基于喷嘴临界流实验对现有物理模型的评价

Evaluation of existing physical models on critical flow based on experiment with a nozzle

  • 摘要: 以水为工质、直径1.41 mm的喷嘴为实验段,在稳态条件下进行临界流实验,覆盖的参数范围为:进口压力,0.4~22 MPa;进口温度,40~371 ℃;进口含汽率,-3.5~0.98。结果分析表明:在欠热度高于一定值下流动未达到临界条件;在低欠热度和低含汽率区域两相间存在热力不平衡性,在较低压力下,它对临界流率的影响十分显著。将实验数据与均匀平衡模型、Moody模型、Henry-Fauske模型、Burnell模型以及Bernoulli公式的计算结果进行比较,显示了各模型在不同条件下的适应性。

     

    Abstract: A critical flow experiment of water was carried out at steadystate in a nozzle with diameter of 1.41 mm, covering the ranges of inlet pressure of 0.4-22 MPa, inlet temperature of 40-371 ℃ and inlet quality of -3.5-0.98. The flow doesn’t exhibit choking behavior at the inlet subcooling larger than a certain value. In low subcooling and low quality region thermal non-equilibrium between two phases has appreciable effect on the critical flow rate, especially at lower pressure. The experimental data were compared with the predictions of several models, including the Homogeneous equilibrium model, the Moody model, the Henry-Fauske model, the Burnell model and the Bernoulli correlation, showing their applicability for different conditions.

     

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