Method for controlling output of coal mill in ignition process of boiler

Abstract

The invention discloses a method for controlling the output of a coal mill in the ignition process of a boiler. According to the method, in the starting ignition process of the boiler of a power station, a raw coal hopper supplies raw coal to a coal feeder, the coal feeder quantitatively supplies the raw coal to the coal mill, the coal mill grinds the raw coal into pulverized coal which is carriedinto a separator by primary air, qualified pulverized coal is screened by the separator, is brought into a combustor by the primary air, and enters a boiler hearth through a nozzle of the combustor to be combusted; the output of the coal mill can be adjusted through adjustment of the rotating speed of the coal mill according to the positive correlation between the rotating speed of the coal milland the output; a high-voltage variable-frequency speed regulation device is used for controlling the rotating speed of the coal mill, so that the rotating speed can be continuously increased and decreased in the one-time ignition process, and the rotating speed of the coal mill is controlled to be changed according to different stages of ignition. According to the method, the high-voltage variable-frequency speed regulation device is used for controlling the rotating speed of the coal mill, continuous change of the rotating speed of the coal mill can be controlled without modifying the interior of the coal mill, and the reduction capacity and the regulation capacity are achieved.

Description

technical field [0001] The invention relates to a control method of a coal pulverizer, in particular to a control method of a coal pulverizer output during boiler ignition. Background technique [0002] At present, supercritical units in thermal power plants mainly use positive pressure direct blowing pulverization systems, and adopt HP, MSP, and ZGM medium-speed coal mills. Such as figure 2 The shown raw coal enters the grinding disc 8 of the coal mill through the coal feeder, and then moves radially outward to the grinding ring 9 under the action of centrifugal force. Due to the radial and axial movement, the coal passes under the grinding roller device that can rotate around the shaft. At this time, the grinding force generated by the hydraulic (spring) loading device is applied to the coal through the grinding roller. The grinding roller device makes the coal grind The coal bed 10 is formed under the roller 7, and it is ground into powder between the grinding ring and ...

AI Technical Summary

Problems solved by technology

However, while these schemes increase the maximum output of the coal mill, they must also increase the minimum output of the coal mill, and cannot take into account both the increase of the maximum output and the reduction of the minimum output, and there is no real expansion of the output range of the coal mill.

In addition, the interior of the coal mill needs to be modified, the construction process is complicated, the speed after the modification is fixed, and it does not have the ability to reduce and adjust

From the perspective of economic operation, none of these schemes have the characteristics of energy saving and efficiency enhancement

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