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Chow T.T.,Hong Kong University of Science and Technology | Tiwari G.N.,Indian Institute of Technology Delhi | Menezo C.,Lyon Center of Thermal Science
International Journal of Photoenergy

The market of solar thermal and photovoltaic electricity generation is growing rapidly. New ideas on hybrid solar technology evolve for a wide range of applications, such as in buildings, processing plants, and agriculture. In the building sector in particular, the limited building space for the accommodation of solar devices has driven a demand on the use of hybrid solar technology for the multigeneration of active power and/or passive solar devices. The importance is escalating with the worldwide trend on the development of low-carbon/zero-energy buildings. Hybrid photovoltaic/thermal (PVT) collector systems had been studied theoretically, numerically, and experimentally in depth in the past decades. Together with alternative means, a range of innovative products and systems has been put forward. The final success of the integrative technologies relies on the coexistence of robust product design/construction and reliable system operation/maintenance in the long run to satisfy the user needs. This paper gives a broad review on the published academic works, with an emphasis placed on the research and development activities in the last decade. © 2012 T. T. Chow et al. Source

Babuty A.,ESPCI ParisTech | Joulain K.,University of Poitiers | Chapuis P.-O.,Catalan Institute of Nanoscience and Nanotechnology | Chapuis P.-O.,Lyon Center of Thermal Science | And 2 more authors.
Physical Review Letters

We report local spectra of the near-field thermal emission recorded by a Fourier transform infrared spectrometer, using a tungsten tip as a local scatterer coupling the near-field thermal emission to the far field. Spectra recorded on silicon carbide and silicon dioxide exhibit temporal coherence due to thermally excited surface waves. Finally, we evaluate the ability of this spectroscopy to probe the frequency dependence of the electromagnetic local density of states. © 2013 American Physical Society. Source

Catalina T.,Technical University of Civil Engineering Bucharest | Virgone J.,Lyon Center of Thermal Science | Blanco E.,CNRS Ampere Laboratory
Renewable Energy

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 variables, energy performance and impact on the environment of the systems are presently data which analysis and quantification is difficult. To deal with this high level of complexity and uncertainty, an evaluation approach is needed. The multi-criteria decision support methodology concept is described (ELECTRE III) and then applied for a case study. The decision support algorithm has its bases on the developed models and makes the outranking of possible solutions. It is also shown that multi-criteria analysis can provide a technical-scientific decision-making support that is capable to justify the clearly rank of the alternatives in the renewable energy sector. The use of multi-criteria decision aid for assessing the multi-source systems showed encouraging results and interesting insights. © 2011 Elsevier Ltd. Source

Merabia S.,University Claude Bernard Lyon 1 | Termentzidis K.,Lyon Center of Thermal Science | Termentzidis K.,Ecole Centrale Paris
Physical Review B - Condensed Matter and Materials Physics

In this article, we compare the results of nonequilibrium (NEMD) and equilibrium (EMD) molecular dynamics methods to compute the thermal conductance at the interface between solids. We propose to probe the thermal conductance using equilibrium simulations measuring the decay of the thermally induced energy fluctuations of each solid. We also show that NEMD and EMD give generally speaking inconsistent results for the thermal conductance: Green-Kubo simulations probe the Landauer conductance between two solids which assumes phonons on both sides of the interface to be at equilibrium. On the other hand, we show that NEMD give access to the out-of-equilibrium interfacial conductance consistent with the interfacial flux describing phonon transport in each solid. The difference may be large and reaches typically a factor 5 for interfaces between usual semiconductors. We analyze finite size effects for the two determinations of the interfacial thermal conductance, and show that the equilibrium simulations suffer from severe size effects as compared to NEMD. We also compare the predictions of the two above-mentioned methods-EMD and NEMD-regarding the interfacial conductance of a series of mass mismatched Lennard-Jones solids. We show that the Kapitza conductance obtained with EMD can be well described using the classical diffuse mismatch model (DMM). On the other hand, NEMD simulation results are consistent with an out-of-equilibrium generalization of the acoustic mismatch model (AMM). These considerations are important in rationalizing previous results obtained using molecular dynamics, and help in pinpointing the physical scattering mechanisms taking place at atomically perfect interfaces between solids, which is a prerequisite to understand interfacial heat transfer across real interfaces. © 2012 American Physical Society. Source

Sanvicente E.,Lyon Center of Thermal Science | Giroux-Julien S.,Lyon Center of Thermal Science | Menezo C.,Lyon Center of Thermal Science | Bouia H.,Electricite de France
International Journal of Thermal Sciences

The work presented here is an experimental study on natural convection flows in a differentially heated open channel configuration. The applications concern the free cooling of both the photovoltaic components integrated within the building envelope (double-skin configuration) and the building itself. Particular focus is given to the identification of integration configurations favorable to both heat transfer on the rear side of components and buoyancy enhancement. The test section consists of a vertical channel with two walls composed of different heating modules. In the present investigation the thermal configuration considers one wall heated uniformly while the other is not heated. We focus on the kinematic characteristics of the flow and convective heat transfer at the heated wall. A PIV system allows investigating the mean velocity field and velocity fluctuations at different levels of the channel height. The experimental procedure allows inferring the wall surface temperature, local heat transfer coefficient and local and average Nusselt numbers. The experimental evidence shows that the flow is neither really turbulent nor purely laminar for the range of Rayleigh numbers considered. Although the average characteristics of the flow seem perfectly consistent with the results obtained, changes of behavior seem to occur intermittently. © 2012 Elsevier Masson SAS. All rights reserved. Source

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