Combustion optimization system and adjustment method for preventing water wall high-temperature corrosion

Abstract

The invention provides a combustion optimization system and adjustment method for preventing water wall high-temperature corrosion. The combustion optimization system comprises air and pulverized coal adjustment devices, secondary air distribution adjustment devices, two water wall near wall region smoke component measuring devices, a plurality of auxiliary over fire air nozzles, a temperature field measuring device and a coal economizer outlet smoke oxygen content field measuring device. A first air and pulverized coal pipeline corresponding to each combustor is provided with the corresponding air and pulverized coal adjustment device. Each secondary air box is internally provided with the corresponding secondary air distribution adjustment device. The two water wall near wall region smoke component measuring devices are separately mounted on the water wall on the two sides of a boiler. The multiple auxiliary over fire air nozzles are separately arranged below over fire air nozzles. The temperature field measuring device is arranged on the portion, below a platen overheater, in a hearth. The coal economizer outlet smoke oxygen content field measuring device is arranged at a coal economizer outlet flue. By adoption of the combustion optimization system, high-temperature corrosion to the water wall of the opposite cyclone combustion boiler can be effectively relieved.

Description

technical field [0001] The invention belongs to the field of thermal power generation equipment, and in particular relates to a combustion optimization adjustment method and system capable of effectively preventing high-temperature corrosion of the water wall of a counter-swirl combustion boiler on the front and rear walls, and is especially suitable for a coal-fired generating set using a counter-swirl combustion boiler. Background technique [0002] As one of the three main combustion methods of power plant boilers, the front and rear wall-contrasting swirling combustion boilers have become one of the main combustion methods used by supercritical and ultra-supercritical boilers in China due to their advantages in combustion equipment and heating surface layout. It occupies a large share in the thermal power units in service. In order to achieve efficient, economical and environmentally friendly operation, this type of furnace usually uses air staged combustion + low nitrog...

AI Technical Summary

Problems solved by technology

[0008] (1) The effect of increasing the oxygen content in the near-wall area of ​​the water-cooled wall on both sides of the wall is not obvious

After a large number of tests and actual operation, it was found that the secondary air valve of the middle burner was closed to 15~20% in the test, and the secondary air valve of the burner close to the side wall was fully opened, and the oxygen content in the water-cooled wall area of ​​the two side walls near the wall increased slightly. , but in actual operation, if the opening of the secondary air door of the burner is adjusted too small, there will be safety hazards in operation, and if the opening of the secondary air door of the burner is adjusted too large, it will affect the ignition and burnout of coal powder. The effect of oxygen content in the near-wall area of ​​the side wall water wall is not obvious

[0009] (2) Air volume and swirl intensity cannot be effectively matched, which affects combustion efficiency and stability

When adjusting, the excessive opening of the damper close to the side wall burner can increase the air volume, but reduces the swirl strength, which is not conducive to the timely ignition of coal powder and affects the burnout of coal powder

If the burner damper in the middle area is too small, the air volume will be reduced, but the swirl intensity will be increased, which will lead to problems such as early ignition, nozzle burning, and wall painting.

[0010] (3) The thermal deviation is large, the amount of desuperheating water is high, and the economic efficiency of the unit is reduced

The horizontal mixing effect in the opposite swirl combustion boiler is extremely poor. The use of non-uniform air distribution combustion will inevitably lead to uneven distribution of the temperature field and flue gas flow field in the furnace. This unevenness will continue from the main combustion area to the coal-saving area. The outlet of the device, which leads to uneven heating of the heating surfaces such as screen pass, high pass, high pass, etc., and there is a thermal deviation, which in turn leads to an increase in the flow rate of desuperheating water and a decrease in the economical efficiency of the unit

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