The place where the wind blows first is in the upwind direction, and the place where the wind blows later is in the downwind direction. It can also be said that the direction where the wind blows is in the upwind direction, and the wind blows from the upwind direction to the downwind direction.Upwind in wind power generation system means that the wind blows firstimpeller, blow totowerThe type of fan for.
The airflow generated by air movement is called wind.It is composed of many small scale fluctuations randomly varying in space-timesuperpositionA three-dimensional vector on a large-scale regular airflow.The wind measured in surface meteorological observation is a two-dimensional vector (horizontal motion), which is expressed by wind direction and wind speed.[1]
The wind direction refers to the coming direction of the wind, and the most frequent wind direction refers to the wind direction that occurs most frequently in a specified period of time.For manual observation, the wind direction is measured by the 16 direction method;Automatic observation, wind direction in degrees (°).Wind speed refers to the horizontal distance of air movement in unit time.The unit of wind speed is meter/second (m/s), and 1 decimal place is taken.The maximum wind speed refers to the maximum 10 minute average wind speed in a certain period.Maximum wind speed (gust) refers to the maximum instantaneous wind speed in a certain period.The instantaneous wind speed refers to the average wind speed of 3 seconds.The average amount of wind refers to the average value in a specified period of time, including the average value of 3 seconds, 2 minutes and 10 minutes.[2]
Geography, architecture, urban planning, etc.
Upwind fan
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The fan can be divided into upwind type and downwind type according to the direction in which it receives wind. The difference between upwind and downwind is the position (relative to the direction of incoming wind) of the rotor blade and the fan tower. The rotor in front of the tower is upwind fan, and the rotor behind the tower is downwind fan.
Upwind fan
Current largeWind power generatorBoth are upwind fans, which have the advantage that they will not be affected by other parts of the fan when the wind blows, and the utilization efficiency of wind energy is higher.However, the upwind fan generally needs some kind of direction adjustment device to keep the impeller windward.
Downwind fan
The downwind fan will be affected by the front tower (tower shadow effect) because of the wind. When it blows through the wind wheel, it has some losses, and the stability of the wind will become worse.It has adverse effects on the unit.At present, some small wind turbines adopt downwind type, because tower shadow effect has little influence on small wind turbines.Its advantage is that it can automatically yaw to wind according to the change of wind direction, saving control costs.
research method
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At present, the commonly used methods for calculating hourly wind direction areArithmetic average method, moving average method, vector average method and frequency maximum method.According to the existing research, the arithmetic mean method has a large error in processing the wind direction passing through 0 °, and the probability of the calculated southerly wind direction becomes larger;Moving average method is also a category of arithmetic average method, which is mostly used forautomatic weather stationIn the collection of wind elements, the processing error of zero crossing wind direction is also large;The results of vector average method are more consistent with the actual situation;The highest frequency method is usually manualweather stationAdopted in.However, the existing correction methods for zero crossing wind direction are not many, and the calculation is complex, which is inconvenient to apply.[2]
Measuring instrument
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The instruments for measuring wind mainly include EL typeElectric wind direction anemometerEN series wind measurement data processor, island automatic wind measurement station, portable wind direction anemometer, single wing wind direction sensor and wind cup speed sensor, etc.[1]
