A Preliminary Calculation of the Combustion Recirculating Flow Behind Flame-Holders

Abstract

In this paper the numerical method is adopted to predict the combustion recirculating flow behind flame-holders. A modified k-ε turbulence model and Magnussen’s combustion model are employed. Becouse of the large variation of density in combustion flow field, the influences of variable density have been considered. The results predicted include: the combustion recirculating flow field and the flame spreading; the variation of recirculation length with equivalence ratio, and inlet velocity, etc. All of these are qualitatively good comparing with experimental results.

Numerical Optimization Study of Combustion and Heat Transfer Characteristics in Municipal Solid Waste Incinerators

“…Although the gas phase incineration data imported into the incinerator are the same, the temperature distribution above the grate under the five conditions is different. Among them, the area of water evaporation area in condition 4 is the smallest under five conditions, which is mainly because the lower the height of the rear arch, more and more obvious the trend of flame pressure flow from the rear arch to the direction of the arch becomes, resulting in the area of water evaporation being at least …”

“…Among them, the area of water evaporation area in condition 4 is the smallest under five conditions, which is mainly because the lower the height of the rear arch, more and more obvious the trend of flame pressure flow from the rear arch to the direction of the arch becomes, resulting in the area of water evaporation being at least. 19 …”

“…Therefore, the incineration rate of volatile matter is mainly affected by two limiting factors, namely, reaction kinetics (temperature dependent) and mixing rate of gaseous fuel and air. This means that the combustion rate of volatiles is limited by the rate of combustion reactions and by the degree of mixing of gaseous fuel and air. , The gas phase mixing rate is as follows: R mix = C mix ρ g [ 150 D g false( 1 − φ ) 2 / 3 d p 2 φ + 1.75 V g false( 1 − φ ) 1 / 3 d p φ ] × min ( C fuel S fuel , C o 2 S o 2 ) …”

“…This means that the combustion rate of volatiles is limited by the rate of combustion reactions and by the degree of mixing of gaseous fuel and air. 19 , 20 The gas phase mixing rate is as follows: …”