Joseph Virgone

• Professor
• Professor (Full) at Claude Bernard University Lyon 1

in this study, we propose the use of phase change materials (PCMs) as thermal insulation in building walls to ameliorate the comfort in the interior of the building; we studied the position of this insulation on the side of the wall, along with a comparison with other types of conventional insulation materials such as plaster and BA13. The inertia...

Cet article présente l'étude numérique de l'utilisation des nanoparticules intégrées dans les matériaux à changement de phase pour stocker l'énergie thermique solaire. Les nanoparticules sont intégrées à une cire de paraffine pour augmenter les performances thermiques de stockage du MCP. Le code ANSYS FLUENT 15 est utilisé pour la simulation numéri...

Le but du modèle : est de déterminer l’évolution de la teneur en eau du produit à sécher, en fonction du temps, et tenant compte des principaux paramètres aérothermiques (température, hygrométrie et débit massique de l’air asséchant). Le modèle est basé sur les bilans d’énergie dans l’air asséchant, et dans les feuilles de menthe verte (Mentha viri...

Notre travail a consisté a l’étude théorique et expérimentale d’un capteur solaire à air à simple circulation en convection forcée destiné pour le chauffage doméstique. La modélisation est basée sur la résolution des équations de transfert entre les éléments du capteur tels que la plaque absorbante, la couverture transparente et le fluide caloporte...

Cet article présente l’étude numérique de l’utilisation des nanoparticules intégrées dans les matériaux à changement de phase pour stocker l'énergie thermique solaire. Les nanoparticules sont intégrées à une cire de paraffine pour augmenter les performances thermiques de stockage du MCP. Le code ANSYS FLUENT 15 est utilisé pour la simulation numéri...

Building envelopes are constantly subjected to temperature and moisture gradients. This loading induces a complex response, particularly for highly hygroscopic insulating materials. Latent effects can no longer be neglected for these materials in which heat and moisture transfers are strongly coupled. The purpose of this article is to analyze the b...

Pixel counting (PxC) emerged as a powerful technique for external solar shading calculations of buildings, providing accurate results with great computational efficiency even for dense geometries. Motivated by this fact and because the technique can be also adapted to cope with interior surfaces without further ado, this paper aims at experimentall...

Nouvelle approche d’évaluation de potentiels de ressources bioclimatiques en climat chaud et humide.

Dans les pays chauds, le défi à relever est celui de la climatisation. L’augmentation de la consommation d’énergie par la climatisation découle du besoin de vivre dans des pièces plus confortables, ce qui est compréhensible. Mais à Djibouti, ce besoin est exacerbé par une architecture voulant imiter celle des pays développés mais inadaptée aux cond...

The development of predictive models to simulate heat and mass transfers in building envelopes is crucial for better energetic and environmental design of buildings. The models in the literature are based on heat and mass balance equations. Many of these use constant or briefly described input data. They use a dimensional formulation where the mech...

The liquid desiccant membrane cooled ceiling (LDMC-C) and displacement ventilation (DV) system removes humidity directly from the space. However, LDMC-C/DV system does not control humidity in the lower occupied zone. In this work, a method for humidity control is proposed where fraction of the dehumidified cool dry air adjacent to the LDMC ceiling...

High temperature metal hydrides used for storing hydrogen have promising future prospect due to the interesting density that characterizes it. This type of hydride offers high hydrogen storage capacities and its formation is highly exothermic. Therefore, the formation enthalpy represents 30% of the lower heating value (LHV) of the absorbed hydrogen...

The amount of solar thermal energy on the earth is not constant; it depends on weather conditions and location. To resolve the mismatch between energy supply and energy demand in solar thermal systems, the useful solutions is to store this solar thermal energy using phase change materials (latent heat) named PCM. In this paper, we studied numerical...

In the Sub-Saharan African countries like Djibouti, the energy situation, the high rate of urban areas growth and the inadequate techniques of construction offer an exciting potential for the bioclimatic approach and sustainable construction. However, this poorly explored potential requires an investigation of different construction types in Djibou...

Buildings are the major consumers of energy in Europe, being responsible for more than 40% of the continent energy demand, where almost 75% of these buildings are from the residential sector. Reducing energy consumption of buildings is fundamental to fulfil the EU’s CO2 emissions and energy savings goals, and many countries in Europe are adopting s...

In the case of highly efficient buildings the solar and internal gains have a higher impact on the energy balance than on classical constructions, with lower insulation. In this context, a model was developed which considers the three dimensional heat transfers through the walls. It simulates the transient behavior of rooms with the use of a refine...

A novel transport model is developed for a space conditioned by a cooled liquid desiccant dehumidification membrane ceiling (LDMC-C) and displacement ventilation DV in which the space is divided into three zones: an occupied cool with fresh air zone; an upper recirculation zone; and a ceiling adjacent boundary layer zone where the air is drawn at t...

In this work we have studied numerically the charging and the discharging of solar thermal energy stored (TES) using latent heat from a storage unit contains PCMs. We have also studied the improvement of the heat transfer between fluid which is the water and the PCMs by adding the fins to our storage unit with various configurations, including in-l...

in this work we have studied numerically the charging and the discharge of solar thermal energy stored using latent heat from a storage unit contains PCMs. We have also studied the improvement of the heat transfer between fluid which is the water and the PCM by adding the fins to our storage unit with various configurations, including in-line fins...

Our work contains two parts, first is an experimental study of the solar air heater with a simple flow and forced convection, we can use thatlaste oneit in many engineering’s sectors as solardrying, space heating in particular. The second part is a numerical study with ansys fluent 15 of the storage of part of this solar thermal energy produced,usi...

Cost optimization is one of the key elements of the EU regulatory framework concerning the energy performance of buildings. From this economic point of view, the optimum occurs when the global cost over the lifecycle of a building is minimized, and the cost-optimal energy performance level is that related to the minimum global cost. To determine th...

Efforts to simulate heat transfer in a PCM (Phase Change Material) storage device are generally led by considerations of Biot number and material thickness, of 2D versus 1D representation, and of possible hysteresis effects arising from the characterisation of the PCM using differential scanning calorimetry (DSC). In this paper we present a numeric...

A thermal transient numerical model (M3D) which considers the three-dimensional heat transfer through the envelope of a room and the sun patch through a window has been developed and validated in a recent paper. The use of a refined spatial and temporal discretization allows considering more precise interactions between the sun patch projection wit...

Phase change materials (PCM) can be an efficient way to improve indoor comfort and to reduce the energy consumption. To study the impact of different PCMs on interior thermal comfort we have used the EFdeN House Project which is a research and educational project representing Romania at Solar Decathlon Europe 2014 from Versailles, France. The EFdeN...

Abstract The work concerns the application of the cost-optimal methodology to a low-consumption French single-family house in order to study how the primary energy system influences the envelope design of a cost optimal nZEB. This is done applying a simulation based optimization method that combines TRNSYS with GenOpt in an iterative process. Four...

This work addresses the use of humidity controlled ventilation with high buffering capacity building envelope. The humidity controlled ventilation rate is associated to the level of moisture in rooms. This paper fits into the idea of reducing the building energy consumption by reducing the duration of air ventilation rate which is usually quite hig...

This paper presents an energy-saving control solution which has been developed for existing public buildings by designing an intelligent ICT-based service system for monitoring and controlling the environmental conditions. The proposed control strategy addresses the required infrastructure and implements the design to properly balance energy saving...

In the current context of thermal improvement in the building sector, research of new solutions to integrate to the retrofitting process is an essential step in the way of saving energy. With the purpose of maintaining or improving the summer comfort after a retrofitting in a residential building, Phase Change Materials (PCM) could be used to bring...

High performance simulation of low energy building requires ever more accurate descriptions of the systems under study to improve the building's performance. This paper describes a numerical model to simulate a single room, using a three-dimensional description of heat conduction in the envelope with environmental conditions that vary over short ti...

This study was born in the context of new challenges imposed by the recast of the EU Energy Performance of Buildings Directive. The aim of this work is to develop strategies to identify and investigate the relationship between decisional variables within a nZEB design concept, providing a useful method to deal with a huge number of simulations corr...

A numerical model has been developed in order to accurately simulate the transient thermal behavior of a building (a single room). This model has already been described in (Rodler et al., 2013): the energy balance equations consider irradiation, convection, air enthalpy and three‐dimensional heat conduction. The particularity of the program i...

This study was developed in the context of new challenges imposed by the recast of the Energy Performance of Buildings Directive 2010/31/EU (EPBD) and its supplementing regulation. The aim is to find the cost-optimal level for the French single-family building typology, while providing an effective method to deal with a huge number of simulations c...

The construction of nearly Zero Energy Buildings implies not only a good envelope design, but also the use of highly efficient systems for heating, cooling and mechanical ventilation. This paper describes a good practice example where the high performance of the all-in one HVAC system was studied through dynamic simulation and resulted in a cost-ef...

The evaporative cooling system has been considered as an alternative to the conventional vapor compression air conditioning system, which offers a simple, low cost, low energy and environmentally friendly solution for building's cooling demand. The aim of the paper is to present a new type of evaporative cooling system, which uses less mechanical e...

RÉSUMÉ. Les simulations des transferts de chaleur, d'air et d'humidité (CAH) dans l'enveloppe du bâtiment est une pratique qui se démocratise. Cela est dû à l'impact des transferts hydriques sur la performance énergétique de l'enveloppe comme le montre les dernières études réalisées sur ce sujet. Dans ce contexte on se propose de concevoir un nouve...

Les simulations des transferts de chaleur et de masse dans l’enveloppe du bâtiment est une pratique qui se démocratise. Les modèles de la littérature sont basés sur l’écriture des équations de bilans thermique et massique. Pour un grand nombre, ils admettent des données d’entrée constantes ou décrites succinctement. Leur formulation est dimensionne...

This paper presents a heat exchanger prototype containing PCM material designed to provide a 1 kW heating power during 2 h (i.e. energy storage of 2 kWh). The exchanger is tested in a closed-loop wind tunnel, used to provide constant airflow rates with temperature changes selected so that the PCM is allowed to melt, then to solidify. Temperature an...

In this paper, the design of an event-driven user-centric middleware for monitoring and managing energy consumption in public buildings and spaces is presented. The main purpose is to increase energy efficiency in buildings and public spaces, thus reducing consumption. To achieve this, the proposed service-oriented middleware has been designed to b...

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...

This article presents a new model to simulate melting with natural convection of a phase change material. For the phase change problem, the enthalpy formulation is used. Energy equation is solved by a finite difference method, whereas the fluid flow is solved by the multiple relaxation time (MRT) lattice Boltzmann method. The model is first verifie...

Avec un plafond refroidi, les températures des surfaces d'une pièce sont inférieurs à ceux des solutions de climatisation et la même chose est vraie quand d'autres surfaces de séparation sont refroidis. Il est possible d'obtenir les mêmes conditions de confort, avec des températures de l'air plus élevées. La sensation de confort produite par un pla...

In this paper, we report a methodology, developed in the context of Smart Energy Efficient Middleware for Public Spaces European Project, aimed at exploiting ICT monitoring and control services to reduce energy usage and CO2 footprint in existing buildings. The approach does not require significant construction work as it is based on commercial-off...

This article presents a novel model to simulate melting of a phase change material, with natural convection and radiation. For the phase change problem, the enthalpy formulation is used. Energy equation is solved by finite differences, whereas fluid flow equations are solved by the lattice Boltzmann method. For radiation intensity, the radiative tr...

Heat exchangers with phase change material (PCM) slabs and air gaps are a solution to store energy in building ventilation systems. Such storage unit can be used both for free cooling and peak load shaving in winter and in summer. However, in order to assess and optimize this system, numerical simulation is mandatory. For that purpose, a numerical...

Are 3D heat transfer formulations with short time sted and sun patch evolution nececessary for building simulation?. ABSTRACT A numerical model is developed to accurately simulate the transient thermal behaviour of rooms with sun-facing windows, with the use of a refined spatial and temporal discretization. For each node, the energy balance equatio...

A numerical model is developed to accurately simulate the transient thermal behaviour of rooms with sun-facing windows, with the use of a refined spatial and temporal discretization. For each node, the energy balance equations are developed based on a consideration of radiation, convection, air enthalpy and three-dimensional heat conduction. As bui...

RÉSUMÉ Un modèle est développé pour simuler le comportement thermique dynamique de l’enveloppe d’un bâtiment. Il est basé sur les échanges radiatifs (radiations courtes et grandes longueurs d’ondes), la conduction tridimensionnelle, le bilan sensible de l’air et la convection sur un nœud d’air. Les données météorologiques d’entrées sont intégrées a...

The presented work addresses the topic of energy savings in existing public buildings, when no significant retrofits on building envelope or plants can be done and savings can be achieved by designing intelligent ICT-based service to monitor and control environmental conditions, energy loads and plants operation. At the end of 2010 the European Com...

This paper provides a new correlation to determine the heat transfer coefficient between an air flow and a plate made of phase change material (PCM). This correlation was built for the simulation of heat storage units containing PCM plates subjected to an inlet temperature step. The presented correlation has the following form: Nu(x,t)(PCM) = Nu(Ps...

In the present work, the authors suggest a bidimensional transitory numerical model in a laminar regime and a forced convection of coupled transfers of heat and mass during mint leaves drying. The modelization is based on the resolution of transfer equations of the air within the interface theory in porous environment. The method used in the resolu...

The strategy to minimize the energy demand stands in several improvements of the building shape form, its thermal mass or envelope insulation. To minimize the heat losses of a building a compact shape is wanted, knowing that the most compact orthogonal building would then be a cube. This design, however, may place a large area of the floor far from...

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...

In this article, an original multi-criteria approach is applied to multi-source systems used for the design and the choice of the optimal alternative. The high number of alternatives and potential solutions when dealing with multi-source systems require a decision support method to be implemented and easy to use. Information data on the economic va...

Le but du modèle : est de déterminer l’évolution de la teneur en eau du produit à sécher, en fonction du temps, et tenant compte des principaux paramètres aérothermiques (température, hygrométrie et débit massique de l’air asséchant). Le modèle est basé sur les bilans d’énergie dans l’air asséchant, et dans les feuilles de menthe verte (Mentha viri...

In order to really assess the potential of Phase Change Material (PCM) wallboards, a renovated office building has been monitored during approximatively one year. A room was equipped with PCM wallboards in the lateral walls and in the ceiling. Another room, identical to the first one, was not equipped but also monitored. This study is the first one...

Phase change material has been installed as a latent heat thermal energy storage system coupled with the ventilation system in an office building located in Lyon, France. The main purpose of this study is to determine if the phase change material system can guarantee the summer comfort of the occupants without energy-consuming cooling devices. Sens...

This paper deals with the results of an investigation into the freecooling efficiency in a low energy building using a PCM/air heat exchanger coupled with the me-chanical ventilation. The numerical model of the PCM system is coupled with the type 56 of TRNSYS in or-der to analyse thermal comfort conditions inside the building but also cooling energ...

Ecole de printemps METTI 5 (Advanced School on Thermal Measurements and Inverse Techniques), Roscoff, June 13-18, 2011, Lecture 5.

TRNSYS is a software dedicated to the simulation of dynamic systems. Some obstacles have been encountered in the use of TRNSYS, particularly in the building model: the type 56, whose interface is TRNBuild. Thus, the integration of thick walls not associated with a correct choice of time steps can lead to miscalculations on the responses considered,...