Low-load vibration control method for axial flow fan of thermal power plant and bypass air duct control loop

Abstract

The invention relates to a low-load vibration control method for an axial flow fan of a thermal power plant and a bypass air duct control loop. The vibration control method is characterized by comprising the following steps: 1) arranging the bypass air duct control loop in the axial flow fan of the thermal power plant, so as to regulate the recirculation flow of the fan; 2) using output flow of the fan under a working condition as an original signal, calculating the minimum recirculation flow needed for the working condition by a function operator, and controlling the recirculation flow under the working condition by the bypass air duct control loop, so that the fan works under a stable operating border condition; and 3) using the output flow under each working condition as the original signal, and calculating the minimum recirculation flow needed for each working condition by the function operator, and controlling the recirculation flow under each working condition by the bypass air duct control loop, so that the fan works in a stable operating border condition under each working condition, thereby ensuring the speed of the fan with a low recirculation flow and reducing the recirculation power consumption. The low-load vibration control method has the following beneficial effects of ensuring the speed of the fan with the small recirculation flow, and remarkably reducing the recirculation power consumption.

Description

technical field [0001] The invention relates to an air duct control circuit, in particular to a low-load anti-vibration method for an axial flow fan in a thermal power plant and a bypass air duct control circuit. The utility model belongs to the technical field of thermal power plant control of an electric power system. Background technique [0002] In the power generation equipment of thermal power plants, the axial flow fan needs to operate under low load, but the axial flow fan is prone to unstable operation and stall when it is running at low load. In the prior art, the bypass air duct from the fan outlet to the fan inlet is usually added on site to return part of the outlet air volume to the fan inlet, thereby increasing the fan inlet air volume so that the fan can run below the stall line and achieve stable operation Purpose. [0003] However, the result of this method of increasing the air volume at the inlet of the fan is that part of the wind circulates in the fan...

AI Technical Summary

Problems solved by technology

[0005] One of the purposes of the present invention is to provide a low-load anti-vibration method for axial flow fans in thermal power plants in order to overcome the shortcomings of the existing technology that cannot control the circulating air volume and affect the efficiency and life of the fans

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