电站锅炉烟气余热回收利用装置的试验分析及研究

Test Analysis and Study of Flue Gas Waste Heat Recovery Device in Power Plant

某台330 MW机组锅炉尾部烟道加装烟气余热回收利用装置,利用烟气余热加热机组凝结水,降低排烟温度。将锅炉排烟温度由140℃降到80℃的最佳脱硫温度,实现排烟余热的第一次提取。从脱硫塔出来的烟气,再进入烟气脱水装置,利用静电将烟气中的水分脱去,同时回收水分的凝结潜热,实现排烟温度余热的第二次提取。试验结果表明:烟气余热回收热量为25.39 MW,回收烟气中水蒸汽凝水量6.4 t/h,热耗降低83.29 k J/k Wh,折合发电煤耗3.09 g/k Wh。此余热装置采用氟塑料换热器解决了换热管束的耐腐蚀和积灰结垢问题且技术成熟,可以在余热回收装置中推广应用。

The flue gas waste heat recovery device is fixed at the rear of one 330MW unit boiler. The flue gas waste heat is used to heat condensate water unit, so it can reduce flue gas temperature. The flue gas temperature is from 140℃ to 80 ℃ the best desulfurization temperature to achieve the first extraction of the waste heat. Then the flue gas leaves from desulfurization tower, and enters the flue gas dewatering device to remove the moisture in flue gas. At the same time, the water condensation latent heat is recycled to realize the second extraction. The test results show that the flue gas waste heat recovery heat is 25.39 MW, and the recycling of flue gas condensate water is 6.4 t/h, and heat consumption decreased 83.29 kJ/kWh, equivalent to coal consumption 3.09g/kWh. The waste heat device with fluorine plastic heat exchanger solved the heat exchange tube bundle of corrosion and scaling problems. And the technology is mature, so the waste heat recovery system should be promoted and used.