Characterization of wind velocity distributions within a full-scale heliostat field

Transcription

1 Photos placed in horizontal position with even amount of white space between photos and header Characterization of wind velocity distributions within a full-scale heliostat field Jeremy Sment, Graduate Intern, NSTTF Clifford K Ho Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a w holly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy s National Nuclear Security Administration under contract DE-AC04-94AL85000.

2 Presentation Overview Introduction (1 min): Commercial Scale Concentrating Solar Technologies Costs and Hurdles, i.e. Why are we doing this? Wind Profile Goals (3 min) Meteorological Wind Loading Model Validation Initial Results (5 min): STOW Configuration 45 Configuration Summary of Future Test Goals (1 min): 2

3 Concentrating Solar Technologies Point Focus: Solar Dish Stirling Energy Systems: 31.25% solar to grid efficiency Credit: Sandia National Laboratories/Randy Montoya Copyright: SNL 2008 Location: SNL 3

4 Concentrating Solar Technologies Line Focus: Parabolic Trough SkyFuel, Inc Credit and Copyright: Skyfuel Inc, 2009 Location: Albuquerque, NM 4

5 Concentrating Solar Technologies Point Focus: Central Receiver Tower with Heliostat Field Solar Two 10MW Plant ( ) 1,818 heliostats Credit and Copyright: Sandia National Laboratories, 1996 Location: Barstow, CA 5

6 How a Solar Power Tower Works Direct Steam (esolar Lancaster, CA 5MW) Molten Salt Storage (SolarReserve Tonopah, NV 110MW) Power Plant Schematic Credit and Copyright: DOE/NREL

7 Costs and Hurdles Heliostats typically contribute ~50% of total plant cost $164/m 2 installed given 5,000/yr R & D should be able to reduce the heliostat price by $17/m 2 Drives and pedestal account for 30% of total materials cost Understanding wind forces and torques can inform possible low cost redesign of Azimuth drives. Winsmith stated that the design of their azimuth drive may be too conservative and that a less-costly drive might be possible with better understanding of wind loads and torques on drive. Improvements in optical performance can result in same power production with a reduction in field size and heliostat area. Source: Gregory J. Kolb 2007, Sandia National Labs Heliostat Cost Reduction Study. SAND

8 Presentation Overview Introduction (1 min): Commercial Scale Concentrating Solar Technologies Costs and Hurdles, i.e. Why are we doing this? Wind Profile Goals (3 min) Meteorological Wind Loading Model Validation Initial Results (5 min): STOW Configuration 45 Configuration Summary of Future Test Goals (1 min): 8

9 Wind Profile Goals: Meterological Meteorological Approaching Wind Velocity Speed Azimuth Elevation Power Law coefficient Site-Terrain Roughness coefficient Turbulence Intensity Gust Frequencies IU z U U z R U z z z r 9

10 Wind Profile Goals: Wind Loads Wind Load Coefficients C m M Q A L r r r, C f F Q A r r Q r 1 2 U 2 r Loading with Wind-Loading without Wind 10

11 Wind Profile Goals: Model Validation Model Validation Boundary Velocity Inputs Perimeter heliostat Response Inner Field and close range velocity inputs Inner field heliostat response 11

12 Presentation Overview Introduction (1 min): Commercial Scale Concentrating Solar Technologies Costs and Hurdles, i.e. Why are we doing this? Wind Profile Goals (3 min) Meteorological Wind Loading Model Validation Initial Results (5 min): STOW Configuration 45 Configuration Summary of Future Test Goals (1 min): 12

13 Experimental Set-Up National Solar Thermal Test Facility, Sandia National Labs 13

14 Experimental Set-up Field Mounted Anemometers F1-23 F2-17 F3-11 Heliostat-Mounted Anemometers H1-20 H2-18 H3-17 H4-15 Solar Two 10MW Plant 14

15 Experimental Set-up Solar Two 10MW Plant Cut plot of mesh used on 45 configuration with 1.8 million cells. Heliostat is rotated 20 in azimuth from plane of cut plot. 15

16 Wind Profile: STOW, 21 mph Empirical Wind Speed Modeled Wind Speed 18 mph 17 mph 16 mph 15 mph 20 mph 20 mph 20 mph 20 mph STOW Position with Boundary Wind Speed 20 mph Height Measured Modeled Relative Turbulence (in) (mph) (mph) Error % Intensity % ± 5 20 ± ± 5 20 ± ± 6 20 ± ± 5 20 ±

17 Wind Profile: 45 Position Empirical Wind Speed Modeled Wind Speed 18 mph 17 mph 17 mph 15 mph 19 mph 18 mph 18 mph 17 mph 45 Position with Boundary Wind Speed 20 mph Height Measured Modeled Relative Turbulence (in) (mph) (mph) Error % Intensity % ± ± ± ± ± ± ± ±

18 Wind Profiles Sample Wind Velocity Measurements 18

19 speed (mph) Speed Profile: FACE-UP Position Wind speed distributions by anemometer location: STOW Overall Statistics Min Mean Max Pooled Std Dev Spread by Anemometer Min Mean Max Std Dev F1 F2 F3 H1 H2 H3 H4 anem. location 19

20 wind heading (deg) Direction Profile: FACE-UP Position Wind heading distributions by anemometer location: STOW Overall Statistics Min Mean Max Pooled Std Dev Spread by Anemometer Min Mean Max Std Dev F1 F2 F3 H1 H2 H3 H4 anem. location 20

21 wind elevation (deg) Elevation Profile: FACE-UP Position Wind elevation distributions by anemometer location: STOW Overall Statistics Min Mean Max Pooled Std Dev Spread by Anemometer Min Mean Max Std Dev F1 F2 F3 H1 H2 H3 H4 anem. location 21

22 speed (mph) Wind Profile: 45 Position Box plot of Speed distributions by anemometer location (45deg) Overall Statistics Min Mean Max Pooled Std Dev Spread by Anemometer Min Mean Max F1 F2 F3 H1 H2 H3 H4 anem. location 22

23 wind elevation (deg) Wind Profile: 45 Position Box plot of wind elevation distributions by anemometer location (45deg) Overall Statistics Min Mean Max Pooled Std Dev Spread by Anemometer Min Mean Max F1 F2 F3 H1 H2 H3 H4 anem. location 23

24 Presentation Overview Introduction (1 min): Commercial Scale Concentrating Solar Technologies Costs and Hurdles, i.e. Why are we doing this? Wind Profile Goals (3 min) Meteorological Wind Loading Model Validation Initial Results (5 min): STOW Configuration 45 Configuration Summary of Future Test Goals (1 min): 24

25 Future Test Goals Wind Loads on Perimeter Heliostats Wind Velocity Profiles Across Full Field Wind Loads on Inner Heliostats Gust Frequency Correlations to Heliostat Modal Vibrations 25

26 Questions? 26