一电厂尿素热解工艺系统研究与改造

Research and Renovation of Urea Pyrolysis Process System in a Power Plant

针对一电厂原电加热器尿素热解系统能耗高、故障率高以及脱硝系统运行不稳定等问题,提出采用炉内气气换热器代替电加热器的改造方案。炉内气气换热器布置在燃煤机组低温再热器水平段上方,换热管材质为06Cr25Ni20。炉内气气换热器导致燃煤耗量增加约2.7%,烟气温度下降低于5℃,锅炉效率降低0.03%,对锅炉效率的影响可以忽略不计。通过经济性分析,改造后该电厂每年节省费用1.267 2×10^(6)元,具有显著的经济效益。

Aiming at the problems of high energy consumption,high failure rate,and unstable operation of the denitrification system in the urea pyrolysis system of a power plant's original electric heater,a renovation plan was proposed to replace the electric heater with a furnace gas-gas heat exchanger.The gas-gas heat exchanger inside the furnace is arranged above the horizontal section of the low-temperature reheater of the coal-fired unit,and the material of the heat exchange tube is 06Cr25Ni20.The gas-gas heat exchanger inside the furnace leads to an increase of about 2.7%in coal consumption,a decrease in flue gas temperature below 5℃,and a decrease of 0.03%in boiler efficiency.The impact on boiler efficiency can be ignored.Through economic analysis,the renovated power plant saves an annual cost of 1.2672×10^(6)yuan,which has significant economic benefits.