The Distributing Characteristics of Thermal Parameters in Oil Shale Semi-coke CFB

The experiment on combustion of oil shale and its semi-coke was conducted on a bench of CFBC.The distributing characteristics of temperature and pressure in the furnace are examined for different conditions when primary air ratio was 50% and 66.7% respectively.The experiment results show that the difference in temperatures between dilute phase and dense phase in the chamber of furnace is obvious(the temperature in the exit is lower) and the combustion stability is not satisfied when semi-coke was used as fuel alone.The combustion in the circulating fluidized bed can be kept stable by mixing a certain proportion of the oil shale into semi-coke;at the same time,the bed temperature characteristics can maintain well,and the pressure distribution can maintain relatively reasonable.The primary air ratio has an important impact on the temperature distribution in the chamber.The increase of primary air ratio would lead to the decrease of the temperature in dense phase and the reduction of the temperature difference between dilute phase and dense phase,which leads to the uniformity of the temperature along the ascending direction of the furnace.It is suggested that the primary air ratio should be above 66.7% for the combustion of oil shale and its semi-coke in CFB.These results could provide a designing support to develop co-firing oil shale and its semi-coke in CFB.