喷淋式助燃空气加湿型烟气冷凝余热回收系统实验研究

提高燃气锅炉烟气冷凝余热回收效率和降低烟气氮氧化物排放浓度研究工作具有重要的工程应用价值。提出了一种喷淋式助燃空气加湿型烟气冷凝余热回收方式。实验研究了助燃空气含湿量变化对燃气锅炉的烟气露点温度、系统热回收效率、氮氧化物排放浓度的影响规律。实验结果表明:当助燃空气的含湿量从3 g/kg增加到60 g/kg时,对应的烟气露点温度可提高8. 0℃;在维持喷淋水温度45℃、喷淋水质量流量0. 075 kg/s的工况下,烟气余热回收效率可达到8. 4%;排放烟气中的氮氧化物平均浓度可从101. 6 mg/m~3降低到53. 3 mg/m~3。当助燃空气含湿量处于40 g/kg时,燃气锅炉运行比较稳定,排放烟气中的氮氧化物平均浓度为70. 1 mg/m~3。

Experimental Research on Spray Type Flue Gas Condensation Waste Heat Recovery System Integrating Combustion Air Humidification

Improving the recovery efficiency of flue gas waste heat and reducing the emission of nitrogen oxides have always been two issues that need to be paid attention to in gas boilers. Relevant research work has important engineering application value. A spay type flue gas condensation waste heat recovery system integrating combustion air humidification was proposed. The effects of changes in combustion air moisture content on the flue gas dew point temperature, system heat recovery efficiency, and nitrogen oxide emissions of gas boilers were investigated experimentally. The experimental results show that, when combustion air moisture content increases from 3 g/kg to 60 g/kg, the dew point temperature of flue gas increases by 8.0 oC. Under the spray flow rate of 0.075 kg/s and the spray water temperature of 45 oC, the heat recovery efficiency of the system can be increased up to 8.4%. The average concentration of nitrogen oxides in the flue gas can be reduced from 101.6 mg/m3 to 53.3 mg/m3. When the combustion air moisture content is 40 g/kg, the gas boiler operation is relatively stable, and the average concentration of nitrogen oxides in the flue gas is 70.1 mg/m3.