The ignition modes transformation and critical parameters for single coal particle under O2/CO2 atmospheres
The ignition modes transformation and critical parameters for single coal particle under O2/CO2 atmospheres
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DOI：
10.1016/j.fuproc.2023.107749
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发表时间：
2023
影响因子：
7.5
通讯作者：
Ting Zhang;Yuegui Zhou;Zhongfa Hu
中科院分区：
文献类型：
--
作者：
Ting Zhang;Yuegui Zhou;Zhongfa Hu
Oxy-coal combustion with the substitution of CO2for N2is a state-of-the-art technology for CO2capture and storage. Pulverized coal particles show various ignition and combustion characteristics under O2/CO2atmospheres due to various physicochemical properties between CO2and N2. A modified transient model with an augmented reduced mechanism (ARM) was developed to predict the ignition delays and ignition modes of the coal particle. Ignition modes transformation and critical parameters for single coal particle under O2/CO2atmospheres were determined by using the modified transient model and the ignition criteria based on different characteristic ignition time scales. The predicted ignition delays were compared with experimental values and the predicted results obtained from the sophisticated model in literature. The ignition processes of the coal particle under O2/CO2and O2/N2atmospheres were analyzed in detail. Then, the contributions of the physical properties of CO2including thermal conductivity and thermal sink, and the chemical properties of CO2including gas mixture reactivity and char gasification to the variation of homogeneous and heterogeneous ignition delays and the transformation of ignition modes were separated at 1200–1800 K and 5%–60% O2. Finally, the ignition modes map under O2/CO2atmospheres was firstly depicted and the critical parameters for ignition mode transformation were compared with O2/N2atmospheres. The results indicated the larger thermal sink of CO2and the reduced gas mixture reactivity played the dominant roles of the prolonged homogeneous ignition delays under O2/CO2atmospheres. The critical gas temperature for the appearance of homogeneous ignition increased by 71 K at 27% O2whereas the critical O2concentrations for the ignition mode transformation from HI-GI to HI-coal changed insignificantly with the substitution of CO2for N2.
