Study on Oxy-Fuel Combustion Charactristic of Oil-fired Boiler
|Keywords||carbon capture oxy-fuel combustion combustion characteristics oil-firedboiler|
With the development on the research of CO2capture, storage and utiliazation, CO2flooding is concerned increasingly. At the same time, steam injection boiler is widely applied with the essential aim for steam driving oil. Based on this, a poly-generation of oxy-fuel combustion applied to steam injection boiler for the purpose of CO2enrichment was proposed. It can drive oil, store CO2and reduce emissions of pollutants effectively.Some basic researches on industrial applications of this technology were done in this thesis. From the technical and economic aspects, feasibility analysis was made on the steam injection oxy-fuel combustion poly-generation. By numerical simulation, we studied combustion characteristics in80KW fuel boiler furnace. Based on this, the oil-fired boiler has been transformed and enriched combustion test system was built. The main research topics include the following aspects:(1) A pilot scale test system was designed and constructed The oxy-fuel combustion test system includes boiler combustion system, gas ratio system, control system, data acquisition system, and carbon dioxide compression system. Test system can be applied to study the combustion characteristics of the boiler and emission characteristics of pollutant, and then the whole technological process can be optimized and used to guide the industrial application.(2) Oil-fired boiler combustion characteristics was investigated by Numerical Simulation using fluid software Fluent. Models for80KW oil fired boiler combustion in air atmosphere and in the oxy-fuel atmosphere were established The results showed that in the oxyfuel combustion mode, since CO2has a higher specific heat, the temperature level of the furnace overall is less than the air atmosphere. However, as the oxygen concentration increases, the temperature level of the furnace overall raises, at the same time, combustion has been strengthened. On the one hand, the amount of radiation heat transfer is more than that in the air atmosphere due to the high concentration of CO2and larger with the increasing of the oxygen concentration; one the other hand, the amounts of convection heat transfer decreases with the increasing of the oxygen concentration. When the concentration of oxygen is32%, the amount of heat transfer is more close to the air condition. It is necessary to consider the temperature of the heating area comprehensively and choose appropriate O2/CO2match ratio in the actual operation with the concentration of oxygen is between25%and32%(3) Feasibility analysis of oxy-fuel combustion poly-generation of steam injection boiler was carried from technology and economy. It can capture carbon dioxide from tail gas of the steam-injection boiler and get a variety of by-product for the comprehensive utilization and realize pollutant integration collaborative removal. In the economy calculation, Oxy-fuel combustion poly-generation of steam injection boiler was feasible when gas utilization rate is30%or more according to analysis of sensitivity factors. It could get better economic benefits when the gas had a better utilization.