Measurement testing of heat transfer coefficients in the evaporator and condenser of heat pumps

Abstract

In our earlier studies, it has been stated that the validity and limits of correlations developed for the calculation of heat transfer processes in the evaporator and condenser of heat pumps are not published in general. The values yielded for model structures and process characteristics indicate extreme ranges of standard deviation. While the description and physical and mathematical modeling of phenomena occurring in heat pump components have developed really much and the mathematical accuracy of solutions can be increased at one’s own discretion, descriptions of changes in heat transfer and heat transfer coefficients in the course of refrigerant flow are quite uncertain. At the same time, these factors highly influence the accuracy of the solution. Our study presents the measurements and the new proposed heat transfer correlations, developed on the basis of such measurements, which can be used for calculating heat transfer in heat pump evaporators and condensers with higher accuracy than existing correlations in the literature.