Applied Thermal Engineering ( IF 6.4 ) Pub Date : 2020-03-17 , DOI: 10.1016/j.applthermaleng.2020.115217 Jiapeng Fu , Zhuhan Liu , Lin Wei , Leteng Lin , Na Li , Qulan Zhou , Chunyuan Ma
To understand the running status of membrane walls in an opposite firing boiler, a scale-down model furnace was established, and the temperature, heat flux, strain and stress distributions are investigated under four heating loads. Results show that the average membrane wall temperature and heat flux present a continuous increase from 42 oC and 16 W/m2 to 96 oC and 50 W/m2, respectively, with the heating load increase from 25% to full load. The average strain and stress also rise from 88.7 µm and 0.094 MPa to 152.5 µm and 0.148 MPa when the heating load increases from 25% to 50%, but then they keep stable when further increasing the heating load. General distribution patterns of each tested parameter are found relatively similar under varying heating loads. High strain and stress distributions are always detected at the middle left zone of side walls and the middle of the rear wall, where wall temperatures are measured high. External fixed constraints and high-temperature thermal strain is found jointly affecting the strain and stress distribution of the membrane wall. A simplified mechanism of how the strain and stress on boiler membrane walls evolve is proposed after comprehensive discussion of the measurement results.
中文翻译:
在变化的热负荷下识别对置燃烧模型锅炉中膜壁的运行状态
为了了解在对面燃烧锅炉中膜壁的运行状态,建立了按比例缩小的模型炉,并研究了在四种加热负荷下的温度,热通量,应变和应力分布。结果表明,平均膜壁温度和热通量从42 o C和16 W / m 2连续增加到96 o C和50 W / m 2分别随着加热负荷从25%增加到满负荷。当加热负荷从25%增加到50%时,平均应变和应力也从88.7 µm和0.094 MPa升高到152.5 µm和0.148 MPa,但是当进一步增加加热负荷时它们保持稳定。发现在变化的热负荷下,每个测试参数的一般分布模式相对相似。总是在侧壁的左中间区域和后壁的中间检测到较高的应变和应力分布,这些区域的壁温很高。发现外部固定约束和高温热应变共同影响膜壁的应变和应力分布。