A parametric study of lycopodium dust flame

Abstract

Dust flames are associated with two-phase combustion phenomena where flame characteristics depend on interactions between solid and gas phases. Since organic dust particles can be effectively utilized in energy production systems, investigation of this phenomenon is essential. In this study, an analytical model is presented to simulate the combustion process of moist organic dust. The flame structure is divided into three zones: preheat zone, reaction zone, and postflame zone. To determine the effects of moisture content and volatile evaporation, the preheat zone is also divided into four subzones: first heating subzone and drying subzone, second heating subzone, and volatile evaporation subzone. The results obtained from the presented model are in reasonable agreement with experimental data for lycopodium particles. An increase in moisture content causes a reduction in burning velocity owing to moisture evaporation resistance. Consequently, the effects of some important parameters, like volatilization temperature, volatilization Damköhler number and drying Damköhler number are investigated. In special cases, like high moisture content, low volatilization temperature, and high drying resistance, the second heating subzone is omitted.

An asymptotic analysis for detailed mathematical modeling of counter-flow non-premixed multi-zone laminar flames fueled by lycopodium particles

“…Biomass is currently estimated to contribute of the order 10-14 per cent of the world’s energy supply (Mastorakos et al , 1992). In this paper, lycopodium particles, which could be used as a reference organic fuel with particular importance for the model development and experimental purposes are burnt in the counter-flow non-premixed flame (Bidabadi et al , 2015; Soltaninejad et al , 2015). A lycopodium particle is typically composed of approximately 50 per cent fat oil, 24 per cent sporopollenin and 2 per cent sucrose, and its bulk density is about 0.48 g/cm 3 (Mastorakos et al , 1992).…”

“…It must be pointed out that moisture exists in lycopodium particles either as bound water within cell walls or as free water (Bidabadi et al , 2015). The moisture content can alter the flame structure and temperature (Bidabadi et al , 2015). Thus, to increase the accuracy and precision of the results, the effect of moisture on the characteristics of flame is considered.…”

“…Afterwards, the dried particles heat up and reach the evaporation temperature. In the vaporization zone, due to the special characteristics of lycopodium, volatiles come out of the particles (Bidabadi et al , 2015) and are asymptotically transformed into gaseous fuel with specific chemical composition (gaseous methane) (Seshadri et al , 1992). In preheat, drying and vaporization zones, no reaction occurs due to absence of oxidizer.…”

Laminar Flame Propagation in a Premixed Particle Cloud: Effect of Vaporization Rate

“…More recently, the need for new energy resources has increased the interest in the use of biomass particles in small power plants. In several works Bidabadi et al (2015, and the references therein) have considered the lycopodium dust flame with the double aim of studying the mechanisms of explosions and flame propagation in dust clouds, and the application of microscale biomass to small power plants as Stirling engines.…”

“…Two reactions occur simultaneously in the mixture: vaporization and combustion. The first one will be modeled by a reaction rate depending on temperature through a Heaviside function (Bidabadi et al, 2015(Bidabadi et al, , 2010, although other approaches are possible (Seshadri et al, 1992), while the combustion will be modeled by a global reaction of Arrhenius type, with activation energy much larger than the thermal energy. This will allow us to use asymptotic techniques in the analysis.…”