Method for reducing steam temperature deviation by using steam soot blowing for boiler of thermal power plant

Abstract

The invention discloses a method for reducing steam temperature deviation by using steam soot blowing for a boiler of a thermal power plant. The method is characterized by comprising step 1 of introducing steam to a soot blowing gun under the condition of normal combustion of the hearth of the boiler; step 2 of performing differential soot blowing on heated surfaces of different regions and parts of at least a one-level super-heater and at least a one-level re-heater in the boiler based on temperature distribution so as to change surface soot formation degrees of different regions and parts of the super-heater and the re-heater; judging whether the steam temperature deviation of different regions and parts of outlets at a certain level of the super-heater and the re-heater reaches to a preset requirement; if the steam temperature of one region and one part at a certain level of the super-heater and re-heater needs to be improved, increasing the soot blowing intensity of a heated surface corresponding to the region and part at the level of the super-heater and the re-heater in the step 2 and/or reducing the soot blowing intensity of the heated surface corresponding to the other region and part at the level of the super-heater and the re-heater, and vice versa.

Description

technical field [0001] The invention relates to a method for reducing the deviation of steam temperature by steam soot blowing, in particular to a method for reducing the deviation of steam temperature by steam soot blowing used in thermal power plant boilers. Background technique [0002] At present, there are many situations where the steam temperature (including main steam temperature and reheat steam temperature) deviation is relatively large during the operation of thermal power plant boilers. There are many factors that lead to the deviation of the steam temperature. Generally, the reasons for the deviation of the steam temperature can be attributed to two types: one is the deviation of the flue gas side, and the other is the deviation of the working fluid side. Flue gas side deviation mainly refers to the difference in flue gas flow rate and temperature, so that the heat transfer is different, the heat absorption of the working fluid changes, and finally affects the t...

AI Technical Summary

Problems solved by technology

[0006] (1) When the reheating steam temperature deviation is large, the use of desuperheating water adjustment will lead to an increase in the steam flow of the medium and low pressure cylinders of the steam turbine, and a corresponding increase in the power of the medium and low pressure cylinders, which is equivalent to an increase in the reheating cycle of the unit A medium-pressure (Rankine) cycle leads to a decline in the economy of the entire unit, and its adjustment range is also limited. Often when the desuperheating water is used to the limit, it still cannot solve the problem

[0007] (2) When the swing angle of the burner swings upwards, the jet flow forms an included angle with the horizontal plane, the horizontal component velocity and the tangential rotational momentum moment are small, so that the external thrust is reduced, the actual tangential circle and the residual torque of the air flow are reduced, thereby reducing the horizontal flue The deviation of flue gas flow rate and temperature on both sides will eventually reduce the deviation of steam temperature, but the adjustment range is limited. In addition, if the swing angle is adjusted upwards too much, the burner is prone to accelerated wear and tear, which is not conducive to the safe operation of the equipment

When local slagging or ash accumulation on the heating surface is serious, it will cause local flue blockage, resulting in uneven smoke velocity and thermal deviation