炼厂燃气动力炉富氧燃烧技术改造方案及性能分析

Oxy-Fuel Combustion Technology Transformation Scheme and Performance Analysis of Refinery Gas Power Furnace

通过实验研究和理论分析,对燃气动力炉富氧燃烧污染物排放与燃烧特性进行研究,分析氧气体积分数对锅炉燃烧性能的影响。结果表明:当氧气体积分数为28%~30%时,炉膛温度基本与空气助燃工况相当,而炉膛的传热效率则随氧体积分数的升高而上升。氧体积分数升高可以提升燃烧效率,降低烟气中CO的排放,同时,富氧燃烧通过屏蔽氮源及控制炉温可大幅降低NO_(x)质量浓度。在70 kW热水锅炉上测试结果表明,当燃气量为3 m^(3)·h^(-1)、富氧助燃氧气体积分数大于28%时,锅炉排烟中NOx质量浓度小于20 mg·m^(-3),CO质量浓度小于80 mg·m^(-3),排烟中CO_(2)体积分数为32%,水体积分数为63%,该烟气经脱水后,CO_(2)体积分数可达到95%以上,满足CO_(2)用于驱油的指标要求。

Through experimental research and theoretical analysis,the emission and combustion characteristics of oxy-fuel combustion in gas-fired power furnaces were studied,and the influence of O_(2)volume fraction on the combustion performance of boilers was analyzed.The results showed that the temperature of the furnace was basically the same as that of the air combustion condition in the range of 28%~30%O_(2)volume fraction,and the heat transfer efficiency of the furnace increased with the increase of O_(2)volume fraction.The increase of O_(2)volume fraction could improve the combustion efficiency and reduce the emission of CO in the off-gas,and at the same time,the oxy-fuel combustion could greatly reduce the NOx mass concentration by shielding the nitrogen source and controlling the furnace temperature.On the 70 kW hot water boiler,the test results showed that when the gas volume was 3 m^(3)·h^(-1)and the oxy-fuel combustion O_(2)volume fraction was greater than 28%,NOx mass concentration in the boiler exhaust gas was less than 20 mg·m^(-3),CO mass concentration was less than 80 mg·m^(-3),the CO_(2)volume fraction in the off-gas was 32%,and the water volume fraction was 63%,and the CO_(2)volume fraction could be more than 95%after dehydration,meeting the index requirements of CO_(2)for enhanced oil recovery(EOR).