The metastable flow through adiabatic and diabatic coiled capillary tubes

Abstract

This paper presents experimental investigation of the two-phase refrigerant flow through helical adiabatic capillary tube and non-adiabatic (diabatic) capillary tubes-suction tube heat exchanger. The experimental results indicate that mass flux ratio is main parameter that affects metastable flow through both type of adiabatic and non-adiabatic capillary tubes. Therefore, an increase of the mass flux ratio represents a decrease of the heat transfer rate between the capillary tube and suction line. The measured and saturated pressure distribution also proof that metastable flow in the non-adiabatic coiled capillary tube with 1.397 mm inner diameter, 30 mm coil diameter, 4360 mm length, exists when the rate of heat transfer between the coiled capillary tube and the suction line is weak with mass flux ratio Gc/Gs> 343.