METHOD AND DEVICE FOR OPTIMISATION OF COMBUSTION CONDITIONS IN BOILER WITH FLUIDISED BED Russian patent published in 2014 - IPC F23C101/00 F23C10/18 F23L7/00 

FIELD: energy industry.

SUBSTANCE: method of optimisation of combustion conditions in the boiler with fluidised bed, where oxygen-containing combustible gas is fed into two or more levels of height, the first of which is a primary level (P) located at the height of the furnace bottom, and the second is a secondary level (S) located at a height near the level (F) of the fuel supply, and over the secondary level (S) other levels (T,…) can also be provided. The combustible gases (15a, 15b; 16a, 16b; 28a, 28b) with different oxygen contents are obtained by mixing air and/or pure oxygen and/or circulating flue gas in such a ratio that each combustible gas has the required oxygen content, and by supplying combustible gases (15a, 15b; 16a, 16b; 28a, 28b) with different oxygen content to at least one of the said layers (P, S, T,…) of supplying the combustible gas in different points in the horizontal direction of the furnace (11) the zones are formed with different oxygen content in the horizontal direction of the furnace (11). The primary level (P) in the horizontal direction is divided into two or more zones and at least into one of these zones the combustible gas (15a) is supplied with oxygen content different from the content of oxygen in the combustible gas (15b) directed at least into the zone adjacent to it. The secondary level (S) and/or one of the levels (T, …) above it is separated into two or more zones in the horizontal direction and in one of these zones the combustible gas (16a, 28a) is supplied with the oxygen content different from the content of oxygen in combustible gas (16b; 28b) directed to the zone adjacent to it. Several points (30) of fuel supply are located on the height of the level (F) of fuel supply and the zone is formed below and/or above each point (30) of fuel supply, to which at the same level (P, S, T, …) of combustible gas supply the combustible gas (15a, 15b; 16a, 16b; 28a, 28b) is supplied with the oxygen content different from the content of oxygen in the combustible gas supplied to the zones located further from the point (30) of fuel supply at the same level (P, S, T …) of the combustible gas supply.

EFFECT: improvement of control of combustion conditions and the reduction of nitrogen oxides in the boiler with fluidised bed.

8 cl, 7 dwg