Microturbine based energy hub design and management in a distributed generation approach

This thesis is focused on the analysis of distributed generation potential and drawbacks in different scenarios. The analysis is divided into three main chapters with the aim of describing the technical and normative framework that regulates the distributed generation application, before moving in the detail of two different applications: a residential and a maritime one. The use of micro Gas Turbines is one of the most promising solutions towards the large diffusion of distributed generation of both thermal and electric energy, anyway, it is worth to mention also other technologies such as Renewables, Fuel Cells and Internal Combustion Engines. The residential application is developed within the H2020 Envision project that aims to foster the transition to positive energy buildings increasing the active surfaces for energy production for solar radiation. In this context, the University of Genoa is responsible for one of the two main demosites, where Envision technologies are tested in interaction with a Smart Polygeneration Microgrid. To do that, a detailed study of the thermo-economic performances of the involved technologies has been developed in order to proper dimension and design the demosite components. In particular, it has been necessary to model and analyse the performance of thermal solar façade panels connected to a Heat Pump, with the aim of evaluating the best configuration of the system and its proper management in interconnection with a District Heating Network. Furthermore, the presence of a micro Gas Turbine, to provide also electric energy, requires more detailed management of the system obtained through a thermo-economic analysis that gives the basis for the tuning of a Model Predictive Control through the experimental campaign. Furthermore, the results obtained from a preliminary test campaign for analysing the impact of insulation on the back of a panel are reported in the conclusion of this section. The overall activities represent a strong and solid basis on which rely during the experimental campaign, in terms of configuration, installation and control of the system. The second application of distributed generation presented in this work refers to a maritime scenario. In this context, a detailed study has been developed in order to understand if the use of micro Gas Turbines and/or PEM Fuel Cells is suitable for Distributed Generation on board of cruise ship. In particular, taking into account the application, the choice of the best solution has to consider not only energetic performances but also aspects related to volumes and weights that could affect the available payload of the vessel. To do that, a steady-state analysis has been developed, in detail, with the scope of analysing and comparing the different solutions in terms of economy, energy and dimensions. After that, a deeper study has been performed in a time-variant scenario, where it has been considered the proper management of the system. This analysis highlights the promising performances of PEM Fuel Cells at partial load, while on the other hand, the mGTs show better behaviour in a CHP application. All those aspects have been considered, evaluating also the performances in terms of emissions for the considered technologies when compared to Internal combustion engines fuelled by LNG. This activity has been the first step towards the development of a comparison tool, HELM, that is able to compare different energy generation solutions for maritime application depending on the considered scenario, suggesting which can be the most suitable solution taking into account the relevance of the main evaluation categories: volumes, weights, costs and emissions.