摘要
对倾斜角为10°、15°、20°周向重叠三分螺旋折流板,由9根12 mm的U型管组成的电加热器方案进行了流动与传热性能及表面温度均匀性的数值模拟,与相同布管方式的弓形折流板的电加热器方案的结果进行了对比。结果表明,在所讨论的方案中,倾斜角为15°三分螺旋折流板电加热器方案的换热系数和综合性能指标h·Δp-1/3较高;计算范围内,其平均换热系数和综合指标h·Δp-1/3的平均值与折流板板间距为100 mm的弓形折流板方案的数值之比分别为1.19、1.51;其壁面平均温度和最高温度的平均值比弓形折流板电加热器方案分别降低46.3 K和88.1 K。
Numeric simulation was conducted to analyze the flow and heat transfer characteristics in four electric heaters of nine U tubes with three schemes of circumferential overlap trisection helical baffles with inclined angles of 10°, 15°, 20° and a segment baffled one for comparison. The simulation results show that the circumferential overlap trisection helical baffle electric heaters with inclined angles of 15° has higher heat transfer efficiency and average comprehensive index h · △p- 1/3. In the calculation range, the heat transfer efficiency and the average comprehensive index h· △p- 1/3 of the 15 o helical scheme over those of the segment scheme are respectively 1.19 and 1.51. And its average and maximum values of the wall temperature are respectively 46.3 K and 88.1 K lower than those of the segment one.
出处
《工业锅炉》
2015年第3期1-5,共5页
Industrial Boilers
基金
国家自然科学基金资助项目(51276035
51206022)
关键词
三分螺旋折流板
电加热器
周向重叠
综合指标
温度均匀性
trisection helical baffles
electric heaters
circumferential overlap
comprehensive index
temperature homogeneity
