EXPERIMENTAL AND THEORETICAL-ANALYSIS OF FLASHING WATER-FLOW THROUGH A SAFETY VALVE

A set of experiments has been carried out on the model of the CROSBY s afety valve for flashing and nonflashing water flow. The pressure dist ribution inside the valve, the inlet and outlet temperatures and the m ass-flow rate have been measured. The characteristics of the valve giv ing the mass-flow rate as a function of the square root of the pressur e drop are given. The experimental results were compared with equilibr ium and relaxation two-phase flow models. The nonequilibrium character of fast evaporation and its substantial influence on the two-phase fl ow behaviour has been emphasized. This could constitute a comprehensiv e base for a better understanding of two-phase flow through safety val ves.