为减小高效超超临界循环流化床锅炉外置换热器受热面热偏差，通过600 MW超临界循环流化床（Circulating Fluidized Bed，CFB）锅炉实炉试验，分析了外置换热器的热偏差特性。结果表明：外置换热器内存在热偏差，靠外置换热器边壁区域温度较低，中间区域温度较高，温差可达50 ℃。根据实炉数据，通过数值计算，复现了外置换热器偏差特性，并提出通过工质侧结构调整分配流量来解决此偏差问题的方案，可使热偏差显著降低，确保660 MW高效超超临界CFB锅炉末级再热器壁温控制在现有材料允许壁温范围内，且有一定裕量，安全可靠。

In order to reduce the heat deviation of the heated surface of the external heat exchanger in an advanced ultra-supercritical circulating fluidized bed boiler,experimental studies on the thermal deviation characteristics of Baima 600 MW supercritical CFB boiler are carried out.The experimental results show that the heat deviation of the external heat exchanger exists.The temperature in the side wall of the external heat exchanger is lower,while the temperature in the middle region is higher,and the temperature difference can reach about 50 ℃.According to the field test results,the deviation characteristics of the external heat exchanger are mimicked by the numerical calculation,and the scheme to solve the deviation by adjusting the distribution flow of the working material side structure is proposed.It can reduce the thermal deviation significantly and ensure that the wall temperature can be controlled within the allowable wall temperature range of the existing materials,and has a certain margin,which is safe and reliable.

TK223.3

国家重点研发计划（2016YFB0600204）