Practical measurement of nitrogen reduction and efficiency improvement of a gas-fired boiler project

 In view of the problems of condensation and corrosion of returning flue gas and high thermal efficiency in the nitrogen reduction reform of gas-fired boilers, adopts a low nitrogen and high efficient scheme based on exhaust gas condensing waste heat recovery as well as improving the air environment in boiler room renovation. After the retrofitting, the practical measurement shows that when the flue gas recirculation rate is 15% to 20% and  the excess air coefficient is 1.36 to 1.55, the NOx content in the exhaust air is 11.5 to 42.7 mg/m3 in the load range of 42% to 67%. Corrosion is not found in the boiler system. The return water temperature of the primary heating is 33.3 to 40.7 ℃, the flue temperature is reduced from 88-112 ℃to 40-44 ℃, gas utilization thermal efficiency is increased by 8.2% to 12.1%, and the unit capacity (700 kW) boiler recovers 0.88 to 1.25 t/d of the flue gas condensate. The flue gas demisting rate is 37% to 50%, and the air quality in the boiler room is effectively improved. According to the comparison of gas consumption in the two heating seasons, the total gas saving rate of the boiler room is 14.8%, the benefits of nitrogen reduction, efficiency increasing, water saving, defogging, energy saving and environmental protection are significant.