MELTING CHARACTERISTICS OF CAPSULATED PHASE CHANGE MATERIALS

Document Type : Original Article

Authors

1 Mansoura University, Faculty of Engineering, Mechanical Power Department, Egypt

2 Al-Diwaniyah Governorate, Al- Diwaniyah Water Directorate, Iraq

Abstract

An experimental and computational investigation studied phase change material melting in a cylindrical capsule with
PCM. The capsule is placed horizontally in a rectangular test section, where it is insulated from all sides’ wall except
the front one. The PCM capsule is heated by passing hot water from downward to upward with different inlet mean
water temperatures (327.9, 333.7, 338 and 343) K, different velocities, varied thermal conductivities of capsule
material wall (copper, iron, pyrex-glass, and polyethylene), and PCM. Experiment during melting inside a pyrex-glass
capsule was performed and compared with prediction analysis by using CFD ANSYS 2019 R2. Image processing of
melting photographs along with melted time were used in comparison. The comparison between the liquid fraction
and energy stored with time for lauric acid and paraffin wax was analyzed. PCM liquid fraction, temperature and
energy stored measurements for lauric acid were assessed numerically. The results reveal for lauric acid that the total
melting time was enhanced 43% for 4.6% increase in water mean inlet temperature, 18% for 500% increase in inlet
water mean velocity, and 7% when used copper capsule wall. The results proved that the lauric acid charged with
energy stored were 47% more than paraffin wax during the total melting time of it, and the effect of different water
mean inlet temperatures was the main factor for the charging process to improve the PCM melting time.

Keywords