Field measurements of wind turbine wake by Doppler SODAR

Transcription

1 論 文 Field measurements of wind turbine wake by Doppler SODAR *1 *2 *3 *4 Takao MAEDA Yasunari KAMADA Tomoki TOMIYAMA Toshihiro NASUDA *1 Professor, Division of Mechanical Engineering, Mie Univ., 1577 Kurimamachiya-cho, Tsu, Mie , Japan, TEL , FAX , *2 Associate Professor, Mie Univ. *3 Graduate Student, Mie Univ. *4 Shirakawa-Denki-Doboku Co.,Ltd., Shirakane, Showa-ku, Nagoya, Aichi , Japan Abstract The purpose of this research is to verify whether wake measurement is possible with the Doppler SODAR. The wind speed in the wake of 1.5MW wind turbine was measured. The measurement site is gently undulating hills about 8m high above sea level surrounded by tea farms and forest. The test wind turbine is located in the position of prevailing wind direction and the distance about 2.7D from Doppler SODAR. The velocity deficit in the wake shows the maximum value at the hub height, and it decreases gradually at the outer region behind the rotor. In optimum operation, the difference of the wake profile by changing wind turbine output was not observed. Wind turbine, Wake, Doppler SODAR, Atmospheric boundary layer (1) (2) CFD (3) CFD CFD *1 ( ) *2 *3 *4 ( ) ~1m (4) 1m 65m 7.5m 12m/s 1.5MW D [m] H [m] u [m/s] u [m/s] U a (=u/u ) U b (=u/u )

2 [deg] U [m/s] TI U deg 9deg ~1m 32 24Hz 26m m 2m 6m 2 2deg 3 3 =276deg 191m( 2.7D) +2m 1m 8m (H=65m) 26deg 4 3km( =276deg) 1km 3km 55m Rotor North Hub height H=65m D = 7.5m 191m(=2.7D) =276deg Fig.1 Mono-static Doppler SODAR 2deg Control volume Altitude [m] deg Doppler SODAR Fig.3 Top view of the site =276deg Doppler SODAR Wind turbine 9deg Fig.2 Control volume of Dopplar SODAR Distance from measurement point [m] Fig.4 Section of the wind turbine upstream (=276deg)

3 ドップラ ソーダによる風力タービン後流の測定 ~ ~ MW C P 1.5MW H=3m u u u/u TI U = U /U (5) Power [kw] Power curve Power (measured) Power coefficient Wind speed [m/s] Fig.5 Power curve and Power coefficient curve Power coefficient C P V V R (1) U R, V R k sin k cos (2) V, V V k (6) k (5) k = (H=65m) =276deg 3m (U a /U b ) 7(a)(b)(c)(H=3m) (H=65m)(H=1m) =1deg BIN 7(a) =262~287deg 7(b)

4 Non-dimensional wind speed u/u Wind direction [deg] Fig.6 Horizontal Non-dimensional wind speed (H=65m) Wind direction [deg] (a) H=3m 1.4 Wake region from measured Wake region from Fig Wind direction [deg] (b) H=65m Wind direction [deg] (c) H=1m Fig.7 Horizontal wind speed ratio (after WT installation / before WT installation) =276deg =257~292deg (7) 2.4D Folkerts (8) (H=65m) (H=3m) 7(c) =265~285deg 8(a)(b)(c) =1deg BIN 8(b) =245~26deg =3deg 7 8(a)(b)(c) =262~287deg 9 =276deg( ) H=3~1m 9 H<1m H=2m

5 ドップラ ソーダによる風力タービン後流の測定 1(a) =276deg() TI U () 1(b) =276deg TI U (H=3m ) 1(a) Wind direction [deg] (a) H=3m Wake region Wind direction [deg] (b) H=65m Wind direction [deg] (c) H=1m Height [m] 1(a) 1(b).3Hz (9).3Hz.15Hz Height [m] Fig.9 Wind speed ratio profile at =276deg (a) Turbulence intensity Height [m] (Reference wind velocity at each height) (b) Turbulence intensity (Reference wind velocity at H=3m) Fig.8 Horizontal turbulence intensity Fig.1 Turbulence intensity profile at =276deg

6 .185Hz 3.455Hz.455Hz 1(b) 11 4kW 8kW 15deg BIN 6 8kW Cp=.434kW Cp= MW (1) (2) (3) Non-dimensional wind speed u/u Turbulent intensity TI U Wind direction [deg] Fig.11 Horizontal wind speed ratio at H=65m kW 8kW 4kW 8kW Wind direction [deg] Fig.12 Horizontal turbulent intensity at H=65m (1) L.J. Vermeer, J.N. Sorensen, A. Crespo: Wind turbine wake aerodynamics, Progress in Aerospace Sciences 39, pp , 3. (2), : 7,, pp.55-56, 2. (3) R.J.Barthelmie, S.T.Frandsen: Modelling and Measurements of Power Losses and Turbulence Intensity in Wind Turbine Wakes at Middelgrunden Offshore Wind Farm, WIND ENERGY, Vol.1, Issue 6, pp (4) Högstrom U., Asimakopoulos D.N., Kambezidis H., Helmis C.G., Smedman A.: A field study of the wake behind a 2 MW wind turbine, Atmos Environ, 22(4), pp.83-82, (5) Yoshiki I: Errors in Wind Measurements Estimated by Five-Beam Phased Array Doppler Sodar, JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY, Vol.14, pp , (6), : Z,, pp , 1997 (7), :,, Vol.27, No.4, pp (8) L. Folkerts,, R. Barthelmie,, P. Sanderhoff,, F. Ormel,, P. Eecen., O. Stobbe.: Sodar Wind Velocity Measurements of Offshore Turbine Wakes, Wind Engineering, Vol.25, No.5, pp (9),, :,, Vol.32, No.B-1, pp