Hervé Noel | Université de Bretagne-Sud (original) (raw)

Papers by Hervé Noel

Energy and Buildings, Mar 1, 2020

This work focuses on the hygrothermal behavior of three external thermal insulation systems: one ... more This work focuses on the hygrothermal behavior of three external thermal insulation systems: one ETICS including EPS insulation and two ventilated cladding systems including either mineral or biobased insulation. These systems were applied on a rendered hollow concrete wall and tested simultaneously between two climatic chambers. Thermocouples, humidity sensors and heat flux sensors allow investigating the hygrothermal behavior of the retrofitted wall at different stages: just after the application of insulations systems, during safe and critical use. The measured data are compared to numerical results obtained by solving a heat and moisture transfer model. Results highlight the key role of adhesive on ETICS, which provides a significant moisture source during the application and forms an additional moisture transfer resistance within the wall. Results on ventilated cladding systems show that using biobased insulation may delay and even prevent the risk of interstitial condensation. The comparison between numerical and experimental results is satisfying for temperature and heat flow density, but underline the sensitivity of relative humidity to the sorption capacity of hygroscopic building materials. In addition, the systems design has a great influence on the condensation risks.

ABSTRACT Owing to the finite supply of fossil fuels and the negative public opinion surrounding n... more ABSTRACT Owing to the finite supply of fossil fuels and the negative public opinion surrounding nuclear energy, alternative energy resources are the subject of considerable research on a global scale. Thermal solar energy seems to be the most promising one but remains relatively expensive. To reduce the cost, we have interest in substituting copper circuit by a low-cost material. Conductive Polymer Composites (CPC) [1] seem to be a good candidate for such application but their resistance to ageing still not yet proved. The purpose of this study was to elaborate a conductive polymer composite (CPC) that could be used in a thermal solar panel. To achieve this goal, we choose to use bio-sourced polymers like polylactic acid (PLA) and polyamide 12 (PA12), which were filled with Multiwall carbon nanotube (CNT) [2] and Graphite [3]. In this work, the degradation of polylactic acid (PLA) and Polyamide 12 (PA12) nanocomposites under natural and artificial weathering was investigated as a function of fillers loadings for different exposure period. The Attenuated Total Reflection Infra-Red Spectroscopy (ATR-IR) was used to show up the photo-oxidation mechanism on CPC and the effect of fillers type and loading on it. Furthermore, the chemical mechanisms responsible for the formation of new chemical groups were identified. Also, electrical resistivity was investigated to check the ageing effect on the network structure. The thermal degradation of the different composites was studied by thermo gravimetric analysis (TGA) and ageing effect was highlighted. In addition, calorimetric properties were shown to analyze the effect of ageing on the polymeric chains and the speculated nucleation effect that fillers could play. Moreover, Young modulus measurements were performed by using nano- indentation technique for mesoscopic scale and tensile test for macroscopic scale. Finally, the weathering effect on the morphology of exposed samples was observed by SEM to detect changes on polymer composites.

Applied Energy, Sep 1, 1996

ABSTRACT This study describes the modelling of the thermal behaviour of aquacultural ponds throug... more ABSTRACT This study describes the modelling of the thermal behaviour of aquacultural ponds through nodal discretisation and the use of correlation formulae for exchanges at the water-air interface. The direct resolution of the resulting system was effected by an interconnected numerical method. The experiments carried out on a test pond provided the database necessary for refining the model. The satisfying comparison of experimental and simulated responses for the pond water justify the choice of theoretical approach. A data-processing tool was developed on a PC computer to determine the water temperature of a parallelepiped pond of variable geometry and composition, subjected to different demands and with or without thermal protection covering.

L'Union Européenne s'est engagée à augmenter de 17 à 27\% la part d'énergie renouvela... more L'Union Européenne s'est engagée à augmenter de 17 à 27\% la part d'énergie renouvelable produite en Europe pour 2030 afin de diminuer les émissions de gaz à effet de serre. C'est dans ce contexte que le laboratoire est impliqué dans le projet Interreg NWE ICaRE4Farms dont l'objectif est de réduire l'usage des procédés de chauffage traditionnels à énergies fossiles par la production d'eau chaude solaire. Nos travaux concernent la mise en œuvre d'une instrumentation adaptée à des suivis in situ pour poser des bilans thermiques et développer des modèles numériques. Le site étudié dans le cadre de cette étude est situé dans les Cotes d'Armor, il est destiné à produire de l'eau chaude pour un élevage. L'installation solaire thermique utilise 24 Capteurs solaires à tubes sous vide non pressurisés avec circulation directe du fluide caloporteur dans les tubes par thermosiphon et ballon de stockage (CSSV). Cette installation est constituée de CSSV...

ABSTRACT CIFQ 2011 / convection09, Xème Colloque Interuniversitaire Franco-Québécois, Saguenay, 2... more ABSTRACT CIFQ 2011 / convection09, Xème Colloque Interuniversitaire Franco-Québécois, Saguenay, 20-22 juin 2011

Applied Energy, 1996

Journal of Physics: Conference Series, 2021

Opaque ventilated façades (OVF) are increasingly used in building envelope because of their posit... more Opaque ventilated façades (OVF) are increasingly used in building envelope because of their positive impact on building energy efficiency. Usually, air flow is driven by natural ventilation. Recently, there were some attempts to drive air flow mechanically to preheat or precool air in combination with HVAC, Heat pump or Latent Heat Thermal Energy Storage (LHTES) systems. In this framework, an experimental real-scale module of an OVF was built (1.9 m width and 3.5 m height). In this study, OVF is tested during autumn under natural and under forced convection by means of ventilator placed at cavity outlet. Inlet air flowrate are changed from day to day or during the day. For each test, temperature, air velocity, air flow rate and thermal flux are monitored at different locations of OVF. Their analysis shows that collector efficiency and amount of collected energy depend mainly on cavity air flow rate. The measurements are compared to simulation results obtained from two thermal models...

Applied Thermal Engineering, 2018

The air-cooling of fresh cauliflowers is studied. • A simple numerical model predicts the product... more The air-cooling of fresh cauliflowers is studied. • A simple numerical model predicts the product temperatures and the water losses. • The modelling approach takes into account the heterogeneities of the vegetable. • The numeral results reveal a good agreement with the measurements.

ABSTRACT Owing to the finite supply of fossil fuels and the negative public opinion surrounding n... more ABSTRACT Owing to the finite supply of fossil fuels and the negative public opinion surrounding nuclear energy, alternative energy resources are the subject of considerable research on a global scale. Thermal solar energy seems to be the most promising one but remains relatively expensive. To reduce costs and allow a wider diffusion of solar absorbers, we have been interested in substituting copper elements by renewable biomaterials. Conductive Polymer Composites (CPC) seem to be good candidates for such application due to their enhanced thermal conductivity. To achieve this goal, we choose to use bio-sourced polymers such us poly(lactic acid) PLA and poly(amide 12) PA12, which were filled with multiwall carbon nanotube (CNT) and Graphite. Nevertheless, the thermal conductivity of prepared CPC depends strongly on the nature of contact between fillers and especially on their dispersion on the polymer matrix. The aim of this study was to study the nature of contact in the interface filler-matrix and the adhesion of fillers to the polymer matrix. In fact, tribological tests were used to determine the effect of fillers fraction on the friction coefficient of the prepared composites. Also, the evolution of friction coefficient with the sliding distance was investigated to pull of the different phenomenon occurring during the friction test. Scanning Electron Microscopy allows to characterize the sliding path and to confirm the observed trends.

Colloque Sustainable Chemitry & Related Areas, 25, 26 février 2010 Communication par affich

5th International Conference on Advances in Mechanical Engineering and Mechanics, ICAMEM2010, 18-... more 5th International Conference on Advances in Mechanical Engineering and Mechanics, ICAMEM2010, 18-20 December, 2010, Hammamet, Tunisi

Materials Letters, 2012

ABSTRACT The aim of the study was to examine the possible use of conductive polymer composites (C... more ABSTRACT The aim of the study was to examine the possible use of conductive polymer composites (CPC) as thermoelectrical material for energy harvesting from temperature gradient. Their ease of processing, low cost and environmental impact compared to typical thermoelectric semiconductor materials were found to be strong advantages for large scale production. Our results show that eGR-CNT hybrid fillers are the most effective to enhance the CPC electrical conductivity up to σ = 4123 S.m− 1, but that eGR is more effective to improve both thermal conductivity (λc = 5.5 W.m− 1.K− 1) and seebeck coefficient (S = 17 μV.K− 1), whereas finally CNT give the best compromise to reach the highest ZT = 7 × 10− 5 at room temperature. This finding is attributed to the ability of CNT network to allow electron circulation by tunnelling, when junctions are separated by an insulating polymer film (even of some nm thick), whereas phonon scattering at nanointerfaces will prevent their effective transmission through the CPC. Although the intrinsic individual physical properties obtained (σ, λc, S) with the different kinds of carbon filler were good, it was not possible to completely uncouple them to maximise ZT. We believe that this value of ZT, too low for commercial application, can be enhanced by increasing the confinement of conducting fillers with exclusion volumes and by decreasing the thermal conductivity of the matrix with voids.

IOP Conference Series: Earth and Environmental Science

As part of the ICaRE4Farms European project, a model of a solar water heater installation has bee... more As part of the ICaRE4Farms European project, a model of a solar water heater installation has been developed. This model is intended to estimate thermal performance of a specific arrangement of several “Water-in-Glass” solar collectors. In this solar field, the WiG collectors are arranged either in serial or in parallel, thus requiring the creation of two models. In this paper, the serial Evacuated Tubes collector’s model is presented. The operational efficiency of a single in-series solar collector is expressed through a second-order expression in accordance with the ISO 9806-1. Its coefficients have been determined thanks to an optimization tool in order to compute thermal performance with reliability. In-situ data from a working installation were compared to simulated values. Two experimental sequences are presented: in May and in September 2021. Results showed that the model is reliable in terms of both collectors’ temperature and energy balance.

Drying Technology, 2014

ABSTRACT This article deals with the drying of the waste by-product of an activated sludge manure... more ABSTRACT This article deals with the drying of the waste by-product of an activated sludge manure treatment plant. The studies concern the low temperature drying of planar plates 3 cm thick. The upper face of the sludge is subjected to a tangential air flow controlled for speed, temperature, and humidity. The lower face can be subjected to contact heating. The maximum temperature for air and the bottom of the product is 60 °C. After characterizing the main thermophysical and hygric properties of the product, the laboratory set-up specifically designed for this study is described. Experiments are performed to determine temperature, mass loss, and deformation evolutions for different boundary conditions. These experimental data are used to build a numerical one-dimensional heat and mass transfer model to predict temperature and moisture content fields. Sludge is assimilated with a hygroscopic porous medium, and shrinkage is not taken into account. To validate this model, several comparisons between simulated and measured data are made for different drying methods (hot or fresh air convective drying, contact drying, and combined drying) and various drying conditions.

L’étude présentée consiste à définir, pour un matériau polymère composite constituant principal d... more L’étude présentée consiste à définir, pour un matériau polymère composite constituant principal d’un absorbeur solaire solaire thermique, des paramètres cibles réalistes lui permettant de rivaliser en performance avec un absorbeur de capteur plan classique. Un modèle thermique paramétré en régime transitoire d’un absorbeur monocouche est mis en oeuvre par une méthode nodale et différences finies. Il sert de base à une étude de sensibilité qui permet de limiter le nombre de paramètres à étudier. Pour chaque paramètre restant, les valeurs maximales escomptables dans l’état actuel de nos compétences sont définies. Des courbes iso-rendement sont alors tracées par couples de paramètres, dans la gamme précédemment définie. Les propriétés cibles réalistes d’un absorbeur en composite polymère, sont ainsi définies. Il s’agit, par cette étude, de contribuer à mettre en adéquation les efforts en recherche de formulations avec les besoins réels en termes de propriétés thermo physiques.

Energy and Buildings, Mar 1, 2020

Applied Energy, Sep 1, 1996

Applied Energy, 1996

Journal of Physics: Conference Series, 2021

Applied Thermal Engineering, 2018

ABSTRACT Owing to the finite supply of fossil fuels and the negative public opinion surrounding n... more ABSTRACT Owing to the finite supply of fossil fuels and the negative public opinion surrounding nuclear energy, alternative energy resources are the subject of considerable research on a global scale. Thermal solar energy seems to be the most promising one but remains relatively expensive. To reduce costs and allow a wider diffusion of solar absorbers, we have been interested in substituting copper elements by renewable biomaterials. Conductive Polymer Composites (CPC) seem to be good candidates for such application due to their enhanced thermal conductivity. To achieve this goal, we choose to use bio-sourced polymers such us poly(lactic acid) PLA and poly(amide 12) PA12, which were filled with multiwall carbon nanotube (CNT) and Graphite. Nevertheless, the thermal conductivity of prepared CPC depends strongly on the nature of contact between fillers and especially on their dispersion on the polymer matrix. The aim of this study was to study the nature of contact in the interface filler-matrix and the adhesion of fillers to the polymer matrix. In fact, tribological tests were used to determine the effect of fillers fraction on the friction coefficient of the prepared composites. Also, the evolution of friction coefficient with the sliding distance was investigated to pull of the different phenomenon occurring during the friction test. Scanning Electron Microscopy allows to characterize the sliding path and to confirm the observed trends.

Colloque Sustainable Chemitry & Related Areas, 25, 26 février 2010 Communication par affich

Materials Letters, 2012

IOP Conference Series: Earth and Environmental Science

Drying Technology, 2014