ASHRAE - American Society of Heating@ Refrigerating and Air-Conditioning Engineers@ Inc.
Scope
ABSTRACT Experimental study of condensation of carbon dioxide in brazed plate heat exchangers is the main objective of this research project. However@ it is essential to characterize the single-phase flow through these minichannel heat exchangers in order to analyze and formulate the two-phase flow. In this manuscript@ the open literature on the subject is reviewed first@ the facility for testing the entire system is then described@ and the initial results on the single-phase flow are presented at the end. Three brazed plate heat exchangers with different interior configurations@ each consisting of three channels@ are considered and tested in this study. For the two-phase analysis@ carbon dioxide is the working fluid@ flowing through the middle channel@ while dynalene is the cooling fluid@ flowing through the side channels. For the single-phase analysis@ data was taken using hot and cold water flow through the middle and side channels@ respectively. Data was also taken using hot water in the middle and chilled dynalene in the surrounding channels. The modified Wilson plot technique was applied to obtain single-phase heat transfer coefficients@ and Fanning friction factor was estimated for the pressure drop. The resulted correlations were within reasonable range of standard deviation and uncertainty@ and compared well with other relevant studies.