The Key Technology Study Of Coal Blending System In Thermal Power Plant

With the development of national economy, energy guarantees the development of national economy. Our country is one of a few countries that use the coal as the main source of energy in the world, and the important part is thermal power. But the coal quality of our country is imbalance and distribution of resources is unreasonable. It's obviously that all the power enterprise use the designed coal is unreasonable, but using the way of automatic coal blending is an effective way to solve thee problem. The main objective of this paper is to control the blending of the kind and quantity of the coal for the thermal power plant.Firstly, this article introduced the purpose and meaning of this subject's study and also introduced the technology of and general situation of home and abroad important coal country. Secondly it explained the development status of the theory of blending coal, then established the optimized mathematical model of blending coal, at the same time it introduced some methods like how to use computer to solve the problem of blending coal model, and provided the theoretical support for blending coal system design.PLC is used as the core controller in the design of coal blending system, PC communicates with PLC to obtain real-time data of system. Through the variation of feeder's speed, the coal blending proportion and quantity is controlled. PLC and HMI interface can realize coal blending system with combined in hands and automatic control. Different coal's distribution quantity is controlled by inverter to change the feeding coal's frequency. The subject use the advanced control technology with the system combined in computer, PLC and DCS to realize data acquisition, coal quantity computation, Programmed control, fault processing of blending coal system.The results of the study showed that this system has high automation level and operation is easy, it can adapt field environment of automatic blending coal system. It can reduce cost, improve boiler's stability, and further restrain the emissions of harmful gas to the environment and solve the mixed coal problem for enterprises, improve electricity plant coal efficiency and economic benefit. The results of this research can realize the resource allocation, enhance economic benefits and core competitivenes for the coal and electricity plant.