Automatic air supply control system and method for power plant boiler

Abstract

The invention discloses an automatic air supply control system for a power plant boiler. The automatic air supply control system comprises an oxygen content measurement module, an oxygen content correction module, an air blower auto-bias module and a manual bias module. The oxygen content measurement module is connected with the oxygen content correction module; and the oxygen content correction module, the air blower auto-bias module and the manual bias module are connected to obtain an opening instruction in the automatic state of an air blower moving blade. After the automatic air supply control system is put into the production, the adaptive degree of the air volume and the fuel amount is increased, the combustion sufficiency is greatly improved, and the combustion economy of the unitis improved. After the automatic air supply control system is put into the production, the system is more stable, so that the problems of hearth pressure fluctuation and insufficient combustion duringcombustion are reduced.

Description

Technical field [0001] The invention relates to a boiler air supply control system, in particular to a power plant boiler air supply automatic control system and method, and belongs to the field of automatic control. Background technique [0002] The air supply control system is an important control system for thermal power plants. Its main task is to adjust the air supply volume, ensure that the furnace air volume supply matches the fuel supply, and maintain the flue gas oxygen content near the target value. Excessive air volume causes flue gas oxygen. If the amount is too high, the boiler exhaust loss is too large, which is not conducive to energy saving and emission reduction, and the air volume is too small, which is not conducive to the complete combustion of the fuel in the furnace, and even affects the combustion stability. The automatic control of the existing boiler air supply mainly adopts oxygen correction and load-air volume control. The secondary air sleeve adopts la...

AI Technical Summary

Problems solved by technology

However, it is common to use fixed PID parameters, poor adaptability to load and coal types, various preset experience curves deviate greatly from the current situation, and the working conditions and matching parameters have not been fine-tuned, resulting in the inability to stably put into automatic operation for a long time

At the same time, the primary and secondary wind measuring points of the furnace are not redundantly configured, and the reliability is not high

[0003] In the automatic adjustment quality test process, the ordinary air supply automatic control strategy can meet the requirements of automatic adjustment, but in the actual operation process, it is interfered by various factors of the unit, such as coal quality changes, air flow measurement device blockage, oxygen measurement Influenced by factors such as large deviations, the operator's manual intervention method is to adjust the manual offset station to increase or decrease the set value of the air volume, but the change of the set value of the air volume by the operator has no direct and clear correspondence with the opening of the fan blade. , causing the blower rotor blades to be in the adjustment state all the time, which has an adverse effect on the combustion stability of the unit

At the same time, the stability and accuracy of the measurement points of the unit's air volume greatly interfere with the automatic adjustment of the air supply, causing the automatic adjustment to be unstable.

In actual operation of the unit, the requirements for the air supply volume are relatively stable and do not require continuous adjustments. Therefore, the operating personnel have resistance to the automatic input of the air supply before optimization, resulting in the automatic air supply has not been actually put into use.

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