Studying the Effect of Fireball Position in the Furnace on the Coal Fired Boiler’s Operation Mode

Abstract

Automating the operation of equipment at modern thermal power plants to the maximal possible extent is becoming an increasingly more urgent problem. For coal-fired boilers, the development of furnace operation mode control systems is of special importance. A significant scatter in the characteristics of the coal delivered for combustion have a strong influence on the boiler’s operation mode and its technical and economic indicators. Essential changes in the combustion mode frequently give rise to problems connected with gas temperature fluctuations at the furnace outlet, with maintaining a stable superheated steam temperature, slagging of heating surfaces, degraded combustion efficiency, etc. For estimating the influence of coal properties on the operation mode of the E-210-13.8KT boiler (the factory designation is BKZ-210-140) at the Tomsk GRES-2 thermal power plant, computational studies of gas temperature at the furnace outlet were carried out using the Boiler Designer software package. With an essential variation in the coal characteristics, the calculated values of temperature varied from 1103 to 1150°С at 100% load and from 910 to 948°С at 50% load. The adjustment of fireball direction at the burner outlet by ±15° made it possible to change the gas temperature at the furnace outlet by approximately 90°С. In the case of introducing a fireball direction adjustment system, it would be possible to solve, to a significant extent, the boiler-operation problems mentioned above. An algorithm for automatically adjusting the combustion mode has been developed, which, in case of having been implemented, would make it possible to achieve more reliable operation of boiler unit components, decrease the risk of the heating surfaces becoming intensely fouled with slag, and maintain a stable superheated steam temperature in different boiler-operation modes. A swirl movable burner able to vary the fireball direction at the burner outlet by ±15° should become the combustion system’s key component.