热偏差和流量偏差对1000MW超超临界锅炉水冷壁壁温影响的研究

Study on the Effect of Flame Offset and Flow Deviation on Wall Water Tube Temperature of 1000MW Ultra-Supercritical Boiler

通过耦合水冷壁的烟气侧和工质侧的换热模型,获得超超临界条件下水冷壁管内工质和管壁的温度分布情况。设置火焰中心和工质流量的偏差变量,研究其对600℃和700℃等级锅炉水冷壁管壁温度安全的影响。通过模型的计算结果与600℃等级的超超临界机组测试值对比,验证模型的准确性。计算结果表明：耦合模型计算温度和实测数据有较好的一致性;对于600℃等级锅炉的水冷壁,流量对壁面温度最高值的影响明显高于火焰中心偏移的作用;700℃等级超超临界锅炉水冷壁管壁和工质的温度分布规律和600℃等级锅炉的变化趋势基本一致。管壁的峰值温度约为619℃,远远超过600℃等级超超临界锅炉管材的允许温度;推荐管材的许用温度为650℃。

The coupled heat transfer model of flame-side and steam-side was adopted to calculate the temperature distribution of tube and water/steam of ultra-supercritical boiler（USC）. Flame offset and flow deviation were set to investigate the safety for water wall tube of 600℃ and 700℃ USC. Results show that the temperature distribution obtained by simulation agree well with the experimental tests, proving the simulation method to be effective; For the 600℃ USC, the influence of the steam flow are much important than flame offset for the tube temperature; 700℃ USC has the same trends of temperatures with 600℃ USC. The peak of the tube temperature is about 619℃, which is much higher than the allowable temperature of 600 ℃ USC. The recommended temperature is 650℃ for water wall tube of advanced USC.