Abstract: In order to ensure the safe and reliable operation of the circulating water system of the cooling tower, the fan speed and blade installation angle of the cooling tower were set according to the maximum heat exchange. However, due to the influence of production process, ambient temperature and other related factors, the heat exchange of the cooling tower fan changes from time to time. Therefore, the cooling capacity of the cooling tower fan does not match the actual demand, resulting in a large amount of energy waste, therefore a new energy saving scheme based on the self-adjustment of the cooling tower fan blade based on the hydraulic system was proposed. Firstly, the working principle of the self-adjusting angle system was analyzed, and the structure of the self-adjusting angle mechanism was designed by using Solidworks software, and the working principle of the hydraulic drive system was analyzed. Then, the curve of the driving force provided by the hydraulic system with the change of installation angle was obtained by the method of calculating the aerodynamic load of the wind turbine. Finally, AMESim was used to explore the working characteristics of self-adjusting angle of various hydraulic circuits, and the influence of throttle valve opening on the stability of hydraulic circuits was analyzed. The research results show that the device can adjust the blade installation angle of the fan without stopping the machine. The PID speed regulating valve hydraulic circuit improves the accuracy and stability of the system. When the speed regulating valve internal throttle opening K equals 0.08, it can effectively reduce the shock time, and reduce the shock peak.
Key words: axial flow fan; energy conservation method; hydraulic system driving force; self-tuning angle device; speed regulating valve; throttle valve opening; hydraulic circuit stability; load analysis