Optimisation of a bladeless fan configuration for driving air through a direct air capture (DAC) system.

IFP Energies nouvelles (IFPEN) est un acteur majeur de la recherche et de la formation dans les domaines de l’énergie, du transport et de l’environnement. De la recherche à l’industrie, l’innovation technologique est au cœur de son action, articulée autour de quatre priorités stratégiques : Mobilité Durable, Energies Nouvelles, Climat / Environnement / Economie circulaire et Hydrocarbures Responsables.

Dans le cadre de la mission d’intérêt général confiée par les pouvoirs publics, IFPEN concentre ses efforts sur :

• l’apport de solutions aux défis sociétaux de l’énergie et du climat, en favorisant la transition vers une mobilité durable et l’émergence d’un mix énergétique plus diversifié ;
• la création de richesse et d’emplois, en soutenant l’activité économique française et européenne et la compétitivité des filières industrielles associées.

Partie intégrante d’IFPEN, l’école d’ingénieurs IFP School prépare les générations futures à relever ces défis.

Optimisation of a bladeless fan configuration for driving air through a direct air capture (DAC) system.

Context

It is increasingly accepted that meeting the 2050 global warming targets will require including direct air capture of CO2 (DAC) in the portfolio of deployed technologies. The large scale deployment of DAC will require driving vast quantities of air through CO2 absorber systems which currently requires using thousands of fans. Bladeless fans may offer various benefits relative to standard mechanical (cost, maintenance, life-cycle…), but their energy efficiency needs to assessed. 

Description

Current DAC plant designs portray vast walls constituted of hundreds of stacked modular absorber units each equipped with mechanical fans with rotating blades. Such a large number of fans leads to concerns about maintenance, noise, cost and environmental impact. An alternative could be to use bladeless fans that are based on the Coenda effect as in common domestic Dyson fans. The later operate by injecting a jet of compressed air (driving air) over a Coenda surface that is shaped  like an airfoil. The low pressure region generated on the Coenda surface improves the entrainement efficiency of surrounding air through the fan and potentially through some device with a head loss. For a Dyson fan the flow of entrained air is roughly fifteen times the injected air.

Applied to a DAC system, a centralized compressor would be needed to generate the compressed air that would be distributed to all the various Coenda surfaces of the plant to drive the atmospheric air through the absorber units. Thus instead of rotating fan blades equipped with electric motors fed by electric wires there would be static insufflation blades fed by an air duct distribution network. Such a system should advantageously reduce noise pollution, maintenance operations and the number of rotating machines.

The proposed intership aims to perform computational fluid dynamic (CFD) calculations to find the geometry and layout of Coenda surfaces that minimize the compressor energy required for entraining the atmospheric air through the absorber units. In contrast to Dyson fan applications, there is a significant head loss to overcome in this application. Hence it can be expected that the optimal geometry will be considerably different from a Dyson Coenda surface. The sofware codes to be used may be one or a combination of COMSOL-Multyphysics, CONVERGE, ANSYS-FLUENT.

Required profile

Fluid mechanics, CFD (Computational Fluid Dynamics), chemical engineering, modelling skills

Additional information

Duration of the internship : 6 months
Workplace : IFPEN Lyon, Rond-point de l'échangeur de Solaize, 69360 Solaize
Transport : public transportation / personal vehicle
Paid internship 1080€/month