Large circulating fluidized bed unit cooperative control device based on intensified combustion

Abstract

The invention relates to a large circulating fluidized bed unit cooperative control device based on intensified combustion, comprising a load control center loop, a steamer main control loop and a boiler main control loop. A novel limiting scheme is adopted for load instruction change rate, wherein the limitation of a load change rate is smoothly and gradually increased according to a degree exceeding a normal range of bed temperature and main vapor pressure by adopting a load coordination fuzzy control loop; a fuzzy feedforward controller and a fuzzy self-regulating PID (Proportion Integration Differentiation) controller are combined in a boiler main control loop to jointly control an electricity generating load and a heat load of a unit, and by combining a control rule of a feedforward control module with the experience of operating personnel and experts, a fuzzy control rule is formed according to the control quantity of boiler main control and steam turbine main control corresponding to different loads in operation; in the steam turbine main control, the fuzzy feedforward controller of the load instruction is additionally arranged and is combined with the fuzzy self-regulating PID controller to jointly control the electricity generating load; and in the boiler main control, the intensified combustion fuzzy feedforward controller is additionally arranged.

Description

technical field [0001] The invention relates to an operation control device for a self-developed circulating fluidized bed (CFB) boiler, especially a device that can better accelerate the combustion of a circulating fluidized bed boiler, coordinately control the output of the boiler and the steam turbine, and meet the requirements of the power grid for the AGC of the unit. The unit coordination control device of the requirement (2%Pe / min). Background technique [0002] Circulating fluidized bed (CFB) boilers have developed rapidly in recent years because of their clean combustion, wide fuel adaptability, and wide load regulation ratio. The independently developed subcritical large-scale (evaporation capacity 1025t / h) CFB has been put into commercial use. my country's CFB has entered the development stage of subcritical parameters, and the self-developed large-scale CFB has become one of the preferred technologies for thermal power plants. However, due to the special combusti...

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Problems solved by technology

[0005] 2. The delay and inertia on the boiler side are large

Since coal enters the CFB furnace, there is a process of heating, drying, blasting, ignition, and circulation, showing a lag in the change of steam pressure; resulting in a large difference in the rate of load change of the machine furnace, and the inertia and delay of the boiler are very large

[0006] 3. There is a large time-varying nature of the boiler

When the boiler load is low, the bed temperature is also low, and the newly added coal is relatively difficult to ignite, so the bed temperature rises slowly, which leads to the slow rise of the temperature of the flue at the tail of the furnace, so the main steam temperature, main steam pressure and main steam Slow flow rate increase

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