Interference Effects On Two Large Cooling Towers And The Finite Element Analysis Considering Underground Structure

The large cooling tower, usually served as a cooling equipment in the power plant, is a typical thin-wall reinforced concrete structure. With the rapid development of national economy, a large number of cooling towers are being built, towards the direction of higher height and greater diameter. Large size but extremely thin shell makes the large cooling tower both sensitive and vulnerable to the wind load. What’s worse, the cooling towers are often constructed in group in practical, making the wind pressure distribution on the tower barrel surface and the structure response of the tower significantly differs from the ones in sigle case, namely wind-induced interference effect.Through wind tunnel test, we shall conduct a series of researches on the two-tower interference problems with change of distance L/D and azimuth β, also taking CFD numerical simulation as a controlled trial with the help of fluid analysis software Fluent. In addition, we will do a comparative analysis of ring base modeling, in the way of beam type modeling or shell type modeling, providing a guidance for engineering application. The main research contents are listed as follows:a) Wind press correlation analysis on tower-barrel surface. This article will do correlation anslysis of press of measuring points layors at top, middle and bottom height of the tower, to obtain the correlation intensity distribution along circumference. And do the same work for the meridian, accordingly.b) Research on two-tower interference effect. Based on the wind tunnel test, this article will research how these wind-induced responses varies with distance L/D or azimuth β, and these wind-induce responses include wind press coefficient, base shears coefficient, base bending moment coefficient and radal displacement, meridian membrane force, circumference membrane force from ANSYS transient analysis.c) CFD numerical simulation of two-tower interference effect. With the help of CFD software Fluent, the wind press distribution on tower-barrel surface in single case and two-tower case can be simulated. And then we will know how the wind-induced responese varies with the distance L/D and azimuth β. Compare these results with those from wind tunnel test,we can find the CFD numerical simulation is consistent with wind tunnel test, but in some certain case, the difference is also remarkable.d) Research on the ring base. In engineering practice, ring base is modeling ordinarily in beam type or shell type. In this article, to begin with, we will study on the influence of piles stiffness on ring base element force, and then do a comparative analysis of ring base modeling with beam or shell, to verify the feasibility of modeling in the two ways. But in comparison, ring base modeling with shell can provide more information about deformation and element force distuibution of ring base group.