Clean Power Solutions Alstom s Geothermal Offering

Transcription

1 Clean Power Solutions Alstom s Geothermal Offering The 6th International Energy Week Moscow Energy Dialogue Jens Werner Moscow, 24 th October 2011

2 Agenda Introduction and Group Background Factors Affecting Geothermal Plant Design Simplified Models of Resource Degradation Conclusions Alstom s Offering Alstom Geothermal References Alstom's Geothermal Plant Offering - Initials - 24 October, P 2

3 Alstom Group: Three sectors Sales by Sector (proforma figures) Employees by Sector Source: Alstom 20010/11 Rail transport infrastructure Power generation infrastructure Power transmission infrastructure Supplier of 1 metro/tram in each 4 Major supplier in 25% of worldwide installed base Leadership in key markets and fast-growing technologies Alstom's Geothermal Plant Offering - Initials - 24 October, P 3

4 Alstom Group: Three plus one sectors Renewable power sector including Geothermal created in 2011 Alstom's Geothermal Plant Offering - Initials - 24 October, P 4

5 Who We Are Alstom Thermal Power Sector Philippe Cochet - President Renewable Power Sector Jerome Pecresse - President Wind Alfonso Faubel SVP Hydro Jerome Pecresse SVP Thermal Renewables Denis Cochet SVP (Acting) Status as at 01/08/2011 Small Steam Turbines Solar Geothermal Steve Moss VP Armand Pineda VP Frederic Sauze VP Alstom's Geothermal Plant Offering - Initials - 24 October, P 5

6 Who We Are Overview Alstom Geothermal active in geothermal since 1950 s with the Wairakei project in New Zealand (first large-scale geothermal plant in the world) Business re-focused in 2008, with worldwide headquarters created in Morelia, Mexico 50MW currently in construction (Los Humeros Units 9 and 10, Veracruz state) East Asia office opening in September 2011 to complement existing sales teams in region Geothermal Headquarters, Morelia Geothermal Turbine in Manufacture Los Humeros Units 9&10 (in construction) Alstom's Geothermal Plant Offering - Initials - 24 October, P 6

7 Agenda Introduction and Group Background Factors Affecting Geothermal Plant Design Simplified Models of Resource Degradation Conclusions Alstom s Offering Alstom Geothermal References Alstom's Geothermal Plant Offering - Initials - 24 October, P 7

8 Plant Integrator Geothermal Power Plants Compact plant layout Advanced control system for maximum plant reliability Key components and engineering supplied by Alstom Architect Engineers Added Value Turnkey/EPC Comp. 3 Competitor 2 Competitor 1 Component suppliers Alstom - the Geothermal turnkey plant supplier Alstom's Geothermal Plant Offering - Initials - 24 October, P 8

9 Mass Flow and Pressure Cold water percolation into reservoir Geothermal reservoir Impermeable Layer (Capstone) Heat Flow Geothermal Well (1-3km) Surface expression Natural system generates steam that is difficult to predict, much less influence. Heat Source Wide range of flows, pressures and temperatures to consider Alstom's Geothermal Plant Offering - Initials - 24 October, P 9

10 Mass Flow and Pressure Resource Steam Dominated > 175 C / 350F < 175 C / 350F Water/Steam Mixture Water Dominated High Enthalpy (Direct Cycle) Low Enthalpy (Binary) Configuration T Geothermal Brine T Secondary Fluid Geothermal Steam Heat Exchanger Technology Dry Steam Single Flash Double or Triple Flash Kalina or ORC Hot Dry Rocks or EGS (emerging technology) Thermodynamic cycle adaptation depending on resource conditions Alstom's Geothermal Plant Offering - Initials - 24 October, P 10

11 Mass Flow and Pressure Steam Conditions for Selected Operating Geothermal Units Worldwide (60Hz) Turbine Inlet Pressure (Bar) = Operating project Note: Graph does not consider customer preference for multiflash Mass Flow (kg/s) 10 bar or greater is considered high pressure for geothermal Alstom's Geothermal Plant Offering - Initials - 24 October, P 11

12 Mass Flow and Pressure Example project Original design point Flexible operating envelope required Alstom's Geothermal Plant Offering - Initials - 24 October, P 12

13 Mass Flow and Pressure Low Pressure Low Mass Flow High Pressure Low Mass Flow Low Pressure High Mass Flow High Pressure High Mass Flow Implications for module architecture are considerable Alstom's Geothermal Plant Offering - Initials - 24 October, P 13

14 Resource and Water Chemistry Particulate Condensate Droplet Steam NCG s Geothermal Steam is a mixture of a) Saturated or nearly saturated steam b) Condensate droplets carried in the steam c) Non-condensable gases (0.5% - 7%) d) Solid particulates carried in the steam Typical Composition: 95% CO 2 4% H 2 S 1% Others Alstom's Geothermal Plant Offering - Initials - 24 October, P 14

15 Resource and Water Chemistry a) Saturated steam: Is wet steam, i.e. is susceptible to condense as heat is removed across turbine stages Necessitates water extraction thru steam path Special treatments for rear stage blades (e.g. Induction hardening) to mitigate droplet erosion Water extraction Induction Hardened zone Alstom's Geothermal Plant Offering - Initials - 24 October, P 15

16 Resource and Water Chemistry b) Condensate droplets: Cause erosion, scaling and corrosion to static and rotating equipment Pipe bends design must consider high droplet content Contain a high concentration of dissolved and exotic minerals, causing corrosion and scaling particularly Condensate Droplet in Steam Flow Typical Condensate Mineral Content Scaling Potential Corrosion Potential Silica (SiO 2 ) X Chloride (Cl) X Sodium (Na) X X Calcium (Ca) X Sulfate (SO 4 ) X Total Iron (Fe) X Total Solids (TS) X Alstom's Geothermal Plant Offering - Initials - 24 October, P 16

17 Resource and Water Chemistry c) Non-condensable gases: Contain significant proportion of Hydrogen Sulphide (H 2 S) - a key component of stress corrosion cracking Must be removed from condenser under vaccum with oversized gas extraction system Gas Extraction System Design Mass Flow (kg/hour): Typical Thermal Power Station (500MW) Typical Geothermal Power Station (50MW) Air Ingress Flashed Air Non condensibles Total Cost of Gas Extraction System (KUSD) Cost of Condenser (DCC) (KUSD) Alstom's Geothermal Plant Offering - Initials - 24 October, P 17

18 Resource and Water Chemistry d) Solid particulates Not usually a problem if upstream separation or filtering is effective for removal Key area of operations and maintenance drastic reduction in turbine wear can be achieved Clean steam High Droplet/SPE content Baffle Separator or Venturi Cyclonic Scrubber Waste Stream Alstom's Geothermal Plant Offering - Initials - 24 October, P 18

19 Site Location Site Conditions Affecting Plant Design (and cost) a) Soil conditions at surface b) Seismic conditions c) Ambient conditions Alstom's Geothermal Plant Offering - Initials - 24 October, P 19

20 Site Location a) Soil Conditions at Surface Loose or poor soil conditions at surface will determine size and type of foundation to be used Large driver on civil works cost Premium to reduce height and weight of equipment Spread foot foundation concept Pile foundation Alstom's Geothermal Plant Offering - Initials - 24 October, P 20

21 Site Location b) Seismic conditions earthquake design Usually high seismic potential in geothermal zones Earthquake design resolves to bulk acceleration of equipment in both lateral and vertical directions All plant equipment susceptible, not just turbogenerator F Lateral Turbine Generator F Vertical Rotor F vertical Rotor F vertical Journal Bearing Thrust Bearing Rotor Bending Stresses Shaft Coupling Reaction Forces Seismic acceleration Rotor bending, and reaction loading at bearings to be checked Alstom's Geothermal Plant Offering - Initials - 24 October, P 21

22 Site Location c) Ambient Conditions Wind direction determines cooling tower placement, performance consideration and H 2 S settlement avoidance Wet-bulb temperature strongly influences cooling system design cold air permits lower vaccum at cheaper price and smaller installation (less cooling) Plume Avoidance Option Low Wet Bulb Option Cold air availability reduces relative cooling system size and cost Alstom's Geothermal Plant Offering - Initials - 24 October, P 22

23 Agenda Introduction and Group Background Factors Affecting Geothermal Plant Design Simplified Models of Resource Degradation Conclusions Alstom s Offering Alstom Geothermal References Alstom's Geothermal Plant Offering - Initials - 24 October, P 23

24 Simplified Reservoir Model Boiling Pot Analogy Vapor/liquid Vapor Liquid Control Volume: consider at constant pressure, P R Geothermal extraction of steam and water begins Pressure in system is reduced over time to P 2 Simplified assumption reduces reservoir modelling complexity Alstom's Geothermal Plant Offering - Initials - 24 October, P 24

25 Case A High Depletion Scenario Constant rate of fluid extraction will reduce pressure in reservoir over time. Natural recharge of fluids may not be sufficient to prevent reduction of pressure Majority of Geothermal reservoirs will behave in this way Alstom's Geothermal Plant Offering - Initials - 24 October, P 25

26 Case B Reduced Depletion Scenario A reduction of extraction rate at t 2 reduces the rate of pressure degradation within the reservoir Stabilisation may occur if natural recharge capacity is not exceeded Alstom's Geothermal Plant Offering - Initials - 24 October, P 26

27 Case C Enthalpy Increase Scenario Over time the well dries out, release only steam instead of water and steam (enthalpy, h, increasing) Analogous to a pot of water starting to boil dry In a two-flash system, vapor for the second flash depends on amount of liquid water extracted from the reservoir Alstom's Geothermal Plant Offering - Initials - 24 October, P 27

28 Agenda Introduction and Group Background Factors Affecting Geothermal Plant Design Simplified Models of Resource Degradation Conclusions Alstom s Offering Alstom Geothermal References Alstom's Geothermal Plant Offering - Initials - 24 October, P 28

29 Conclusions 1. The presentation has demonstrated and discussed some of the important factors in geothermal power plant designa and their influence on the relevant power plant components 2. A simplified method of reservoir modelling has been demonstrated which provides a guideline basis for typical geothermal reservoir behaviour over the lifetime of the project 3. This gives the turbine designer a basis on which they must consider an adaptable turbine design and power plant for the geothermal application Alstom's Geothermal Plant Offering - Initials - 24 October, P 29

30 Agenda Introduction and Group Background Factors Affecting Geothermal Plant Design Simplified Models of Resource Degradation Conclusions Alstom s Offering Alstom Geothermal References Alstom's Geothermal Plant Offering - Initials - 24 October, P 30

31 Basic Product Scope Alstom + Partner Steam Gathering System Core Alstom Scope Inside the Fence Alstom Grid Power Export Alstom can provide an EPC wrap for full power plant with sub-contract partners Alstom's Geothermal Plant Offering - Initials - 24 October, P 31

32 Power Plant Packages Full Turnkey Scope: Geothermal Power Plant (GPP) Geothermal Power Island (GPI) Geothermal Power Train (GPT) Geothermal Steam Turbine (GST) Equipment scope (GST,GPT,GPI) or turnkey scope available (GPP) Alstom's Geothermal Plant Offering - Initials - 24 October, P 32

33 Power Plant Packages Equipment scope: Geothermal Steam Turbine (GST) Steam turbine, valves and auxiliaries (including lube-oil system) Turbine Instrumentation and Control System (TCS) with a 2oo3 security architecture shipped as standard Engineering, delivery, erection and commissioning 60Hz Turbines 50Hz Turbines GST62: 15-30MW Single Flow Top Exhaust GST65: 25-60MW Double Flow Lateral Exhaust GST52: 15-30MW Single Flow Top Exhaust (Lahendong unit) GST55: 25-65MW Single Flow Axial Exhaust GST510: MW Double Flow Lateral Exhaust Comprehensive range of geothermal turbines for power plant flexibility Alstom's Geothermal Plant Offering - Initials - 24 October, P 33

34 Key Component Focus Steam Turbine Flexible architecture to adapt for differing project size and steam conditions Robust blade paths, designed to take account of wet steam causing erosion and entrained chemicals for corrosion and/or fouling Induction hardened Last Stage Blades (LSB), machined from rough forgings or made by precision die forging. High performance blades, milled from rolled bars, incorporating shrouds at the tips for reduced tip leakage. Water extraction traps at each stage with replaceable reinforced blade ring inserts for enhanced erosion protection. Leveraging extensive wet-steam know-how from geothermal and nuclear Alstom's Geothermal Plant Offering - Initials - 24 October, P 34

35 Agenda Introduction and Group Background Factors Affecting Geothermal Plant Design Simplified Models of Resource Degradation Conclusions Alstom s Offering Alstom Geothermal References Alstom's Geothermal Plant Offering - Initials - 24 October, P 35

36 Geothermal References Los Humeros CFE, Mexico 2 x 25 MW Planned COD: 2011, 12 Scope Power Island and HV Substation Cooling tower Civil works Project management Mechanical BoP Engineering Site supervision Scope Los Azufres CFE, Mexico 4 x 25 MW COD: 2003 Power Island and HV Substation Cooling tower Civil works Project management Mechanical BoP Engineering Site supervision Alstom's Geothermal Plant Offering - Initials - 24 October, P 36

37 Geothermal References Lahendong Perusahaan Listrik Negara, Indonesia 1 x 20 MW COD: 2001 Scope Power Island and Project management Mechanical BOP Engineering and site supervision Scope Las Tres Virgenes CFE, Mexico 2 x 5.5 MW COD: 1998 Power Island and HV substations Project management Mechanical BOP Engineering and site supervision Alstom's Geothermal Plant Offering - Initials - 24 October, P 37

38 Geothermal References La Bouillante CFG,(BRGM), EDEV (EDF), French W Indies 1 x 5 MW COD: 1980 Scope Power Island and Construction of power plant Engineering Manufacturing Purchasing Sub-contracting Construction and Commissioning Scope Wairakei Contact Energy Limited, New Zealand Units 1+2: 2 x 6.5 MW Units 3-10: 8 x 11 MW Units 11-13: 3 x 30 MW COD: 1958 Power Island and Engineering Implementation Erection & commissioning Alstom's Geothermal Plant Offering - Initials - 24 October, P 38

39 Thankyou

40 Agenda / Backup Solutions for Turbine Design Alstom's Geothermal Plant Offering - Initials - 24 October, P 40

41 Solutions for Turbine Design Case A High Depletion Scenario Turbine Solution: Remove Upstream Blade Rows 1 Initial Condition P1 > P2 Mass Flow 1 = Mass Flow 2 Volume Flow 1 > Volume flow 2 2 After degradation Benefits: Simple solution No affect to cooling system and gas extraction system design Drawbacks: Casing Geometry must not allow choking on inlet for larger volume flow Cannot be implemented onload, without turbine stop Alstom's Geothermal Plant Offering - Initials - 24 October, P 41

42 Solutions for Turbine Design Case B Reduced Depletion Scenario Turbine Solution: Reduce Pressure With Constant Volume Flow 1 Initial Condition P1 > P2 Mass Flow 1 > Mass Flow 2 Volume Flow 1 = Volume flow 2 2 After degradation Benefits: Turbine architecture remains the same Reduces mass flow drawdown of reservoir Drawbacks: Check required that low flow stall velocity not reached at exit to LSB or changes to cooling system configuration may be required Alstom's Geothermal Plant Offering - Initials - 24 October, P 42

43 Solutions for Turbine Design Case C Enthalpy Increase Scenario Turbine Solution: Ensure Second Flash Inlet Connected by Valve 1 Initial Condition to Upstream Stage Reservoir is drying out 2 After degradation Flash Vessel Insufficient Water to Flash LP Steam (2 nd Flash) HP Steam Gen. HP Steam only Gen. Exhaust Exhaust Without second stage steam, 2 inlet turbine operates poorly Alstom's Geothermal Plant Offering - Initials - 24 October, P 43

44 Solutions for Turbine Design Case C Enthalpy Increase Scenario Turbine Solution: Ensure Second Flash Inlet Connected by Valve to Upstream Stage Benefits: Solution: HP Steam only HP inlet shut off Control and Throttle Valve Only LP inlet utilised Exhaust Gen. For two flash system turbine architecture and installation remains the same Drawbacks: Turbine and plant loses operating efficency due to throttling of HP steam to lower inlet pressure Cooling system will require adaptation for new operating point at lower mass flow Components now oversized for steam flow Costly equipment is left redundant Last resort solution to be avoided by accurate reservoir prediction Alstom's Geothermal Plant Offering - Initials - 24 October, P 44