Laurent Zalewski

Université d'Artois · Faculty of applicated sciences

Façades built with integrated passive solar systems hold great promise for improving the energy performance of buildings and achieving indoor comfort conditions. Among these techniques, solar air preheating systems with different configurations have proven their ability to reduce the energy consumption of buildings during the heating season. In thi...

This paper presents the work carried out as part of a study of a proactive interior coating based on both plaster and a phase change material (PCM), intended to improve the energy efficiency of buildings. This bio-based PCM is composed of a mixture of vegetable oils, methyl stearate, and methyl palmitate micro-encapsulated into polymer capsules. Th...

An in situ estimation of the thermal properties of bio-sourced building wall insulation components is of critical importance in improving both the energy efficiency of buildings and the development of construction materials with a smaller environmental footprint. Depending on weather conditions, passive methods are not always feasible; they require...

This study presents an experimental comparison of three characterization methods for phase change materials (PCM). Two methods were carried out with a calorimeter, the first with direct scanning (DSC) and the second with step scanning (STEP). The third method is a fluxmetric (FM) characterization performed using a fluxmeter bench. For the three met...

The use of biobased materials in building construction allows the reduction of fossil resource use and energy consumption. Among biobased materials, hemp lime concrete has been investigated in many studies highlighting its capacity to regulate interior relative humidity and its high insulation capacity. In order to design high-performance biobased...

Phase change material (PCM) experiencing supercooling and phase change hysteresis are widely reported in the literature. However, only few studies model analytically such PCM, and they mostly focus on either supercooling or phase change hysteresis, but rarely on both phenomena. Moreover, partial phase change cycles, with an incomplete melting or so...

To promote the development of thermal energy storage (TES), the sodium acetate trihydrate (SAT) presents interesting thermal properties. However, this material may suffer from aging throughout thermal cycles. Various solutions were explored in the literature to limit this aging, mainly based on the use of additives such as water. In this study, two...

Phase change materials, such as sodium acetate trihydrate, are efficient materials for Latent Heat Thermal Energy Storage (LHTES) according to their interesting thermal properties (high latent heat and specific heat). Their main drawback is a large degree of supercooling, up to 90 K for sodium acetate trihydrate, where the material may remain liqui...

Modelling of latent heat thermal storage systems is mainly achieved with an analytical formulation describing the thermodynamic state of the phase change material (PCM). In literature, different models exist to describe the evolution of the liquid fraction, the effective heat capacity and the enthalpy as a function of temperature. The main issue is...

An important prerequisite to select a reliable phase change material (PCM) for thermal energy storage applications is to test it under application conditions. In the case of solid-liquid PCM, a large amount of thermal energy can be stored and released in a small temperature range around the solid-liquid phase transition. Therefore, to test the long...

Thermal energy storage (TES), which features an innovative technology, can enhance energy efficiency in the building sector and reduce CO2 emissions. Due to their high heat storage capacity, phase change materials (PCMs) have impressed many researchers. This paper investigates the energy performance of an individual house integrating a solar Trombe...

As the heating demands of buildings drop considerably, the use of solar walls makes increasing sense. One of the obstacles to the development of such walls is their need for on-site implementation by specialized companies. On the other hand, a storage wall is generally composed of heavy materials with high inertia, which prevents prefabrication of...

The present work addresses the numerical and experimental study of natural convection inside an asymmetrically heated open double vertical facade. Two heating cases were considered independently, the constant heat flux (Neumann condition) and the constant temperature (Dirichlet condition). The double facade has been modeled using a vertical two-dim...

This article studies a composite solar wall with latent storage (TES) designed to heat rooms inside buildings during the cold season. No numerical model of the composite solar wall is currently available in the Dymola/Modelica software library. The first objective of this work is to develop one such model. The article describes the elementary compo...

Cet article présente les travaux menés dans le cadre d'un projet collaboratif entre le laboratoire LGCgE de l'université d'Artois et le laboratoire LTI de l'université de Picardie Jules Verne. Ce projet avait pour objectif de concevoir un béton de chanvre intégrant un matériau à changement de phase (MCP), ayant à la fois des propriétés de régulateu...

Les matériaux à changement de phase (MCP) sont de bons candidats pour le stockage de l'énergie thermique, grâce à leur chaleur latente importante. Cependant, certains présentent une large surfusion, limitant l'utilisation dans les applications actuelles. Cet inconvénient pourrait devenir un avantage si une technique reproductible, telle que l'utili...

An experimental device was designed to perform the thermal and dynamic study of natural convection airflow in an open vertical channel. The two side walls of the vertical channel are made of Plexiglas allowing the visualization of the flow via the particle image velocimetry (PIV) method. For the two other vertical walls, one is heated at a constant...

The determination of both the thermal and thermodynamical properties of a composite material containing phase change material is done thanks to an inverse method, which combines experimental measurements and numerical computations. Given first an in-house experiment, which allows us to test samples at a macroscopic scale (i.e., close to the real co...

Supercooling is an undesired property of phase change materials due to the poorly predictable occurrence of crystallization during cooling. For such situations, the stored latent heat cannot be recovered which can be an issue for temperature-controlled applications. This review illustrates the techniques used for triggering crystallization in phase...

Salt hydrates are often used as heat storage materials according to their interesting thermal properties (high latent and specific heat). Their main drawback is their large supercooling, where the material may remain liquid below its melting point. However, this property should be turned into a benefit if a reliable way of triggering crystallizatio...

In this article, we study the influence of the insertion of a phase change materials (PCMs) in the ceiling of a community hall on its comfort during the summer period. This study was realized using a dynamic thermal simulation of the building using a modelica library (BuildSysPro). Initially, we have defined materials used for the building includin...

Solar thermal energy storage is used in many applications, from building to concentrating solar power plants and industry. The temperature levels encountered range from ambient temperature to more than 1000 °C, and operating times range from a few hours to several months. This paper reviews different types of solar thermal energy storage (sensible...

First, this article introduces a comparison between experimental results and the results issued from a numerical model of a composite Trombe solar wall incorporating a concrete storage wall with the help of the Dymola/Modelica software. The validation of the model is realized from the comparison between simulated and measured heat flux, external an...

Cette étude porte sur l'étude numérique de la convection avec surfusion dans un matériau à changement de phase (MCP) via la méthode de Boltzmann sur réseaux (LBM) à un seul temps de relaxation (SRT). Le traitement de ces phénomènes physiques a été réalisé avec des fonctions de distribution doubles (FDD-LBM) couplée à une formulation enthalpique en...

An overview on the recent results on the engineering and characterization of sorption materials, PCMs and TCMs investigated in the working group WG A1 “Engineering and processing of TES materials” of IEA SHC Task 42 / ECES Annex 29 (Task 4229) entitled “Compact Thermal Energy Storage” is presented.

Recent studies concerning phase change material (PCM) characterization show that important errors occur if differential scanning calorimetry (DSC) experiments are misinterpreted. Therefore, it is important to know the influence of such misinterpretation on system modeling. The present work deals with phase change materials integrated in building st...

A numerical method is proposed to calculate earth-energy of earth-air-pipe heat exchanger during winter heating. The proposed method is based on using numerical computation developed on Scilab a free open source software. Authors showed the comparison between their simple numerical model called Heatground with the well-known Amitrano results. The c...

Solar walls constitute an important green architectural feature that positively contributes to energy saving in buildings. Different configurations may be proposed, such as, solar wall with Phase Change Material (PCM), composite solar wall, photovoltaic solar wall, zigzag solar wall, and solar hybrid wall. Being environmentally friendly, these pass...

The support of this study is a cement mortar containing a micro-encapsulated phase change material (PCM). The aim of this article is to identify by an inverse method the thermophysical properties of this composite material and all the parameters that are needed to build a physical model able to simulate the thermal behavior of a material containing...

Lately, the lattice Boltzmann method (LBM) has proven to be a promising approach to solve complex fluid flows and transport phenomena. In the present contribution, the LB-BGK model, also called single relaxation time (SRT), is used to handle fluid flows in complex geometries. The model is first benchmarked via the 2D Poiseuille flow problem to cond...

The objective of this study is to evaluate three different phase change models used to predict the energy behaviour of a PCM cement mortar sample. Reference data are measured on large samples of composite material using a special experimental set-up. The phase change models tested are: the apparent specific capacity method, the enthalpy method assu...

Current environmental concerns have promoted efforts to reduce the consumption of energy. In moving towards improving existing buildings, the study of the thermal behaviour of a wall is not easy because its actual thermophysical properties are not well-known. These parameters are nevertheless fundamental for the economic optimisation of building re...

Energy and Buildings j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / e n b u i l d: Gypsum tile Inverse method In situ wall thermal properties Infrared thermography Thermophysical properties Building energy saving Experimental methodology a b s t r a c t Current environmental concerns have promoted efforts to reduce...

In a recent meeting of IEA's Annex 23, several members presented their conclusions on the modeling of phase change materials behavior in the context of building applications. These conclusions were in agreement with those of a vast review, involving the survey of more than 250 journal papers, undertaken earlier by the group of École de technologie...

Solar energy, along with the other energy resources such as wind, tidal waves, hydroelectricity, and biomass, accounts for most of the available renewable energy on earth. Due to the growing use of solar and the other renewable energy technologies, many educational institutions are developing undergraduate and graduate courses and programs in renew...

The storage of thermal energy as latent heat of fusion presents advantages over sensible heat due to its high storage density and to the isothermal nature of the storage process at melting temperature. Latent heat thermal energy storage systems find application in space craft, solar energy system, greenhouses, heating and cooling of buildings and s...

Solar walls have been studied for decades as a way of heating building from a renewable energy source. A key ingredient of these wall is their storage capacity. However, this increases their weight and volume, which limits theirs integration into existing building. To aleviate this problem, storage mass is replaced by a phase change materials. Thes...

In a recent meeting of IEA’s Annex 23, several members presented their conclusions on the modeling of phase change materials behavior in the context of building applications. These conclusions were in agreement with those of a vast review, involving the survey of more than 250 journal papers, undertaken earlier by the group of École de technologie...

The application of phase change materials (PCMs) for solar thermal-energy storage capacities has received considerable attention in recent years due to their large storage capacity and isothermal nature of the storage process. This study deals with the comparison of numerical and experimental results for a PCM conditioned in a parallelepipedic poly...

The major objective of this project is to use phase-change materials (PCMs) as integrated components in passive solar heat recovery systems. The suggested approach involves experimental investigations and characterization of the global behavior of a parallelepiped “material wrap” filled with the PCM. The experimental apparatus permits simultaneous...

Energy storage components improve the energy efficiency of systems by reducing the mismatch between supply and demand. For this purpose, phase-change materials are particularly attractive since they provide a high-energy storage density at a constant temperature which corresponds to the phase transition temperature of the material. Nevertheless, th...

This work is a contribution to the characterization of the thermal efficiency of complex walls of buildings with respect to the ever increasing requirements in thermal insulation. The work specifically concerns the quantitative evaluation of heat losses by thermal bridges. The support of the study is the envelope of industrial light construction wa...

This paper presents a numerical investigation of turbulent forced convective flow in a horizontal channel. An exchanger isothermal test plate is embedded in the lower wall, in the fully developed region of the flow close to the exit of the channel. Above this isothermal plate, on the upper surface, a black coated isothermally heating resistance fac...

This article presents the first research effort of our group to formulate, implement and validate a numerical method in order to optimise the design of solar passive walls involving phase change materials (PCMs). The fusion of ice, gallium and the commercially available PCM 27 (hydrated salt), engineered by Cristopia and later embedded within an ex...

The recourse to the passive wall systems in building envelopes can significantly decrease the energy consumption in the building. This paper presents a novel concept of Trombe Walls in building envelopes for optimizing energy efficiency while improving the building environmental impacts.

Les technologies permettant une meilleure maîtrise de l’énergie dans l’habitat sont diverses. L’un des moyens les plus importants est d’intervenir au niveau de l’enveloppe du bâtiment. Parmi ces solutions, les systèmes passifs sont particulièrement intéressants et sont par principe conçus pour avoir un fonctionnement optimisé en fonction des sollic...

Nous avons entrepris de réfléchir aux possibilités d'intégrer des matériaux à changement de phase (MCP) dans les composants solaires passifs intégrables dans les parois de l'enveloppe des bâtiments. Le stockage par chaleur latente apparaît en effet très intéressant en comparaison avec un stockage par chaleur sensible. Les principaux avantages étant...

Les technologies permettant une meilleure maîtrise de l'énergie dans l'habitat sont diverses. L'un des moyens les plus importants est d'intervenir au niveau de l'enveloppe du bâtiment. Parmi ces solutions, les systèmes passifs sont particulièrement intéressants et sont par principe conçus pour avoir un fonctionnement optimisé en fonction des sollic...

The final objective of the research presented here is to use PCM (hydrated salts or others) as integrated components in a dynamic or active solar wall. The suggested approach involves experimental investigations of the global behavior of a particular polyolefin container filled with phase change material (PCM) starting with simultaneous measurement...

The storage of thermal energy as latent heat of fusion has attractive features over sensible heat due to its high storage density and isothermal nature of the storage process at melting temperature. Latent heat thermal energy storage systems find application in space craft, refrigerated cargo transport, solar energy system, greenhouses, heating and...

The final objective of the research presented here is to use PCM (hydrated salts or others) as integrated components in a dynamic or active solar wall. The suggested approach involves experimental investigations of the global behavior of a particular polyolefin container filled with phase change material (PCM) starting with simultaneous measurement...

The storage of thermal energy as latent heat of fusion has attractive features over sensible heat due to its high storage density and isothermal nature of the storage process at melting temperature. Latent heat thermal energy storage systems find application in space craft, refrigerated cargo transport, solar energy system, greenhouses, heating and...

The objective of this research is to use PCM (hydrated salts or others) as integrated components in a passive solar wall. The proposed Composite TROMBE Wall allows daily storage of the solar energy in a building envelope and restitution in the evening, with a possible control of the air flux in a ventilated air layer. In this particular application...

This paper presents a numerical investigation of turbulent forced convective flow in a horizontal channel filled with rectangular obstacles located on the lower surface. An exchanger isothermal test plate is embedded in the lower wall, in the fully developed region of the flow. Immediately above this plate, on the upper surface, a black coated isot...

It is very difficult to calculate and analyze with precision the thermal behavior of the walls of building envelope when coexist various modes of thermal transfer and because of the particularly random climatic phenomena. These problems are very complex in the case of special components such as passive solar wall used in “bio-climatic” architecture...

The laboratory LAMTI has worked for several years on the study and the optimization of the thermal performances of passive solar walls like solar Trombe wall. These components of the buildings envelope have very complex behaviour because they are the seat of various coupled heat transfers modes and are subjected to the random variations of the mete...

The passive solar walls use the solar energy to heat the buildings. The composite wall solar collector system consists of a glazing, a massive wall and an insulating wall. Thanks to the big thermal resistance of the insulating wall, there is little inverse thermal flux that crosses from the interior to the exterior. In this paper, the thermal perfo...

The aim of this article is to present the results of a comparative study of four different types of solar wall. These results have been obtained using a numerical simulation model. In order to validate the model, an extensive experimental study has been conducted on a composite solar wall. The first part of the article is devoted to the particular...

In this article we present solution for experimental studies in natural convection heat transfer. This work is based on the use of thermoelectric sensors conceived in our laboratory and which allowed us to measure heatflux and then convective exchange coefficient. First, we present the sensor and the calibration methods, then for experimental valid...