POWER-GEN Middle East, Abu Dhabi, October 4 - 6, 2015...

Copyright © Siemens AG, 2015. All rights reserved.

POWER-GEN Middle East, Abu Dhabi, October 4 - 6, 2015

Meeting the Middle East EnergyDemand with Proven Gas Turbines

Juergen Voss, 4000F Product Manager, Siemens AG, Germany;Armin Staedtler, 8000H Product Manager, Siemens AG, Germany;Dr. Keramat Fakhari, Vice President Sales Middle East, Siemens UAE

POWER-GEN Middle East in Abu Dhabi, October 4 - 6, 2015

Copyright © Siemens AG 2015. All rights reserved. 2

Abstract

Reliable electricity supply remains key driver for the power sector in the Middle East region. Thismeans besides meeting the increased demand also maintaining grid stability with highly reliable powerplants.

This paper will outline how the heavy duty gas turbine portfolio from Siemens is meeting this de-mand by offering proven and reliable as well as efficient and cost-effective products and solutions.The paper will highlight some successful projects using Siemens technology for SGT5/6-2000E andSGT5-4000F engines which has demonstrated its perfect fit for meeting the requirements of theMiddle East in multiple projects in various countries of the region. The vast SGT5-4000F fleet inthe Middle East region of over 80 gas turbines has accumulated more than three million EOHs invarious project-specific plant configurations and with a broad range of fuel qualities. Improved fuelchange-over times, the unique capability of dry fuel oil operation over the whole load range withNOx emissions not exceeding 58 ppm, and power augmentation by Wet Compression (WetC) arehighlighted below. It will also provide an overview of the capabilities the SGT5/6-8000H gas tur-bine series, especially for the Middle East region. This gas turbine series has not only set new stand-ards for efficiency (still holding the world record of 60.75% plant net efficiency), but it also hasbecome a benchmark in the industry in terms of reliable operation and robustness of design. Withlow life cycle costs, high reliability and availability, operational flexibility, and low emissions it is atrendsetting solution for clean fossil power generation all over the world. With more than 72 unitssold and 16 units in commercial operation, and each unit handed over in time while meeting guaran-tees, the 8000H is widely accepted as a fully proven product series which is perfectly suited forlarge power projects in the Middle East region.



Table of contents

Abstract ...................................................................................................................................2

1. Introduction ......................................................................................................................4

2. Middle East market characteristics .......................................................................................4

3. The Siemens Portfolio overview ..........................................................................................5

4. The proven and reliable SGT5-4000F gas turbine ..................................................................5

4.1 Fuel flexibility.....................................................................................................................7

4.2 Dry oil operation and fuel change over ...................................................................................7

4.3 Power augmentation by Wet Compression ..............................................................................8

5. The high efficient SGT5-8000H gas turbine ........................................................................10

5.1 Operational Flexibility .......................................................................................................12

5.2 Fuel flexibility...................................................................................................................13

6. Conclusion ......................................................................................................................14

References .............................................................................................................................15

Disclaimer .............................................................................................................................16

Nomenclature

BoP Balance of PlantBTU British Thermal UnitCAPEX Capital expenditureCC Combined CycleCHP Combined Heat and PowerEC Evaporative CoolingE-LNG All-electric liquefied natural gasEOH Equivalent Operating HoursGCC Gulf Cooperation CouncilGT Gas TurbineHCO Hydraulic Clearance OptimizationHRSG Heat Rejection Steam GeneratorI&C Instrumentation and ControlsIWPP Independent Water and Power ProjectKSA Kingdom of Saudi ArabiaO&G Oil and GasOPEX Operating expensePG Power Generationppm Parts per Millionr.h. relative humiditySC Simple CycleSGT Siemens Gas TurbineTT1-ISO Turbine Inlet Temperature acc. to ISO 2314WetC Wet Compression1S single shaft



1. Introduction

The market for power generation and power plant construction in the Middle East region differs fromcountry to country and depends on a variety of factors, such as the geopolitical situation, economicgrowth expectations, regulatory policies, grid infrastructure or the availability of local fuel resources.Population growth, economic expansion, technology evolution, need for water desalination, changingconsumption patterns and industrialization have led to a significant increase in energy demand of morethan 6% per year in the Middle East region over the last decade.

Having the world’s largest hydrocarbon reserves it is of no surprise that energy consumption in thisregion is highly dominated by fossil fuels (>95%). In consequence, the elevation in energy consump-tion in the Middle East region has resulted in an increase in pollution levels. Also, energy losses ingeneration, transmission and distribution in this region are about 19%, which is almost twice the worldaverage and four times the European Union average. Introducing efficiency measures, integratingrenewables and optimizing the grid infrastructure (e.g. GCC interconnection which has completed allthree phases [1]) are vital actions to shape the energy future in a way to save limited and valuable nat-ural resources and to foster economic growth and competitiveness. On power plant level, mainmeasures to increase efficiency are refurbishing, retrofitting and replacing old power plants by highlyefficient new ones. This will reduce the amount of fuel required as well as the amount of CO2 emittedfor each kWh generated.

2. Middle East market characteristics

Lowest CAPEX and OPEX, maximal power output, customized service concepts including retrofita-bility and utmost availability and reliability are key success factors for a successful power project:financial security for investors, predictable cost of electricity and security of supply for the consumers(public, industrial and private).

Already today the installed power generation capacity in the Middle East region needs to cope withsharp daily load fluctuations and to cover the important peak load demand during the summer season.Taking the potential future energy mix scenarios into account where renewable energy sources couldplay a bigger role in the future, the fossil fleet is expected to deal with even higher load fluctuations.Peaking solutions like Wet Compression can support peak loads coverage so that the overall installedbaseload capacity can be reasonably lower and thus reduces low-efficient part load operation.

Especially in the Gulf region, fuel flexibility remains important. On one hand this is driven by a strat-egy of resource diversification and security, and on the other hand on the ability to export certain re-sources (e.g. higher quality natural gas) rather than using it for its domestic power generation. Nearlyall power plants in the Middle East are equipped with dual fuel capability to ensure stable power sup-ply in case of local fuel gas shortages. Fuel changeover times are critical to ensure grid stability evenfor sudden fuel gas supply interruption.

Various Grid Code requirements in the Middle East region demand flexible plant solutions. E.g. thereare certain countries in the region which have an under-developed grid that is incompatible with cer-tain capacities and technologies.



3. The Siemens Portfolio overview

Siemens offers a variety of customized scope solutions to meet these requirements for various powerplant sizes, all based on the proven SGT5/6-2000E, SGT5-4000F, SGT6-5000F and SGT5/6-8000Hseries, as shown in Figure 1.

Figure 1: Heavy-duty Gas Turbine portfolio.

The SGT5-2000E is capable to cover the need for oil & gas industrial applications for E-LNG or com-pressor drives or for power generation. It has the highest operational flexibility, grid stabilization ormaximum power on demand, and the broadest fuel flexibility, i.e. from heavy fuel oil to low calorificsyngases. The latest developments of the SGT5-2000E have been recently outlined at Power GenAfrica 2015 [2]. Even the scaled 60 Hz Version SGT6-2000E is present in the Middle East region with25 packages operating in KSA. The SGT6-5000F was covered at Power Gen Middle East 2013 [3].

Selected features of the advanced Siemens 50 Hz F-Class and 50/60 Hz H-Class gas turbines are de-scribed in the following chapters.

4. The proven and reliable SGT5-4000F gas turbine

Since the introduction of the SGT5-4000F in Didcot, UK, in 1992, Siemens has continuously investedinto evolutionary design improvements. Beneath significant increases in power and efficiency, Sie-mens also enhanced the features of the gas turbine to meet needs from different regions. The SGT5-4000F engine is capable to be operated from -50°C to 55°C ambient temperature. The first SGT5-4000F in Near Middle East was sold in 1998 and has already achieved more than 100.000 equivalentoperating hours (EOH). While the SGT5-4000F fleet of 81 GT’s accumulated already more than threemillion EOHs in the Middle East region, Siemens has improved the SGT5-4000F fuel flexibility forgaseous fuel with high sulfur content or a wider Wobbe range. With its advanced burner systems, theSGT5-4000F (see Figure 2) is capable to meet the emission standards of the World Bank, even in con-tinuous oil operation and without any water injection. The system can also switch between premixgaseous fuel and premix fuel oil within approx. four minutes and even without a complete de-loadingat high loads of the gas turbine.



Figure 2: Siemens SGT5-4000F with proven design for high reliability and flexibility

The combination of pre-engineered package designs with modular add-on options provides the idealbase for customer specific needs or site-specific requirements. This approach drives live-cycle costsdown while providing the flexibility to meet individual plant needs. Figure 3 gives an overviewabout the standard configurations such as simple cycle and combined cycle multi-shaft (with triplepressure cycle as standard) as well as single-shaft arrangements.

Figure 3: Standardized Siemens heavy duty gas turbine packages

Project specific multi-shaft configurations, such as 3x1, 5x2 and special steam turbine applications(steam extraction, thermal desalination, dual pressure cycle, etc.) can easily be realized by combin-ing multiple simple cycle gas turbine packages with corresponding steam turbine packages, asshown in the examples in Figure 4.



Figure 4: SCC5-4000F Steam Turbine Configurations for dual-pressure cycle applications

The latest project is the combined cycle power plant Jebel Ali M extension that adds another 700 MWto the existing Jebel Ali plant. All features, described in the next chapters, are implemented in theSGT5-4000F gas turbines. Jebel Ali is the biggest gas powered combined cycle power plant site and itincludes the worlds’ largest desalination plant which significantly contributes to the power and watersupply in Dubai. The Jebel Ali M Extension turn-key project includes, among other plant equipment,two SGT5-4000F gas turbines in multi shaft configuration.

4.1 Fuel flexibility

For a Wobbe range of 36 to 50 MJ/kg, operational experience is available with engines of the latestdesign upgrade. However, the whole Wobbe range is covered by engines with identical combustionhardware. Based on project specific fuel specification, engines can be optimized for even wider Wob-be indices or for low NOx emissions (15 ppm), both without loss in power output [4]. With projectspecific corrosion considerations, H2S concentrations up to 4000 ppm are possible.

4.2 Dry oil operation and fuel change over

The SGT5-4000F has a choice of different burners to cope with a broad range of fuel qualities. Asmany customers ask for fuel oil as back-up fuel, Siemens has developed one burner capable to gaseousfuels and fuel oil with one hardware configuration.

The SGT5-4000F engines are capable to run in dry fuel oil operation (no water injection or emulsionoperation required) over the whole load range, with NOx emissions not exceeding 58 ppm. By admix-ing water to the fuel oil (emulsion operation), power output increases by 10% compared to dry fuel oiloperation while NOx emissions decrease by more than 25%. There are currently 26 engines SGT5-4000F with emulsion mode in operation in the Middle East region.

An improved procedure for the online switchover from fuel gas operation to fuel oil operation and viceversa has been successfully tested on various engines in the Middle East region. This procedure allowsswitch over from premix gas operation directly to premix oil operation at 75% of gas baseload opera-tion within about four minutes (see Figure 5). Prior deloading to the oil diffusion oil transfer windowis not required anymore.



Figure 5: Transfer from fuel gas operation to fuel oil operation

4.3 Power augmentation by Wet Compression

Wet Compression (WetC) is a reliable and proven method of injecting water into the gas turbine inletin order to provide additional power and cover peak demand efficiently. This enables electricity pro-ducers to react to increased power demand, especially during summer peaks.

There are four basic effects that lead to increased power output of the gas turbine:- evaporation of water droplets on the way from spray rack to compressor inlet reducing air

temperature, thus increasing air massflow and GT power- additional mass flow and power increase by the water evaporating inside the compressor- compressor intercooling due to a decreased temperature level in the front section of the com-

pressor- a shift in cooling air supply pressure ratios from compressor extractions to the turbine

The injection of water results in more than 25 MW power increase (value can vary based on unit con-figuration, site specific conditions and BoP limitations). This has been proven on several SGT5-4000F engines. Even higher power increases up to 50 MW are possible under hot and dry ambientconditions by combining a Wet Compression system with an Evaporative Cooler (Table 1). Beyondthe power increase, the higher water content in the air entering the combustion chamber leads to adecrease in NOx emissions in the range of approx. 3 ppm, which has been measured with calibratedequipment at multiple engines. Wet Compression power increase is less dependent on ambient condi-tions (especially humidity) than other inlet air conditioning systems such as fogging, chiller or evapo-rative cooler. This makes Wet Compression more suitable for power augmentation all over the year inthe Middle East region as long as the ambient temperatures are above 10°C.

Table 1: Power increase at different ambient conditions



The first WetC system was applied on a SGT5-4000F in 2010. Within the past years, the number ofSGT5-4000F gas turbines operating with Wet Compression has grown steadily and reached 25 unitstoday with 18,000 operating hours of which the fleet leader accumulated more than 6,500 hours. Morethan 20 additional units are booked and will commence operation until 2017. Wet Compression forSGT5-4000F is available for new engines as well as for Service engines as upgrade for all upgradesteps and can be operated both in fuel gas mode as well as in dry fuel oil premix mode. A summaryabout WetC references is shown in Table 2.

Table 2: Wet Compression experience in the Middle East region

The Siemens WetC system consists of the core components spray rack (inside the air intake), pumpskid, pre-system, and a full integration into control logic and protection system (see figure 6). Except amodified compressor coating no changes to the core engine are required [5].

Figure 6: Schematic of the Wet Compression system



5. The high efficient SGT5-8000H gas turbine

The Siemens 8000H series marks the top of the Siemens portfolio with high power outputs of 600MWand above in CC application and allowing for plant net efficiencies beyond 60%.

Figure 7: SGT5-8000H with highest efficiency and best-in-class flexibility and reliability

This GT series was always intended to not only to achieve unprecedented efficiencies but also tomeet flexibility requirements while maintaining the robustness and reliability of the existing designheritage (see Figure 8) – which meant e.g. avoiding the introduction of risky new technologies.

Figure 8: Proven Siemens and Westinghouse design features come together

Today, 7.5 years after first fire and 4.5 years of commercial operation of the first installation, a fleetof 16 engines successful in commercial operation that accumulated >150.000 fired hours, it is fair tosay that the Siemens SGT-8000H really has met all its targets, satisfying plant operators and theirstakeholders.. The SGT-8000H series has left the prototypical design status far behind and is beingrecognized a proven, reliable design in the industry.History shows that any new gas turbine introduction came with significant risk. And when rollingout a new product directly to customer sites, this introduction risk does hit those early customers.Especially in the Middle East region there is a high risk awareness and averseness, triggered by theneed for highly reliable and available power and water production, consequently accepting onlymature gas turbine designs with a proven track record.



The Siemens SGT-8000H series today fully confirms with this requirement. In fact, the SGT-8000Hseries is the only proven high performance gas turbine model on the market, with 150,000 firedhours achieved in multiple installations and reliable operation even at the first installations from dayone on.There are three major drivers that make to 8000H the robust and reliable product it is today:

1. Siemens took it’s time to come up with an engine design (see Figure 9). It took 7 years fromstart of development to first fire of the prototype unit, another 2 years until sales release and3.5 years until first commercial operation – enough time to incorporate the learnings fromtesting into the commercial product.

Figure 9: Development timeline SGT5/6-8000H

2. Siemens decided to go for a full inhouse validation of the SGT-8000H series for both 50 and60Hz turbine versions. In fact, only after the SGT5-8000H had proven to be reliable after anintense 1.5 years testing phase - including a 1200 hours full load run to capture at least someinformation on durability - the SGT-8000H series was released for commercial sales activi-ties. This approach allowed to ensure that even the first commercial customers were deliv-ered a mature and learned out product.

3. Siemens decided to reduce the technology risk to the minimum by keeping the design pa-rameters within the available experience range, thus avoiding the related extrapolation risk.Examples are e.g. not to increase firing temperature compared to existing experience (e.g.W501G) and in general not to apply risky technologies like steam cooling etc. but focus onoptimizing existing proven design features.

The result of this huge undertaking is a new gas turbine product line that has proven its advantagesregarding flexibility, performance and robustness in power plants commercially operating aroundthe globe:

- The Siemens SGT5-8000H was the first gas turbine to power a commercial project exceed-ing 60% plant net efficiency, demonstrating a world record efficiency of 60.75% already in2011, and with further projects all meeting high CC efficiencies of up to 61%.

- All commercial projects so far have been handed over on schedule (including fast track pro-jects with 24 month execution time), with several projects handed over even ahead schedule,proving again the robustness and reliability of the core engine design.

- The fleet is running stable with five units having achieved already more than 20.000 operat-ing hours.



This track record impressively demonstrates the capability of the SGT-8000H series. A further dis-play of the capabilities will soon be demonstrated at the German Lausward CHP project, where theSGT5-8000H will again set new benchmark levels for performance and efficiency.

5.1 Operational Flexibility

The Siemens SGT5-4000F and SGT5-8000H share some common design features that allow for in-herent operational flexibility:

Rotor designThe Siemens heavy duty gas turbine rotors consist of individual discs being spanned to a stiff rotorby a central tie rod. The individual discs are aligned with the so called ‘Hirth’ serration on their in-terface areas which allows for

a) self-centering of the rotor discs during assembly andb) high torque transfer through the rotor while avoiding individual discs slipping and result-ing rotor imbalance (e.g. in case of grid faults).

The rotor design also allows for internal cooling air passages from compressor to turbine section,which ensure fast thermal response of the rotor in case of high load transients, fast cold starts andalike, basically eliminating the lifetime impact on rotor for such operation.

Hydraulic Clearance Optimization HCOOne of the major concerns for flexible operation with fast load transients are the clearances betweenstationary and rotating parts in a gas turbine, mainly in the turbine section. Due to faster thermalresponse of the rotor, especially during the start-up of a GT, the clearances get reduced and evenrubbing may occur - with impact on performance (degradation) and potentially also hardware integ-rity. As a result, this transient state normally defines the width of the clearances for thermally stableoperating condition. With the HCO system a Siemens GT will have large enough clearances to avoidany rubbing in the turbine for startup. During stable condition the system will then push the rotor afew mm’s towards the compressor end, reducing the turbine clearances due to the conical flow-pathto the design value. So the system avoids the effects on degradation and hardware integrity.

Figure 10: Hydraulic Clearance Optimization

Turbine CoolingBoth SGT5-4000F and SGT5/6-8000H frames employ a full self-sustaining on-board cooling airsystem, meaning cooling air is extracted at the appropriate compressor stage and directly routed tothe turbine; there are no cooling-air coolers required, no interfaces to BoP/HRSG exist. Besides



advantages in project engineering and execution (less complexity, less hardware) this approach en-sures that no interdependencies to water-steam-cycle condition will limit the operational flexibilityof the GT and the plant. Also plant control has much less parameters to take care of when operatingwith high load transients.

The SGT5-4000F and SGT-8000H operational flexibility is displayed in Figure 11. All relevant ca-pabilities like grid support operation, high load transients (e.g. islanding of IWPP projects) or peakpower (e.g. Evaporative-Cooling or Wet Compression) are available.

Figure 11: Operational capabilities of SGT-8000H series and SGT5-4000F

However, please note that the gas turbine capability alone is not sufficient for reliable plant opera-tion; the whole plant – turboset, I&C system, auxiliaries, HRSG etc. – needs to be designed to copewith such capabilities. In this respect Siemens is in the fortunate position to offer tailored scopesfrom pure turbosets over power islands up to full turnkey plant solutions.

5.2 Fuel flexibility

In general heavy duty gas turbines are fired with either gaseous or liquid fuels (oil #2), the latter typi-cally only as backup fuel. With regards to gas turbine capabilities, large differences in Wobbe-rangewill have an impact on combustion stability and must be taken care of. Siemens heavy duty gas tur-bines always allow a Wobbe variation of +/-5% and above (“no questions asked”) but of course cansupport much wider ranges, e.g. running on H or L gas qualities. However, the Wobbe number is notthe only driving parameter for combustion stability. So e.g. higher hydrocarbons (Ethane, Propane,Butane, H2 etc.) have significant impact on the reactivity (e.g. flame speed) irrespectively of the Wob-ble number and thus are directly influencing combustion stability. As a general statement it can be saidthat Siemens heavy duty GTs can cope with quite wide Wobble variations beyond +/-10%. However,the aforementioned effects from individual components in the fuel gas demonstrate that statementsbased on pure Wobble-Index can be misleading, so Siemens will thoroughly assess the individual pro-ject with its boundaries; as a first step typically by fuel gas temperature conditioning and fuel stagingadjustment only and as a potential second step also by adapting the burner hardware to the projectspecific needs like low BTU firing.

To foster the fuel capabilities of its heavy duty gas turbines, Siemens has just recently inaugurated anew combustion test center in Ludwigsfelde [7]. This addition to the existing test capabilities willensure that all market needs are addressed appropriately.



6. Conclusion

The Middle East market faces several main challenges, such as a variety of fossil fuels, demand forlow CAPEX and OPEX, various plant sizes and configurations, flexible plant operation and peakingpower requirements, demand for reliability and proven technologies, increased plant efficiencies, etc.To cope with those challenges, Siemens offers a variety of customized solutions based on its LargeGas Turbine portfolio. As outlined in Figure 12, each Frame has its unique characteristics with themain application areas:

- SGT5/6-2000E with low CAPEX, great fuel flexibility and the high operational flexibility, ro-bust design and easy maintenance

- SGT6-5000F, the proven 60 Hz F-Class technology- SGT5-4000F with proven and reliable 50 Hz F-Class technology, suited for advanced effi-

ciency needs, and with a large fleet in the Middle East region- The proven SGT5/6-8000H series with best available efficiency at world class flexibility

Figure 12: Heavy-duty Gas Turbine portfolio.

The combination of pre-engineered package designs with modular add-on options provides the idealbase for customer specific needs or site-specific requirements; examples shown in Figure 13.

Figure 13: Power plant projects with Siemens heavy duty gas turbines (examples)



References

[1] Ahmed Ali Ebrahim: Super Grid Increases System Stability. Transmission & Distribution

World, May 2012

[2] Frank Richter et al: Siemens SGT5-PAC 2000E, recent developments to serve customer needs

in Africa. Power Gen Africa, July 15-17, 2015, Cape Town

[3] Adam Foust: Siemens Expands Footprint in the Middle East with SGT6-5000F Power Plant

Solutions and New Gas Turbine Manufacturing Facility. Power Gen Middle East, February 4-

6, 2013, Doha, Qatar

[4] Eberhard Deuker, et. al.: SGT5-4000F – Trusted Operational Excellence, Power Gen Europe

2014, paper no. T3S5P2

[5] Jan Dirk Beiler, Peter Trauner: “High Efficient Peak Power on Demand” PowerGen Middle

East 2012.

[6] W. Fischer, S. Abens, “SGT5-8000H Design and Product Validation at Irsching 4 Test Center”,

VGP Power Tec 09/2009

[7] R. Obertacke, “Siemens Clean Energy Center, The new Siemens High Pressure Test Center in

Ludwigsfelde”, 9.VDI-Fachtagung Stationäre Gasturbinen, Nürnberg, November 2014



Permission for useThe content of this paper is copyrighted by Siemens and is licensed to PennWell for publication anddistribution only. Any inquiries regarding permission to use the content of this paper, in whole or inpart, for any purpose must be addressed to Siemens directly.

DisclaimerThis document contains statements related to our future business and financial performance and futureevents or developments involving Siemens that may constitute forward-looking statements. Thesestatements may be identified by words such as “expect,” “look forward to,” “anticipate” “intend,”“plan,” “believe,” “seek,” “estimate,” “will,” “project” or words of similar meaning. We may alsomake forward-looking statements in other reports, in presentations, in material delivered to sharehold-ers and in press releases. In addition, our representatives may from time to time make oral forward-looking statements. Such statements are based on the current expectations and certain assumptions ofSiemens’ management, of which many are beyond Siemens’ control. These are subject to a number ofrisks, uncertainties and factors, including, but not limited to those described in disclosures, in particu-lar in the chapter Risks in the Annual Report. Should one or more of these risks or uncertainties mate-rialize, or should underlying expectations not occur or assumptions prove incorrect, actual results,performance or achievements of Siemens may (negatively or positively) vary materially from thosedescribed explicitly or implicitly in the relevant forward-looking statement. Siemens neither intends,nor assumes any obligation, to update or revise these forward-looking statements in light of develop-ments which differ from those anticipated.

Trademarks mentioned in these documents are the property of Siemens AG, its affiliates or their re-spective owners.

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