Abstract: The performance improvement of the heat pump dryer needs to take into account the needs of increasing the air volume of the fan and reducing the noise of the fan. However, the increase of the air volume is usually accompanied by the increase of the aerodynamic noise of the fan, which makes it difficult to meet these two needs at the same time. By changing the structural parameters of the fan impeller that affect the air volume and the aerodynamic noise of the fan, the air volume and aerodynamic noise are simulated and analyzed, and the influence law of the structural parameters of the fan impeller on the air volume and noise is found respectively. Based on this law, an optimized fan impeller structure design method that takes into account both air volume increase and noise reduction is proposed. The results show that the most important factors affecting air volume and noise are impeller width and impeller inlet angle. The air volume increases with the increase of impeller width and impeller inlet angle. The noise increases with the increase of impeller width and the decrease of inlet angle. Compared with the original structure, the air volume of the proposed optimized structure increases by 14.2 m³/h, and the noise of the monitoring point decreases by 2.08 dB(A) on average. The optimization design method of fan impeller considering the demand of air volume and noise is proposed, which provides guidance and reference for the design of fan structure with high air volume and low noise in the actual operation of dryer.

Key words: Heat pump dryer, Fan, Aerodynamic noise, Air volume, Optimized design