Research And Application Of Horizontal Dense-dilute Burners Combustion Technology

In this thesis, cold experiment and numerical simulation on the areadynamic fields of the horizontal dense-dilute coal burners is conducted. The areadynamic fields of the nozzle of the burner are studied on the cold model, which is built on the basis of the Similarity Theory, the distribution of velocity fields of the burner are ditermined on the five-hole probe. The effect on the areadynamic fields is considered through the position and angle of the blunt-body.The fluent graghs of all kinds of work condition are gained, and the regularities of distribution of axis velocity, radial velocity and tangential velocity on the burner is generalized.The numerical simulation on the burner is conducted by the software of PHOENICS, the result of the calculation and the experimental result is qualitative concordance. The main result by the analysis of the cold model and numerical simulation contains two parts:(l) If the position of the blunt-body shifts inboard, circulation area will be greatly deseased, the position is closer to the nozzle, circulation area is longer, and the steability is increased. It is considered: after the position of the blunt-body shifting inboard, the free expansion of primary air is limited by table firing chamber , the extended angle is deseased, at the same time, the velocity of boundary layer is increased, which makes the deflection of air deseased, and the confluence moves to the front. (2) The change of the length of circulation area is gentle because of the change of the angle of the blunt-body, from 30° -70° , the lenth is increased by the increment of the angle.So the best position and angle of the blunt-body is gained from the result, and it can use for reference and instruction. The burner is used in the DG300/100-5 boiler of Heshan power plant, after the reformation of the correlative experiment, the boiler can maintain the steady combustion without adding oil at the load of 70%MCR, the coal quantity of fly ash deseased from 16.59% to 8.57%, the efficiency of the boiler increased from 82% to 86%, and the combustion condition was improved greatly.