Air Cooling Fan System Runtime Vertical Force Experimental Study

For the reasons of serious shortage of water resource in China, and direct air-cooling system shares obvious effect on water resource conservation, so this technology has been widely promoted in China, and has good application foreground. However, fan bridge vibration of direct air-cooling fan system is one of the major difficulties in the engineering design. The fan bridge vibration is caused by disturbance of fan; therefore study of the characteristics of the fan disturbance force is of great significance on the engineering design.The1:1fan system prototype was used as test model in this study, the fan equipment and installation of precision consistent with the actual project, which can ensure the consistency of the test model, as well as physical and engineering.On the basis of the existing literature, this study adjusted the experimental conditions including:increased the fan speed, changed the number of fan blades to six, symmetrical arranged the position of fan blades, expanded the test coverage of the fan operating conditions.In this paper, the characteristics of the disturbing force produced by the fan shaft during the operation of direct air cooling fan system were discussed, and focus on the characteristics of vertical disturbing force. The test process used the wireless dynamic strain testing technology, collected and analysis the fan axial strain data, accurately measured the strain values and the fan speed values in the operation. The centrifugal force caused by the rotor mass eccentricity, the bending moment caused by the blades of vertical vibration, the torque caused by the drive fan rotating, the vertical disturbing force caused by the air reaction was determined by using the strain separation techniques. This study also analyzed the characteristics of four disturbing forces in different conditions, different speed, different the number of blades. The strain curve produced by centrifugal force, moment and torque was obtained after separation, and compared with the pre-test data, the results were nearly consistent, then the strain curve of the vertical disturbing force during the fan running was studied, and the characteristics of vertical disturbing force was obtained, the results obtained in this paper could be referenced for engineering design.For the reasons of large number test data and the complex processing, to avoid manual handling errors, this study used the PASCAL language, write the data processing program through the visual control, and complete the data processing, ultimately improved the efficiency and accuracy of the work.