Technical scheme and energy-saving potential analysis of flue gas condensing heat deep-recovery in large gas-fired boilers

Focusing on the problems of the high exhaust gas temperature, high energy consumption and huge emissions of large gas-fired boilers, as well as others such as limit space, huge heat recovery equipment, high resistance, high investment and energy saving reconstruction funds constraint in the deep utilization of the flue gas waste heat, puts forward different technical schemes of the gas-fired boiler flue gas condensing heat deep-recovery. Energy-saving analysis results for an existing large gas-fired boiler reconstruction project in the north of China show that the exhaust temperature can be reduced from 160 ℃ to 30-50 ℃, with energy-saving rate up to 10%-13%, and one boiler can produce flue gas condensate water of 70-160 tons per day, with drainage rate of 27%-60%，fog emissions being reduced and carbon dioxide and nitrogen oxide exhaust being decreased more than 10%.