燃烧无烟煤的W火焰锅炉热流密度分布的数值模拟
Numerical simulation of the heat flux distribution of water wall of an anthracite coal fired arch-fired boiler
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摘要: 对600 MW超临界W火焰锅炉的流动,燃烧和传热过程,以及水冷壁热流密度的分布特征进行了数值计算,并研究了不同拱上风倾角,不同拱上二次风比例及不同OFA倾角对水冷壁热流密度分布的影响规律。结果表明,在炉膛燃烧器区域,炉膛中部的前拱气流对于后拱气流存在挤压作用,而在侧墙附近后拱气流对前拱气流存在挤压作用。炉膛前后墙水冷壁的热流密度在水平方向呈M型双峰分布,而侧墙水冷壁的热流密度则呈中间高两边高的单峰分布。拱上风倾角对于炉内热流密度分布的影响最为敏感,OFA倾角影响次之,拱上二次风比例的影响相对较小。Abstract: Numerical simulation was conducted on the flow dynamics, combustion and heat transfer processes in a 600 MW supercritical arch-fired boiler,and the distribution and variations of heat flux distribution on the water wall membranes under the conditions of different primary air angles,the secondary air ratios and OFA (over fire air) angles. The results show that the primary and secondary air streams from the burners located on the front arch push those coming from the burners located in the furnace middle zone of the rear arches,while the tendency is opposite near the side walls. The heat flux horizontal profiles on the front and rear walls have two peaks and those on the side walls have one. The primary air angle is the most sensitive influencing factor to the heat flux distribution in the supercritical arch-fired boiler furnace,while the OFA angle and secondary air ratio are relatively less sensitive over the simulation ranges.
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