Impact of research on development of large cooling towers

Abstract

The rapid development of cooling towers during the last two decades has only been possible through fundamental research on structural aspects, on assessment of wind induced forces, and on buckling behaviour. Different computation techniques exist which were developed to obtain the shell stresses with sufficient accuracy. The buckling behaviour can best be understood in buckling tests carried out on models under axisymmetric loading and also in wind tunnels. Wind load research has focused on the dynamic effects induced by wind gustiness and vortex separation, and on interference effects. The shape of the meridian influences the stress state and the buckling behaviour substantially. Therefore, more emphasis has been devoted to the optimization of the cooling tower shape. With increasing sizes, however, stiffening of the shell may be necessary for an optimal design. In this case, stiffening rings proved to be the most effective. The method of construction: allowing the erection of the cooling tower shell with a high accuracy is of vital importance and in the future, more attention needs to be paid to the durability of the reinforced concrete shell.