垃圾焚烧电站空气预热器与低压省煤器的组合分析

垃圾焚烧电站的低温腐蚀十分严重。目前，尾部受热面（主要是空气预热器）防腐蚀措施主要是在空气预热器前增加暖风器，以提高空气预热器的金属温度，减轻腐蚀，但增加暖风器会降低锅炉乃至电厂的效率。针对深圳市环卫厂150t／d垃圾焚烧锅炉的改造方案，以蒸汽空气加热器和低压省煤器的联合使用的方案进行计算分析，兼顾尾部受热面防腐和整个机组效率，综合考虑尾部受热面布置和热力系统的优化，并对垃圾焚烧电站热力系统优化设计提出了原则性的建议。

Combination Utilization of Air Preheater with Low-Pressure Economizer in MSW Incineration Power Plants

Cold end corrosion in MSW(municipal solid waste) incineration power plants is generally very severe.At present,a main way to reduce corrosion at heat recovery areas(mainly the air pre-heater) is to add a steam air heater in front of the air pre-heater so as to raise the latter one's metallic temperature.However, this way will reduce the efficiency of the boiler or even of the whole power plant.In the renovation project for a 150 t/d MSW incinerator of Shenzhen Municipal and Sanitary Comprehensive Treatment Plant,joint utilization of steam air heater and low-pressure economizer was applied for calculation and analysis purposes,by simultaneously paying attention to both the heat recovery area's anticorrosion property and the whole unit's efficiency,comprehensively considering reasonable arrangement of the area as well as optimization of the thermodynamic system,with a principle suggestion for its design proposed.It is concluded that under allowable conditions,the way to add a low-pressure economizer,after all, is a good solution in raising the unit's efficiency.Furthermore,a critical threshold extraction formula is derived,which shows that the extraction efficiency has no relationship with that of the incinerator.Fig 1,tables 2 and refs 7.