Dynamics Of The Reaction Of Pulverized Coal In O₂/CO₂ Recirculated Combustion And The Study Of The Formation And Emission Of NOx At Poilt-scare Experimental Bench

Presently Global warming which results by excessive emission of CO2 becoming a Global hot issues , to reduce the emission of CO2, Carbon capture and storage technology (CCS)is necessary. Among CCS technology , The O2/CO2 recirculated combustion is considerd to be the lowest risk technology of reducing the emission of NOx. The O2/CO2 recirculated combustion is different to general combustion, the fundament reason is that atmosphere of the combustion is changed. So there are many differents on pulverized coal dynamics and character of pollution's emission.Take Thermogravimetry to deal with the study, make a great deal of O2/CO2 and O2/N2 atmosphere Thermogravimetry experiments among different oxygen composition. The oxygen composition is 10%, 20%, 30%. Three kinds of coal are taken for the contrastive experiments. A lot of Thermogravimetry contrast experiment make it clear that in different atmosphere the velocity of combustion, ignition point, time of combustion is different. Experiments, calculation and analysis show that: the coal's dynamics of the reaction in O2/CO2 and O2/N2 atmosphere are both can be described with nucleus and nucleation. And in the same composition of oxygen, the reaction can be expressed with the same reaction mechanism. Analyze CO composition of the fumes, it can be found that, in the same composition of oxygen, O2/CO2 atmosphere vent more CO then the O2/N2 atmosphere. It shows that maby high composition of CO2 have some effect of the coal's combustion reaction. In the same composition of oxygen, pulverized coal of oxygen has different character of combustion in O2/CO2 and O2/N2 atmosphere, this may because of the volatile's release.But both in O2/CO2 and O2/N2 atmosphere, the concentration of oxygen has great effect in pulverized coal's combustion: while increase the concentration of oxygen, velocity of combustion is larger, ignition point will come earlier, time of combustion is shorter.Take the poilt-scare O2/CO2 recirculated combustion pallet for debugging and experimen. Pay more attention to compare the formation and emission of NOx in air, O2/CO2, O2/RFG atmosphere. Comparing the formation of NOx at different location of the hearth,it clear that an area in where the composition of NOx fleetly grow, that is from first fireboxâ… to first fireboxâ…¡. The growing velocity is fastest in air atmosphere, in O2/CO2 and O2/CO2 recirculated atmosphere the growing velocity is not so fast. Investigating the emission of NOx at the end of the firebox, it shows that in this condition, Oxy-fuel combustion technology obviously reduces the emission of NOx, and O2/CO2 recirculated combustion makes it even better.Their Nitrogen rate are 60.87% and 73.78%.