Energy-saving optimal control system and method for outlet temperature of medium-speed coal mill in supercritical unit

Abstract

The invention discloses an energy-saving optimal control system and method for the outlet temperature of a medium-speed coal mill in a supercritical unit. The system comprises a primary draught fan, an air pre-heater, a hot primary air pipe, a cold primary air pipe, a smoke recycling bypass pipeline, a coal mill hot air bypass pipeline, a coal mill hot air adjusting baffle, a coal mill cold air adjusting baffle, a smoke recycling bypass baffle, a coal mill hot air bypass adjusting baffle, a coal mill, a coal feeder, a rough powder separator, a primary air powder pipeline, a combustor, a boiler, a controller, a coal mill outlet temperature detector, a coal mill outlet oxygen concentration detector and a powder pipe temperature detector. By means of the energy-saving optimal control system and method, the smoke recycling bypass pipeline is additionally arranged in a medium-speed coal mill direct blowing type powder manufacturing system, the outlet temperature of the coal mill is increased, and single powder consumption is reduced; and the coal mill hot air bypass pipeline is additionally arranged at the outer portion of the coal mill so that decoupling control over the outlet temperature of the coal mill and the air powder temperature in the primary powder pipe is achieved, the coal powder fire catching and combustion stabilizing performance is improved, and the adaptability of acoal-fired powder unit participating in depth peak regulating is improved.

Description

technical field [0001] The invention belongs to the technical field of coal mill automatic control and energy saving, and in particular relates to an energy-saving optimization control system and method for outlet temperature of a medium-speed coal mill of a supercritical unit. Background technique [0002] The pulverizing system is an important part of coal-fired thermal power units. At present, most of the large coal-fired power plants in my country are equipped with medium-speed mill direct blowing pulverizing systems. The direct blowing pulverizing system has the advantages of less land occupation, compact layout, simple structure, flexibility and convenience, etc. However, compared with the intermediate storage pulverizing system, the output of the pulverizer in the direct blowing pulverizing system needs to follow the demand of the boiler load in real time , Continuously and evenly supply the pulverized coal required for stable combustion of the boiler. In order to ad...

AI Technical Summary

Problems solved by technology

However, the outlet temperature of the coal mill should not be too high, as it will lead to the precipitation of volatile substances in the pulverized coal and increase the risk of deflagration and ignition of the coal mill

At the same time, the high outlet temperature of the coal mill will also affect the safe and stable operation of the lubricating oil system of the coal mill

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