600MW机组引风机及其进出口烟道流场研究

Study on Flow Field of the Induced Fan with Inlet and Outlet Flue Gas Duct in a 600 MW Unit

采用数值模拟对某600 MW机组引风机本体和全烟道系统进行对比分析。结果表明:进出口烟道在小流量工况下对引风机性能有一定影响,引风机内流场与进出口烟道流场相互影响。锅炉最大连续蒸发量(BMCR)工况下,全烟道系统的引风机内部流场特征有利于改善进口烟道流场的均匀性,但会加剧出口烟道的能量损耗、扰乱出口烟道流场。在对进出口烟道进行优化改造时,应充分考虑引风机内部流场的影响。

Based on numerical simulations, comparisons and analyses were carried out for the induced fan proper and the whole flue gas duct system in a 600 MW unit. Results show that the inlet and outlet flue gas duct has a certain effect on the induced fan performance under small flow condition, and there is an interaction effect between the inner flow field of the induced fan and the flow field of the inlet and outlet flue gas duct. With the whole flue gas duct system under boiler maximum continuous rating(BMCR) condition, the uniformity of the flow field of the inlet flue gas duct can be improved by the characteristics of the inner flow field of the induced fan under design condition, which may result in the aggravated energy loss and the more disordered flow field. The effects of the inner flow field of the induced fan should be fully considered while optimizing and retrofitting the inlet and outlet flue gas duct.