Investigation on the Frictional Pressure Drops at Low Mass Fluxes in an Internally-ribbed Tube
Investigation on the Frictional Pressure Drops at Low Mass Fluxes in an Internally-ribbed Tube
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发表时间：
2015
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通讯作者：
Wang Jian-gu
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作者：
Wang Jian-gu
在低质量流量下，对Siemens AG优化设计的φ 31.8 mm × 6.0 mm绝热水平内螺纹管内高压汽水两相流的摩擦压降进行了实验研究。在相同的实验条件下，还测量了φ 31.8mm × 6.0mm绝热水平光管的两相摩擦压降，为比较提供了数据基础。此外，还得到了超临界压力下内螺纹管内的摩擦压降。根据实验数据计算了两相流摩擦系数，得到了摩擦系数随压力、质量流量和干度的变化规律。分析了超临界压力下摩擦压降随质量流量、体积焓和压力的变化规律。通过比较发现，在高干度区域，水平内螺纹管的两相摩擦系数有一个明显的峰值，其值远大于水平光管。与亚临界压力下的单相摩擦因数相比，超临界压力下的摩擦因数的特点是在拟临界温度点处出现突变，即出现峰值。
At low mass fluxes, experimental investigation on the frictional pressure drops of high pressure steam water two-phase flows in an adiabatic horizontal Siemens AG optimized internally-ribbed tube with a diameter of φ 31.8 mm × 6.0 mm was carried out. The two-phase frictional pressure drops of an adiabatic horizontal smooth tube with a diameter of φ 31.8 mm × 6.0 mm were also measured under the same experimental conditions to provide a data base for comparison. In addition, the frictional pressure drops at supercritical pressures in the internally-ribbed tube were obtained. According to experimental data, the two-phase flow friction multiplier was calculated and its variations with the pressure, the mass flux and the steam quality were obtained. At supercritical pressures, the variations of the frictional pressure drops with the mass flux, the bulk enthalpy and the pressure were also analyzed. By comparison, it is found that the two-phase friction multiplier of the horizontal internally-ribbed tube has an obvious peak value, which is much larger than that of the horizontal smooth tube, in the region with high steam qualities. Comparing to the single-phase frictional factor at subcritical pressures, the characteristic of frictional factor at supercritical pressures is that there is a sudden change at the point of the pseudo-critical temperature, that is to say, there is a peak value.