The Water-Monopropylene Glycol Mixtures Flow Rate Measurement

This paper presents measured errors of different measuring principles of flow meters, which are typically used in thermal energy measurement for cooling applications. The study involves single-jet, multi-jet, electromagnetic, and ultrasonic flow meters. Experimental measurements were performed at drinkable water and water-monopropylene glycol mixtures with varying concentrations, aiming to analyze the accuracy, repeatability, and reliability of the different flow meter types under variable fluid density and kinematic viscosity conditions. Reference measurements were performed by a mass flow meter, which allows precise determination of the mass flow rates. Based on the measured values and densities, the glycol mixtures and the volumetric flow rates were evaluated.The measured results reveal significant differences in the measurement errors of the various flow meter types, influenced by both the physical properties of the glycol mixture and the specifications of the measurement principle. The discussion focuses on recommendations of selecting an appropriate flow meter and the influence of parameterization of specific application and composition of the measured liquid. This study contributes to a deeper understanding of flow measurement challenges in cooling systems and highlights the importance of proper parameterization, setup, and calibration of the flow meter itself and of the entire cooling circuit