Coal?fired boilers and thermal power plants are the primary heating resource in the district heating field. However, they have great energy?saving potential because of the significant heat loss from the high?temperature discharging flue gas. In view of the existing problems, a waste?heat recovery system for coal?fired boilers based on a spray tower is presented. It could efficiently recover the latent heat and improve the system efficiency and economic performance by using a spray?tower heat exchanger and absorption heat pump. In this study, a model was built for this system and validated with measured data in a practical project. The system was then evaluated from the points of view of energy saving, emission reduction, and economic feasibility. The results show that the simulation results of the model are roughly in line with the trend of the observed results, and the absolute and relative errors are in a reasonable range, which proves that the model is reasonable. Meanwhile, the boiler thermal efficiency can rise to 104. 5％, the pollutant emissions can obviously decrease, and the quantity of collected condensate water can reach 18,000 tons a year. In addition, the payback period is 3. 96 years. In summary, the proposed system has higher energy efficiency and better economic benefits than existing systems.%在城市供热领域,燃煤锅炉和燃煤热电厂作为主力供热热源,尚存在着系统排烟温度高,热损失严重的普遍现象.本文提出基于喷淋换热的燃煤锅炉烟气余热回收系统,利用吸收式热泵和喷淋塔有效回收烟气余热,对系统建立模型,并利用工程实测参数进行模型验证,同时从节能减排效果及经济性方面进行评价.结果表明:模型的模拟结果与工程实测值变化趋势一致,绝对误差与相对误差均维持在合理范围内,可认为模型可靠;锅炉热效率达104.5％;CO2、SO2、NOx等污染物排放明显减少,烟气的年冷凝水量可达1.8万t,节能减排潜力巨大;经计算,该系统增量投资回收期为3.96 a,回收期较短,具有较好的经济性.
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