Le défi clé a pour ambition de contribuer à combler les lacunes technologiques actuelles identifiées dans le domaine du Photovoltaïque (PV) pour des utilisations dans des conditions non standards. Les solutions dans ce domaine sont multiples, elles peuvent être le fruit de concepts physiques non encore exploités jusque-là, d’adaptation de principes existants ou de mise en oeuvre de matériaux non encore utilisés dans le domaine du PV. Sur cette base cinq domaines scientifiques ont été définis : 1. Physique de la conversion d’énergie photovoltaïque en conditions non standards. 2. Synthèse de matériaux innovants. 3. Nouveaux concepts pour l’hybridation des modes de conversion de l’énergie solaire. 4. Exploration des limites : fortes concentrations solaires et conditions extrêmes. 5. Apport du numérique dans l’analyse et la collecte des données en conditions non standards.
Catégorie : Doctorats – Post-doctorats
Context and motivations
Solar thermal technologies rely on the collection of the solar radiation to generate heat (by heating a fluid) that can be used for domestic, residential and industrial purposes. If solar irradiance is concentrated using mirrors, this heat can in turn be used to produce electricity via a turbine. These technologies call for optically efficient components with complex and sometimes conflicting optical behaviors. In particular, the solar receiver should be highly absorbing in the solar range (0.28 – 4 µm) to harvest as much solar radiation as possible, but also lowly emissive in the infrared range (1 – 50 µm) to limit radiative thermal losses. This spectral selectivity can be achieved using multilayered coating architectures, associating lowly emissive (e.g. metals) and highly absorptive materials (e.g. dielectric/ metal/dielectric multilayers or metal-ceramic composites), that need to be optically designed and optimized in terms of layer thicknesses and compositions, to guarantee their high optical performance.
A judicious preselection of materials is also paramount, as the solar receivers should also be resistant to harsh operating conditions such as high temperatures, high solar irradiation, oxidant and erosive atmospheres and high thermomechanical stress for long durations, while remaining optically efficient.
The objective of the project is to explore an innovative avenue for the production of oxygen on the Moon by the concentrated solar pyrolysis of the regolith. This process consists in heating the rocks from the lunar soil (regolith) at very high temperature to extract different materials, including the oxygen necessary for any lunar base project. This process has the advantage of not requiring any resources from the Earth. Preliminary studies have been carried out by CNES/ESA and the proof of concept requires the use of efficient solar concentrators available at the PROMES laboratory in Odeillo. The work will consist in continuing theoretical studies, designing, building and testing a solar pyrolysis device to extract oxygen from rock composed of a mixture of oxides. Other products (i.e. metals or other strategic elements) may also be separated and must be analyzed for recovery. This work should bring out new perspectives for the establishment of a lunar base by in-situ use of the resources present for a further away exploration of space.
L’objectif de cette thèse est la mise en oeuvre d’une démarche PHM destinée aux tubes échangeurs des centrales solaires à concentration équipées de collecteurs cylindro-paraboliques. Les résultats attendus sont le développement, l’analyse et la validation d’algorithmes, utilisant l’apprentissage machine, capables de détecter l’occurrence, de diagnostiquer la nature et de prédire l’évolution des défauts qui peuvent survenir en utilisant des mesures ultrasons. Ces algorithmes devront permettre de diminuer les coûts de maintenance et donc de rendre ces centrales solaires économiquement plus compétitives. De plus, les résultats peuvent aussi être exploités pour optimiser le rendement des centrales conjointement aux travaux qui sont menés actuellement à PROMES sur le contrôle-commande avancé des centrales solaires équipées de collecteurs cylindro-paraboliques.
L’alliance européenne des batteries lancée par la Commission Européenne en 2017 pour bâtir une chaîne de valeur intégrée sur le sol européen porte ses fruits. Quinze projets d’usines de batteries Li-ion ont été lancés en Europe avec une capacité de production de 500 GWh d’ici 2030. Alors qu’elle ne représentait que quelques pourcents de la production mondiale de batteries en 2019, l’Europe pourrait être en mesure de répondre à sa demande intérieure dès 2025. Mais de nombreux défis restent à relever dont la recyclabilité des batteries qui demeure un défi majeur pour l’industrie européenne.
La thèse proposée vise à démontrer, à travers une première approche numérique, la faisabilité des cycles à sorption hybrides pour assurer des fonctions de stockage d’énergie thermique (sous forme de potentiel chimique) et pour produire un effet frigorifique.
L’objet du travail porte sur l’hybridation de l’énergie solaire à concentration et du dessalement de l’eau de mer. A l’aide du rayonnement solaire concentré, il est possible d’élever la température d’un media et apporter la puissance nécessaire afin de générer la vapeur à partir d’eau salée. La difficulté souvent rencontrée est le dépôt de sel sur la paroi chauffante suite à l’évaporation. La réduction des performances thermiques du procédé à cause du dépôt nécessite sa suppression.
Les objectifs de cette thèse sont (i) d’explorer les capacités d’un solveur Euler-Euler pour simuler les écoulements gaz-particules mis en jeu et (ii) d’analyser les simulations réalisées pour étudier la physique des lits fluidisés transportés anisothermes.
La compréhension du vieillissement et de l’endommagement de matériaux destinés à la fabrication des récepteurs solaires est un enjeu dans le cadre de la conception et de la maintenance des centrales à concentration. L’objectif principal de cette thèse est de détecter l’apparition de défauts mécaniques sur des récepteurs CSP avant qu’une éventuelle rupture ne se produise et mette en péril l’intégralité de la centrale.
Framework of the TOPCSP project
Ten PhD positions are available in the TOPCSP doctoral network funded by the Horizon-MSCA DN- 2021 call. The Towards Competitive, Reliable, Safe and Sustainable Concentrated Solar Power (CSP) Plants (TOPCSP) project will
offer a unique international, intersectoral and interdisciplinary research and innovation framework to 10 promising doctoral candidates and will boost their excellence in the development of innovative technologies and so that they will be capable of solving the challenges that currently face the solar thermal power industry. The overall research objective of the project is to improve the design of the different systems of a CSP plant to increase its cost- competitiveness, reliability, environmental profile, and operational safety.
Core research skills will be acquired by each doctoral candidate through the doctoral-level investigations of the task associated with his/her individual research project. Additional research skills will be delivered in the network-wide workshops, international conferences and training
modules. A training in transferable skills, will help the doctoral candidates project their careers towards innovative and hi-tech applications in the non-academic sector. Every doctoral candidate will undertake secondments in academic and non-academic institutions of the consortium institution to develop their intersectoral and interdisciplinary skills.
Specific background of the PhD thesis
One of the concentrated solar technologies currently being developed consists of direct steam generation (DSG) in the solar receiver. This eliminates the need for a HTF, reduces the number of heat exchangers and potentially increases the efficiency of the plant. The steam produced can either drive a turbine to generate electricity or be directly used by an industrial process or a heating network. DSG in the receiver
of parabolic trough collectors is proven technology although numerical studies are limited due to the lack of knowledge about the thermo-physical process of two-phase flow boiling in the horizontal and inclined DSG receivers. Current numerical modelling and experimental correlations are limited to specific case studies. At the entrance of the solar field, pressurized water enters the receiver. Under the effect of convective heat exchange between the fluid and the tube
wall, water evaporates, and a boiling two-phase flow is created in the receiver. Considering the tube lengths (~ 100m) and the heat fluxes involved (~ 40kW=m2), the vapour volume fraction varies depending on the position in the receiver tube. Reliable prediction of the two-phase flow regime in the receiver is of critical importance for two reasons: (i) predicting the amount of steam produced and, thus, plant production, and (ii) assessing the thermomechanical stresses
imposed on the tube materials. CNRS has previous experience modelling these flows using a Euler-Euler approach, showing the ability of the method to reproduce the physics involved in a case of evaporation of a freon in a horizontal coiled tube. In this PhD project this methodology
will be applied to a solar receiver.
Objectives and research plan
The candidate, hosted by CNRS, will set up numerical simulations using NEPTUNE_CFD software to model the flow in the DSG plant. The thermal conduction in the walls of the receiver will be considered with Syrthes software. A coupling between the two codes will be implemented to perform massively parallel simulations on European supercomputers. Due to the recent emergence of this type of power plant, experimental operating data, essential for validating numerical tools, are currently unavailable in the literature.
The researcher will set up a small-scale experiment, without solar irradiation, to reproduce the physics of boiling flows in a DSG receiver. The experimental data will be compared with the computational results to validate the modelling approach.
Applicant profile : We are looking for candidates with a master degree in fluid mechanics or energetics. Good English speaking/writing/reading skills is required along with a solid
knowledge of heat transfer and applied thermodynamics. Given the research program, an appetite for experimental and numerical work is essential. Previous experience in programming would be appreciated but is not required.
Location : PROMES Laboratory – Perpignan, FRANCE.
Salary : The base salary is 3043 €/ month gross. A family bonus is also possible depending on the situation of the person recruited
Eligibility criteria : Recruited researchers can be of any nationality and must comply with the following mobility rule: they must not have resided or carried out their main activity (work, studies, etc.) in France for more than 12 months in the 36 months immediately before their recruitment date. Compulsory national service, short stays such as holidays and time spent by the researcher as part of a procedure for obtaining refugee status under the Geneva Convention are not taken into account.
Contacts : Samuel Mer –
Adrien Toutant –
- Application deadline : Applications must be performed before November 1, 2022
- Selection process : Candidates must apply on the online platform of CNRS (CNRS) and join the following informations/documents :
- the application form to be found on EURAXESS portal
- a detailed CV, including the list of the applicant’s publications (if any).
- a motivation letter
- a transcripts of bachelor and master’s degrees (including the grade range)
- an english language certificate (if available)
- the e-mail address and telephone number of two referees, who can provide a letter of recommendation if needed.