Contino, FrancescoPonet, AliceAlicePonetDelos, LucaLucaDelos2025-05-142025-05-142025-05-142022https://hdl.handle.net/2078.2/26552In the actual context of energy transition, a structural change is experienced by the energy system. The latter was conventionally centralized and is now becoming more renewable, spread out, thus requiring small-scale applications. A gap to fill exists for small-scale combined heat and power (CHP) units with flexible operations because of the intermittency of the renewable energy sources. Usually, Internal Combustion Engines (ICE) are the technology used for this application. However, Micro gas turbines (mGT) could be used as CHP in those smart energy grid. This technology shows potential thanks to some advantages that they present over the ICE; mostly their lower emissions levels, lower maintenance requirements and high fuel flexibility. However, they did not enter the small-scale CHP market yet because of their rather low electric efficiency (about 30 %). When the heat demand is low, the efficiency is limited to the electrical one because the exhaust gases are not valued. In this context, a bottoming cycle valorizing the waste heat of a mGT (namely, the Turbec T100) could be added to increase the electrical efficiency of this mGT. Thanks to its interesting fluid properties (high fluid density while keeping gas-like viscosity), supercritical CO2 has shown interest in waste heat recovery applications. The present thesis will hence assess the potential of a supercritical CO2 bottoming cycle for waste heat recovery. First, by comparing its steady-state performances with the conventional technology used in the case of waste heat recovery for the temperature ranges of the Turbec T100 exhaust (about 270 [°C]), namely, the Organic Rankine Cycles (ORC’s). Then, because the aim of the use of the mGT is to compensate the intermittency of energy sources, they must operate in transient and part-load operations hence the bottoming cycle must also satisfy these constraints. Therefore, an analysis of the dynamic behavior of the CO2 bottoming cycle receiving transient heat load from the mGT is required for potential future construction of such installations. In order to achieve this, the varying exhaust conditions of the Turbec T100 were used. A dynamic model, using the open-source programming language Python was thus developed in this thesis and calibrated with the aid of data obtained in literature. Special care was taken regarding the different components’ behavior (especially the compressor and recuperator) when the working fluid was approaching critical conditions due to the sharp changes of CO2 properties in this region.mGTWaste heat recoveryDynamic analysisBottoming cycleSupercritical CO2text::thesis::master thesisthesis:35639