Objective This article aimed to investigate the influence of forced-draft parameters on the thermal performance of a super-large mixed-draft cooling tower for coastal nuclear power plants.

Method A three-dimensional numerical simulation was conducted to analyze the thermal performance of a mixed-draft cooling tower with a drenching area of 20000 m². The correlations between performance parameters (such as air-water ratio and outlet water temperature) and forced-draft parameters were examined. The mechanisms by which blower distance and blower number affect the velocity and temperature fields were elucidated.

Result When the blower number was fixed, increasing the blower distance expanded the coverage of high-velocity zones induced by jet diffusion, thereby enhancing the ventilation and heat transfer processes. Meanwhile, increasing the blower number introduced more fresh air and augmented the air-water heat exchange. The beneficial effects of increasing blower distance became more pronounced with a greater blower number. Compared with the condition without blowers, the cooling tower with 20 blowers at an installation distance of 16 m achieved a 20.4% increase in air-water ratio and a 0.76 ℃ reduction in outlet water temperature.

Conclusion Mixed-draft cooling towers represent a key approach for achieving efficient cooling of circulating water in coastal nuclear power units. During the selection and design process, the thermal performance of mixed-draft cooling towers can be enhanced by increasing the blower number and raising the blower distance.