Combustion-Driven Oscillation in a Furnace with Multispud-Type Gas Burners : 3rd Report, The Effects of Burner Arrangements on Combustion Oscillation in a Multiburner Furnace

Abstract

Combustion-driven oscillation is excited in the burning zone of a furnace, and its magnitude is determined by the position and heat release strength of the heat sources. In previous papers, it was shown that "the resonance factor" is useful in detecting the degree of combustion oscillation in a furnace. In this paper, by applying this method to multiburner furnaces, the effects of burner arrangements, two-stage combustion rate, excess air ratio and gas mixing ratio on the occurence of oscillation are examined. Consequently, the following results are obtained. (1) The oscillation condition is characterized by the fuel flow rate and primary and secondary air flow rates in the burner throat. (2) The low-positioned burner has stronger ability to excite the depth mode oscillation of the gas column in a furnace than the middle and high-positioned ones. (3) The effects of the two-stage combustion rate and excess air ratio on combustion oscillation are found to be represented only by the primary and secondary air flow rates. (4) The exhaust gas mixing combustion method suppresses the combustion oscillation.