In terms of design, the axial flow fan uses the scientific research results of the components such as the impeller and the volute, and further improves the manufacturing precision, and strives to increase the efficiency of various fans by 5% to 10% on average. It is a problem that needs to be highly valued. In the development of centrifugal spiral sand washing machine compressor, the ternary flow impeller should be used more, so that the impeller efficiency is increased by 2% to 5% on average. The industry believes that energy conservation and environmental protection are the eternal theme of the development of the wind turbine industry. With the application of the fluid coupler and the frequency converter in the fan, the operating efficiency of the fan is greatly improved, but the number of applications is extremely limited. Appropriate improvements have been made to the shape of the flow parts such as the volute and the impeller, effectively preventing the occurrence of eddy currents and flow separation. When the working point of the axial flow fan is on the right side of the K point (demarcation point), the fan operation is stable.
When the axial fan load drops below Qk, it enters the unstable zone (ie, the saddle-shaped area of the left half of the axial fan performance curve). When the flow rate of the axial flow fan Q < QK, then the maximum pressure head generated by the axial flow fan will decrease accordingly and be less than the pressure in the pipeline, because the air duct system has a large capacity, in this moment the air passage The pressure is still PK.
Therefore, the pressure of the axial flow fan in the air duct is greater than the pressure head generated by the wind turbine, so that the air flow starts to flow backward in the opposite direction, and the air passage is poured into the wind turbine, and the working point is quickly moved from the K point to the C point.
However, the backflow of the airflow reduces the air volume in the air duct system, so the pressure in the air duct decreases rapidly, and the working point becomes the E point. Since the axial flow fan continues to operate, the axial flow fan flow rate QF>QE, and the wind turbine starts to output the flow again. As the pressure rises, in order to balance with the pressure in the air duct, the operating point jumps from F to the corresponding working point D. At this time, QD>QC wind starts to flow backward again. Therefore, as long as the flow required by the outside world is less than QK, the above process is repeated. As long as the operating point does not enter the above unstable zone during operation, the fan surge can be avoided.
The adiabatic efficiency is 5%~10% higher than that of the original centrifugal blower. The centrifugal vane is equipped with an inlet guide vane device, each with an adjustable efficiency of 82%. The multi-stage centrifugal blower adopts continuous automatic adjustment of the inlet guide vane. After that, the energy saving rate is up to 20%; after the high-speed single-stage centrifugal blower adopts the high-speed, high-pressure ratio semi-open radial ternary impeller, the efficiency can be increased by 10%; the other is provided at the other end of the blower main shaft. There is an exhaust gas turbine device that meets environmental protection requirements and achieves energy saving purposes.
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