Steam Turbines – reliable Solutions for Geothermal · PDF fileSteam Turbines – reliable Solutions for ... SST-500 GEO Core Turbine Design Double-flow casing Steam path designed

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Steam Turbines – reliable Solutions for Geothermal Power PlantsRobert Wilms, Proposal Manager Geothermal Turbines, Oil & Gas

Unrestricted © Siemens AG 2013 All rights reserved.

2013-06-20Page 2 R.Wilms / E O IP

Overview

• Geothermal power - General overview

• Challenges and technical solutions

• Siemens - Geothermal experience

• Siemens Solutions for geothermal applications

• SST-400 GEO

• SST-500 GEO

• Industrial Steam Turbines family



Geothermal Power- General Overview

Source: Stefansson V., 2005: World Geothermal Assessment. Proc. World Geothermal Congress

“Geothermal energy is thermal energy generated and stored in the Earth”

„Geothermal energy provides continuous, 24-hour a day, clean, sustainable energy production“Source: „Wikipedia“




Geothermal energy occurs in the form of hot rock, hot liquid, or in steam form. Wells are drilled deep into the surface of the Earth to obtain the geothermal energy and bring the hot liquid or the steam to the Earth’s surface



The highest conventional geothermal potential is sited along the plate boundaries.

Countries with most ambitious expansion programs: USA, Indonesia, and Philippines

Little near-term growth in existing market for conventional geothermal generation because of development risks and difficulties. “Easy” sites have been already developed.





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1950 1960 1970 1980 1990 2000 2010 2020

Inst

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paci

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Constant growth of capacity



Challenges and special Demands for Geothermal Steam Turbines

Different site conditions:flow rate, NCG content, pressure, pH, solid levels

Harsh geothermal environment: Corrosion attacks conventional materials , presence of H2S

Low steam parameters:Pressure ~3.5 – 16 bara saturated steam; temperature up to 250°C

Challenging installation:‘large’ piping compared with industrial equipment

Need for re-rates:Geo resources can degrade over time

Special material selection to meet geothermal specific steam chemistry and to resist corrosion attacks and corrosion-assisted fatigue cracking .



Geothermal Cycles

Dry Steam

Rock Layers

Injectionwell

Productionwell

GeneratorTurbine Load

Flashed Steam

GeneratorTurbineFlashtank Load

Rock Layers

Injectionwell

Productionwell

Indirect Cycle

GeneratorTurbine Load

Heat exchangerwith working fluid

Rock Layers

Injectionwell

Productionwell

Combined Cycle

Steam TurbineSeparator

Productionwell

Heat exchangerwith working fluid

Generator Load

Rock Layers

Injectionwell

Binary FluidTurbine

Types of geothermal power plants

• Four technologies used to generate electricity: Dry Steam, Flashed Steam, Indirect and Combined Cycle• The type of plant is determined primarily by the nature of the geothermal resource at the site




Steam

From Reservoir Separator

Brine

Brine PumpCondensateInjection wellsProduction Wells

Hot Brine Injection Wells

Brine pond

Generator

CondenserCoolingTower

Scrubber Demister

Test Unit

Turbine



Siemens Geothermal ExperienceProven Siemens Steam Turbine Technology

The SST-500 GEO is a joint development between Siemens Oil & Gas Industrial Power and the geothermal steam turbine service provider Siemens Energy Service TurboCare.

The turbine combines the proven turbine casing of the Siemens SST-500 and SST-600 as well as the steam turboset accessories (gears, generator, base frame) with the geothermal steam path and moisture

removal features introduced by TurboCare and proven in geothermal service.

Long experienced in the after-market and well known in the industry for turbomachinery services and improving reliability, efficiency and output of geothermal power plants

World leader in steam turbine technology, offering versatile, reliable and proven industrial steam turbines which meet all customer requirements for economic installation and operation



Siemens Geothermal Steam Turbine Family

SST-400 GEO Size 2 SST-500 GEO Size 6SST-400 GEO Size 4



SST-400 GEO Turbogenerator

SST-400 GEO

• Power output:5 – 55 MW (condensing)

5 – 60 MW (non-condensing)• Frequency:50 or 60 Hz• Speed:

max. 6000 rpm• Live steam:Up to 250°C

(482°F)/12 bara• Exhaust steam:

Up to 0.4 bara (condensing)Up to 1.4 bara (non-condensing)







Low stress design and optimized material

selections

Robust impulse design and generous

nozzle spacing




SST-500 GEO

• Power output:60 - 120 MW (condensing)

• Frequency:50 or 60 Hz• Speed:

Direct drive (3000/3600 rpm)• Live steam:

Up to 250°C (482°F)12 bara (218 psia)

• Exhaust steam:Condensing, up to 0.4 bara (5.8psia)



SST-500 GEO Core Turbine Design

Double-flow casing

Steam path designed to customer’s steam conditions

Inlet and admission pipes in lower half

2Cr rotor standard(12Cr available)

Effective moisture removal

Protective coatingson rotor seals

Radial downward exhaustModular design



Features of Siemens Geothermal Steam Turbines

Design features

• Suitable for air- and water-cooled plants • Tailored to customer requirements• Available in condensing and non-condensing

solutions• Non-condensing turbines suitable for atmospheric

exhaust or ORC bottoming cycle• Robust and reliable, designed with an industrial

application background• Design tools and adaptations have been proven

on a wide range of applications



Siemens solutions for geothermal power plants



Industrial Steam Turbines – Portfolio Overview

SST-500 GEO

SST-400 GEO

Steam TurbinesType Power Output (MWe)

SST-900SST-800SST-700SST-600SST-500SST-400SST-300SST-200SST-150SST-111SST-110SST-100SST-060SST-050SST-040 0.3

0.75

0,5 1 2 5 7 10 15 75 1003 20 30 50 150 250

6

8.5

7

12

20

10

50

65

100

150

175

250

250



Thank you for your attention



Dipl. Ing. Robert WilmsProposal Manager Geothermal Applications

Frankenstrasse 70-8090461 Nuremberg

Phone: +49 (911) 4130 313Fax: +49 (911) 4130 9313Mobile: +49 (172) 7296409

E-mail:[email protected]

Contact

siemens.at/future-of-energy

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Steam Turbines – reliable Solutions for Geothermal · PDF fileSteam Turbines – reliable Solutions for ... SST-500 GEO Core Turbine Design Double-flow casing Steam path designed