Simulation of producer gas flameless combustion with fresh reactant diluted by hot flue gas

Abstract

Summary Flameless combustion is considered as a flexible and efficient combustion process for low heating value gas fuel. This paper presents numerical simulations of premixed flameless combustion using producer gas as a fuel. Different initial conditions of the premixed fresh reactant (air/fuel mixture) and dilution levels are taken into account for the investigation. The numerical simulations were investigated using a network of chemical reactor models with the detailed reaction mechanism of GRI‐Mech 3.0. A threshold dilution level for flameless combustion fuelled by producer gas was determined. The numerical results show that dilution of the fresh reactant with hot combustion products and initial fresh reactant temperature play important roles in flameless combustion formation and its auto‐ignition behaviour, rather than equivalence ratio of the fresh reactant. In the flameless combustion regime, temperature and chemical concentrations were reduced while chemical kinetics process was decelerated, resulting in delay of the auto‐ignition process.

Swirl flow field analysis of producer gas premixed charge in a flameless cyclone combustor

“…30 Therefore, it can be concluded that the current combustor configuration can provide long enough in-combustor residence time for complete PG combustion. 30 Therefore, it can be concluded that the current combustor configuration can provide long enough in-combustor residence time for complete PG combustion.…”

“…29 The chemical reactor network is illustrated in Figure 4. 30 The hot flue gas (m g ), which generated in a separate equilibrium reactor, was assumed as combustion products entrained to mix with the fresh reactants (m a + m f ). 30 The hot flue gas (m g ), which generated in a separate equilibrium reactor, was assumed as combustion products entrained to mix with the fresh reactants (m a + m f ).…”

“…This modeling has been described in more detail in our previous work. 24 Herein, T ig of PG was calculated based on the flameless mixture conditions in a separate closed homogeneous batch reactor, 30 T in obtains from the Gas mixer, and ΔT is the difference between the maximum temperature of PSR and T in . To take into account the heat losses when translated into the actual combustor, hot flue gas temperature must be lower than 1780 K, which is the adiabatic flame temperature of the present PG.…”

Numerical study of further NO x emission reduction for coal MILD combustion by combining fuel‐rich/lean technology

“…[2][3][4][5][6][7][8][9][10][11][12][13] The essence of this technology for coal combustion is to achieve strong recirculation of the injected streams so that the coal particles are heated and combusted in a highly substoichiometric condition. [2][3][4][5][6][7][8][9][10][11][12][13] The essence of this technology for coal combustion is to achieve strong recirculation of the injected streams so that the coal particles are heated and combusted in a highly substoichiometric condition.…”

Numerical investigation on ignition intensification of n‐butane with tert‐butyl hydroperoxide (TBHP) addition

“…In this paper, the promoting effects of TBHP addition under different initial temperatures, pressures, and equivalence ratios were investigated by CHEMKIN‐PRO software . Furthermore, the acting mechanism of TBHP addition was studied in detail using the mole fraction and rate of production and consumption (ROP) analysis, sensitivity analysis, and reaction pathway analysis …”