Paper Title
Geometric Optimization Of High Temperature Shell And Tube Latent Heat Thermal Energy Storage

Abstract
A simple geometry shell and tube heat exchanger provides a straightforward design for near-term integration of latent heat thermal energy storage systems in concentrated solar thermal plants, but currently there is no literature available for this configuration in the 286-565 ˚C temperature range. Therefore, the objective of this work is to evaluate the potential of this configuration for CST-tower plants by proposing a proper design method. The work has been done by optimizing the main geometric parameters involved along with considering a market ready phase change material (H500 salt). The optimization consisted of fixing the PCM volume while varying the other geometric parameters simultaneously over a wide range. The goal was to achieve the highest amount of total stored/delivered energy in a certain amount of time with a minimum heat transfer surface area. For the selected PCM, the optimum area was found 36-63 m2.GJ-1 (0.12-0.22 m2.kWhth-1). The storage charging and discharging efficiency for the selected PCM over a cycle of continuous charging and discharging were found ~99% and 85%, respectively. The results also imply that the shell and tube LHTES system is technically competitive with the conventional two-tank molten salts because of its high efficiency. Keywordsó High temperature, Phase change material, Optimization, Shell and tube tank