{"id":41,"date":"2021-01-27T14:49:15","date_gmt":"2021-01-27T13:49:15","guid":{"rendered":"https:\/\/www.univ-lorraine.fr\/erc-reacher\/?page_id=41"},"modified":"2022-09-06T09:22:10","modified_gmt":"2022-09-06T07:22:10","slug":"the-project","status":"publish","type":"page","link":"https:\/\/www.univ-lorraine.fr\/erc-reacher\/the-project\/","title":{"rendered":"The project"},"content":{"rendered":"\n

The Concept<\/h2>\n\n\n\n

The present role of thermodynamic cycles.<\/strong><\/h3>\n\n\n\n

Thermodynamic cycles constitute the backbone structure of fossil-fuelled and renewable thermal power systems, refrigerators and heat pumps (Carnot, 1824). In thermodynamic cycles, input energies are converted into output useful energy forms (work or heat) by means of an energy carrier, an inert working fluid, which undertakes cycles of thermodynamic transformations. Power cycles have been dominating the global electricity production; and it is expected that refrigerators and heat pumps will represent one of the future major electricity consumers. Improvements of their backbone-thermodynamic structure thus plays a crucial role in the achievement of energy-policy objectives addressing climate change and reducing air pollution, such as the increase of the efficiency of energy use and of the deployment of renewable technologies.<\/p>\n\n\n\n

Performance improvement by working fluid selection.<\/strong><\/h3>\n\n\n\n

To increase performances of thermodynamic cycles, researches mainly focus on the improvement of their unit operations, on the optimisation of the networking of these components and on the optimal selection of a working fluid crossing the whole cycle. Among these possible measures, the choice of the optimal working fluid represents the core of the process of adaptation of conventional fossil-fuelled thermal engine configurations to exploit lower-grade renewable and waste heat sources, as well as the primary action to reduce the environmental impact of and heat pumps.<\/p>\n\n\n\n

Getting stuck on inert working fluids.<\/strong><\/h3>\n\n\n\n

It is a fact that only inert working fluids (pure fluids or mixtures) are currently employed and that, despite their optimal selection, the thermal efficiency of these energy conversion systems remains far from the maximum achievable ones, dictated by Carnot limit (Cullen and Allwood, 2010).<\/p>\n\n\n\n

Involving chemical energy in thermodynamic cycles: a hint for scientific progress.<\/strong><\/h3>\n\n\n\n

A breakthrough idea was suggested by Lighthill (Lighthill, 1957): he proposed to convert the chemical energy like the \u201clarge energy change involved in dissociating gases\u201d into work. Practically, he put forward the idea to use reactive working fluids, instead of inert ones, in closed power cycles. Differently from current energy conversion systems for electricity production which are formed by one or more devices being the place of distinguished energy-type transformations, Lighthill\u2019s idea consists in a novel energy conversion process, where the transformation of thermal energy into mechanical one is made possible by the concurrent thermal and chemical conversion of the energetic state of a reactive fluid, all along a closed \u201cthermo-chemical\u201d cycle<\/em>.<\/p>\n\n\n\n

REACHER: why now?<\/strong><\/h3>\n\n\n\n

Starting from 1960s, some researchers have investigated the performances of classical power cycles operating with some reactive working fluids, mainly N2<\/sub>O4(g)<\/sub> \u21c4 2NO2(g)<\/sub> \u21c4 2NO(g)<\/sub>+O2(g) <\/sub>(Krasin and Nesterenko, 1971; Bradley, 1976; Angelino, 1979; Sorokin, 1979; Kesavan and Osterle, 1982). Probably due to the fact that, at the time of these studies, the potential of inert fluids was not yet totally investigated, the more advanced idea of using reactive fluids was not fully appreciated and thus remained scientifically unexplored. Now that the use of inert fluids reveals limitations, REACHER intends to revive Lighthill\u2019s idea.<\/p>\n\n\n\n

The methodology<\/h2>\n\n\n
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WP1 <\/strong>– Development of a computational tool for the prediction of thermodynamic properties of reactive multiphase fluids.<\/strong><\/h4>\n\n\n
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The achievement of REACHER\u2019s targets relies on the realization of a reliable tool to predict thermodynamic properties of reactive fluids. That requires the preliminary selection, improvement and implementation of a predictive equation of state for mixture modelling, and of algorithms for chemical equilibrium calculation. This is the aim of WP1.<\/p>\n\n<\/div><\/div>\n<\/div><\/div><\/div>\n\n

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WP2 <\/strong>– Establishment of a list of \u201csuitable\u201d reactive fluids<\/strong>.<\/h4>\n\n\n
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The objective of this work package is the definition of a list of reactions, considered suitable for the set of studied applications, and the characterisation of their thermodynamics and kinetics. That consists in the implementation of the following steps:<\/p>\n\n\n\n