Energia dal mare: analisi prestazionale di dispositivi per la conversione energetica da moto ondoso in ambiente rilevante

L\u2019attuale scenario energetico globale ed ambientale, focalizzato sempre di pi\uf9 sulla ricerca di soluzioni energetiche sostenibili in grado da rappresentare un\u2019alternativa efficace e conveniente all\u2019utilizzo delle risorse fossili, vede nell\u2019energia dal mare, ed in particolare del moto ondoso, una risorsa energetica molto interessante, visto l\u2019enorme potenziale di cui dispone. Tuttavia, la grande variabilit\ue0 del fenomeno e l\u2019estrema complessit\ue0 ed aggressivit\ue0 dell\u2019ambiente ove si intende operare rende l\u2019individuazione di una tecnologia efficiente, robusta, replicabile ed a basso costo una sfida estremamente impegnativa. Di fatto, nonostante molte soluzioni siano state proposte nel corso degli anni, tutt\u2019oggi non vi \ue8 una tecnologia che riesca a soddisfare appieno i requisiti di affidabilit\ue0 ed economicit\ue0 necessari ad una naturale affermazione sul mercato. In questo contesto il presente lavoro ha come obiettivo l\u2019analisi di dispositivi di conversione energetica del tipo point absorber e lo sviluppo di una infrastruttura dedicata alla sperimentazione in ambiente significativo ed \ue8 articolato in diverse attivit\ue0 quali dimensionamento e progettazione, modellazione numerica, attivit\ue0 sperimentali. In particolare, nel capitolo 4 viene riportata l\u2019attivit\ue0 svolta in merito al dispositivo di conversione da moto ondoso chiamato SeaSpoon, sviluppato dal Thermochemical Power Group del Dipartimento DIME dell\u2019Universit\ue0 degli Studi di Genova. Sono state condotte diverse campagne sperimentali e sono stati sviluppati diversi codici di calcolo al fine di valutare le prestazioni potenziali del dispositivo in diverse condizioni marine, equipaggiandolo con diverse tipologie di profili. La ricerca sulle tematiche della conversione dell\u2019energia da moto ondoso ha portato allo sviluppo del progetto SeaWHAM, illustrato nei capitoli 5 e 6, il cui scopo \ue8 stato quello di progettare, realizzare e caratterizzare un generatore di onda artificiale installato su banchina connessa al mare aperto che consente dunque di eseguire test in ambiente controllato ma significativo (facility unica in Europa), oltre alla progettazione, l\u2019installazione e campagna sperimentale su un sistema di conversione energetico da moto ondoso del tipo \u201cpoint absorber\u201d in grado di convertire l\u2019energia delle onde in altre forme, quali energia idraulica, pneumatica ed elettrica: si \ue8 quindi potuto caratterizzare sperimentalmente l\u2019intero sistema integratoThe current global and environmental energy scenario, increasingly focused on the search for sustainable energy solutions able to represent an effective and convenient alternative to the use of fossil fuels, considers the energy from the sea, and in particular from the waves, a very interesting resource, thanks to its enormous potential. However, the great variability of the phenomenon and the complex and harsh environment where it is intended to operate makes the identification of an efficient, robust, replicable and low-cost technology extremely challenging. In fact, although many solutions have been proposed over the years, today there is not a technology that is able to fully satisfy the requirements of reliability and low costs necessary for market success. In this context the present work aims at analysis of point absorber type wave energy converters and the development of a facility dedicated to experimental campaign in relevant environment, compassing in various activities such as dimensioning and design, numerical modelling, experimental activities. Chapter 4 shows the activity carried out regarding the wave energy converter called SeaSpoon, developed by the Thermochemical Power Group of the DIME Department of the University of Genoa. Several experimental campaigns have been carried out and different calculation codes have been developed in order to evaluate the potential performance of the device in different marine conditions, equipped with different types of profiles. Such technology has led to the development of the SeaWHAM project, illustrated in chapters 5 and 6, whose purpose was to design, implement and characterize an artificial wave generator installed on a quay connected to the open sea, to enable tests in a controlled but relevant environment (unique facility in Europe). Furthermore the project targeted the design, installation and experimental campaign on a integrated system able to convert the wave power (caught thanks to a "point absorber" wave energy converter) in other forms, such as hydraulic, pneumatic and electrical energy, with experimental characterisation of the entire efficiency chain

Energy management and load profile optimisation of 10 kWh BESS integrated into a Smart Polygeneration Grid subnetwork

Smart Polygeneration Grids integrate different prime movers, such as traditional generators, renewable energy sources and energy storage systems to locally supply electrical and thermal power to achieve high conversion efficiencies and increase self-consumption. Integrating different energy systems poses some challenges on the plant Energy Management Systems (EMS), which must accommodate different operational requirements while following the electrical and thermal loads. Battery Energy Storage Systems (BESSs) can provide additional flexibility to the system. This paper intends to evaluate the impact of integrating a Ni-Zn-based BESS into an existing cogeneration plant through a dedicated sensitivity analysis over the operative characteristics of the BESS itself (maximum power and capacity). The IES LAB of the Savona’s Campus already contains different energy systems: a cogenerative micro gas turbine, a heat-pump, solar thermal panels and two thermal energy storage systems that provide electricity and thermal power to the Smart Polygeneration Grid of the Campus. A new developed energy scheduler accommodates the integration of the new battery and meets the electrical and thermal demands. The aim is to demonstrate that integrating the BESS provides additional benefits in the system management and can reduce fuel usage and OPEX

A guideline to link the off-design performance of a micro-gas turbine to a heavy-duty gas turbine in a test rig that aim to investigate flexibility of GTCC

In the era of coal power station phase-out, natural gas fired combined cycle will drive the energy transition towards sustainable power generation. In a panorama of strong requirement for grid flexibility and non-dispatchable renewable penetration, the survival of a thermal power plant is strictly linked with operating successfully in compensating the renewable fluctuating production through flexible generation. The Italian case is taken as reference, considering that energy transition and renewable energy penetration may have similar effects also in different countries. In this direction, a test rig to investigate gas turbine compressor inlet conditioning techniques has been developed at the Tirreno Power laboratory of the University of Genoa, Italy. This is based on a Turbec T100 micro gas turbine (or microturbine), a Mayekawa heat pump and a phase-change material energy storage. The whole test-rig is virtually scaled up, through a cyber-physical system, to emulate a real 400MW combined cycle, with the heat pump governing the inlet conditions at the compressor. The microturbine is therefore used as the physical feedback for the system, whilst the steam bottoming cycle is simulated in real-time according to microturbine operation. The scope is to present the test rig and the procedure adopted to virtually scaleup a microturbine to a heavy-duty GT. the advantage of using microturbine for testing combined cycle flexibility options lays also on the possibility to make accelerated tests and to simulate multiple situations in compressed time windows

Energy management and load profile optimisation of 10 kWh BESS integrated into a Smart Polygeneration Grid subnetwork

Smart Polygeneration Grids integrate different prime movers, such as traditional generators, renewable energy sources and energy storage systems to locally supply electrical and thermal power to achieve high conversion efficiencies and increase self-consumption. Integrating different energy systems poses some challenges on the plant Energy Management Systems (EMS), which must accommodate different operational requirements while following the electrical and thermal loads. Battery Energy Storage Systems (BESSs) can provide additional flexibility to the system. This paper intends to evaluate the impact of integrating a Ni-Zn-based BESS into an existing cogeneration plant through a dedicated sensitivity analysis over the operative characteristics of the BESS itself (maximum power and capacity). The IES LAB of the Savona's Campus already contains different energy systems: A cogenerative micro gas turbine, a heat-pump, solar thermal panels and two thermal energy storage systems that provide electricity and thermal power to the Smart Polygeneration Grid of the Campus. A new developed energy scheduler accommodates the integration of the new battery and meets the electrical and thermal demands. The aim is to demonstrate that integrating the BESS provides additional benefits in the system management and can reduce fuel usage and OPEX

Gas Turbine Combined Cycle Range Enhancer - Part 2: Performance Demonstration

In the current energy scenario, gas turbine combined cycles (GTCCs) are considered key drivers for the transition towards fossil-free energy production. However, to meet this goal, they must be able to cope with rapid changes in power request and extend their operating range beyond the limits imposed by the environmental conditions in which they operate. The European H2020 project PUMP-HEAT (Pump-Heat Project, 2021, D4. 6 – “Validation Results in Energy -Hub of MPC With Cold Thermal Storage,”) aims at achieving this goal thanks to the integration of the GTCC with a heat pump (HP) and a thermal energy storage (TES). To study this setup, a dedicated cyber-physical facility was built at the University of Genova laboratories, Italy. The plant includes physical hardware, such as a 100kWel microgas turbine, (mGT), a 10 kWel HP and a 180 kWh change phase material-based TES. These real devices are up-scaled thanks to performance maps and real-time dynamic models to emulate a full-scale heavy-duty 400 MW GTCC with a cyber-physical approach. The control system determines the optimal configuration of the whole plant and the operative point of the real devices to minimize the mismatch with a real electric power demand curve. Different operative configurations are tested: one for reducing the power production of the plant below the minimum environmental load (MEL) and two for augmenting the plant maximum power under certain ambient conditions. From the analysis of these tests, it is possible to verify the effectiveness of the proposed concept and characterize the transient behavior of the real component

GAS TURBINE COMBINED CYCLE RANGE ENHANCER - PART 1: CYBER-PHYSICAL SETUP

Natural gas turbine combined cycles (GTCCs) are playing a fundamental role in the current energy transition phase towards sustainable power generation. The competitiveness of a GTCC in future electrical networks will thus be firmly related to its capability of successfully compensating the discontinuous power demands. This can be made possible by enhancing power generation flexibility and extending the operative range of the plant. To achieve this goal, a test rig to investigate gas turbine inlet conditioning techniques was developed at the TPG laboratory of the University of Genoa, Italy. The plant is composed of three key hardware components: a micro gas turbine, a butane-based heat pump, and a phase-change material cold thermal energy storage system. The physical test-rig is virtually scaled up through a cyber-physical approach, to emulate a full scale integrated system. The day-ahead schedule of the plant is determined by a high-level controller referring to the Italian energy market, considering fluctuations in power demands. By using HP and TES, it is possible to control the mGT inlet air temperature and thus enhance the operational range of the plant optimizing the management of energy flows. This article (Part 1) introduces the new experimental facility, the real-time bottoming cycle dynamic model, and the four-level control system that regulates the operation of the whole cyber-physical plant. The experimental campaign and the analysis of the system performance are presented in the Part 2

Energy management and load profile optimisation of 10 kWh BESS integrated into a Smart Polygeneration Grid subnetwork

Smart Polygeneration Grids integrate different prime movers, such as traditional generators, renewable energy sources and energy storage systems to locally supply electrical and thermal power to achieve high conversion efficiencies and increase self-consumption. Integrating different energy systems poses some challenges on the plant Energy Management Systems (EMS), which must accommodate different operational requirements while following the electrical and thermal loads. Battery Energy Storage Systems (BESSs) can provide additional flexibility to the system. This paper intends to evaluate the impact of integrating a Ni-Zn-based BESS into an existing cogeneration plant through a dedicated sensitivity analysis over the operative characteristics of the BESS itself (maximum power and capacity). The IES LAB of the Savona’s Campus already contains different energy systems: a cogenerative micro gas turbine, a heat-pump, solar thermal panels and two thermal energy storage systems that provide electricity and thermal power to the Smart Polygeneration Grid of the Campus. A new developed energy scheduler accommodates the integration of the new battery and meets the electrical and thermal demands. The aim is to demonstrate that integrating the BESS provides additional benefits in the system management and can reduce fuel usage and OPEX

Centrifugal Compressor Surge In Innovative Heat Pump - Part 1: Fluid Dynamic And Vibrational Analysis

Abstract In the current energy scenario, it is necessary to reduce fossil fuel consumption to achieve the far-sighted and stringent decarbonization goals. To date, heat is mainly produced through fossil fuels. Alternatively, electrically driven heat pumps can exploit renewable power to recover environmental and waste heat, offering energy efficient and environmentally friendly heating and cooling for applications ranging from domestic and commercial buildings to process industries. Centrifugal compressors are already used as prime movers of the working fluid in heat pumps, thanks to their industrial replicability, compact size, affordable costs, and good performance in terms of efficiency and low noise. However, they are subject to instabilities such as surge and stall like any other dynamic compressor and these phenomena develop quite differently than in classic open-loop systems such as gas turbines. In fact, such peculiarity is mainly due to the closed loop configuration with real gases in two-phase conditions, occurring in typical heat pump cycles. The aim of this paper is to experimentally investigate the behavior of a centrifugal compressor installed into an innovative close loop heat pump system under stable and unstable conditions from both vibrational and fluid-dynamic points of view. The impact of the main process parameters on the evolution of the instability is shown, highlighting how surge cycles change by varying system operating conditions. The experimental results shown in this paper can be a basis for the future development of validated mathematical models of closed loop heat pumps systems equipped with dynamic compressors