墙式锅炉屏式过热器低负荷热偏差特性数值模拟研究  

Numerical Investigation on Thermal Deviation Characteristics of Platen Superheater in a Wall-fired Boiler at Low Load

作　　者：杨雨 刘岗 刘欣 张超群 李文甲 王赫阳 YANG Yu;LIU Gang;LIU Xin;ZHANG Chaoqun;LI Wenjia;WANG Heyang(School of Mechanical Engineering,Tianjin University,Tianjin 300072,China;Anhui Tongling Power Generation Co.,Ltd.,CHN Energy Investment Group,Tongling 244153,Anhui Province,China;Yantai Longyuan Power Technology Co.,Ltd.,Yantai 264006,Shandong Province,China)

机构地区：[1]天津大学机械工程学院,天津300072 [2]国家能源集团安徽铜陵发电有限公司,安徽铜陵244153 [3]烟台龙源电力技术股份有限公司,山东烟台264006

出　　处：《动力工程学报》2023年第10期1268-1275,1293,共9页Journal of Chinese Society of Power Engineering

基　　金：国家自然科学基金青年科学基金资助项目(51906176)。

摘　　要：为缓解热偏差造成的锅炉屏式过热器超温爆管现象,研究了某600 MW超临界墙式对冲燃烧锅炉屏式过热器的热偏差特性,分析了此锅炉屏过热偏差的形成机理并给出优化方案。为克服燃烧器与锅炉间巨大尺寸差异的限制,使计算结果准确体现燃烧器设计对炉内流动与热偏差分布的影响,首先提出一种分别模拟计算燃烧器与锅炉,以燃烧器出口平面计算结果作为锅炉燃烧器入口边界条件的计算方法,并提出了降低中层燃烧器风量及调整锅炉左右侧燃烧器风量的方法,以降低屏过高热偏差区域的烟气通量。结果表明:由于相邻燃烧器旋流相互作用,在炉内形成2束较为集中的烟气流,使高温烟气在流经屏过时形成左低右高的双峰形吸热分布,这是形成屏过双峰形热偏差分布的主要原因;所提出的2种风量调整方法均可有效降低屏过热偏差峰值,大幅降低屏过超温爆管的风险。The thermal deviation characteristics of platen superheater in a 600 MW supercritical wall-opposed firing boiler was studied to alleviate the tube failures by overtemperature.The formation mechanism of thermal deviation in the platen superheater was analyzed,and the subsequent optimization schemes were proposed.In order to overcome the limitation by the huge scale difference between the swirl burners and furnace and incorporate the effect of burner design on the flow and thermal deviation distribution in the furnace,the flow in the burner and furnace was simulated separately,and the calculated results at the outlet of burner were taken as the inlet boundary conditions of the furnace model.Then the method of reducing the air flow rate of middle-layer burners or adjusting the air flow rate of the left-side and right-side burners was proposed to reduce the flue gas flux in the high thermal deviation area of platen superheater.Results show that the interaction between the swirling flow of adjacent burners leads to the formation of two concentrated gas streams in the furnace.As the flue gas passes through the platen superheater,its heat transfer distribution demonstrates a right-dominant double-peak shape,which is the main mechanism of thermal deviation distribution in the platen superheater.The two proposed methods can effectively decrease the peak thermal deviation in the platen superheater and dramatically lower the risk of tube failure caused by overtemperature.

关 键 词：墙式对冲燃烧 旋流燃烧器 屏式过热器 热偏差 低负荷 

分 类 号：TK227[动力工程及工程热物理—动力机械及工程]