流化床O_2/CO_2燃烧(Ⅲ)-氧浓度对粒径的影响

O_2/CO_2 Combustion in a Fluidized Bed(Ⅲ)-Influence of the Oxygen Concentration on Particle Diameters

为研究氧浓度对燃料粒径的影响,在15 kW循环流化床试验系统和0.15 MW循环流化床试验系统上进行不同氧气浓度、不同燃料、不同粒径的燃烧试验。试验结果表明,燃烧高挥发分的煤时,氧气浓度对燃料的热破碎有较大影响,进而影响燃料粒径。50%左右氧气浓度下时,燃烧高挥发分燃料,平均粒径要比在常规空气下燃烧增加约35%。低挥发分的神木半焦在燃烧过程中热破碎较弱,氧气浓度对热破碎特性影响不大,粒径和空气燃烧条件下无明显差异。

To study the influence of the oxygen concentration on particle diameters of fuel,a combustion test was performed at different oxygen concentrations,fuels and particle diameters in a 15 kW and 0.15 MW circulating fluidized bed test system respectively.The test results show that when coal with a high volatile content is burned,the oxygen concentration has a relatively big influence on the thermal fragmentation of fuel and subsequently affects the particle diameters of fuel.During the combustion at an oxygen concentration of about 50%,for fuel with a high volatile content,the average particle diameter will increase by about 35% when compared with the conventional air combustion.During the combustion process,the thermal fragmentation of Shenmu-originated semi-coke with a low volatile content is relatively weak and the oxygen concentration has no big influence on the thermal fragmentation characteristics and the particle diameters have no obvious difference to those under the condition of air combustion.