Experimental investigation on heat transfer and pressure drop of brazed plate heat exchanger using LiBr solution

Abstract

To improve the performance and miniaturization of the absorption system, it is required to use a plate heat exchanger as a solution heat exchanger and to predict its performance accurately. In this study, the thermal performance of solution heat exchangers was investigated under operating conditions of the solution heat exchanger in the double-effect absorption system and new correlations of Nu and Fanning friction factor were developed and compared. As a result, the hot-side Nu of the high-temperature solution heat exchanger was 6.3–23.1, which was higher than that of the low-temperature solution heat exchanger (4.8–20.1). The thermal properties of the LiBr solution depending on the temperature were significantly sensitive. The developed Nu correlation (Nu = 0.273Re0.693Pr1/3) had a high accuracy with experimental results. In addition, the Fanning friction factor correlation was proposed as f = 1.601/Re0.123. The developed Fanning friction factor was lower than in other literature because the Fanning friction factor was affected by geometry parameters (chevron angle, pitch, height, and size).