Automatic boiler combustion control system of circulating fluid bed

Abstract

The invention discloses an automatic boiler combustion control system of a circulating fluid bed, which is applied to machine sets for coal-fired power generation, heat supply or combined heat and power generation. The system comprises hardware and control program software, wherein the control program software comprises a fuel control part, an air volume control part and a deslagging control part, and the control program software can automatically and timely control the input quantity of boiler fuel, the oxygen content in the boiler and the boiler deslagging device. The combustion control system is applicable to all sorts of complicated operating conditions, has consistently correct and reliable reaction, advanced and reasonable algorithm design as well as good control effect, is safe and effective, has the capabilities of improving boiler combustion condition, increasing boiler combustion efficiency and reducing unburned carbon in flue dust, leads main steam pressure control to be stable, enhances the capability of tracking the change in load of the boiler and greatly improves the running safety performance, leads main steam temperature control precision to be effectively improved, avoids temperature excursion of an overheater, reduces the danger of steam turbine water slug caused by low-temperature steam, and improves the thermal efficiency and automation control degree of the steam turbine.

Description

Technical field: [0001] The invention relates to a boiler combustion control system for coal-fired power generation, heat supply or combined heat and power generation units, especially a circulating fluidized bed boiler that is suitable for isolated grid operation, has large load changes, and needs to be frequently adjusted to undertake peak-shaving operation. Combustion automatic control system. Background technique: [0002] Circulating fluidized bed (CFB) boiler has wide fuel adaptability, low combustion temperature and large load adjustment range, especially it can burn low-quality coal and garbage, and achieve desulfurization by adding limestone powder in the furnace. A clean and environmentally friendly boiler is widely used in industry. However, compared with the pulverized coal boiler with mature combustion control technology, the circulating fluidized bed (CFB) boiler has a relatively short application time, and the combustion control principle is not very mature, ...

AI Technical Summary

Problems solved by technology

At any moment, the user load is random and unpredictable, and the uncertainty of the load change is great. The serious imbalance between energy supply and demand will have two consequences: 1. The low-frequency load shedding action of the power grid will cause the load shedding of the power grid to cause the power supply interruption of the user. Here If the low-frequency load shedding protection fails during the process, it will cause serious consequences such as generator protection tripping and grid collapse; 2. The main steam pressure is high, the emergency exhaust steam protection action and even the boiler safety valve action, if the exhaust steam and safety valve fail during the process Refusal to move will lead to overpressure of the steam system, and in severe cases, it will cause serious consequences of explosion of the steam-water system of the boiler, resulting in huge personal and property losses

[0005] For the boilers operated by the main control, there are still problems of load grabbing, load distribution and operation optimization between boilers. Due to the uneven technical level of the operating personnel, different people have different opinions on the technical understanding and practice of combustion adjustment, and the existing boiler operation regulations are only limited. Limited to guiding instructions, it is impossible to make detailed formulas and guidelines for every situation and every step of operation, which gives operators a lot of room for personal use; on the other hand, operators are required to follow the load changes all the time Follow-up adjustment is also impossible. Everyone has different judgments on the future direction of the load, and the timing and range of adjustments are also different. Therefore, manual adjustments have inherent deficiencies of asynchrony, which will inevitably cause large fluctuations in steam pressure, even exceeding the normal range. make the operation less safe

Since manual adjustments cannot be adjusted frequently and finely, the combustion efficiency of the boiler is reduced

[0006] In view of the above difficulties, at present, the CFB boilers of domestic parent control units have not been able to completely solve the technical problems of automatic combustion control

Images