Measurement analysis of large gas-fired boiler flue gas heat deep recovery reconstruction project

Based on the problems of high flue cost  and heavy fog emission of the large boiler transforming from coal-fired to gas-fired in severe cold zone, using the anti-corrosive, high-efficient and low-resistant flue gas condensing heat recovery technology and facility, applies the full recovery of the flue gas condensate heat and condensate water heat and energy saving renovation of defogging to the large gas-fired heating boiler with heat capacity of 70 MW at Qimashan heating station in Xinjiang. The heating area increases 0.3 million square meters after renovation. The test results show that the exhaust gas temperature can drop from 88-180 ℃ to 33-54 ℃ under different boiler loads, the efficiency of gas utilization can increase 13% and the total efficiency of gas-fired boiler can reach 107.3%. Supplemented by natural air cooling and dehumidifying, exhaust gas temperature can reach 21-35 ℃, each boiler produces flue gas condensate water of 70-130 tons per day, the flue gas dehumidification rate reaches 70%, which significantly improves the fog emissions and contributes to energy saving, water saving, emission reduction and economic benefit.