A natural draft dry cooling tower (NDDCT) is demanded to save water for power generation in arid area, but itsperformance could be degraded greatly by the crosswind. To overcome the degradation, this paper proposes theinstallation of a windbox, which consists of windbreaks, an enclosure, a back barricade and a wind top toimprove the pressure distribution outside the heat exchanger bundle of a NDDCT, so as to increase the venti-lation rate under crosswind condition. Full dimensional computationalfluid dynamics (CFD) modelling wasconducted for the windbox installed around the NDDCT of a large scale coal-fired power plant. Different con-figurations of the windbox were studied. Theflow characteristics along the streamline in the NDDCT wereanalyzed and quantified by adopting the concept offlow loss factor (FLF). Based on simulation and experiments,the installation of the windbox is shown to be effective. The windbox with a 120 m radius enclosure and a fullsize louver-type top could improve the ventilation rate of a NDDCT by∼60% in gale crosswind condition, andkeep high performance in breeze crosswind condition. Consequently, an annual reduction of coal consumption of30,000–45,000 tons could be achieved on a 1000 MW unit, which is∼3000,000–4500,000 $/a.
