Numerical investigation on the optimized arrangement for high-temperature corrosion after low NOx transformation.

In response to high-temperature corrosion after low NOx transformation with separate over fire air (SOFA), combined arrangement of corner and wall tangential firing burners, as well as anti-tangential and deflecting air technology are studied. Numerical simulation with realizable k - ε two equation and Non-premixed combustion including probability density function model (PDF) is carefully adopted. Result conveys that application of combined arrangement can remarkably reduce the tangent circle in the furnace, lowering the probability that coal particles might strike the furnace wall. Also, lower CO and temperature near the wall would greatly decelerate the high-temperature corrosion. Further studies conclusively show that the performance has no linear relation to the angle in deviation cases. If properly arranged, combined burners layouts behave better than deviation (including anti-tangential) methods in restraint of high-temperature corrosion. All the technologies play effective roles in NOx reduction that the best-performing anti-tangential case 4 has a 50.7% drop from original case. Remission of high-temperature corrosion will have great economic and security importance. [ABSTRACT FROM AUTHOR]