Abstract
An experimental study of flow boiling heat transfer and pressure drop was conducted using R245fa in stainless steel, brass and copper tubes of 1.1mm internal diameter. Experimental conditions include: mass flux range 100–400kg/m2s, heat flux range 10–60kW/m2, pressure of 1.8bar and exit vapour quality range 0–0.95. The tube surfaces were compared using scanning electron microscopy (SEM) and surface data acquired from confocal laser microscopy (CFLM), both showing differences between the surfaces. The heat transfer coefficient is similar in magnitude for all three materials but with a slight variation in trend. The heat transfer coefficient is seen to peak at high vapour qualities for stainless steel and brass, which is less evident with copper. The results were compared with past heat transfer correlations. These results showed better agreement with stainless steel compared to copper and brass. The pressure drop was shown to differ with surface characteristics, with the pressure drop for brass having a much steeper increase with heat flux. The pressure drop correlations tested did not show good agreement with the experimental results.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
