不同截面螺旋通道的热阻及熵产特性对比分析

Comparative analysis of characteristics of thermal resistance and entropy generation in helical channels with various cross sections

工程应用中螺旋夹套流道截面形状常为半圆形、矩形和三角形。为确定其中何种截面螺旋通道的传热性能和综合性能最佳,在等截面积、等加热面积及等进口流量条件下,采用数值方法对比分析3种螺旋通道的热阻及熵产特性。由结果可知:相同操作流量(或泵功)下,矩形螺旋通道的热阻最小,三角形次之,半圆形最大,表明矩形螺旋通道中的对流换热量最大,经济性能最好;研究范围内总熵产率可用于评价螺旋通道的综合性能,相同雷诺数下,矩形螺旋通道总熵产率最小,三角形次之,半圆形最大,表明矩形螺旋通道的热能利用程度最高,综合性能最优。

The most popular cross sections of flow channel in helical jacket were half circular, rectangular and triangular in engineering application. In order to determine which cross section has the best heat transfer performance and overall performance, the characteristics of thermal resistance and entropy generation in helical channels with 3 cross sections were comparatively analyzed using numerical method at a constant inlet flux, fixed cross section area and heating area. The results show that the thermal resistance of helical channel with rectangular cross section is minimum at same operating flux or pump power, the next is triangular cross section, and the last is half circular cross section. It also shows that the performance of convection heat transfer and economy is the best in helical channel with rectangular cross section. The total entropy generation rate can be used to evaluate the overall performance of helical channel in studied scope. The total entropy generation rate of helical channel with rectangular cross section is minimum at same Reynolds number, the next is triangular cross section, and the last is half circular cross section. The helical channel with rectangular cross section shows the highest level of thermal energy utilization and the best overall performance.