evolution of the solar turbines titan 130 industrial gas...

!.

EVOLUTION OF THE SOLAR TURBINES TITAN 130 INDUSTRIAL GAS TURBINE

G. Rocha and C. J. Etheridge Solar Turbines Incorporated

San Diego, California

ABSTRACT Solar Turbines Incorporated has extended the size-range of its'

turbomachincry products with development of the TiJanTM 130 industrial gas turbine. The 13 megawatt-class, simple-cycle machine is designed to produce 13.3 'MW (17 ,800 hp) output power with a thcnnal efficiency of 34.5% at ISO inlet conditions with no losses. The larger gas turbine is intended to meet increasing market demands in gas compression and mechanical pump-<lrive industrial applications.

The overall engine design is based on aerodynami�scale of the 7 'MWclass Taurus™ 70 gas twbine with similar operating cycle parameters. The engine configuration consists of hardware that has been scaled from the Tauru.s 70 and components that are common with theMars® gas turbine. As with the Taurus 10 and Mars products, the Titan 130 gas turbine features a low emissions combustion system based on Solar's proven dry, lean-premix, pollution-prevention technology. The enhance system is capable of reducing pollu1ant emissions over an extended operating range from part-load to full-load conditions.

This paper discusses 1he evolutionary design of the Titan 130 from the Taurus 10 and Mars gas turbines products. Descriptions of the basic configuration, component scaling techniques and modular design construction are presented.

INTRODUCTION The Titan™ 130 industrial gas turbine system was developed in

response to increasing application demands for higher perfonnance industrial turbomachinery products in the 10-to-15 'MW (13.SOO-to-20,000 hp) size range. The simplo-cycle, 13-'MW (18,000-hp) class machine represents the largest gas turbine in Solar's family of turbomachincry products and is available in two-shaft (Figure 1) and single-shaft configurations (Figure 2). Initially, the two-shaft version was introduced with a performance rating of 13.3 'MW (17,800 hp) and 34.5% efficiency, based on JSO..ratod conditions, for industrial service in gas compression and pump-drive applications. Introduction of a single-shaft version will follow for electrical power generation applications, with a predicted ISO rating of 12.4 �<and 32.l % efficiency at the generator terminals.

Using Sola.r's traditional development strategy of product evolution, the Titan 130 gas turbine design incorporates proven technology and design features for rugged, durable industrial service operation with minimal lifecycle costs. The gas twbine operating-cycle and overa11 aerodynamic design is similar to the 7-'MW (9500-hp) size class Taurus™ 10 gas tarbine introduced in 1995 (Rocha, 1995). Proven aerodynamic scaling techniques were implemented to establish flow path and airfoil component designs from the smaller T tnJTUS 70 turbine. Thus, the basic design of the Titan 130 gas turbine features components directly scaled up from the Taurus 10 as well as hardware common to the 11·� (15,000-hp) size classMar.s® gas turbine. It also includes a dry, lean-premixed, low pollutant emissions combustion system based on Solar's SoLoNOx™ technology and demonstrated operating experience.

DEVELOPMENT PROGRAM M.arlcct: studies indicated continued growth in turbomachincry product

demands and greater power requirements for both oil and gas and industrial power generation applications. In response to these market indicators and a conunitrnent to meet customer expections for increased power applications, general product specifications were defined for the Titan 130 which included requirements for output perfoanance, design features, service life objectives, product costs, maintenance features and life-oycle costs. A new product introduction (NPI) team was formed consisting of representatives from all organizations within Solar to establish an integrated product development strategy and prepare an aggressive program plan. A key aspect of the plan relied on product evolution from proven technology to satisfy overall product requirement objectives. The gas turbine design approach adopted was based on aerodynamically scaling the smaller Taurus 70 compressor and turbine to achieve similar operating performance while minimizing development risks and reducing development time.

The overall program goals were to introduce a low risk, durable, highly servicable 13-'MW (18,000-hp) size class industrial gas turbine in approximately 24 months. To meet the aggressive introduction schedule, the development program relied on a teaming approach and concurrent

Presented at the International Gas Turbine & Aeroengine Congress & Exhibition Stockholm, Sweden - June 2-June s, 1998

Downloaded From: http://proceedings.asmedigitalcollection.asme.org/ on 07/06/2018 Terms of Use: http://www.asme.org/about-asme/terms-of-use

--------------------- ---- ---

FIG.1- TITAN130 TWO-SHAFT GAS TURBINE

FIG. 2 - mAN 130 SINGLE-SHAFT GAS TURBINE (PRELIMINARY)

engineering design practices to maximize communication and participation throughout all organizations, while paralleling as many activities as possible to shorten the typical product development cycle. A key benefit to NPI teaming is an integrated product development approach that ensures all product requirements and customer expections are met prior to product introduction.

GAS TURBINE DES CRIPTION

Two-Shaft Model The two-shaft version of the Titan 130 gas turbine is a direct scale of

the smaller Taurus 10 two-shaft gas turbine and is intended only for industrial service in gas compression and pump-drive applications. The basic layout consists of independent gas generator and power turbine modules close coupled in a traditional axial configuration similar to current Solar®

gas turbine products. This typical design configuration with modular construction, as demonstrated with the Taurus 10 gas turbine, makes the

2

Titan 130 gas turbine well-suited for rugged industrial service and provides easy access for field inspcclions and/or scheduled maintenance. To facilitate field service, the machine incorporates 60 borescope access ports for inspection of internal flow path components (Figure 3). A vertically split compressor casing design enables removal of either case half for greater access to internal compressor components for inspection and cleaning or service.

Similar to the Taurus 10 gas turbine, the gas generator module incorporates a 14-stage axial compressor derived from the Mars air compressor driven by a two-stage, high pressure turbine aerodynamically scaled from the Taurus 10 gas turbine. The in-line, annular combustor, housed between the compressor and turbine assemblies, utilizes the latest dry, lean-premixed technology developed from extensive operating experience with Solar's SoLoNO:x pollution-prevention combustion systems. The combustion system includes design enhancements such as a new fueVair ratio control air management system which directly controls airflow to the lean-premixed technology injectors for reduction of pollutant


l

14-R.IB. INJECTOR PORTS

-FIG. 3 - mAN 130 GAS TURBINE BORESCOPE ACCESS LOCATIONS

emissions over an extended operating range from full-load to part-load conditions. The gas generator rotor is supported by three fluid-film, tiltingpad journal bearings with a thrust bearing located in a bearing housing at the forward end of the compressor. The rotor loads are transmitted to the slructutal shell via radial struts in the radial air inlet housing and compressor diffuser housing. The rugged, structural shell of the gas generator module consists of the radial air inlet, compressor, compressor diffuser and turbine support housings. The Titan 130 gas turbine features the integral accessory drive gearbox assembly from the Mars gas turbine, which is flange mounted, to the front face of the scaled air inlet housing for optional gas turbine-driven hydro-mechanical systems.

The power turbine module is a direct scale of the Taurus 10 power turbine which is completely prcasscmbled and independent from the gas generator module. The two-stage axial turbine is flange mounted to the aft end of the turbine case housing in a close-coupled arrangement The two modules can be separated in the horizontal position with less than 50 mm (2 in.) of engagement depth for lateral clearance between modules. This minimal engagement distance between modules enables removaV replacement of either module assembly from the turbomachinery package. The overhung power turbine rotor assembly is supported by two journal bearings with a thrust bearing located at the output end of the shaft An enhanced version oftheMars power turbine bearing housing has been adapted to the Titan 130 power turbine module. A fabricated exhaust collector redirects the exhaust flow radially outward at the aft end of the module and can be rotated in various circumferential orientations. Gas compression or pumpdrive equipment is coupled to the power turbine rotor by a dry-flex coupling shaft assembly.

Gas turbine specifications and material used for major components of the gas turbine are listed in Table 1. The Titan 130 gas turbine weighs approximately 12400 kg(27,.300 lb) and is 6.1 m (19.9 ft) long, 2.1 m (6.9 ft) high, and 2.6 m (8.6 ft) wide in overall envelope dimensions.

Single-Shaft Model Following the introduction of the Titan 130 two-shaft gas turbine

model, a single-shaft version of the Titan 130 gas turbine will be made available in a generator set package for electrical power generation. The single-shaft version will utilize the same gas generator module, but will be modified for a cold-end output drive configuration through the foiward end of the compressor. A new single-stage power turbine will be adapted to the

3

existing two-stage high pressure turbine for a total of three turbine stages to drive the air compressor and generator loads. As with the two-shaft version, the new stage will be aerodynamically scaled from the Taurus 10 cold-end drive gas turbine. Similar operating cycle parameters of rotor speed. mass flow, pressure ratio and firing temperature from the two-shaft version will be maintained for the cold-end drive gas turbine.

The entire rotor assembly will be supported by three identical journal bearings. A n� reduction gearbox will be integrated to the front end of the air inlet housing for speed reduction to the desired generator frequency and gas turbine accessory drive capability. Thus, the integral accessory drive gearbox used on the two-shaft model will be replaced by the reduction gearbox assembly. Also, the exhaust diffuser housing and radial collector will be replaced by an axial diffuser duct typical ofSolar's single-shaft gas turbine products.

GAS TURBINE PERFORMANCE The selected operating cycle for the Titan 130 gas turbine was

influenced by the design approach to aerodynamically scale the Taurus 10 gas turbine and use identical cycle parameters of pressure ratio and firing temperature. Cycle evaluations determined that using Taurus 10 gas turbine operating cycle parameters, component efficiencies, cooling/leakage flow rates at a larger aerodynamic design scale could produce the targeted introductoiyperfonnance of l33 "MW (17,800 hp) and 34.So/o simple-cycle thermal efficiency for the two-shaft version. In addition, using a proven aerodynamic design and operating cycle, successfully demonstrated with the Taurus 10 gas turbine, satisfied the program strategy of minimizing product development risk, cost and time.

The Titan 130 gas turbine cycle incorporates a 16:1 pressure ratio at a maximwn tUibinc rotor inlet temperature of 1121°C (2050°F) with a mass flow of 47.7 kg/sec (105.2 pps) to achieve the desired introductory performance rating. The predicted output performance with no inlet and exhaust losses for the two-shaft gas turbine over a range of ambient operating conditions and output speeds is shown in Figure 4. The power turbine is designed to deliver optimum power at a rated speed of 7900 rpm and can operate up to a maximum continuous design speed of 8855 rpm in direct-drive applications. Table 2 shows the predicted ISO performance and design parameters at the design rating with a comparison to the Taurus 10 and Mars I 00 gas turbines. Table 3 shows predicted nominal perfonnance for the Titan 130 two-shaft and single-shaft gas turbine versions.


Features

Compressor Type Sages Pressure Ratio Mass Flow Design Speed, rpm

Combustor Type

Ignition Injectors

Gas Generator Type Stages Design Speed, rpm

Power Turbine Type stages Speed Range, rpm

Bearings Racfial GGThrust PT Thrust

Materials of Construction

Compressor Ajr Intake Case Rotor Blades Variable Stators Fixed stators Diffuser

Combustor Liner Housing

Gas Generator Turbine Nozzzle Case Nozzle, First Stage Nozzle, Second Stage Rotor Blades, First Stage Rotor Blades, Second stage Disks, First & Second Stage

Power Turbine Nozzles, Third/Fourth Stage Blades, Third/Fourth Stage Disks, Third/Fourth Stage Exhaust Diffuser Exhaust Collector

Journal Bearings

Tilting-Pad Thrust Bearings

TABLE 1 -TITAN 130 GAS TURBINE SPECIFICATIONS

Taurus 70 Mars 100 Titan 130

Axial Axial 14 15 Axial 16:1 17.2:1 14 26.6 kg/sec (57.9 pps) 41.7 kg/sec (920 pps) 16:1 15,200 11,168 47.7 kg/sec (105.2 pps)

SoloNOx SoloNOX Annular Annular SoloNOx torch torch Annular 12 14 torch

14

Axial Axial Axial 2 2 2 15,200 11,168 11,215

Axial Axial Axial 2 2 2 6000-12000 4750-9500 4425-8855

Titing Pad Tilting Pad Tilting Pad Tilting Pad Tilting Pad Tilting Pad Tilting Pad Tilting Pad Tilting Pad

Nodular Iron Nodular Iron Nodular Iron Cast 410SS Nodular lronlVVC 1 Alloy Steel Nodular Iron/WC 1 Alloy Steel 0 to 9 = 17-4 PH SS / 10 to 12 -IN 718 IN 718 Nickel Alloy 0=17-4 PH SS / 1-13 =IN 718

· 17-4PH SS 17-4PH SS 17-4PH SS 17-4 PH SS/410 SS 410SS 410SS WC 6 Alloy Steel WC 6 Alloy Steel WC6 Alloy Steel

Hastelloy X/HA 214/HA 230 HA 230 and HA 214 HA 230 and HA 214 410SS 410SS 410SS

lncoloy 903 Nickel Alloy lncoloy903 Nickel Alloy lncoloy903 CM247LC CM247LC CM247LC CM247LC MAR-M509 CM 247LC CM247LC OS CMSX-4 Single-Crystal CM247LC OS CM247LC IN 792 HiPPed CM247 LC Waspaloy Waspaloy Waspaloy

IN 939/N 155 N 155 IN 939/N 155 IN 100 IN 792 HiPPed IN 100 Waspaloy/forged alloy 718 Waspaloy/Forged Alloy 718 WaspaloyForged Alloy 718 05B Ni-Resist Ductile Iron 056 Ni-Resist Ductile Iron 05B Ni-Resist Ductile Iron 409SS 409SS 409SS

Bimetal (steel-backed with tin-based Trimetal (steel-backed) copper/lead/ Bimetal (steel-backed with tin-babbitt overlay) faced, lead/tin overlay, tin flash based babbitt overlay)

Bimetal (chromium/copper-backed with Bimetal (chromium/copper-backed Bimetal (chromiumcopper-backed tin-based babbitt overlay) with tin-based babbitt overlay) with tin-based babbitt overlay)

4


TAB LE 2 - MAN 130 ENGINE PERFORMANCE PARAMETERS

s 0 0 x

,g; � er: w

� a.

5 Q. I-::> 0

s 0 0 )( a. :S � :!: c:i w

� a..

!3 a.. I-::::i 0

Taurus 70

"MW(hp) 7.2(9660) Efficiency, % 34.0 TRIT, oc (OF) 1 121 (2050) GG Turbine, rpm 15,200 Power Turbine, rpm 10,700 (12,000 max.) Exhaust Gas Temperaure, °C (0F) 488 (910) Airflow, kg/sec (lb/s/ec) 26.7 (58.9)

Pressure Ratio 16:1 NOx/CO/UHC, ppmv 25150125

22.4 40.0 'O� (30)

38.0 >=" (.)

14.9 36.0 z (20} w

(3 34.0 u::

LL w

7.4 32.0 ..J (10) �

::lE 30.0 a:

LIJ 0.2 :c

28.0 I-(0)

-40 -30 -18 -7 4 16 27 38 50 (-40) {-20) (0) (20) (40} (60) (80) (100) (120)

TEMPERATURE. �c (0F) 122-')04!.I

14.2 (19)

13.4 (18)

12.7 (17) 100°4

Max. Speed 11.9 8855 rpm (16)

I Rated Speed I

I 7900 rpm I

1 1.2 I I (15) I I

I I I I

10.4 I I

(14) 50 60 70 80 90 100 110

POWER TURBINE SPEED,%

FIG. 4 - MAN 130 GAS TURBINE PREDICTED PERFORMANCE CURVES

122-00SM

PRODUCT EVO LUTION

Evolutionarv Design To understand the evolutionary approach utilized for development of

the Tilan 130, the evolu1ionary history and aerodynamic commonality of the Taurus 70 and Mars gas turbines must be reviewed. Solar's traditional product development strategy is for product evolution from proven technology and operating experience with previous designs. This philosophy

5

Mars 100 Titan 130

1 1.2 (15,000) 13.3 (17,800) 34.0 34.5 1 121 (2050) 1 121 (2050) 1 1.168 1 1,215 9230 (9500 max.) 7900 (8855 max.)

486 (907) 488 (910) 423 (93.2) 483 ( 106.4) 17.4:1 16:1 25/50/15 25125125

has been applied to all of Solar's family of gas turbine products. For instance, the 15-stage axial air compressor for the Mars gas turbine was originally aerodynamically scaled up from the 1 1-stage air compressor in the Centaur® gas turbine (Waldheim, 1992) (Fig. 5). Additional stages were added, one forward and three aft, to achieve the higher pressure ratio and mass flow needed for the Mars gas turbine operating cycle. As the 4-MW (5000-hp) class Centaur gas turbine product evolved into the 5.2-MW

PRODUCT EVO LUTION

Evolutionarv Design To understand the evolutionary approach utilized for development of

the Titan 130, the evolutionazy history and aerodynamic commonality of the Taurus 70 and Mars gas turbines must be reviewed. Solar' s traditional product development strategy is for product evolution from proven technology and operating experience with previous designs. This philosophy has been applied to all of Solar's family of gas turbine products. For instance, the 15-stage axial air compressor for the Mars gas turbine was originally aerodynamically scaled up from the I I-stage air compressor in the Centaur® gas turbine (Waldheim, 1992) (Fig. 5). Additional stages were added, one forward and three aft, to achieve the higher pressure ratio and mass flow needed for the Mars gas turbine operating cycle. As the 4-MW (5000-hp) class Centaur gas turbine product evolved into the 5.2-MW (7000-hp) class Taurus 60 gas turbine, a zero-stage was added to the forward-end of the Centaur air compressor. Proven aerodynamic scaling methods were once again used to scale down the first-stage of the Mars air compressor (van Leuven, 1994) to produce the new zero-stage. Thus, aerodynamic similarity between the 12-stage Taurus 60 air compressor and Mars air compressor was maintained by scaling from the proven Mars air compressor forward stage.

TAB LE 3 -TITAN 130 SING LE-SHAFT AND TWO-SHAFT PERFORMANCE

Two-Shaft Single-Shaft

Output Power, MW (hp 13.3 (17,800) 12.4Mwe

Thennal Efficiency, 5 34.5 32.1

Firing Temperature, °C (0F) 1 121 (2050 1 121 (2050


CENTAUR40

TAURUS60

14-Stage

Scaled

Scale<!

MARS 100

(I) I Cl I t'll I

Ci5 : �. <D I z ,

15·Stage

Stage 13 Scaled

TITAN 130

I I <D I Cl I t'll I WI ' I o ,

I I

Stages 1-13 Only

14-Stage

I :3New ,Stages I I

122--0Z!M FIG. 5 -TITAN 130 AIR COMPRESSOR EVO LUTION

. Likewise, as the Taurus 70 gas turbine grew from the Taurus 60 gas tu�b�ne, the adopted low risk development strategy was to modify the existing 12-stage Taurus 60 compressor for enhanced performance. Cycle studies determined that adding another forward stage (Stage 00) and an aft stage (Stage 12), for a total of 14 stages, the required cycle performance pmmctcrs of 16:1 pressure ratio and 29.6 kg/sec (57.9 pps) airflow could be achieved. The ()().stage would be a new design since no forward compressor stage components existed for scaling. The additional aft stage, however, could be scaled from the existing Stage 13 of the Mars compressor. Therefore, the aft 13 stages of the Taurus 70 compressor (Stages 0 through 12) are aerodynamic scales from Stages 1 through 13 of 1heMars compressor. Only the newly designed 00-stage was unique to the Taurus 70 compressor.

Along� 1he upgraded compressor, a new advanced two-stage, high pressure turbine and two-stage power turbine were developed to produce the targeted output power of 7 2 MW (9700 hp) and 34% thermal efficiency.

Aerodynamic Scaling Based on the exceptional aerodynamic performance and successful

in1roduction of1he Taurus 70 gas turbine, concept studies for the Titan 130 g� turbine focused on selecting a similar operating cycle of 16: 1 pressure ratio and TRIT ofl 121 "C (2050°F). Because of the aerodynamic similarity bctwccn 1he Taurus 70 andMars compressors, evaluations determined that the newly designed Taurus 70 00-stage could be scaled up and added to S1agc:i 1through 1� of the Mars compressor. The resulting 14-stage Titan

130 air compressor 1s an aerodyanmic scale of the smaller 14-stage Taurus

70 compressor and uses cxistingMars compressor components wi1h proven aerodynamic and mechanical performance characteristics to achieve a total mass flow of 47.7 kg/sec (1052 pps). Similarly, using scaled-up versions of the well-proven Taurus 70 gas generator and power turbines reduces product development risks on performance, cost and schedule.

6

---

TAURUS70 TITAN 130

FIG. 6 -STAGE 1 TURBINE BLADE SCA LING COMPARISON

As described in the previous section, Solar has successfully utilized aerodynamic scaling and 0-staging techniques to enhance or expand its gas turbine product line, while preserving the general design philosophy of product evolution from proven technology and operating experience. The geneml rules of dimensional scaling used to define the larger Titan 130 gas turbine from the Taurus 70 gas turbine arc shown in Table 4. To satisfy Titan 130 power-class requirements, the scale factor was determined by the square-root value of the output power ratio from the two turbines. As the flow path diameter is increased linearly by the scale factor, the rotor speeds arc decreased by1he inverse of the scale factor from 15,200 to 11,215 rpm, which matched the design speed of the existing Mars compressor rotor components.

TAB LE 4 -AERODYNAMIC RU LES OF SCA LING

Rule Relationship to the Scale Factor

1 Linar dimensions scale directly

2 Rotor speeds scale inversely

3 Flows scale with the square

4 Power scales iwth the square

5 Weight and volume scale with the cube

When the rules of scaling arc followed, most of the original aerodyrwnics and mechanical safety margins are not changed. This means that 1he original aerodynamic values of airfoil quantities, Mach numbers, velocity triangles, gas temperatures and gas pressures arc maintained in the new design (Ragland, 1997). This also applies to 1he structural aspects of scaled component designs because the original stress margins, vibrational responses and critical speed margins arc maintained. Figure 6 illustrates a comparison of the scaled-up Titan 130 Stage-1 turbine blade versus the Taurus 70 Stage 1 turbine blade.

Using an aerodynamically scaled flow path wi th identical operating cycle parameters of pressure ratio and firing temperature results in comparable gas temperatures and pressures throughout the compressor and turbine sections. The larger rotating and stationary components, while


FIG. 7 ·TITAN 130 COMPRESSOR ROTOR

maintaining identical design features, cooling flows and delivc.ry schemes, and reduced rotational speeds, result in identical mechanical stress conditions at comparable metal temperatures. Implementing a gas turbine design strategy based on aerodynamic scaling greatly reduces analytical efforts and technical risks , as well as enables the application oftest results and operating experience gained from an existing gas turbine product

GAS GENERATOR MODULE

Compressor The Titan 130 air compressor assembly represents a scaled-up version

ofthe 14-stagc Tauru.s70 axial air compressor. As described previously, the 14-stage Titan 130 air compressor consists of the Taurus 70 forward compressor stage directly scaled to match 13 existing stages from the Mars air compressor. Rotor design speed for the larger Titan 130 air compressor was slowed to 11,215 rpm, using the inverse of the scale factor, from the Taurus10 gas generator speed of 15,200 rpm to match the original design speed of the Mars compressor rotor.

The scaled-up forward stage is characterized by a low aspect ratio, wide-chord airfoil design (Fig. 7). Use of wide-chord airfoil designs manufactured from forged materials results in a robust compressor blade with ample mechanical strength for maximum tolerance to ice ingestion in cold-ambient operating conditions. Self-aligning, curvic coupling teeth arc used to mate the forward-bladed disk assembly to a welded-drum rotor assembly from theMars gas turbine Stages 1through 13. CommonMars compressor blades are manufactured from high strength, corrosion-resistant, nickel-based alloys using forged and investment cast processes. They have demonstrated component durability with millions of hours of service in adverse industrial operation. Similar to the Mars gas turbine, all compressor blades can be removed from the welded-drum rotor for cleaning or repair without major gas turbine disassembly. The entire rotor assembly, including a forward cone and aft-hub shaft, is held securely together with a solid centerbolt threaded into the aft-hub shaft and stretched with a centerbolt nut at the front end of the forward cone. The compressor rotor assembly features trim-balance capability successfully demonstrated with the Taurus 70 rotor. Balance planes at the forward and aft ends of the rotor have been established and are accessible through ports in the housings to facilitate trim-balance correction of synchronous vibration levels in field service

7

envirorunents without disassembly. Similar to 1he Taurus 70 andMars gas turbines, the vertically split case

design allows greater access to flow path components for inspection. cleaning or service. Due to exit flow temperatures, a separate aft compressor case manufactured from stainless steel, similar to the Mars gas turbine, is required. Both forward and aft cases feature dedicated borescope ports for internal inspection of blades and stators. A compressor bleed port is located on each side of the aft case for extraction of interstage bleed air from the eighth-stage for turbine cooling and seal buffering. The forward case, manufactured from cast ductile iron. contains the variable geomct.ry stator vanes common to the Mars compressor. Unison rings around the case actuate the variable vanes simultaneously via lever anns attached to ea.ch vane stem. The unison ring actuation system features an electromechanical linear actuat.or with a built-in feedback positioner for improved position response and accuracy. Six rows of variable stator geometry help provide sufficient surge margin control for 1he gas turbine during normal transient and steady-state operation.

Combustor The Titan 130 combustion system represents the latest evolution of

Solar's unique SoLoNO:x technology (Etheridge, 1994). It uses advanced combustor liner impingement/effiision cooling techniques developed for the Mars gas turbine and incorporates a new fueVair ratio control air management system which directly controls airflow to 14 lean-premixed technology injectors (Fig. 8).

FIG. 8 • mAN 130 GAS TURBINE SoloNOx COMBUSTOR CROSS SECTION

This combustion system provides compressor delive.ry air into the combustion plenum through the diffuser similar t.o other Solar gas turbines. Combustor cooling and dilution air is taken directly from this plenum, and the injector air is fed into an injector plenum �urrounding the combustion section via 14 variable air control valves. These valves have been designed


I

together using an actuation ring located around the outer combustor casing. The ring is moved using clcc1romcchanical actuators under feedback control from the programmable logic controller (PLC) (Fig. 9). This. in turn, rotates the valves via linkages. The controls use an algorithm consisting of measured engine parameters that place the valves close 1o the position necessary to meet emissions. An additional system is also included which directly measures carbon monoxide (CO). A feedback control is provided to fine tune the injector airflow which maintains CO and NOx emission levels inside guarantee over the required operating range ..

FIG. 9 - mAN 130 COMBUSTOR VARIABLE AIR CONTROL VALVES

Til.an 130 injectors include a scaled-up version of the T auru.s 70 lean· premixed swirler/fuel injection system, the heart of Solars lean-premixed technology (Fig, 10). This technology, in conjunction with the new air management system, has enabled Solar to design the Titan 130 for emissions performanoe guanuitce levels of25 ppmv corrected for both NOx and CO between 50-and-l 00% load at ambient temperatures above -l 8°C (O"F), and 25 NOx/50 CO between 30 and 50% load, while at the same time making significant improvements to part-load thermal efficiency (Table 5).

TABLE 5 • mAN 130 GAS TURBINE INJECTOR

I Emissions, ppmv

Gas Fuel Liquid Fuel (@ 15% 021 Dry)

NOx 25 60

co 25 50

UHC 25 25

8

FIG. 10 - mAN 130 GAS TURBINE INJECTOR

A dual fuel combustion system is also planned for introduction in 1999 as part of the cold-end drive package. This technology will be developed from the Mars gas turbine SoLoNOx dual fuel system now in production. The design goal for the Til.an 130 is to meet 60 ppmv NOx guarantees over a50-to-l�/o load range.

The TiJ.an 130 combustion system has been designed initially for onsitc maintenance. Both injectors and variable air control valves are easily removable for inspection, cleaning and maintenance. Inspection of the combustion system internals and first-stage turbine components is achieved by using methods developed and proven on the Mars and Taurus 10 gas turbine SoLoNOi combustion systems. These methods utilize borescope techniques with specially developed guide tubes located through injector ports to provide complete, clo�p coverage of all internal combustion system components, and Stage l turbine nozzles and blades.

Gas Generator Turbine The two-stage high-pressure turbine driving the air compressor is

scaled directly from the smaller Taurus 10 turbine with identical detail component designs, cooling schemes and material selections. Nozzle vanes and the first-stage turbine blades are internally cooled with compressor discharge air delivered internally within the gas turbine. Turbine cooling technology and design specifications used were derived from Mars gas turbine development and operating experience and verified through extensive component development testing during the design phase of the Tawus 10 gas turbine.

The first. and second-stage turbine blades are investment cast from high strength, nickel-based superalloys with protective alurninidc-diffusion coatings for corrosion/oxidation resistance (Fig. 11 ). Cooling air for the first· S1Bge blade and disk root attachments is supplied to the rotor by a first-stage diaphragm/prcswi.rler delivery system. Forward and aft disk rim seals arc used on the first-stage rotor to meter cooling airflow rates into the main gas path and minimize hot gas ingress along the inner hub region. Both blade stages have under-platform friction dampers/seals between adjacent blades to dissipat.e bl.a.de vibration energy and to seal hot gases from the blade root attachments.


122013M�

FIG.11 - TITAN130 VS TAURUS 70 TURBINE AIRFOIL COMPONENTS

An important tip-<:learance control feature, demonstrated with the Taurus 70 design, allows tight tip clearances to be set and maintained through transient and steady-state operations, including hot restart conditions (Fig. 12). Independent nozzle support rings have been sized to match the thcnnal response of the rotor disks during thermal transients. This design characteristic and use of blade tip seals faced with 1tbradable coating minimizes occurences of tip rubs ensuring optimum output performance. Both individual nazzle support ring assemblies can be installed and removed in modular form to simplify gas turbine assembly and disassembly. The module design coofigmlllion enables the turbine disk assemblies and nozzle support ring assemblies to be horizontally removed from the gas generator as a bundle with proper field tooling (Fig. 13). Removal of the turbine bundle and diaphragm/prcswirler assembly enables access to the combustor liner for inspection and/or repair in field service environments.

POWER TURBINE MODULE

Two-Shaft Model The scaled two-stage power turbine assembly is configured as an

independent module close coupled to the gas generator module. The twostage axial turbine design provides the nominal output power to the driven equipment with a flat-response petformance characteristic across ll broad operating speed range. Optimum performance is delivered at a rated speed of7900 rpm with less than 1.5% drop in power from ll speed range 10% below rated speed up to the maximum continuous design speed limit of 8855 rpm. Similar to the Titan 130 air compressor, the power turbine module features scaled-up turbine components from the Taurus 10 with a

9

FIG. 12 - GAS GENERATOR STAGE 1 TURBINE TIP-CLEARANCE CONTROL

common, modified version of the Mars power turbine bea.ring housing assembly.

The rotor is similllr in design and construction to the gas generator turbine, but aD blades and nozzle components are uncooled due to lower gas stream temperatures at the power turbine inlet (Fig. 14). Rotor disk assemblies include scaled blade root-1tttachment designs with underplatform damper seals to dampen undesirable blade dynamic excitations and vibrations. Only the third-stage disk assembly is cooled using compressor bleed air delivered externally to the third-stage nozzles and transferred through ll hollow nozzle vane to the forward disk cavity for rim cooling and hot gas buffering. The two disk assemblies and output shaft are bolted together, similar to the gas generator turbine rotor, using five through-bolts and curvio-coupling interfaces. The rugged rotor design. utilizing ll dry, flcxi"ble membrane interconnect shaft system, is well-suited for all expected operating loads from typical gas compressor and pump-drive applications.

Single-Shaft Model The cold-end drive, single-shaft version of the Titan 130 will be

derived from the hot-end drive, two-shaft model, but without a 5CpllfalC power turbine shaft system. A new singl�stage axial power turbine will be integrated into the second-stage of the gas generator turbine with one common rotor assembly. The three-stage turbine will produce the required


I

FIG. 13 - TIAN 130 TWO.SHAFT GAS TURBINE MODULAR CONSTRUCTION

FIG. 14 - POWER TURBINE ROTOR ASSEMBLY

powa-to drive the Tilan air compressor and electrical generator loads via an integral reduction gearbox.

The aerodynamic and mechanical design features of the single-stage power turbine will be directly scaled from the single-shaft model of the Taurus 10 gas turbine. The high aerodynamic work turbine stage will feature high� ratio (blade height/airfoil chord length) rotor blades with shrouded airl'oil tips for tip sealing and blade vibration dampening. The lightweight rotor disk will be assembled to the existing gas generator turbine disks via a curvic coupling interface with slightly larger through-bolts for increased clamp load and torque capacity. Similar to the two-shaft model, external cooling air will be delivered to the third-stage disk assembly through hollow nozzle vane passages for impingement cooling of the disk rim and prevention of bot gas ingress into the forward disk cavity. The thirdstage nozzle assembly is supported by an independent nozzle support ring thennally matched to the rotor for optimum blade tip clearance control through transient and steady-state operation. The static structure also

10

supports the axial discharge diffuser duct designed and sized for optimum acro-perfonnance recovery with minimal losses.

ROTOR BEARINGS AND SEAL SYSTEM Similar to the Taurw 70 and Mars gas turbines, the TitJJn 130 turbine

rotors are supported by five tilting-pad journal bearings, three for the gas generator and two for the power turbine, designed with the latest fluid-film bearing technology for stable rotordynamic operation. The physically larger journal bearings have a length-to-diameter ratio (IJD) greater than that of the Mars gas turbine bearings to provide additional damping and enhance rotordynamic stability through all modes of operation. Typical with larger gas turbines. rot.or shaft displacements and vibration characteristics are monitored during operation by two proximity probes mounted at each journal bearing location to ensure that acceptable levels are maintained and to initiate gas turbine shutdown when limits are exceeded. For field service maintenance, a trim-balance feature suceessfully demonstrated in the Taurus 70 has been incorporated into the Titan 130 gas generator rotor. This feature enables trim-balance corrections for reduction of synchronous vibrations to acceptable levels in field service environments and with minimal gas turbine hardware disassembly.

Tiuust bearings for each rotor are located at the front and back ends of the gas turbine adjacent to the front (No. 1) journal bearing in the compn:ssor and rear (No. 5) journal in the power turbine. The gas generator rotor thrust bearing assembly consists of self-aligning, tilting-pad type bearings on the forward. active-side with a fixed, tapered-land bearing on the aft, inactive-side. The standard thrust bearing assembly for the power turbine rotor includes self-aligning, tilting-pad type bearings on both active and inactive sides for enhanced thrust-load reaction in forward and aft directions. Bearing protection and temperature monitoring during operation is provided by two temperature sensors embedded into pads on the loaded sides of each thrust bearing. Axial proximity probes installed in each thrust bearing assembly t.o monitor rotor axial motion also arc available as a standard package option. As in the Taurus 10 and Mars gas turbines, location of the thrust bearings in the Titan 130 gas turbine provides easy access by field service persoMel for inspection and service without major component disassembly or gas turbine removal.

Lube oil seal designs incorporated into the Titan 130 gas turbine are consi.stcnt with current labyrinth-type seals used at journal bearing locations in the TalD"US 70 and Mars gas turbines. Typical seals consist of machined labyrinth teeth featuring tungstcn-<l8.rbide tips, which enhances tooth wear resistance, and stationary interface rings made from bronze abradable material. These design features enable close clearances over the rotating teeth to be maintained for effective sealing during operation, with minimal


lcak:age flows into the lube oil sumps. Compressor air bled from the eighth· stage is used as seal buffer air for the compressor front (No. 1) bearing seal and forward (No. 4) power turbine bearing seal.

To further enhance seal effectiveness at the aft compressor (No. 2) bearing seal, seal bypass leakage flow is bled away from an intermediate point in the seal to reduce the pressure drop across the last rows of labyrinth t.eeth. This bleed scheme and corresponding pressure-drop reduction minimizes bypass air leakage into the lube oil sump and improves the package lube oil tank vent system. Air bled from the seal is removed through bleed passages in the compressor diffuser housing and routed externally to the exhaust diffuser housing to buffer the outer-shroud nozzle cavity of the power turbine module.

DEVELOPMENT TESTING Development test plans for the aerodynamically scaled Titan 130 gas turbine consisted of actual-size combustor rig simulations, factory gas turbine tests and extended field evaluation testing. According to the rules of aerodynamic scaling described previously, gas temperatures and pressures -along with mechanical load conditions acting on all internal components - remain consistent for both machines. Therefore, additional design verification relied heavily on comprehensive test results obtained during development testing of the Taurus 10 gas turbine. Development testing and design verification prior to full product introduction is a key element of Solar's product development philosophy and NPI process.

Extensive component. Ml-scale rig and instrumented gas turbine development testing was conducted during the design phase of the Taurus 70 gas turbine to validate technologies used in the gas turbine. Testing for cooled components included thennal imaging, flow visualization and hot· cascade testing to validate heat transfer characteristics and predicted metal temperatures. Furthermore, blade dynamics were verified using frequency and holography test methods to correlate to analytical predictions. Full-scale compressor and half-scale turbine rig testing verified overall aerodynamic perfonnance parameters and component efficiencies necessary to achieve predicted gas turbine performance. Finally, instrumented gas turbine testing and ongoing production qualification testing have determined actual power and heat rate results consistently met or exceeded the original predicted performance targets. These demonstrated test results can be expected for the Titan 130 gas turbine based on the rules of scaling and similar operating cycle to the T auru.s 70 gas turbine.

As in the Taurus 70 gas turbine, the pollution-prevention combustion system (Fig. 15) is thoroughly being tested in full-scale atmospheric and high pressure rigs to simulate actual operating conditions. Development testing is ongoing to optimiz.e emissions, metal temperatures and uniform cxit-tlow temperatures while operating on natural gas fuel. Initial test results have been favorable and indicate primary combustion system parameters arc within the limits of the required design specifications. Current test plans include development of a dual fuel option for future availability.

Gas turbine development testing began January, 1998 at Solar's Kearny Mesa production test facilities in San Diego, California. Initial ti:sting will verify gas turbine performance and mechanical integrity over a broad operating range. Additional combustor tests will be performed to finalize control system parameters of fuel, bleed and inlet guide vane schedules for further optimization of combustion system emissions and performance across all expected gas turbine operating conditions. Factory testing will be ongoing afttr initial product introduction for continued optimi:zation of output performance, evaluation of potential product uprates, and future enhancements. As with the Taurus 10 gas turbine, the devclopmcnttc& program will culminate with extended durability testing of a gas turbine and pack.age system in actual field operating conditions.

11

A firm commitment was made to install the first Tilan 130 gas turbine mechanical-<lrivc package in a direct-<lrive application for gas compression service along a major natural gas transmission pipeline in the northwestern region of the United States. Expected commission date of the installation is mid-1998. This unit will be field tested and monitored by Solar's engineering personnel over an extended test period to gain operating experience and to assess product durability in actual industrial service conditions. Similarly, the Taurus 10 gas turbine product was thoroughly field t.estcd over an extended evaluation period with the placement offour packages in electrical power generation and gas compression applications. Extended product testing of the Titan 130 gas turbine, along with proven durability testing of the Taurus 10 gas turbine in actual field operating conditions, will dcmonstra!c product durability and provide useful operating experience prior to full production release to the marketplace.

SUMMARY Development of the Titan 130 industrial gas turbine (Fig. 16) was

based on a design philosophy of product evolution from the TflllTW 70 and Mars gas turbines to meet increased market demands for 13-MW (18,000-bp) size class industrial power applications. Initially available in a two-shaft configuration, the Titan 130 gas turbine has an introductory design rating of133MW(l7,800 hp) and 34.5% simple-cycle thermal efficiency at ISO operating conditions with no duct losses. The two-shaft version is intended for mechanica!-<lrive applications in gas compression and pump-drive

FIG.16·TITAN130 GAS TURBINE


industrial service. Future introduction of a single-shaft version, derived from the two-shaft machine, is planned for electrical power generation applications.

A cross-functional NPI team established a traditional Solar gas turbine product development strategy for low risk, evolutionary product design using proven rechnology to meet customer expectations for a reliable, durable, highly serviceable and cost-effective industrial gas turbine product Thus, the Titan 130 gas turbine design approach was to aerodynamically scale up the successful Taurus 70 air compressor and turbine, with identical operating cycle parameters, to minimize development risk, cost and time.

The larger 14-stage Titan 130 air compressor uses a forward stage scaled up from the Taurus 70 air compressor and mat.ched to .J3 existing slages fiom theMarsaircompressorto achieve the same 16:1 pressure ratio and increased mass flow of 47.7 kg/sec (105.2 pps). Common Mars gas turbine components also used in the Titan 130 gas turbine include an integral accessory drive gearbox and a modified power turbine bearing housing assembly. The dry, lean-premixed, pollution-prevention combustion system was derived from technology and operating experience demonstrated with Solar's SoLoNO:x combustion system and features design enhancements for improved low emission performance over an extended operating range.

1 2

Factory testing and ext.ended field durability of the Titan 130 turbomachinery package system, in addition to extensive test results and operating experience gained from the Taurus 70 gas turbine development, will provide proven operating experience and demonstrated product durability prior to full-production release to the marketplace. Modular construction, field service features and a design evolved from proven technology make the Titan 130 gas turbine well-suited for rugged, reliable industrial service in electrical power generation, gas compression and pumpdrive applications.

REFEREN CE S Etheridge, CJ., 1994, ''Mars SoLoNOx - Lean Premixed Combustion

Technology in Production'', ASME Paper 94-GT-225, The Hague, The Netherlands.

Ragland, T., 1997, ''Industrial Gas Turbine Uprates", ASME Paper 97-GT-409, Orlando, Florida.

Rocha, G., 1995, ''Development of the Taurus 70 Industrial Gas Turbine", ASME Paper 95-GT-41 1 , Houston, Texas.

Van Leuven, V., 1994, "Solar Turbines Incorporated Taurus 60 Gas Turbine Development", ASME Paper 94-GT-1 15, The Hague, The Netherlands.

Waldheim, C.M, 1992, "Evolution and Introduction of the Mars T-14000 Gas Turbine", ASME Paper 92-GT-332, Cologne, Germany.


evolution of the solar turbines titan 130 industrial gas...

Documents