Melting and solidification of phase change materials in metal foam filled thermal energy storage tank: Evaluation on gradient in pore structure

Recent developments in nano-enhanced phase change materials for solar thermal storage

Melting behavior of the latent heat thermal energy storage unit with fins and graded metal foam

In order to improve the photothermal conversion efficiency of solar energy collectors, the laminar convection of nanofluids in five types of solar energy collectors was numerically studied with a two-phase lattice Boltzmann model. In the current simulation, Cu–water nanofluids (volume fraction φ = 0.3%) were chosen. The equilibrium distribution function with D2Q9 model and the boundary conditions of nonequilibrium extrapolation scheme were applied to establish the lattice Boltzmann model. The effects of different Rayleigh numbers (Ra = 104–106), structures (rectangle cavity, trapezoid cavity and parallelogram cavity) and aspect ratios (A = 2:1, 4:3 and 1:1) of solar energy collectors on the heat transfer were considered. The temperature distribution, streamline and entropy generation of nanofluids in the solar energy collectors were analyzed. Results demonstrated that the increase in Rayleigh number heightens the heat convection of nanofluids. The trapezoid cavity and parallelogram have a special structure, which will form a flow dead zone, weaken the heat transfer effect and determine the position of maximum entropy generation.

Natural convection of nanofluids in solar energy collectors based on a two-phase lattice Boltzmann model

Expedition of solidification with dispersing nanoparticles utilizing numerical method

Heat transfer enhancement in latent heat thermal energy storage using copper foams with varying porosity

Flow and heat transfer simulation in porous volumetric solar receivers by non-orthogonal multiple-relaxation time lattice Boltzmann method

Phase change material (PCM) is an essential component in latent heat thermal energy storage (LHTES). Using nanoparticles and metal foams could overcome the low thermal conductivity of PCM. In the present study, the effect of metal foams with varying porosity and nanoparticles on the solidification process of LHTES was numerically investigated. Parameters such as solidification time, temperature response rate, temperature distribution and exergy efficiency were analysed. As the volume fraction of nanoparticle was increased from 0 to 0.1, the solidification time was reduced by 30.15%, and the heat release exergy efficiency was increased from 55% to 60%. Compare with pure PCM, the solidification time of porous PCM with uniform porosity was reduced by 81.2%. Moreover, the heat release exergy efficiencies were 90.7% and 93.0% for the uniform porosity and the increasing porosity along x-direction, respectively.

Solidification enhancement of phase change materials using nanoparticles and metal foams with nonuniform porosity

Computational study on structures of vertical columns formed by successive droplets

A mesoscopic simulation based on random packing powder bed model was established to study the heat behavior of CP-Ti during selective laser melting. The characteristics of the molten pool under the interaction of laser and powder, and the influence of laser power on the thermal behavior, hydrodynamics and surface morphology evolution of the molten pool were studied. The results show that with the increase of laser power, the maximum temperature, temperature change rate, lifetime of molten pool and size are greatly improved. In addition, the characteristics and heat behavior of the molten pool under the double track are mainly studied in this study. It is found that the maximum temperature, lifetime, and the length and width of the molten pool of the second track are higher than those in the first, and with the increase of laser power, the length width ratio of the second track in molten pool becomes larger.

Jie Lei

Papers

Heat transfer enhancement in latent heat thermal energy storage using copper foams with varying porosity

Flow and heat transfer simulation in porous volumetric solar receivers by non-orthogonal multiple-relaxation time lattice Boltzmann method

Solidification enhancement of phase change materials using nanoparticles and metal foams with nonuniform porosity

Computational study on structures of vertical columns formed by successive droplets

Multiphysics Modeling of Thermal Behavior of Commercial Pure Titanium Powder During Selective Laser Melting