ISSN Online: 2377-424X
ISBN Print: 978-1-56700-474-8
ISBN Online: 978-1-56700-473-1
International Heat Transfer Conference 16
HEAT TRANSFER ENHANCEMENT OF THE EUTECTIC SALT PCM IN A SHELL-AND-TUBE LATENT HEAT STORAGE
Abstract
Latent Heat Storage (LHS) unit is an essential component for commercial direct steam generation (DSG) power plants, which can significantly increase the hours of electricity generation and lower the cost of solar generated electricity. Considering the working temperatures and costs, the most suitable Phase change material (PCM) adopted in LHS unit for DSG power plants is eutectic salt KNO3-NaNO3. However, its low thermal conductivity (~0.5 W/m K) significantly affects the performance of the storage unit. In the present work the model of solidification of PCM (KNO3-NaNO3) is explored in a shell-and-tube LHS unit with circumferential graphite finned tubes to which a constant heat flux is applied, then unsteady two dimensional simulations are
performed using the CFD software. A detailed parametric investigation, such as fin pitch and thickness, tube radius, tube pitch and applied heat flux, are carried out to account for the solidification performance of the storage unit. The computation results show that the enhancement effect on the heat transfer process is obvious by reducing fin and tube pitch or by increasing fin thickness, tube radius and heat flux.