Freezing of phase change materials is an important process in latent heat thermal energy storage systems.It is vital to predict the freezing rates accurately under different thermal boundary conditions for freezing in cylinders.

Three PCMs were considered.The PCMs n-octadecane,Lauric acid and paraffin waxes have a range of melting points and differ significantly in their thermophysical properties.A preliminary study indicates interface (solid/liquid)of n-octadecane during freezing in cylinders under conduction mode is irregular under different coolant conditions and the freezing rates are about 40% higher than theoretical values.Partial freezing data are being obtained with the three PCMs in vertical copper cylinders(

L/d:0.5 to 4)with holding capacity of 50cc to 1000cc.Comparisons would include transient temperature profiles in the PCMs during freezing under a range of temperature drops across the solid layer,partial and total freezing rates.