Method for controlling optimized burning in circulating fluid bed boiler

Abstract

A method for controlling combustion of circulation fluidized bed boiler includes using turbine to regulate load and using boiler to regulate pressure as well as using control system to receive load command when machine set is under coordination control system; carrying out uncoupling operation on load, main steam pressure, bed temperature and bed pressure of fluidized bed boiler when turbine load is changed greatly; and controlling carbon residual content in firepot for realizing energy balance control of machine set.

Description

1. Technical field [0001] The invention relates to an operation control method of a circulating fluidized bed (CFB) boiler, in particular to a control method for better controlling the combustion of a circulating fluidized bed boiler. 2. Background technology [0002] Circulating fluidized bed (CFB) boilers have developed rapidly in recent years due to their high efficiency, low pollution, and wide fuel adaptability, gradually replacing other boiler types. However, due to the special combustion process of CFB boilers, the problem of automatic combustion control has not been well resolved, which limits the large-scale popularization and application of CFB boilers. For a long time, CFB units have not been able to be put into the control of AGC, and cannot realize the function of participating in power grid peak regulation. [0003] The goal of circulating fluidized bed (CFB) boiler control is to ensure safe, stable and high-efficiency combustion of the boiler on the one hand,...

AI Technical Summary

Problems solved by technology

[0007] 3. Big lag and uncertainty

[0010] 1. Use the coal feed to directly control the main steam pressure (boiler load). Since it takes about 9 to 11 minutes from the change of the coal feed to the change of the main steam pressure of the boiler, there is a very large lag, which often easily leads to overshooting. The main steam pressure fluctuates greatly, and the adjustment period is too long

[0011] 2. Use the primary air to control the bed temperature, and the main task of the primary air is to establish a stable circulating fluidization state, the adjustment range is very narrow, and it requires stability

However, the bed temperature changes frequently due to factors such as coal quality disturbances (such as particle size, calorific value, and volatile matter), and the primary wind also changes frequently due to the influence of the bed temperature, which seriously affects the fluidization state of the bed material and threatens the safe operation of the boiler.

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