As far as advanced heat-pump and refrigeration systems are concerned, new manufacturing techniques for gas-solid reactors must be developed, particularly those involving anisotropic transfers by using expanded graphite or inserted graphite fibers, or thermal wave reactor transformations. These techniques allow a high rate of internal heat recovery in the thermal wave adsorbers or in the new multi-salt gas-solid reactive processes.
This project is a follow-up of a previous JOULE-1 project
(JOUE-CT90-0038) and aims at developing a new generation of solid-gas sorption systems. An air conditioning machine will be tested with an expected coefficient of performance of 1.4 minimum for a heat source above 200(C (equivalent to 3.5 for a compressor-type chiller in terms of primary energy input) .
The transfer characteristics (heat and mass transfer) in fast bed reactors are being studied under extreme operating conditions (especially at low pressure). These researches concern reacting media (CNRS-IMP) and adsorption media (CNRS-LIMSI). The same objectives of which are to be reached by compact evaporators and condensers (IKE).
New adsorbents of hydrophobic zeolithe type will be studied in order to obtain a better adsorption capacity and good heat transfer properties (CECA, CNRS-LIMSI, CNR and Uni CRACOW).
Implementation of IMPEX (achieved by compression of expanded natural graphite and then crystallization of the salt inside) or mixtures of salt with expanded natural graphite leads to anisotropic transfer properties in the reactant blocks. Theses reactants are currently being manufactured by LCL. Specific properties must be studied: porosity, heat capacity, thermal conductivity, permeability (CNRS-LIMSI, IMP, CNR and CECA). Performance of a hydride reactor with IMPEX or mixture implemented will be tested (IKE, GfE, LCL). Intercalation compounds are prepared by using carbon fibers (INPG); their thermal properties will be measured (UCL). Reactor tests and comparison with other heat storage materials should be performed (INPG, CNRS-IMP).
The performance of thermal wave reactors (in adsorption, CNRS-LIMSI) and multi-salt reactors (CNRS-IMP) will be investigated. They will be compared with classical solutions (isotropic media, thin beds). These anisotropic consolidated materials should be able to get better regenerative parameters than classical solution of thin beds .
Modelling and experimental comparison among chiller-heaters (2-7 C in cold or 80 C in heat production) with thermal wave adsorption systems (CNRS-LIMSI), multireactant systems (CNRS-IMP) and gas-solid reactions with recovery of the heat of reaction (IKE) will be studied (collaboration with UPC for system analysis and numerical problems). Those machines should have an output power typically about 2 or 3 kW. The performances of the various systems will be defined in terms of COP and irreversibilities. Simulations (using the model validated by experiments) will allow the dimensioning of a 50 kW chiller-heater. The economic viability of such processes will be evaluated by C.M. and will be discussed with SNEA and GdF (final industrial partners).
Funding SchemeCSC - Cost-sharing contracts