New Requirements for Steam Turbines due to Renewable Energy Innovative Concepts for Thermal Power Plants

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1 New Requirements for Steam Turbines due to Renewable Energy Innovative Concepts for Thermal Power Plants NTPC Conference Green Power - Challenges and Innovation Noida / Delhi, June 9th 2017 Peter Brueggemann Restricted Siemens AG 2017 All rights reserved. Answers for energy.

2 Gross Electricity Production Germany 2014 Hard Coal Gas Oil Others Hydro Bio Mass Nuclear In Total 610 TWh Renewables Wind Solar Lignite Biomass fraction of waste Source: AG Energiebilanzen, Stand: Dezember 2014 Renewables with 50% installed capacity generate > 25% of gross electrical production Page 2 Noida,

3 Tomorrows Load Requirements Energy from Renewables has Right of Way in the grid Scenario 2020 Tomorrow (Scenario 20XX) source: Spliethoff: et. al, CIT 2011 Lignite / Nuclear Hard Coal Gas 2011 Base Load Intermediate Load Intermediate Load 2020 Intermediate Load Intermediate Load Peak load 20XX Intermediate Load?? Feeding of renewable energy requires flexible fossil fired power plants Page 3 Noida,

4 Volatile intensifies Requirements for Transient Operation Power Flex Operation Line Standard Operation Line Base Load Time Fast Start Up Primary Frequency Response Secondary Frequency Response Peak Power & Off- Frequency Part Load Fast Shut Down Prepared for Start up Fast Start Up Integrated Start up Concept High Load Gradient High Load Gradient High Load Gradient Extra Power Off-Frequency operation Lower Minimum Part Load Improve part load efficiency High Deload Gradient Optimized Preservation Heating concept Integrated Start up Concept High Load Gradient Page 4 Noida,

5 Service / Lifetime Extension: Fatigue of major steam turbine components Main Steam and Reheat turbine valve casings Low cycle fatigue due to starts and shutdowns Creep damage due to steady state operation LP turbine rotor Low cycle fatigue due to starts and shutdowns HP and IP turbine casings and rotors Low cycle fatigue due to starts and shutdowns Creep damage due to steady state operation IP/LP bypass valve casings Low cycle fatigue due to bypass operation Page 5 Noida,

6 Service / Lifetime Extension: Service concepts for turbine plant components Component Failure Probability Design Service (NDE, RLA) Operational Hours Real Life Time of Component Up To Failure NDE Non-Destructive Examination RLA - Remaining Life Analysis Page 6 Noida,

7 Service / Lifetime Extension: Service concept for steam turbine components Steam turbine overhauls 25k EOH concept (see VGB Guideline R 115 M) / 300 Minor Medium Minor Major Minor Medium Minor LTE LTE = Lifetime Extension Goal: Completeness of the LTE at 200k / 300k EOH Start of preparation at the previous overhaul EOH = Equivalent Operating Hours: T EOH = T OH + S N s * n S T OH Operating hours; N S Number of starts; n s as follows: until 2001: constant factor n s until 2006: constant factor n s for three fixed gradients since 2006: factors according to the usage of temperature gradients during operation today: Turbine Stress Controller (TSC) / Turbine Stress Evaluation (TSE) Page 7 Noida,

8 Service / Lifetime Extension: Type of overhauls and scope of lifetime assessments Types of Steam Turbine Overhauls Minor Overhaul Medium Overhaul Major Overhaul De- and re-installation of bearings and auxiliaries De- and re-installation of bearings, auxiliaries and valves Complete de- and re-installation of bearings, auxiliaries, valves and turbines Lifetime Assessment Visual testing and boroscoping Mainly: Functional tests Lifetime Assessment Valves and bearings Last stage blades Weld seams of main steam valves (depending on code requirements) Lifetime Assessment All turbine components, valves and bearings Extended NDT as required Page 8 Noida,

9 Service / Lifetime Extension: Scope of a lifetime assessment Lifetime Assessment : Assessment of the actual component properties by Standard NDT Extended NDT Material Investigations Engineering Assessment Visual Testing Magnetic Particle Testing Liquid Penetrant Testing Ultrasonic Testing Eddy Current Testing X-ray Testing Automated Ultrasonic Testing Ultrasonic Phased Array Testing Ultrasonic TOFD Tailor-made solutions Metallography / Micrograph Page 9 Noida, Hardness Testing Mechanical properties Sample * Assessment of NDT results Structural mechanics * Fracture mechanics * * depending on fact finding results

10 Service / Lifetime Extension: Lifetime Extension of steam turbine components Step 1: Lifetime assessment by NDT Component Damage D (Creep + LCF) DD Warning Time Point (Outage required) Operational Time Step 2: Evaluation of operational history Damage reduction ΔD and component release for the further operations based on: Updated computational conditions Local repair Transient and steady state operational conditions adjustment Evaluation repair vs. replacement by three steps Step 3: Remaining lifetime analysis Page 10 Noida,

11 Modernization Technology: Product portfolio Upgrade solutions for fossil and nuclear steam turbines All power output ranges (approx MW) HP, IP, LP turbines Condenser, generator and I&C upgrades Siemens (incl. KWU), Parsons and Westinghouse designs (incl. licensees) Other OEM products (LMZ, GE/Alstom, etc.) Continuous R&D investment for technology improvements and product range enlargement Large list of references > - 30 years of experience More than 300 fossil units modernized (OEM and O-OEM) Page 11 Noida,

12 Modernization Technology: Upgrade Products Siemens and O-OEM (Examples) Frame Turbine HP K-200 HP LMZ 200 / 210 MW IP K-200 IP LP N30-2x5m² principle example HP H30-25 KWU 200 / 210 MW IP M30-25 LP N30-2x5m² principle example KWU 500 MW HP IP H30-63 H M30-50 M30-63 LP N30-2x10m² principle example Page 12 Noida,

13 - Modernization Technology: Overview of key technologies for efficiency improvements for modernization projects State-of-the-art 3DS TM Drum Stage Blading 3D Blading Stationary Blades Benefits Rotating Blades Efficiency Modern 3D Blade Earlier Blading + 2 % World-class performance Wide range of application Specific design for each application within short delivery times Long life & high reliability Stage Load Additional 2.5 % efficiency increase possible when exchanging impulse blading Page 13 Noida,

14 - Modernization Technology: Overview of key technologies for efficiency improvements for modernization projects LP Blading Design Features State-of-the-art fully 3D design by means of advanced computational methods Optimized last stage blade size Optimized LP exhaust area New shrouded L-2, L-1 and freestanding Last Stage Blade with trans- and supersonic tip sections, 3D flow design Customized Design L-2C LE-0 L-1C LE-0 p 1 L-2R LA-0 L-1R LA-0 - L-0C p LE-0 21 L-0R LA-0 Standardized Stage Package Benefits Improved blade efficiency by advanced 3D blade design Increased efficiency by shrouded rotating blades Reduced exhaust losses Page 14 Noida,

15 Modernization Technology: Overview of key technologies LP Blading Reliability features Fir tree root design for improved strength and reliability by residual stress application and control Highly effective erosion protection measures based on extensive experience and use of high alloy materials Suction of the water film into interior of guide blade Benefits Increased reliability and service life due to reduced stress levels and effective erosion protection measures Reduction of maintenance costs Suction of the boundary-flow water into blade-carrier ring Page 15 Noida,

16 - Modernization Technology: Overview of key technologies for efficiency improvements for modernization projects Optimized sealing concept Brush seals in bladepath & shaft sealing Abradable coatings in shaft sealing Spring-backed seal segments Abradable Coatings Brush Seals in Bladepath Benefits Minimization of clearance losses for higher efficiency Page 16 Noida,

17 Modernization Technology: Concepts for efficiency improvement technologies Blading Technology Protection via coating Retrieve original roughness Application of shrouded L-1 standard stage Reblading 3DS Sealing Technology (Shaft & Blading) Improved seal strips Advanced segment design Abradable coating Brush seals TE 1 2 HP 3 IP LP GE Page 17 Noida,

18 I&C upgrades Integrated I&C solutions / Big Data Each module is integrated in the platform Modules independent from each other Harmonized interfaces between all modules Page 18 Noida,

19 Reduction of start-up time of steam turbine and plant Improved turbine start-up time Start-up times can be reduced by about 20% for hot start conditions Main & re-heat steam temperatures are reduced for start-up This prevents excessive thermal stresses during start-up processes Improved plant start-up time Overall plant start-up times can be reduced by about 40% In collaboration with total plant operation, steam turbine roll-off has been improved Focus was set on hot start-conditions Page 19 Noida,

20 Requirements for Frequency Control Frequency Control Primary Secondary 30 s 5 min 15 min valid in Germany Requirements for primary frequency control are defined in respective grid codes Country Additional power within Ramp rate Germany, Austria 2% 30 s 4%/min United Kingdom 10% 10 s 60%/min Poland 5 % 30 s 10%/min Page 20 Noida,

21 Steam Power Plant Water Steam Cycle I&C Measures 1 2 HP IP LP LP G Steam Generator 5 Extraction Steam Valves Fast control Butterfly Valves 3 Condenser Condensate Pumps Fast Condensate Control Station 4 HP Feed Water Heaters 100% HP Feed Water Heater Bypass Feed Water Pumps Power LP Feed Water Heaters 1. Throttling 2. Addl. valve 3. Condensate Stop 4. HP Heater 5. Fuel Increase Time Page 21 Noida,

22 Increase of Swallowing Capacity Boiler Storage 1 2 HP IP LP LP a. Remove throttling of control valves b. Opening of last main steam valve Power 1 2 Time Page 22 Noida,

23 Condensate Throttling Feed Water Storage HP IP LP LP G Condenser a. Enlarge storage volume b. Fast condensate control valve c. Fast control valves in LP extractions Power Fast control Butterfly Valves Enlarged Feed Water Tank 3 LP Feed Water Heaters Enlarged Condenser Hotwell Condensate Pumps Fast Condensate Control Station 3 Time Lünen, Germany 2013, 800MW Page 23 Noida,

24 Concept for Staggering of Measures Frequency Additional output Measure 50 Hz +0%... decrease e increase Start increasing firing + Opening of throttled HP CVs + opening of last control valves + condensate throttling + increase of spray water + closing of HP heater extractions 49.5 Hz +10% Page 24 Noida,

25 Simulation of power increase Combination of all measures (Example) Page 25 Noida,

26 Improved performance at part loads Top heater concept 5% 300 4% 280 w/o power of BFWP 3% 2% D HR final feed water temp. [ C] 1% 220 0% % 50% 60% 70% 80% 90% 100% Load Part load efficiency can be increased with a top feedwater heater Page 26 Noida,

27 Lower minimum load Reduced emissions by top heater concept Temperature T DeNOx limit Load Page 27 Noida,

28 Lower minimum load Reduced emissions by top heater concept Temperature 3 after Top Heater T No DeNOx limit Benefit: better part load optimization of the boiler Load Page 28 Noida,

29 Thanks you for your attention Please feel free to contact me! Siemens AG Power Generation Services Dipl.-Ing. Peter Brueggemann Senior Expert Turbine Island Rheinstr Muelheim an der Ruhr Germany Phone: Mobile: Page 29 Noida,

30 Disclaimer This document contains forward-looking statements and information that is, statements related to future, not past, events. These statements may be identified either orally or in writing by words as expects, anticipates, intends, plans, believes, seeks, estimates, will or words of similar meaning. Such statements are based on our current expectations and certain assumptions, and are, therefore, subject to certain risks and uncertainties. A variety of factors, many of which are beyond Siemens control, affect its operations, performance, business strategy and results and could cause the actual results, performance or achievements of Siemens worldwide to be materially different from any future results, performance or achievements that may be expressed or implied by such forward-looking statements. For us, particular uncertainties arise, among others, from changes in general economic and business conditions, changes in currency exchange rates and interest rates, introduction of competing products or technologies by other companies, lack of acceptance of new products or services by customers targeted by Siemens worldwide, changes in business strategy and various other factors. More detailed information about certain of these factors is contained in Siemens filings with the SEC, which are available on the Siemens website, and on the SEC s website, Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those described in the relevant forward-looking statement as anticipated, believed, estimated, expected, intended, planned or projected. Siemens does not intend or assume any obligation to update or revise these forward-looking statements in light of developments which differ from those anticipated. Trademarks mentioned in this document are the property of Siemens AG, its affiliates or their respective owners. Page 30 Noida,