Radouane Elbahjaoui

Numerical Study of a Shell-and-Tube Latent Thermal Energy Storage Unit Heated by Laminar Pulsed Fluid Flow

ABSTRACT The present study aims to investigate the effect of the pulsed fluid flow on the thermal performance of a latent heat storage unit (LHSU). The storage unit consists of a shell-and-tube in which phase change material (PCM) occupied the shell space and the heat transfer fluid (HTF) flows in the inner tube. The present study is motivated by the need to intensify heat transfer and accelerate melting process in LHSU. A mathematical model based on the conservation equations of energy in both HTF and PCM has been developed. The finite volume approach was used for the discretization of equations. The developed model has been validated by comparing the obtained numerical results with experimental, analytical, and numerical data found in literature. The effects of the pulsation frequency and amplitude, the Reynolds and Stefan numbers on the thermal performance and behavior of the LHSU were investigated. The parametric study showed that the pulsating parameters (frequency and amplitude) affect the thermal performance of the LHSU. The results reveal reduction in the melting time for low pulsating frequency (less than 0.052) and high pulsating amplitude. For pulsating amplitude of 6 and pulsating frequency of 0.01, a reduction up to 13% (at Reynolds number of 500 and Stefan number of 0.16) was obtained. The results also showed that the Reynolds and Stefan numbers strongly affect the heat transfer rate, and the low melting time is obtained for high Reynolds and Stefan numbers.

Modeling and Numerical Investigation of Latent Heat Storage Unit Using Paraffin Wax P116

The present work concerns the modeling and numerical simulation of the melting of a phase change material (PCM) in a latent heat storage unit. A mathematical model based on the conservation equations of mass, momentum, and energy has been developed. These equations are then discretized using the finite volume approach and the pressure correction method for the treatment of velocity-pressure coupling. The energy conservation equation of PCM was formulated using the enthalpy method. A series of simulations were carried out on a type of phase change material (Paraffin Wax P116) to study the impact of the mass flow rate and heat transfer fluid (HTF) inlet temperature on the performance of the storage unit. The flow structure and the temperature field are also investigated.

Numerical study of solar latent heat storage unit using Paraffin Wax P116

The present work concerns the modeling and numerical simulation of the melting of a phase change material (PCM) in a storage unit of solar thermal energy. The studied storage unit consists of an enclosure filled with Paraffin wax which exchanges heat by forced convection with a heat transfer fluid (water) coming from a solar collector and circulating in a rectangular duct. All walls of the enclosure are assumed adiabatic except that in contact with the rectangular duct. A mathematical model based on the equations of conservation of mass, momentum and energy has been developed. These equations are discretized using the finite volume approach. The SIMPLE algorithm is adopted for the treatment of velocity-pressure coupling. The equation of energy conservation of PCM was solved using the enthalpy method. A series of simulations was performed for meteorological data for the town of Marrakech: incident solar power, ambient temperature and wind speed to find the optimum configuration. The optimization aims to determine the mass of the PCM, the number of rectangular channels, the aspect ratio and the mass flow rate through the solar collector that maximize the efficiency of heat storage.