Heat transfer and pressure drop during condensation of low-GWP refrigerants inside bar-and-plate heat exchangers

The measured heat transfer coefficients suggest that the condensation process is strongly affected by the surface tension effects in the whole range of operating conditions, while the effect of mass flux is very limited. This is related to the non-circular shape of the parallel minichannels. Condensation heat transfer has also been studied during flow of superheated vapor. The experimental data have been compared against prediction methods available in the literature. Fourteen models have been applied for the heat transfer coefficient, ten models have been applied for the pressure drop. Relevant suggestions are given for the design of condensers using such a technology.