Frequency Conversion Renovation Of High Power Adjustable Rotor Blade Axial Flow Fans In Thermal Power Plant

The application of high power adjustable rotor blade axial flow fan in high consumption enterprises is studied in this paper. High power fan is the most important auxiliary equipment of the Boiler Combustion System, of which reliability and safety is always been strictly required. The fan species are from early development of centrifugal fan to static blade axial flow fan, and then to adjustable rotor blade axial flow fan which is extensively promoted and widely applied. Implementation of the national energy saving and exhaust reduction policy,more and more improvement technologies are applied for high power fans and high power pumps energy-efficient running, in which frequency conversion technology was a new born and widely used in the last 20 years. After installation of variable frequency drive,centrifugal fan and static blade axial flow fan can get obvious energy saving by using VFD,which proved many site successful cases, but there is no research in this area of frequency conversion of adjustable rotor blade axial flow fan or any application cases.Firstly, this paper introduces the operation status of adjustable rotor blade axial fan and the necessity of its frequency conversion renovation. According to analyzing of the Pressure-Flow characteristic curve and efficiency characteristic curve and other fan s when fan works at 50Hz,we propose a new frequency conversion calculation method. This calculation method will provide the Pressure-Flow characteristic curve and efficiency characteristic curve at some required adjustable blade installation angle of adjustable rotor blade axial fan runs in variable frequency operation mode. According to the data and the curve, assisted by the control optimization method to make the best opening of installation angle and the best speed match perfectly, the adjustable rotor blade axial fan will run at the most efficient and economical state, and furthermore reduce the energy loss.Finally, this paper uses an actual site application case to demonstrate the frequency conversion energy saving calculation method and control optimization method of adjustable rotor blade axial fan to be feasible.