Large-eddy simulation of the non-adiabatic reforming process of hot coke oven gas using a flamelet-based approach

Abstract

Large-eddy simulation (LES) coupling with a non-adiabatic flamelet progress variable (NA-FPV) approach with reconstructed flamelet chemistry states is employed to simulate the hot coke oven gas (HCOG) reforming process. In the NA-FPV model, the chemistry states are first computed based on the correction factor for enthalpy defects and then modified by substituting the species statistics in the maximum heat loss state with those of less heat release to compensate for the unphysical results. The numerical results of LES coupling this NA-FPV model have been compared with the experimental measurement data in terms of temperature and yields, and reasonable agreements have been achieved. According to the LES results, it is seen O₂ only participates in the combustion process in the upper stream and the combustion process which mainly consumes H₂ and CO is to provide the other reforming process with heat and steam. In the upper and middle streams, the main HCOG jet is wrapped by the swirling high-temperature combustion products, and the reforming process primarily takes place by consuming CH₄, polycyclic aromatic hydrocarbons (PAHs), and steam, while considerable H₂, CO, and CO₂ are produced. It is observed that accompanying the reforming process C₂H₂ is generated and it peaks in the middle stream, thus it is considered soot is formed in the complex reactions.