半焦加压燃烧特性的试验研究

半焦加压燃烧是第二代PFBC-CC技术的重要组成部分．分别在实验室规模的喷动流化床和热输入1 MWt中试规模的增压流化床燃烧装置上,进行了系统的半焦加压燃烧特性试验研究．研究结果表明,随系统压力的增加,炉膛温度逐渐升高,半焦燃烧效率也相应增大；在压力接近0．5 MPa时,压力增加,煤的燃烧效率增加减缓,但半焦的燃烧效率仍然增加显著．在较高的系统压力下,压力对燃烧的影响占主导因素；在较低的过量空气系数下半焦燃烧仍能获得较高的燃烧效率．床层温度提高后,燃烧反应速度加快,颗粒燃烧较完全,有利于提高燃烧效率．

Experimental Study on Combustion Characteristic of Coal-Chars at Elevated Pressures

The re-combustion of gasified coal-chars plays an important role in the second-generation PFBC-CC technologies for pursuing higher overall power generation efficiency.The research on pressurized combustion characteristic of coal-chars were systematically conducted in a bench-scale pressurized spout fluidized bed combustor and the results were fed into a pi- lot-scale pressurized fluidized bed combustor with heat input of 1 MWt to verify its utility combustion effects.The results show that the combustion temperature and efficiency increase with the increase of the system pressure.When the pressure approached 0.5 MPa,the combustion efficiency of coal increased slowly but the combustion efficiency of coal-char contin- ued rising.Under operational condition of higher pressure of the test case,the pressure turned to have a dominant effect on the combustion efficiency,and the combustion efficiency could be high with lower excess air coefficient.Higher temperature made the coal-chars burnt completely as a result of speeding up the combustion reactions between air and coal-chars and thus benefited the combustion efficiency.