Even though many researchers have dealt with numerical analysis
to solve PCM systems, it involves high time consuming. Therefore,
Tay et al. [73] and Amin et al. [74] studied the applicability of
the effectiveness-NTU method for characterizing a cylindrical and
spherical PCM encapsulation TES system, respectively. Here the
average heat exchange effectiveness of the storage tank was determined
and a characteristic design curve was developed as a function
of the measured average NTU.
On the other hand, Chen et al. [75] analyzed the thermal response
of a thermal storage tank during the charging process containing
cylindrical capsules. The main conclusions from the work
was that cold energy can be fully stored in the form of latent heat,
and that the heat transfer coefficient increases as the coolant flow
rate increases.