Underpressure of vaporization of refrigerant R-134a through a diabatic capillary tube

Experimental test results with R-134a have demonstrated the phenomenon of metastable flow through a diabatic capillary tube, and showed that the metastable flow of the refrigerant exists when the heat transfer is weak between the capillary tube and the suction line flows. Using homogeneous nucleation theory, a correlation predicting the underpressure of vaporization (a characteristic quantity for the metastable flow) for a diabatic capillary tube has been developed based on the experimental results.