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With the increasing global interest in energy savings, latent heat thermal energy storage (LTES) systems are used for energy harvesting and preservation, thus reducing the demand for traditional energy sources. The main concept of solid–liquid LTES systems is to absorb and release the latent heat of a material through consecutive melting/solidification cycles. Supercooling is a phenomenon that prevents the solidification of a liquid having a temperature lower than its melting temperature. Considering this phenomenon in designing the numerical models gives a better prediction of the system’s energy performance. This work is the first attempt to include supercooling in a two-dimensional COMSOL model. The model accommodates natural convection during the melting process and supercooling during the cooling process of the phase change material (PCM). A set of experiments using octadecane PCM are performed. The effect of supercooling and natural convection on the temperature curve and the energy behavior of the PCM are shown. The effect of cooling rate, volume of PCM and container structure on the degree of supercooling are also discussed. A small degree of supercooling in octadecane is recorded when having small volume, low cooling rate and a smooth surface. The obtained experimental results validate the proposed numerical model.

•The conductive and convective mode of heat transfer is considered during melting and solidification.•The effect of variable heating and cooling were computationally investigated.•The energy storage capacity is also calculated with time.

Detecting particles in the air and observing the movement of airflow through 3D particle tracking technology can be widely used in smart homes, environments, energy, and other fields. In this research, we develop a rapid prototyping of the three-dimensional particle tracking velocimetry (3D PTV) system on LabVIEW. This paper presents the design of an embedded PTV system following these aspects: a formal model of intelligent instrument, behavioral specification, design and implementation. The PTV data processing has two parts of work. The image processing is performed on the customized processor Field Programmable Gate Array (FPGA), while the remaining procedures are executed on PC Windows. The bus PCI express connects these two parts and transfers the data by FIFO (First In First Out). This study also proposes and verifies performance optimization methods such as parallelism and pipelining.

In France, and in Europe in general, the building sector is the largest consumer of energy, and accounts for about 43% of the total energy consumption and around 25% of CO2emissions. The building sector offers significant potential for improved energy efficiency through the use of high-performance insulation and energy-efficient systems. In this study, the thermal behaviour of buildings with an advanced thermal insulation system, particularly, with an aerogel-based rendering/mortar exterior insulation system is examined. In addition to new buildings, the rendering is very suitable for application to retrofit existing ones since it offers high insulation performance and its application is easy, compatible with traditional masonry facades, and using common well-known techniques. Numerical modelling simulations are carried out on three different scales: (a) 1D envelope scale to examine the aerogel rendering’s impact on the thermal and moisture transfer of exterior walls, (b) 2D envelope scale to examine its impact on limiting the heat losses through some types of thermal bridges, and (c) full-scale house to examine its impact on reducing the heating demand. Results show that adding an aerogel-based rendering on the exterior surface of un-insulated or already internally insulated walls reduces significantly or removes entirely the risk of moisture. It also reduces wall heat losses significantly, especially for old un-insulated buildings, and consequently the building’s energy consumption. In addition, this insulating rendering can act as a very suitable solution for some thermal bridges such as the window reveals. Due to its application technique and its high insulating performance, a small thickness can have great impact on reducing such heat losses. So, this type of insulating renderings/plasters can serve as a good solution for places where traditional insulation is difficult to apply or where small insulation thicknesses are needed due to space or construction constraints.

Considering the increasing gap between energy demand and clean energy supply availability, there is a strong need to impart novel design structures to effectively utilize the available resources and energy storage systems. Nature-inspired fin structures embedded with well-chosen phase change materials (PCM) can play an essential role in improving the heat transfer in thermal energy storage devices. The present work investigates the melting and solidification processes in a metallic heat exchanger filled with n-octadecane as working PCM, with tree-shaped fins. The study is conducted for various fin generation numbers, volume fractions, length ratios, and angles between the Y-shaped tree fin branches. The results are discussed in the form of melt fraction of PCM, heated surface average temperature variation, and thermal energy stored. The results clearly indicate that the heat transfer is significantly improved with increasing branches of the tree-structured fins because of an increased area available for heat transfer. This study can be utilized to enhance the performance of PCM embedded thermal energy storage devices.

•One-dimensional mathematical model is developed and experimentally validated.•Comprehensive analysis of encapsulated PCM based thermal energy storage is performed under varying flow and geometric parameters.•The great convenience in adopting lumped system model is achieved with an absolute accuracy loss of only 2%.