R32 and R410A condensation heat transfer coefficient and pressure drop within minichannel multiport tube. Experimental technique and measurements

The present paper reports the construction of an experimental installation to measure local condensing two-phase flow heat transfer coefficient and frictional pressure drop within mini-channel tubes, the validation measurements developed with R134a and the experimental measurements of heat transfer coefficient and frictional pressure drop made with R32 and R410A. This experimental work is carried out in a test apparatus which allows determining the local heat flux extracted from the condensing fluid. For this purpose, the wall temperature is measured along the test section in several points. The saturation temperature is determined from the saturation pressure, which is measured at the inlet and the outlet of the test channel. Experimental data of R32 and R410A are also compared with some predicting models widely accepted in the literature. (C) 2016 Elsevier Ltd. All rights reserved.