1. An object carrying device, comprising:
a first net body bent to form a bottom portion and two lateral portions, the bottom portion having a front side, a rear side, and two opposing lateral sides, the two lateral portions extending from the two opposing lateral sides of the bottom portion, respectively, and facing each other;
a frame clipped to the first net body and disposed at an outer periphery of the first net body;
a front baffle panel fixed to the frame and disposed at the front side of the bottom portion of the first net body; and
a rear baffle panel fixed to the frame and disposed at the rear side of the bottom portion of the first net body.
2. The object carrying device of claim 1, wherein the frame comprises two clip sheets each bent to form a top section, two upright sections, and two bottom sections, wherein a length of each top section equals a length of each long side of the two lateral portions of the first net body, wherein a length of each upright section equals a length of each lateral side of the two lateral portions, wherein a length of each bottom section equals a half of the length of the front and rear sides of the first net body.
3. The object carrying device of claim 2, wherein a gap is formed between the top of each upright section and the top section.
4. The object carrying device of claim 1, wherein the rear baffle panel comprises a second net body and a rear slat, wherein two lateral sides and a bottom side of the second net body are fixed to the frame, wherein the rear slat is clipped to a top side of the second net body, wherein two terminal ends of the rear slat are fixed to the frame.
5. The object carrying device of claim 4, wherein the front baffle panel comprises a third net body and a front slat, wherein two lateral sides and a bottom side of the third net body are fixed to the frame, wherein the front slat is clipped to a top side of the third net body, and two terminal ends of the front slat are fixed to the frame.
6. The object carrying device of claim 4, wherein the front baffle panel comprises a front panel and a front slat, wherein two lateral sides and a bottom side of the front panel are fixed to the frame, the front slat being coupled to a top side of the front panel.
7. The object carrying device of claim 1, wherein the front baffle panel comprises a front panel and a front slat, wherein two lateral sides and a bottom side of the front panel are fixed to the frame, the front slat being coupled to a top side of the front panel, wherein the rear baffle panel comprises a rear panel and a rear slat, wherein two lateral sides and a bottom side of the rear panel are fixed to the frame, wherein the rear slat being coupled to a top side of the rear panel.
8. The object carrying device of claim 1, further comprising two supporting units each having a bottom panel and an upright panel extending from a lateral side of the bottom panel, the two bottom panels abutting against two sides of the bottom portion of the first net body, respectively, and the two upright panels abutting against the two lateral portions of the first net body, respectively.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for operating a wind energy installation having a tower, a nacelle arranged on the tower, and a rotor having at least one rotor blade, wherein an azimuth of the nacelle is adjustable, wherein a blade angle of the at least one rotor blade is adjustable, the method comprising:
detecting and monitoring tower oscillations during operation of the wind energy installation using at least one measuring apparatus; and
switching off power operation of the wind energy installation if a measurement variable of the tower oscillations exceeds a tower oscillation limit value;
wherein the tower oscillation limit value is defined, at least during load operation of the wind energy installation, as at least one limit value function which is dependent on prevailing wind speed andor a parameter associated therewith, and which has different functional dependencies in a plurality of different value ranges of prevailing wind speed andor the parameter associated therewith.
2. The method as claimed in claim 1, wherein the measurement variable is a sliding average.
3. The method as claimed in claim 2, wherein the sliding average is of prevailing wind speed andor a parameter associated therewith
4. The method as claimed in claim 3, wherein the tower oscillation limit value has different functional dependencies in a plurality of different value ranges of the sliding average of prevailing wind speed andor the parameter associated therewith.
5. The method as claimed in claim 1, wherein the value of the limit value function corresponds to a first limit value aGrenz0 or runs below a first limit value aGrenz0 at wind speeds below a starting speed vStart of the wind energy installation, decreases toward wind speeds between vStart and a first wind speed limit value vWind0, where vWind0>vStart, and increases toward wind speeds between a second wind speed limit value vWind1 and a third wind speed limit value vWind2, where vWind2>vWind1>vWind0, to a value which is greater than the limit value aGrenz0.
6. The method as claimed in claim 1, wherein the limit value function is dependent on at least one second parameter for one or more special meteorological conditions andor special operating conditions, the limit value function comprising a constant correction term aGrenzOffset or a correction term, which is dependent on the wind speed and is added to the tower oscillation limit value when special meteorological conditions or special operating conditions occur.
7. The method as claimed in claim 1, wherein a positive additive term or offset is added in the event of a change from one operating state to another for a short period.
8. The method as claimed in claim 7, wherein the short period is from 1 to 10 minutes.
9. The method as claimed in claim 1, wherein the value of the limit value function does not undershoot a minimum first limit value aGrenz1.
10. The method as claimed in claim 9, wherein the minimum first limit value aGrenz1 is used at a medium wind speed or in a medium wind speed range.
11. The method as claimed in claim 1, wherein the value of the limit value function does not exceed a maximum second limit value aGrenz2.
12. The method as claimed in claim 11, wherein the maximum second limit value aGrenz2 is used at high wind speeds.
13. The method as claimed in claim 1, wherein an averaging duration for the tower oscillations is greater than an averaging duration for the prevailing wind speed by at least a factor of 5.
14. The method as claimed in claim 1, wherein an averaging duration for the tower oscillations is greater than an averaging duration for the prevailing wind speed by at least a factor of 10.
15. The method as claimed in claim 1, wherein the sliding average of the tower oscillations is averaged over a duration of between 2 and 20 minutes, andor the sliding average of the prevailing wind speed is averaged over a duration of between 10 and 60 seconds.
16. The method as claimed in claim 1, wherein tower acceleration is measured as the measurement variable for the tower oscillations.
17. The method as claimed in claim 1, wherein two different limit value functions are used for tower oscillations in a direction of a rotor axis and for tower oscillations in a plane perpendicular to the rotor axis.
18. A wind energy installation comprising:
a tower;
a nacelle arranged on the tower, wherein an azimuth of the nacelle is adjustable;
a rotor having at least one rotor blade, wherein a blade angle of the at least one rotor blade is adjustable;
at least one measuring apparatus configured and arranged to detect tower oscillations; and
an operation control device comprising a data processing system with operation control software set up to monitor the tower oscillations and to switch off power operation of the wind energy installation if a tower oscillation limit value is exceeded by the tower oscillations;
wherein at least one limit value function is defined as the tower oscillation limit value in the operation control software, which limit value function is dependent on prevailing wind speed.
19. The wind energy installation as claimed in claim 18, wherein the operation control software is set up to monitor the tower oscillations and to switch off power operation of the wind energy installation if a tower oscillation limit value is exceeded by a sliding average of the tower oscillations.
20. The wind energy installation as claimed in claim 18, wherein the limit value function is dependent on a sliding average of prevailing wind speed.