The fan is a kind of driven fluid machinery, which relies on the input mechanical energy to increase the gas pressure and discharge gas. Fan is the abbreviation of Chinese custom for gas compression and gas transmission machinery. Generally speaking, fans include fans, blowers, and wind turbines.
Fans are widely used for ventilation, dust discharge and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings, as well as ventilation and induced draft of boilers and industrial furnaces; Cooling and ventilation in air conditioning equipment and household appliances; Drying and delivery of grain, wind source of wind tunnel and inflation and propulsion of hovercraft
Gas compression and gas transmission machinery is a machine that converts rotating mechanical energy into gas pressure energy and kinetic energy and transports gas.
The main structural components of the fan are impeller, casing, air inlet, support, motor, pulley, coupling, silencer, transmission parts (bearings), etc.
The unpowered fan uses the air thermal convection caused by the natural wind force and the indoor and outdoor temperature difference to drive the turbine to rotate, thus using the centrifugal force and negative pressure effect to exhaust the indoor stale hot air.
The fan is related to the transmission and distribution energy consumption of the system, and is a very critical part of building energy conservation. According to the fan inspection conducted by the National Air Conditioning Equipment Quality Supervision and Inspection Center for many years, many fans have problems under rated conditions, so it is necessary to produce and manufacture fans in strict accordance with product standards. As shown in Figure 1.
At the beginning of the fan operation, the vibration of the bearing is very small, but with the extension of the operating time, the dust in the fan will be unevenly attached to the impeller, gradually destroying the dynamic balance of the fan, making the bearing vibration gradually increase. Once the vibration reaches the maximum allowable value of 11mm/s of the fan (the maximum allowable value expressed by the amplitude value is as follows), The fan must be shut down for repair (dust accumulation shall be removed and dynamic balance shall be redone). 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 ℃, an alarm should (will) be given if there is an electric control. 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 rises rapidly to 90 ℃, and if there is an electric control, the alarm and shutdown signal shall be (will be) sent again
In the process of fan startup, shutdown or operation, if any abnormal phenomenon is found, it shall be checked immediately. If any small fault is found during the check, it shall be timely found out the cause and eliminated. In case of major fault (such as severe vibration, impact of fan, sharp rise of bearing temperature, etc.), stop the machine immediately for inspection.
The lubricating oil (or grease) shall be renewed and replaced one month after the first operation of the fan. In addition to replacement after each overhaul, the lubricating oil (or grease) can be replaced once every 1~2 months under normal conditions, or according to the actual situation.
Fans include fans Turbine blower 、 Roots blower And turbine compressor, which are divided into 7 categories in detail, including centrifugal compressor, axial compressor, centrifugal blower, roots blower, centrifugal fan, axial fan and Yeh's blower
