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Factors Affecting the Reliability of Axial Fan Other Design Measures

Release Time：2021-07-20

Fan is the key auxiliary equipment in thermal power plant. Axial flow fan is widely used because of its high efficiency and low energy consumption. In actual operation, many power plants have frequent failures due to poor reliability of axial flow fan, which is especially adjustable blade axial flow fan, resulting in unplanned shutdown or load reduction of power plant, affecting the power generation capacity of the unit.

Factors affecting the reliability of axial flow fans Classification of power station fan accidents.
Class 1 accident: the thermal power unit is out of operation due to fan failure.
The second axial flow fan accident: the fan failure only causes the output of the thermal power unit to decrease, and has not caused the thermal power unit to withdraw from operation, or only one of the induced draft fans is sent out of operation.
Class 3 accident: the fan is not seriously damaged and does not need to be sent, and the induced draft fan is out of operation for maintenance.
Category 1 and 2 accidents directly affect the reliability of fan operation, while Category 3 is a potential factor.
If the fan load can be reduced, it can always be combined, such as oil-fired boilers. However, for axial flow fans in some coal-fired boilers, such as the cold primary fan of medium-speed direct-blown pulverizing system, because the pulverizing system must have a minimum drying output requirement and powder feeding head, there are two methods to solve the problem of parallel operation under the condition that the fan output reduction is limited.
One is to calculate the system resistance when a single fan is operated under the required working conditions when the fan is selected, so that the S point is higher than the resistance line, which means that the design point is located at the lower end of the characteristic curve, and the efficiency of the axial flow fan is lower due to the higher pressure head. The second is to add a bypass valve on the air duct of the axial flow fan. When starting the fan, first close the outlet valve and open the circulation valve, after the second fan crosses the stall line, open the exit door and close the circulation door. The disadvantage of this is that it increases the initial investment and increases the possibility of leakage of the air supply back.
In the design of the fan inlet and outlet connection pipe, to avoid the possibility of vortex, some turns should also take measures to install the deflector.
Shandong Xingheng Environmental Technology Group Co., Ltd. is located in Luquantun Development Zone, Dezhou, Shandong, the hometown of FRP in China. The company has Grade II qualification for fire protection facilities engineering, Grade II qualification for construction mechanical and electrical installation engineering, Grade II qualification for environmental protection engineering, and safety production license. It is the first in the industry to pass ISO9001 quality management system certification, ISO14001 environmental management system certification, OHSAS18001 occupational health management system certification, and an axial fan invention patent, A fan utility model patent, environmental assessment, safety assessment, three simultaneous and other procedures are complete.