Full-variable-frequency pulverizing system without minimum coal quantity limitation and debugging method

Abstract

The invention discloses a full-variable-frequency pulverizing system without minimum coal quantity limitation and a debugging method. A raw coal bunker communicates with a belt coal feeder through a coal discharging pipe, and the belt coal feeder communicates with a grinding disc of a roller type coal mill through a coal falling pipe; the grinding disc of the roller type coal mill is driven to rotate by a coal mill motor through a speed reducer, and the rotating speed of the coal mill motor is adjusted through a coal mill frequency converter; the rotating speed of the grinding disc is furtheradjusted, and the grinding force is adjusted; and the belt coal feeder is driven by a coal feeder motor, and the coal feeder motor is controlled by a coal feeder frequency converter 4 to realize speedregulation. The rotating speeds of the grinding disc of the coal mill and a belt of the coal feeder are cooperatively adjusted, so that deep matching of the coal feeding quantity and the grinding force is realized, then the minimum coal quantity limitation set by an existing belt coal feeder is completely cancelled, the force of the pulverizing system can be adjusted from zero, therefore, in thevariable load process of a boiler, the total coal quantity can not have jump-changes when the coal mill is increased or decreased, and thus the stable combustion and stable steam temperature and steampressure in the boiler are ensured.

Description

technical field [0001] The invention relates to a pulverized coal grinding system in a thermal power plant, in particular to a motor-driven medium-speed roller coal mill with frequency conversion and speed regulation function combined with an electronic weighing belt coal feeder without minimum coal quantity restrictions Full frequency conversion milling system and debugging method. Background technique [0002] At present, the pulverizing equipment combination of "frequency conversion coal feeder + fixed frequency coal mill" is generally used in thermal power plants. In this combination, the driving motor of the coal mill has a fixed frequency, and the rotating speed of the grinding disc is a constant value, while the electronic weighing belt coal feeder has a drive motor with a frequency converter, and the rotating speed of the belt can be adjusted. For continuous adjustment, the adjustment of the coal amount of the coal feeder is realized by the change of the belt speed....

AI Technical Summary

Problems solved by technology

However, if the amount of coal fed is too small, it will cause severe vibration of the coal mill and damage the equipment.

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