State Administration of Work Safety

ABSTRACT A nonpremixed methane jet flame was modeled using the flamelet‐generated manifold (FGM) approach in the context of large‐eddy simulation (LES). The effects of radiation and buoyancy were critically examined, and nonpremixed versus premixed tabulation methods were compared. Results demonstrate that incorporating radiation and buoyancy in the FGM significantly improves temperature prediction, which is better validated by experimental results. The FGM results also agree well with the predictions based on the infinitely fast chemistry model in fireFoam. Buoyancy is identified as a more dominant factor than radiation, which enhances the turbulence and the fuel consumption rate, thereby reducing flame height. Furthermore, the laminar nonpremixed counterflow flamelet is established as the superior tabulation method for this case, whereas the premixed tabulation overpredicts the flame height due to differences in species chemistry. It is proposed that accurate FGM predictions for such nonpremixed jet flames require the inclusion of both radiation and buoyancy and the selection of an appropriate flamelet prototype.

As an important organicchemical raw material, propylene oxide(PO) has a large demand for its production. However, due to its lowboiling point (34 °C), the subsequent transportation, loading,and unloading process also faces the risk of leakage of a large amountof volatile gases of propylene oxide, which will have a negative impacton the environment. Therefore, the design of efficient propylene oxideadsorbents has an important impact on the chemical production andtransportation process and the environment. This study examined howthe pore size of porous carbon affects propylene oxide adsorptionusing molecular simulation. The results identified the micropore rangeas optimal for adsorption. Comparative analysis of the impacts ofthe pore size distribution on the adsorption performance of propyleneoxide revealed consistent results between experimental and theoreticalcalculations. To further enhance the PO uptake performance, amine-functionalizedporous carbon was synthesized. Compared to unmodified porous carbon(C0, PO uptake capacity: 3.78 mL/g), the amine-modified porous carbon(C1) exhibited a significant improvement in PO uptake, reaching 12.5mL/g. The results of Fourier transform infrared spectroscopy showthat the primary amine group on porous carbon reacts with propyleneoxide via a ring-opening addition reaction during the adsorption process,resulting in better PO uptake performance of amine-functionalizedporous carbon than pristine porous carbon. The regeneration performanceof the amine-functionalized porous carbon material was also evaluatedand proved to be excellent. These experimental and theoretical findingsprovide new ideas for further designing and developing adsorbentswith enhanced uptake performance for propylene oxide.