Pulverized coal reburning, ammonia injection and advanced reburning in a pilot scale drop tube furnace were inves- tigated. Premix of petroleum gas, air and NH3 were burned in a porous gas burner to generate the neede...Pulverized coal reburning, ammonia injection and advanced reburning in a pilot scale drop tube furnace were inves- tigated. Premix of petroleum gas, air and NH3 were burned in a porous gas burner to generate the needed flue gas. Four kinds of pulverized coal were fed as reburning fuel at constant rate of 1g/min. The coal reburning process parameters including 15%~25% reburn heat input, temperature range from 1100 °C to 1400 °C and also the carbon in fly ash, coal fineness, reburn zone stoichiometric ratio, etc. were investigated. On the condition of 25% reburn heat input, maximum of 47% NO reduction with Yanzhou coal was obtained by pure coal reburning. Optimal temperature for reburning is about 1300 °C and fuel-rich stoichiometric ratio is essential; coal fineness can slightly enhance the reburning ability. The temperature window for ammonia injection is about 700 °C^1100 °C. CO can improve the NH3 ability at lower temperature. During advanced reburning, 72.9% NO reduction was measured. To achieve more than 70% NO reduction, Selective Non-catalytic NOx Reduction (SNCR) should need NH3/NO stoichiometric ratio larger than 5, while advanced reburning only uses common dose of ammonia as in conventional SNCR technology. Mechanism study shows the oxidization of CO can improve the decomposition of H2O, which will rich the radical pools igniting the whole reactions at lower temperatures.展开更多
SNCR（选择性非催化还原）过程试验是在CRF（Cornbustion Research Facility）试验装置上进行的。使用尿素、氨水、（NH4）2CO3、NH4HCO3还原烟气中的NOx，通过雾化喷嘴在CRF炉膛内喷入还原剂。试验结果表明，对于所使用的还原剂随着NH3...SNCR（选择性非催化还原）过程试验是在CRF（Cornbustion Research Facility）试验装置上进行的。使用尿素、氨水、（NH4）2CO3、NH4HCO3还原烟气中的NOx，通过雾化喷嘴在CRF炉膛内喷入还原剂。试验结果表明，对于所使用的还原剂随着NH3／NO摩尔比的增加，NO还原效率逐渐提高；对于尿素、氨水、（NH4）2CO3等还原剂，氨氮比为1-2.5，脱硝效率分别为65％-89％、62％-86％、45％-84％；对于NH4HCO3，氨氮摩尔比0.8-1.5，脱硝效率为46％-73％。不同还原剂的温度窗口不同，适宜尿素进行SNCR过程的反应温度最高，氨水最低。展开更多
文摘Pulverized coal reburning, ammonia injection and advanced reburning in a pilot scale drop tube furnace were inves- tigated. Premix of petroleum gas, air and NH3 were burned in a porous gas burner to generate the needed flue gas. Four kinds of pulverized coal were fed as reburning fuel at constant rate of 1g/min. The coal reburning process parameters including 15%~25% reburn heat input, temperature range from 1100 °C to 1400 °C and also the carbon in fly ash, coal fineness, reburn zone stoichiometric ratio, etc. were investigated. On the condition of 25% reburn heat input, maximum of 47% NO reduction with Yanzhou coal was obtained by pure coal reburning. Optimal temperature for reburning is about 1300 °C and fuel-rich stoichiometric ratio is essential; coal fineness can slightly enhance the reburning ability. The temperature window for ammonia injection is about 700 °C^1100 °C. CO can improve the NH3 ability at lower temperature. During advanced reburning, 72.9% NO reduction was measured. To achieve more than 70% NO reduction, Selective Non-catalytic NOx Reduction (SNCR) should need NH3/NO stoichiometric ratio larger than 5, while advanced reburning only uses common dose of ammonia as in conventional SNCR technology. Mechanism study shows the oxidization of CO can improve the decomposition of H2O, which will rich the radical pools igniting the whole reactions at lower temperatures.
文摘SNCR（选择性非催化还原）过程试验是在CRF（Cornbustion Research Facility）试验装置上进行的。使用尿素、氨水、（NH4）2CO3、NH4HCO3还原烟气中的NOx，通过雾化喷嘴在CRF炉膛内喷入还原剂。试验结果表明，对于所使用的还原剂随着NH3／NO摩尔比的增加，NO还原效率逐渐提高；对于尿素、氨水、（NH4）2CO3等还原剂，氨氮比为1-2.5，脱硝效率分别为65％-89％、62％-86％、45％-84％；对于NH4HCO3，氨氮摩尔比0.8-1.5，脱硝效率为46％-73％。不同还原剂的温度窗口不同，适宜尿素进行SNCR过程的反应温度最高，氨水最低。
