Interference factors for natural draught cooling towers based on wind tunnel experiments

Abstract

Wind tunnel experiments were conducted under simulated terrain category 2 for evaluating interference factors using pressure models on four sets of cooling tower models, each when located in tandem. The full-scale dimensions of the cooling towers are 180 m, 165 m, 173m, and 143 m heights with diameters at throat, Dth, of 79 m, 71 m, 70 m and 61 m, respectively. The tower corresponding to 165 m height had a geometric scale of 1:500 and the rest of the models corresponded to 1:300 scale. The model of 165 m tall cooling tower was additionally tested under increased turbulence intensity corresponding to terrain category 3. The tests were conducted for various non dimensionalised spacing, r=a/Dm, ranging from 1.4 to 10, where a is the c/c distance between the models and Dm is the mean diameter, defined as the mean of bottom diameter and Dth. Measurement of pressures was carried out at 30° interval at four levels for all the models. The paper consolidates the data base of experiments conducted at CSIR-SERC to see whether there is a discerning pattern in interference factors that can be recommended for design.