| An experimental study was conducted to measure the heat transfer characteristics and pressure drop of supercritical carbon dioxide (CO2) in gas cooling conditions while flowing through a horizontal micro channel tube. Five experiments were conducted at operating conditions that included an inlet temperature of 70°, inlet pressures of 8 to 10 MPa, a mass flux of 400 kg/m2s, heat fluxes of 10 and 15 kW/m2, and oil concentration ratios of 6.58 to 10.72 wt.% with ND-8, polyalkylene glycol (PAG) oil. The main objective of the study was to determine how the oil concentration ratio (OCR) of this miscible oil affected the heat transfer coefficient of CO2 and determine if there is a region of test conditions to target or avoid. The secondary goal of the study was to determine if the varying OCR amount also affected the pressure drop seen over the micro channel. Tests were performed using a micro channel that is 600 mm long and is made up of ten parallel circular ports that are 1 mm in diameter. (Abstract shortened by UMI.)... |
