火电厂双管式烟囱内筒的流动特性

采用计算流体力学的方法,分析常规烟囱内筒的流动特征,包括流动角区的分布、流动压降的分布,以及横截面积和侧面积对流动阻力的影响。针对半圆形内筒压降较大的问题,提出一种优弧弓形内筒,可有效结合圆形内筒和半圆形内筒的优点,具有结构紧凑、横截面积小且流动压降低的特点。研究表明,当内筒横截面积相同时,优弧弓形内筒的压降小于半圆形内筒,略大于圆形内筒的压降。为确保与圆形内筒具有相同压降,半圆形内筒应增大横截面积约5%,而优弧弓形内筒应增大横截面积约3%。该结果可为电厂烟囱内筒的设计提供参考。

Flow characteristics of dual inner-tube chimney in thermal power plant

Computational fluid dynamics method was used to analyze the flow characteristics of conventional chimney, including the distribution of flow dead zone, the distribution of pressure drop, and the influence of cross-sectional area and side area on flow resistance. According to the large pressure drop in semicircular inner tube, a kind of superior arcuate inner tube was proposed, which could effectively combine the advantages of circular tube and semi-circular tube, and had the characteristics of compact structure, small cross-sectional area and low flow pressure. The results showed that, under the same cross-sectional area, the pressure drop of the superior arcuate tube was smaller than that of the semicircular tube, and slightly larger than that of the circular tube. In order to ensure the same pressure drop as the circular tube, the cross-sectional area of the semicircular tube was increased by about 5%, while the superior arcuate tube should be increased by about 3%. The results provided a reference for the design of the inner tube of power plant chimney.