火电厂锅炉送风流量测量装置的数值研究

Numerical study on the air flow measurement device of thermal power plant boilers

为了提高燃煤火电厂锅炉送风流量测量的准确度,解决流量仪表在含尘气流中的堵塞和耐磨等问题,对某电厂锅炉送风管道的弯曲段进行CFD数值模拟,通过采用不同数量导流板布置来探究转弯后的水平直管道的流场分布,同时对设计的多点式风量测量装置的准确度进行数值验证。结果表明:布置合理数量的导流板不仅可以有效改善流场分布均匀性、完全消除涡流或二次流,而且能大幅度减小流动阻力和能量损失;设计的多点式风量测量装置具有很高的测量准确度,测量流量误差在±1%以内。

In order to improve the accuracy of boiler air flow measurement in coal- fired power plants and solve the problems of blockage and wear resistance of flow meters in dusty airflow, the CFD numerical simulation of the bending section of boiler air supply pipeline in a power plant is carried out. The distribution of flow field in horizontal pipe is analyzed by using different number of flow deflectors, and the accuracy of the designed multi-point air flow measurement device is numerically verified. The results show that using a reasonable number of flow deflectors can not only effectively improve the uniformity of the flow field distribution and completely eliminate the vortex or secondary flow, but also greatly reduce the flow resistance and energy loss. The designed multi-point air flow measurement device has high measurement accuracy, and the measurement flow errors are within ±1%.