✍ Scribed by Yongbin Cui; John F. Stubington
No coin nor oath required. For personal study only.
The combustion ef®ciency of Australian coals in PFBC is being studied in a batch-fed rig. Elutriation of unburnt char is the main source of combustion inef®ciency and is proportional to the char loading in the bed. Hence, in-bed char combustion is being studied to identify those coal-related factors which signi®cantly affect the in-bed char loading and thereby combustion ef®ciency. This paper describes a mathematical model designed to simulate in-bed char combustion speci®cally in the PFBC rig, with the aim of identifying those aspects which need to be studied further experimentally. Through a sensitivity analysis of in-bed char loading to model input parameters, coal-related parameters were ranked in priority order as follows: char reactivity, the C/O 2 molar ratio consumed on the surface of a burning char particle in the bed and secondary fragmentation. In further work, these signi®cant parameters will be chosen for experimental study and the model will be used to extract coal-speci®c values from PFBC experiments.
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found that, char combustion rate increase with increasing ugQg or ug.o. Combustion rate can be expressed by using the oxygen concentration at standard temperature and pressure, Co, or the partial pressure of oxygen, P02, as the gas reactant term in the rate equation. However, explanation of pressure
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