Engineering acid dew temperature: the limitation for flue gas heat recovery  

作　　者：Yuetao Shi Xiangyu Zhang Fei Li Lei Ma 

机构地区：[1]School of Energy and Power Engineering, Shandong University

出　　处：《Chinese Science Bulletin》2014年第33期4418-4425,共8页

基　　金：supported by the National Basic Research Program of China(2011CB710702);Shandong Provincial Science and Technology Development Plan(2012GGE27012)

摘　　要：In order to study how deep we can reduce the temperature of exhaust flue gas, an experiment focusing on the combined influence of ash deposition and acid condensation on the heat transfer characteristics of the heat exchanger was carried out in a 300-MW boiler unit. An annular tube was inserted into the flue gas duct between the air preheater and the electrostatic precipitator. The water with given temperature firstly entered the inner tube and then flowed into the outer tube at the end of the inner tube. It is found that heat transfer performance drops sharply at fixed temperature range under given coal quality. The turning temperature is defined as the engineering acid dew temperature(EADT). When the inlet water temperature is under the EADT, ash sticks to the tube and is difficult to blow off, and thus the flow resistance rises. Furthermore, the corrosion can be observed obviously. From the point of economy and reliability, EADT is the limitation for flue gas heat recovery. The EADT is at least 30 °C lower than ADT calculated by traditional empirical and theoretical equations.In order to study how deep we can reduce the temperature of exhaust flue gas, an experiment focusing on the combined influence of ash deposition and acid condensation on the heat transfer characteristics of the heat exchanger was carried out in a 300-MW boiler unit. An annular tube was inserted into the flue gas duct between the air preheater and the electrostatic precipitator. The water with given temperature firstly entered the inner tube and then flowed into the outer tube at the end of the inner tube. It is found that heat transfer performance drops sharply at fixed temperature range under given coal quality. The turning temperature is defined as the engineering acid dew temperature （EADT）. When the inlet water temperature is under the EADT, ash sticks to the tube and is difficult to blow off, and thus the flow resistance rises. Furthermore, the corrosion can be observed obviously. From the point of economy and reliability, EADT is the limitation for flue gas heat recovery. The EADT is at least 30 ℃ lower than ADT calculated by traditional empirical and theoretical equations.

关 键 词：烟气余热回收 酸露点温度 工程 进水温度 静电除尘器 空气预热器 传递特性 热交换器 

分 类 号：X706[环境科学与工程—环境工程]