If the wind farm development project as a war, wind engineering was undoubtedly the careful arrangement of military action, the wind tower has become a vital scouts in the operation.
Statistical analysis showed that 10% of wind data error may lead to the error of wind field capacity by about 30%, therefore, to improve the accuracy and reliability of wind data of wind field development has very important significance.
According to the wind power development part of the industry standard and project experience for many years, the wind tower representative location and the number of choice is the main factor affecting the wind data accurate and reliable.
A representative site selection, wind tower
Wind farm wind tower when installation should be located in the most can represent the position of wind farm wind energy resources, need to stay away from tall trees and obstacles, if the wind tower must be situated near the obstacles, under the prevailing wind direction of the wind direction and the horizontal distance obstacles should not be less than 10 times the height of the obstacles to install, if the wind tower must be set up in the trees populated place, should be at least the top 10 m above the trees.
For different terrain, the typical wind tower location selection method is also different.
1, flat terrain,
Flat terrain refers to the wind farm area and within a radius of 5 km of the terrain height difference is less than 50 m, at the same time, the slope topography is lower than 3 ° terrain. Flat terrain in the site within the scope of the same level on the wind speed distribution is uniform, the wind profile only related to surface roughness. Airflow movement mechanism based on flat terrain, with uniform roughness of flat terrain around the central wind tower installation. Surface roughness changes when the shape of the contour line is divided into two parts, the upstream or downstream, respectively corresponding to the surface of the wind profile shapes, cohesion, there was a sharp change in the middle wind tower to avoid such areas, changes in the surface roughness before and after the installation of the wind tower, respectively. Of obstacles, when installation should avoid wind tower on the prevailing wind direction of the wind, the obstacles of the lateral and wake zone, to prevent turbulence makes small wind data, loss of authenticity.
2, uplift terrain
Uplift terrain on the airflow movement acceleration, average air velocity to maximize the ridge. Bottom to prevail when the wind blows the uplift terrain, the minimum wind speed, the top of the mountain wind speed, the largest mid-hill and wind speed tends to the middle, generally for greater use of wind energy resources, the fan arrangement are arranged on the ridge, so should be installed on the top of the ridge wind tower, at the same time, the registry location relative to the surrounding area is higher, not because of affected by wind around the mountain shade and the authenticity of the data.
3, dips terrain
By dips airflow movement mechanism of the terrain, only if the prevailing wind direction towards consistent with dips terrain, dips in the terrain of airflow can accelerate, appropriate construction of wind farms, or complicated airflow changes of valleys, unfavorable construction of wind farms, reason should be the prevailing wind direction of the wind tower is located in the dips terrain at the entrance to the upper hand, only representative wind data, and then based on the mechanism of air movement and wind speed of wind speed field mathematical model to estimate the other location.
For more complex terrain need more detailed analysis, at the same time should be according to the local hydrogeological data, wind tower location to avoid loose soil, underground water level is higher, prevent landslides occurred during construction, such as water safety accidents.
Wind tower site representative not only affected by terrain conditions, also influenced by other conditions and restrictions, such as ground vegetation and site construction conditions, traffic conditions and so on.
1, ground vegetation,
Due to the effect of blocking of the tall vegetation on wind speed, so the wind tower location should be avoided, surrounded by tall vegetation near or in the thick woods, reduce the wind turbulence and wake effect of the tower. Wind tower location should be chosen as far as possible and no tall in the surrounding vegetation roughness is quite consistent with the open zone.
2, the construction site condition
80 m wind tower installation schematic diagram
Now mainstream wind tower height is 70 m or 80 m commonly, there are 4 ~ 5 layers pull, pull the outermost layers based of about 40 ~ 50 m away from the center, so in order to guarantee the construction of the wind tower has enough space, the wind tower site should fall in the open field, there is enough space for wind tower construction and material storage, at the same time that the slope of the site should not be too big. If the surface there are rocks, should be recorded, there may be artificial explosions.
3, transportation conditions
Convenient transportation conditions for wind transport equipment installation and construction of the tower is very good, reduce the cost of handling equipment and construction time, so the wind tower representative location, transportation condition is a factor to consider.
Second, the wind tower number of choices
For flat terrain and ground roughness consistent, just in the middle of the field location to set up a wind fan hub after height not less than the height of the wind tower, if the site have the area of roughness change sharply, lead to wind speed change, it should be in the area before and after the change, respectively, set up a wind tower wind. For a complicated terrain such as uplift terrain and dips, should according to the venue size, dominant wind direction and landform and increase the quantity of wind tower, the wind tower represented by the area that covers the entire wind field. Local shape is more complex, encrypted wind should be represented in different terrain area, in order to obtain more reliable data of wind resources.
According to experience, different terrain conditions of wind tower representative regional scope of reference:
Flat terrain, roughness is 5 ~ 6 km
More complex terrain: hills, undulating hills or roughness change large area 3 ~ 4 km
Complex terrain: rolling mountain 2 km
In order to be able to obtain the wind engineering an all-round victory in the war, as a scout wind tower is not only to individual operational capability is strong, but also has a number of advantages, in order to understand the situation clearly grasp the overall situation.
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