INLET STEAM QUALITY OF A TOP BREAK HOLE ON HORIZONTAL PIPE

The inlet steam quality of the top break on horizontal pipe was invest igated on the high pressure steam-water two-phase loop of Xi' an Jiaot ong University using the gamma-ray attenuation technique. The mass att enuation coefficient of the gamma-ray penetrating high pressure satura ted water was measured, and it is shown that such a coefficient nearly keeps constant. The correlation of the inlet steam quality to the dim ensionless number h/h(b) was obtained. The Experimental results also i ndicate that the break inlet pressure was reduced due to the Bernoulli effect induced by the two-phase mixture advancing into the break. Suc h a pressure loss was verified to be an important and sensitive parame ter to determine the critical discharge mass flow rate.