燃气锅炉能效与排放实测调研及节能减排潜力分析
Measurement and investigation of energy efficiency and emission of gas-fired boilers and potential of energy saving and emission reduction
摘要：
对宁夏地区46座供热和工业锅炉房（167台锅炉）的设置情况、能耗与锅炉热效率及氮氧化物排放进行了调研，分析了其节能减排潜力。结果表明：调研锅炉以中小型锅炉为主，氮氧化物排放量为43～130 mg/m3，比当地低氮改造氮氧化物排放要求的30 mg/m3高43%～333%；调研的供热锅炉85%以上排烟温度为130～190 ℃，回水温度为20～47 ℃，若将排烟温度降到25～53 ℃，排烟余热回收利用可提高锅炉热效率6%～17%，余热回收率为34%～95%，其中回收的潜热占23%～66%,单位容量锅炉每天还会产生烟气冷凝水0.3～2.4 t/d，烟气除雾率为11%～81%；工业锅炉排烟温度为62～175 ℃，若将排烟温度降到25 ℃，排烟余热回收利用可提高锅炉热效率10%～14%，余热回收率为93%～95%，其中回收的潜热占56%～85%,单位容量锅炉每天还会产生烟气冷凝水1.7～2.5 t/d，烟气除雾率为80%～82%。该地区燃气锅炉降氮和排烟余热利用的节能、节水、减排及社会环境经济效益巨大。
Abstract：
Investigates the installation, energy consumption, boiler thermal efficiency and nitrogen oxide emission of 46 heating and industrial boiler rooms (167 boilers) in Ningxia, and analyses their energy saving and emission reduction potential. The results show that the investigated boilers are mainly small and medium-sized boilers, and the nitrogen oxide emission is 43 to 130 mg/m3, which is higher by 43% to 333% than the nitrogen oxide emission criterion of 30 mg/m3 for the local low-nitrogen retrofitting. The exhaust gas temperature of more than 85% of the heating boilers investigated is 130 to 190 ℃, and the return water temperature is 20 to 47 ℃. If the exhaust gas temperature is reduced to 25 to 53 ℃, the thermal efficiency of boilers can improve by 6% to 17% through the recovery and utilization of waste heat from exhaust gas. The recovery rate of waste heat is 34% to 95%, of which the latent heat recovered accounts for 23% to 66%. The unit capacity boiler produces flue gas condensate of 0.3 to 2.4 tons every day, and the fog-removing rate is 11% to 81%. The exhaust gas temperature of industrial boilers is 62 to 175 ℃. If the exhaust gas temperature is reduced to 25 ℃, the thermal efficiency of boilers can improve by 10% to 14% through the recovery and utilization of waste heat from exhaust gas, and the recovery rate of waste heat is 93% to 95%, of which the latent heat recovered accounts for 56% to 85%. The unit capacity boiler produces flue gas condensate of 1.7 to 2.5 tons every day, and the fog-removing rate is 80% to 82%. The energy saving, water saving, emission reduction and social, environmental and economic benefits of nitrogen reduction and exhaust waste heat utilization of gas-fired boilers in this area are huge.
Keywords:gas-fired boiler, energy efficiency, thermal efficiency, nitrogen oxide emission, energy saving and emission reduction, waste heat from exhaust gas, exhaust gas temperature, fog-removing rate