R1233zd(E) and R1234ze(Z) condensation inside a 4 mm horizontal smooth tube.

Abstract

R1233zd(E) and R1234ze(Z) have been proposed as low Global Warming Potential (GWP) refrigerants for high temperature heat pumps. But their application is still not widespread and their heat transfer performance are still poorly investigated. This paper investigates the effects of refrigerant mass flux and mean vapor quality on experimental heat transfer coefficients and frictional pressure drops measured during R1233zd(E) saturated vapor condensation inside a 4 mm ID horizontal smooth copper tube. New experimental tests were carried out at 40 °C of saturation temperature, with refrigerant mass flux in the range 75–200 kg m -2 s -1 at decreasing vapor quality. The data are compared against some well-known literature correlations and against other experimental data collected by using R1234ze(Z) as two-phase fluid under the same testing conditions.