A Theoretical Approach to Two-Phase Critical Flow : (4th Report, Experiments on Saturated Water Discharging through Long Tubes)

抄録

Flow rate, distributions of temperature and pressure and exit steam void fraction in long channel are measured for steam water two-phase mixtures under higher reservoir pressure conditions, resulting the following parameters. critical pressure 4∼48 ata reservoir pressure 9∼70 ata exit steam quality 2∼14% critical flow rate 0.5×10⁴∼3×10⁴kg/m²sec channel diameter 10mm∼50mm channel length 100mm∼2200mm The conclusions are as follows. (1) Saturated condition is satisfied even at the exit of shorter channel (L/D∼3) when steam bubbles are absorbed into channel inlet. (2) Critical conditions among critical pressure, quality and flow rate coincide well with theoretical solutions reported in the previous paper. (3) Measured critical slip ratio may be almost explained by theoretical predictions. (4) Critical pressure ratio gradually decreases with increasing channel length in such a way that has been theoretically predicted. (5) The channel whose diameter is up to 50 mm can be treated as axial saturated flow.