Experiment key factors of coal-bed gas and coal gangue co-combustion in circulating fluidized bed

The co-combustion test of coal-bed gas and coal gangue were performed in circulating fluidized bed ( CFB) ,the studies about bed temperature field and combustion efficiency were done when the test parameters including the gas/gangue mixing rations ( R) ,second air rate ( r2) and excess air coefficient ( α) were different. The results show that the co-combustion has an important effect on the combustion optimization,compared with combustion of coal gangue only,the distribution of bed temperature becomes well-proportioned and the combustion efficiency increases when the coal-bed gas has been mixed. The combustion efficiency is higher when the gas/gangue mixing rations is 0. 2. The second air rate and the excess air coefficient have different effect on temperature in dense bed and dilute phase region,but both parameters have an optimum value corresponding to the highest combustion efficiency. With the increase of the second air rate,the combustion efficiency increases firstly and then reduces. With the increase of excess air coefficient,the temperature in dense bed and dilute phase region fall,the combustion efficiency increases firstly and then reduces. The integrated combustion effect is more preferable when R =0. 2,r2 =0. 3 and α =1. 3.