助燃空气加湿对燃气锅炉低氮燃烧性能的影响

Influence of combustion air humidification on low nitrogen combustion performance of gas boiler

为降低燃气锅炉的NO_(x)(氮氧化物)排放质量浓度,可以利用助燃空气加湿方法实现燃气锅炉降氮,重点针对该方式的燃烧过程和实施效果开展模拟与实验研究。研究不同助燃空气含湿量对燃气锅炉排烟温度、NO_(x)排放质量浓度的影响规律。结果表明,助燃空气加湿可以明显降低炉膛出口的NO_(x)平均排放质量浓度。当助燃空气加湿至76.90 g/kg时,燃气锅炉的NO_(x)排放质量浓度可降低至38.05 mg/m^(3),降氮效率高达71.96%。当助燃空气含湿量高于57.30 g/kg时,炉膛出口的CO质量浓度增长率急剧增加,燃烧的稳定性变差,继续提高助燃空气中的水蒸气含量不利于燃气锅炉的稳定运行。提出的助燃空气加湿技术为已有燃气锅炉的低氮改造方面提供技术参考。

To reduce the concentration of NO_(x)emissions from gas boilers,the use of humidified air as combustion air was explored to achieve nitrogen reduction.This study focused on simulating and experimentally investigating this approach′s combustion process and efficacy.Different levels of humidity in the combustion air were studied to assess their impact on flue gas temperature and NO_(x)emission mass concentrations.The results show that humidified air can notably lower the average NO_(x)emission mass concentration at the furnace exit.When the humidity in the secondary air is increased to 76.90 g/kg,NO_(x)emission mass concentration from the gas boiler can be reduced to 38.05 mg/m^(3),achieving a high nitrogen reduction efficiency of 71.96%.However,when the humidity in the air exceeds 57.30 g/kg,the rate of increase in CO mass concentration at the furnace exit rises sharply,leading to decreased combustion stability.Continuously elevating the water vapor content in the humidified air is unfavorable for the stable operation of the gas boiler.The introduced humidified air approach provides valuable technical insight for the nitrogen reduction retrofit of existing gas boilers.