8% -0.3% MS9001E +1.0% -0.4%

Reduced Cooling Flow Controlled by Tuning Pin

-8

Conversions, Modifications, and Uprates

GTD-222 Stage 2 Nozzle

Figure 4


S.

Design Improvements With GTD-450 High-Flow IGV Designs

• Improved Airfoil Geometry for Higher Power

• New Material for High Corrosion Resistance Without Coating

• Variable Airfoil % Thickness to Maintain Reliability With New Geometry

• Greater Fatigue Resistance Properties

11% TIC

6% VC

E 0.6

0.4

0.2

1.8

1.6

Gm 460

A SI403

• 1.4

U 12 ih 1.0

Higher Performance AirfoU Fa 0.8

, Variable 0 0 Thicimess

`‘‘

Airfoil %_, 0

10 20 30 40 50 60 70 Mean Stress (lull)

137237813A

Figure 5


Side View of the Three Stages of Shrouded Compressor Blades

NJ

Compressor Discharge

Caning it S17 r i EGV-1 r LI EGV-2

I

1 1

Inner Barrel Casing

GT21358A

Figure 6


MS7001 B TO E COMBUSTION SYSTEM (DLN-I CONFIGURATION)

TRANSITION PIECE ARR. COMBUSTION ri (SEE ML-07M

TI

rri

TYPICAL VIEW OF CONS CHANDER

CAP AND LINER TRANSITION PIECE ASSY. (SEE Mt ITEM

-7- 0702) ! 1.1

TRANSITION PIECE

L-11 L

MS7001 B COMBUSTION SYSTEM (LOUVERED LINERS)

L—. DOWNSTREAM

Figure 7

13


NEW COMBINED STARTING MEANS AND TURNING GEAR ARRANGEMENT WITH SSS CLUTCH ADDING

MUCH IMPROVED STARTING RELIABILITY AND AVAILABILITY

HTDRAUUC ACTUATED r JAW CLUTCH MECHANISM

CONVENTIONAL ELECTRIC MOTOR STARTING ARRANGEMENT WITH TORQUE CONVERTER AND HYDRAULIC ACTUATED JAW CLUTCH MECHANISM

Figure 8


85

80 —

75 —

rs 70 _

M

I- D a_ I-D 0 65 —

M57103/E) Option #3 Per Contract for GT Prime

60 —

55 —

20 40 60 80 100

COMPRESSOR INLET TEMPERATURE (F)

50 120

1

o

Houston Light and Power CT Prime Project

FIGURE 9

i


OPTION (1) (2)* ( 3)*

• FIRING TEMP 'IF 1840 1905 1965 • IGV ANGLE GM-45018E GTD-450184* GT13-450184* • % OUTPUT IMPROVEMENT 4.3% 8.4% 10.7% • EXHAUST TEMPERATURE •F -38 0 +37 • % EXHAUST FLOW INCREASE 5.0% 5.0% 5.0% • % THERMAL EFFICIENCY IMPROVEMENT +2.1% +1.6% +2.7%

REQUIRED MATERIAL CHANGES*

STAGE 1 STAGE 1 STAGE 2 STAGE 2 STAGE 3 STAGE 3 STAGE 17 STATOR OPTION IGV BUCKET NOZZLE BUCKET NOZZLE BUCKET NOZZLE COMPRESSOR** BLADES AND EGV'S COMBUSTION

(1) C-450 X X X X (2) C•450 X X X X X X X (3) C-450 X X X X X X X X X

• GENERATOR AND STATION ELECTRICAL EQUIPMENT UPRATE MAY BE REQUIRED

•• ALL NEW COMPRESSOR BLADES MAY BE REQUIRED.

'BLADES MUST BE REPLACED IN THE SEVENTEENTH EGV1, AND EGV2 STATOR ROWS. A NEW SEVENTEENTH STAGE WHEEL IS ALSO REQUIRED IF REPLACEMENT WITH A CURVED IMPELLER HAS NOT BUN MADE

Figure 10. MS7001B and MS9001B Uprate Estimated Performance with Current Production EA/E Hardware


Figure 11 Houston Light & Power Wharton Site

GT PRIME Uprate Performance Results

Site Unit # HLP #43 HLP #44 HLP #42 HLP #41 HLP #32 HLP #33 HLP #34 HLP #31 Turbine Serial Number 217792 217793 217761 217759 217760 217758 217757 217756 Site Conditions at Time of Testing

Ambient Pressure 14.59 14.54 14.76 14.66 14.81 14.67 14.7 14.54 Ambient Temperature 95.63 92.55 87.04 87.85 • 62.83 88.42 69.7 83.28 Inlet Drop 1.75 1.1 1.6 3.23 1.26 3.23 3.53 1.33 Exhaust 15.9 15.3 14.66 15.8 18.5 15.8 17.2 15.9 Relative Humidity 49.23 54.58 87.43 66 30.58 57.36 70.42 61.2 Fuel Nat Gas Nat Gas Nat Gas Nat Gas Nat Gas Nat Gas Nat Gas Nat Gas

Output* Guarantee % 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 Pre Test 47251 48755 45894 45833 45410 45695 48260 45156 Post Test 55438 58113 57875 58088 56425 55494 55982 57150 Actual % 17.3 19.2 26.1 26.7 24.3 21.4 16.0 26.6 Heat Rate* Guarantee % -2.6 -2.6 -2.6 -2.6 -2.6 -2.6 -2.6 -2.6 Pre Test 13693 13723 13782 13876 13939 13968 13393 13967 Post Test 12824 12628 12521 12663 12885 12838 12792 12418 Actual % -6.3 -8.0 -9.1 -8.7 -7.6 -8.1 -4.5 -11.1


HOUSTON LIGHTING AND POWER - CT PRIME PROGRAM

steam 1 uroine benerator UUUUL versus compressor i ni et temperature I

130

E • ...... -...,

.

I

%.. N

7--

N

' \ ' N

1 E5TIMATED PERFORMANCE

128 \

. \

3 126 -8 Based .

C I eatt-C on Original

teed-St,. New and

Tr b Flow .

-,

•-.

. • . 4J

z.

. Passing C-0 • Based

Capability on Original

ity (Opticn on Assumption

Fliw Pas.-s iWg

(Option 3) New and Clean

-Ex pecte4-S4eamarbino-:Flow-Fa-ss4rig--- 4., = o a.' 0 • 124

; Capatil - E : Based

• Til;ls i ne

3) : • 1 : . : of 'Unlimited Steam .

Cipab 4 lity- - • 1 07 • s...

W C W

: (Option 3): •

W - C .

re1 122

—7 re' . sa.

VI

120

:Condi •

ions • • •

- 7 ---1.-- on 2 .

Is_AL ' ifl 51/ _ahoy

-

• - 118

2. Gas Turbi e Inlet/Ex ust - Pressure raps of 2. 20 Inches Opt,

of IaterJ Rospnctivibly 3. Steam Turbine Exhaust Pressure

.17 3.5 • 140 . . . 4; ttticiit - TurbinelanIa.1 IrcssUrn is 84 0_p:S14

(S Over Pressure) 5. Natural - Gai.Fuel. with GT Water Iitjection to

Control t x Entsclons to 42 npmvd q 15% Oxygon • 1 116 • • ' 1 6. Estimated performance is - Based - on New and Clean

Conditions and is Stated per STAG 407 .. '''''' • • '

-

t

. .. i • 114 • "" ----

,

' • - - '

. - - . . ...

. . :

... _ - - • - • . . n CMG:in--0.n

: : : . . . • - • • • • •Cormaressar- . . . . Qn

: : .. :•: : • . • . • Ø • . • . I .

int t- Temperature ( F) 100. -

• •

r-n , n4acr•

Figure 12


80

P..;

4 0

0 al B

ase

Loa

d

fi e

100

GT PRIME HOUSTON LIGHTING & POWER CO.

TH Wharton Station

OPERATING RANGE

,Includes Steam Cycle Constraints

I I I Exceeds Expected Flow Pestling Math tg

LI111

"" " • 1GV Modulation'

Hum throttle Tempereture

1 Minimum 101 Angle TO ICU EMISSIONS =RANT=

r!r•r.: 74rnurrure

Compressor Pressure Retto Ltrmt

20 30 40 50 60 70 80 90 100 a AfIlt!frit Temperature. F

Figure 13

19


• C.

HOUSTON LIGHT 8c POWER ESTIMATED COMPRESSOR INLET TEMPERATURE EFFECT

ON STEAM TURBINE OUTPUT

1.75 / 15.9 INCHES WATER INLET / EXHAUST PRESS DROP TURBINE IN NEW AND CLEAN CONDITION

NATURAL GAS FUEL

14.6

144

142 .

140:

138:

136: 4

134:

132

130

I. CURRENT STEAM GENERATOR MW OUTPUT at .90 PF. • 2. CURRENT STEAM GENERATOR MW OUTPUT at .95 PF. • 3. UPRATED STEAM GENERATOR MW OUTPUT at .90 Pr. •

• 4. UPRATED STEAM GENERATOR MW OUTPUT at .95 PF. • _5. EXPECTED STEAM TURBINE OUTPUT LEVELS.

• • • • ASSUMES INLET ACNEMP.15 10 DEG F ABOVE THE COLD UOUID TEIAPERATURC1/4;;;.7,0.

•

10 20 30 40 50 60 70 80 90

100 110

COMPRESSOR INLET TEMPERATURE (F) RE LAZZURI 10/31/94

Figure 14

SKETCH RFL-1159

20

OU

TPU

T M

W

128

126-

120 0

124-

122- 1


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