Field measurements of shelter efficacy for installed wind fences in the open coal yard

• Mean wind speed within the yard is decreased by about 50%.
• The protection benefit may be extended up to 6–7th consecutive stockpiles.
• TSP is entrapped 50–80% within the yard.

To investigate the shelter effect of porous fences with 40% porosity installed along two sides of Yard 1 in Qinghuangdao Port, the full scale field measurement campaigns are carried out in this study. A time series of the velocity signals are recorded. It is found that instantaneous velocities and turbulent intensity within the yard are largely reduced. The shelter effect produced by the fences has been analyzed in terms of wind reduction ratio and time-average velocity reduction profiles are obtained among the horizontal and longitudinal directions within the yard. The actual protection distance caused by the fence and stored piles themselves may be extended up to 6–7th consecutively stockpiles. Then, the value of average wind reduction coefficient (ζζ) is obtained to evaluate the fence sheltering under various wind incidents. It is calculated that the average wind reduction ratio in the whole year is about 51.5% at the 6.0 m measurement height from the ground. In addition, the particle concentration measurements are conducted to ascertain the fences prevention of dust erosion. The results reveal that about 50–80% of total suspension particles are entrapped by the fence and the emission levels of the reference location satisfy the environmental regulations after the fences were installed along the yard boundary.