Numerical and experimental study on the solidification of PCM around a vertical axially finned isothermal cylinder

Thermal performance of a pcm storage unit

Outward phase change in a cylindrical annulus with axial fins on the inner tube

Experimentally validated two dimensional numerical model for the solidification of PCM along a horizontal long tube

The results of an experimental study are presented where the growth rate of ice on the outside of cooled copper tubes was studied. The tubes, which were immersed in water in an insulated vessel, were internally cooled by circulating glycol through them.

It was found that axial growth rate of ice is distinct at low values of the coolant Reynolds number and short freezing times. The slope of the ice thickness with axial distance showed moderate dependency on time but varied with coolant flow rate, and with Stanton and Biot numbers.

A key result from the experiments is the abrupt ice thickness enlargements on the surface of tube bends. This anomaly may be attributed to internal flow disturbances of the coolant, and creation of local eddies inside the bends that enhance growth of ice. The effect was evident for a low Reynolds number (Re = 251.9 and Bi < 1), and fades out for large Reynolds number flows.

T.K. Sinha

Papers

Solidification in an annulus