A system and method for predicting the main steam pressure of a supercritical circulating fluidized bed unit

Abstract

The invention relates to the technical field of circulating fluidized bed boiler unit control, and provides a supercritical circulating fluidized bed unit main steam pressure prediction system and method. The system identifies the functional relationship among CFB unit key parameters by building a CFB boiler heat releasing model and a CFB unit steam-water side working medium heat absorption modeland determining corresponding parameters; and accordingly a supercritical CFB unit main steam pressure prediction model is built up, and the unit dynamic main steam pressure is predicted according toinput data and coal quality data of real-time operation of the unit. According to the supercritical circulating fluidized bed unit main steam pressure prediction system and method, the supercritical CFB unit heat transition model is built up, the input and output relationship is made clear, the unit main steam pressure capable of representing energy balance can be predicted on the basis that the input quantities of current and future moments are known, the variation trend of energy demand can be predicted in advance, design of unit control logic and algorithm is facilitated, and the operationcontrol level of the unit is improved. The method is high in prediction accuracy, and suitable for being applied and promoted.

Description

technical field The invention relates to the technical field of circulating fluidized bed boiler unit control, in particular to a supercritical circulating fluidized bed unit main steam pressure prediction system and method. Background technique Driven by the energy conservation and emission reduction of energy companies around the world, China is under increasingly severe pressure to eliminate outdated production capacity and promote comprehensive energy conservation planning and transformation of coal power units. Compared with pulverized coal boilers, Circulating Fluidized Bed (CFB) boiler technology has a wider range of fuel adaptability and lower air pollution control costs, and has developed into the most successful practical clean coal combustion technology one. At present, the vast majority of CFB units in my country are subcritical parameters with the rated gauge pressure of the superheater outlet steam at 14-22.2Mpa, which does not have obvious advantages in achie...

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Problems solved by technology

The inertia of CFB boilers is larger than that of conventional pulverized coal boilers, which makes its control more difficult

The multi-variable strong coupling characteristics of the supercritical CFB unit are concentrated in the mutual influence of the control actions on both sides of the machine furnace, and the dynamic characteristics of the machine furnace are quite different. The volume and bed material of the 600MW supercritical CFB boiler are larger than those of the 300MW subcritical CFB boiler. a lot, so the thermal inertia increases

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