Experimental evaluation of single- and two-phase pressure drops through inlet and outlet ports in a plate heat exchanger

초록

In this study, the port (inlet and outlet) and frictional pressure drops of a single-phase flow using liquid water and a two-phase flow using R1234ze(E) in a plate heat exchanger (PHE) are measured and analyzed by varying the flow direction, number of channels, temperature, mass flux, and vapor quality. The port-pressure drops are significantly dependent on the resistance of the flow through the channel guide in the PHE. In single-phase flow of liquid water, the port-pressure drop is proportional to the number of channels and the Reynolds number, while the frictional pressure drop exhibits little dependence on the number of channels. Additionally, the port-pressure drop is affected by the flow direction owing to gravity. In two-phase flow of R1234ze(E), the port-pressure drops are significantly dependent on the flow direction owing to the distinctive non-uniformity of the two-phase flow distribution over the channels. The existing correlation substantially underpredicts the measured port-pressure drops. Accordingly, new empirical correlations for the port-pressure drops are developed with high precision, in terms of the kinetic energy of the fluid, the Reynolds number, the normalized density ratio, and the number of channels. (C) 2020 Elsevier Ltd. All rights reserved.

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