The main structural components of the fan are impeller, casing, air inlet, bracket, motor, pulley, coupling, muffler, transmission parts (bearings), etc. The unpowered fan uses the air heat convection caused by the natural wind and the indoor and outdoor temperature difference to drive the turbine to rotate so as to use the centrifugal force and negative pressure effect to exhaust the indoor fresh hot air.
Fan is related to the energy consumption of transmission and distribution of the system, and is a very important part of building energy saving. According to the national air conditioning equipment quality supervision and Inspection Center for many years, fan testing shows that many fans have problems under rated conditions, so it is necessary to produce and manufacture fans in strict accordance with product standards. At the beginning of the fan, the vibration of the bearing is very small, but it increases with the running time.
The dust in the fan will adhere to the impeller unevenly, and gradually destroy the dynamic balance of the fan, so that the bearing vibration will gradually increase. Once the vibration reaches the maximum value of 11mm / s allowed by the fan (the maximum allowable value expressed by the amplitude value is as follows), the fan must be shut down for repair (remove the dust accumulation, and do the dynamic balance again). Because it is very dangerous at this time, users must not use it forcibly. When the fan vibration is close to the dangerous value, the vibration measuring instrument will give an alarm.
When the bearing temperature of the fan is normal, it is ≤ 70 ℃. If it rises to 70 ℃, the fan with electric control shall (will) give an alarm. At this time, the reason should be found out. First, check whether the cooling water is normal? Is the bearing oil level normal? If the cause cannot be found for a while, the bearing temperature will rise rapidly to 90 ℃. If there is electric control, the alarm and stop signal shall be sent again. In the process of fan start-up, stop or operation, if abnormal phenomenon is found, it shall be checked immediately, and the small fault found in the check shall be found out in time to eliminate the cause.