TY - JOUR
TI - Coupled simulation on flue gas and steam deviation of final reheater in a 600 MW tangentially fired boiler with reversed separated overfire air under different loads
AU - Wang Zhengjiang
AU - Wang Xingjun
AU - Yang Yang
AU - Li Jiawei
AU - Su Yongning
AU - Jiang Qi
AU - Li Xiaojun
AU - Xing Wenbin
AU - Yi Jinhao
AU - Liu Hu
JN - Thermal Science
PY - 2025
VL - 29
IS - 2
SP - 983
EP - 997
PT - Article
AB - Flue gas and steam deviation of the final reheater is an inevitable problem in the tangentially fired boiler due to the remaining gas spinning at the furnace exit. An in-house 1-D process simulation code coupled with comprehensive 3-D combustion simulation was adopted to accurate investigate the characteristics of the flue gas and steam maldistribution of the final reheater in a 600 MW supercritical tangentially fired boiler. Firstly, the combustion simulation result was validated by the in-house fire-side heat transfer calculation data, then the effect of boiler loads and reversed separated overfire air (SOFA) deflection angles on the gas temperature deviation, velocity deviation and outlet steam temperature of reheater were conducted. The results showed that the deviation of flue gas temperature and velocity increases as the boiler load decreases. The reversed SOFA deflection angle plays a crucial role in improving the gas distribution under low loads, and the deviation of flue gas temperature and velocity is the smallest when the angle is –18° under 100% boiler maximum continuous rating (BMCR), 75% and 50% turbine heat acceptance (THA), but it is the smallest when the angle is –9° under 35% BMCR load. Moreover, the maximum outlet steam temperature difference between parallel heating surfaces of the final reheater increases from 84.68-106.48 K as the boiler load decreases from 100% BMCR to 75% THA, and it is mainly affected by the flue gas temperature deviation rather than the mass-flow rate maldistribution when the deflection angle changes from –9° to –18°.