A novel method for enhancing the thermal performance of mechanical draft cooling towers through the integration of induced and forced draft fans

To address the deteriorated performance in the inner region of induced draft cooling towers, this study proposes a novel hybrid draft cooling tower configuration that integrates induced and forced draft fans. A three-dimensional numerical model is developed to evaluate the thermal characteristics of the proposed hybrid draft cooling towers. The velocity and temperature distributions under different installation positions of the forced draft fan are analyzed. In addition, the effects of several critical operating parameters on the performance of the hybrid draft cooling tower are systematically assessed. Results demonstrate that the airflow generated by the forced draft fan increases the horizontal velocity in the inner region, thereby enhancing the overall cooling effect. Among all studied configurations, the HCT 2 exerts the optimal performance by decreasing the outlet water temperature by 0.56 °C at most under an inlet water temperature of 42 °C. The superiority of HCT 2 is irrelevant to water spraying density, but benefit from a higher inlet water temperature. Under various crosswinds, the performance of HCT 2 is superior to that of a conventional tower due to the attenuation of transverse vortices on the windward side, with an increment of 9.1% in air-water ratio and a decline of 0.45 °C in outlet water temperature at most, respectively. This study provides a theoretical foundation for the optimized design and efficient operation of hybrid cooling towers.