What Factors Affect the Performance of Axial-Flow Fire Ventilation Fans

What Factors Affect the Performance of Axial-Flow Fire Ventilation Fans

It is generally accepted that the aerodynamic design of axial-flow fire ventilation fans performs best under operating conditions that correspond to the design flow. Many axial-flow fire ventilation fans employ an off-axis design, where deviations in flow direction and dimensions are related to the specific speed. After analyzing the causes, specific speeds can be selected based on the user’s design requirements to predict and optimize performance variables, ensuring optimal performance under design conditions and providing users with high efficiency. Clearly, performance has been improved across various operating conditions. The new axial-flow fire-rated fan is the subject of adjustment and research. Dynamic simulation techniques were used to model the evolving aerodynamic characteristics, and the mechanisms of vortex generation and vortex-induced noise were analyzed. Two types of cylinders—the Cylindrical and the Conical—were incorporated. After installing anti-vortex rings, both simulation and experimental results indicate that the aerodynamic characteristics have been significantly improved, and large-scale vortices have been effectively dissipated. Noise and spectral experiments conducted after adding the anti-vortex rings confirm this. Currently, axial-flow fire fans are widely used in agricultural production. The impeller is one of the main components of the axial-flow fire fan and has a significant impact on its performance. This study focuses on the impeller of an axial-flow fire fan used in a wheat thresher. A three-dimensional model of the impeller was imported into finite element analysis software for static and modal analysis. Grain harvesters are typically used for small-scale threshing and grain handling, and the design of dual-outlet air duct cleaning devices follows specific standard specifications. Due to factors such as machining technology and manufacturing costs, two-dimensional blades are still widely used in axial flow fire fans. Because of the relative velocity of the airflow within the impeller, the airflow changes are relatively stable. According to the design requirements during the process, the average flow will be controlled along the line. To improve design quality, two blades can be connected in the blade design on the rotating surface, ensuring that the two blades meet the needs of distribution control and serving as a reference for calculating blade loads when adjusting the distribution.