Combustion control method for four-corner tangential circle boiler

Abstract

The invention discloses a four corner tangential boiler combustion control method. When boiler combustion tests are carried out for various kinds of coal under the different working conditions, the opening degrees of baffles which are located at the corners and used for separating over fire air and / or the nozzle upwards-swinging angles are adjusted, and the reheat steam temperature departure between the left side and the right side is detected, wherein at least two opening degrees of the baffles which are located at the corners and used for separating the over fire air are different, and / or at least two nozzle upwards-swinging angles are different; if the reheat steam temperature departure is smaller than the preset threshold value, the current opening degrees of the baffles located at the corners and used for separating the over fire air for the coal under the working condition serve as the optimal opening degrees of the baffles, and / or the current nozzle upwards-swinging angles serve as the optimal nozzle upwards-swinging angles; the corresponding optimal baffle opening degrees and / or the optimal nozzle upwards-swinging angles are selected according to the actual combustion working condition of the boiler and the coal so that boiler combustion can be controlled. By means of the method, the reheat steam temperature departure between the left side and the right side can be effectively reduced, and the operating efficiency of a unit can be improved; the frequency of boiler pipe cracking can be reduced, and the operating safety of the boiler can be improved.

Description

technical field [0001] The invention relates to the technical field of boiler combustion control, in particular to a combustion control method for a four-corner tangential circle boiler. Background technique [0002] With the rapid development of my country's national economy and the increasing demand for electricity, in order to use energy more effectively, thermal power generating units are constantly developing to higher parameters and larger capacity. Most of the pulverized coal power plant boilers of large thermal power units in service are arranged in four corners and fired in a tangential circle. The characteristic of this tangential combustion method is that the air flow in the furnace rotates, and the fuel, air and flue gas are strongly mixed to form a good combustion condition; due to the rotation of the air flow, the flame ignites the adjacent air flow from the upstream to the downstream, and the pulverized coal is ignited; this This swirling airflow rises spiral...

AI Technical Summary

Problems solved by technology

However, the four-corner tangential combustion boilers of these methods require the SOFA air nozzles on the same layer to collide with each other on the same plane at the same wind speed, thus forming a strongly rotating tangential circle and entering the rotating and rising main air flow to strengthen the main air flow The rotation of the furnace will increase the residual rotation of the flue gas at the refraction angle of the furnace, which will increase the deviation of the flue gas temperature and flow rate on the left and right sides of the reheater, which will lead to an increase in the deviation of its heat absorption, and an increase in the temperature deviation of the reheated steam.

On the one hand, the increase of this heat deviation will reduce the average reheat steam temperature and affect the unit efficiency; on the other hand, in the case of serious reheat steam temperature deviation, the reheat steam temperature on one side will exceed the set operating temperature, making The local metal temperature of the reheater exceeds the set operating value, and long-term metal overheating will lead to metal fatigue, greatly reducing its strength and life, and it is very likely that the tube will burst, reducing the safety and economy of boiler operation

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