This paper is based on findings resulting from ASHRAE Research Project RP-1394.

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.

Units: Dual