1,407 research outputs found
Transient Analysis of a Micro Gas Turbine With Fuel Composition Change
No full textThe aim of this study is to analyze the effect of fuel composition change on the performance and dynamic behavior of a T100 micro gas turbine. Fuel flexibility is a key asset of micro gas turbines and can support the energy transition when alternative fuels obtained from renewable energy sources are used. While the current research is mainly focusing on improving combustor performance, it is also required to investigate the effects of different fuel blends on the overall system. During transient operation, the use of fuels with a low LHV requires an increased fuel mass flow that can potentially reduce the compressor surge margin. Conversely, sudden composition changes of high LHV fuel can cause temperature peaks, detrimental for the turbine and recuperator life.
In this paper, a validated transient model for the T100 machine has been used to simulate the injection of different fuels in the natural gas line (feeding the burner). Injection of hydrogen and ammonia, two promising carbon-free fuels, have been tested. A transient analysis was performed with this tool to monitor the main performance parameters with the aim to (i) verify compressor safe operations during different working conditions and (ii) to identify appropriate fuel composition change schedules to ensure Turbine Outlet Temperature values within an acceptable range, while keeping the original fuel control system
Distributed bounded-error state estimation based on practical robust positive invariance
No full textWe propose a state estimator for linear discrete-time systems composed by coupled subsystems affected by bounded disturbances. The architecture is distributed in the sense that each subsystem is equipped with a local state estimator that exploits suitable pieces of information from parent subsystems. Furthermore, each local estimator reconstructs the state of the corresponding subsystem only. Different from methods based on moving horizon estimation, our approach does not require the online solution to optimisation problems. Our state estimation scheme, which is based on the notion of practical robust positive invariance, also guarantees satisfaction of constraints on local estimation errors and it can be updated with a limited computational effort when subsystems are added or removed
Experimental characterization of a micro gas turbine fueled by ammonia-natural gas blends
No full textGiven the need to decarbonize the current energy production sector, to mitigate climate change and reduce greenhouse gas (GHG) emissions, innovative fuels are gaining increasing attention. In this context, ammonia represents a promising carbon-free energy carrier that can be used in energy storage, agriculture, transportation, and power conversion. This study focuses on an experimental analysis of a micro gas turbine (mGT) powered by various blends of natural gas and ammonia. The plant was developed within the framework of the FLEXnCONFU (FLEXiblize Combined Cycle Power Plants through Power-to-X Solutions using Non-CONventional Fuels) European project and is located at the Innovative Energy Systems laboratory of the University of Genoa. In this paper, the test rig, including the mGT retrofitting, fuel mixing system, and injection lines, is fully described, along with all the instrumentation required for control, measurement, and safety. The experimental campaign was conducted using different ammonia contents in the fuel blend at different mGT loads. The main operating mGT data (e.g., rotational speed, mass flow rate, injection pressure, turbine inlet, and outlet temperatures) that were acquired during the tests are presented and discussed. The measured results were used to develop an mGT performance map, which demonstrates the benefits of using ammonia in terms of total power production and CO2 reduction
Portrait of the Author in (Him/Her)self
No full textA fragment of a philosophical essay by Jean-Luc Nancy and Federico Ferrari titled Iconographie dell’auteur (Paris, 2005), published for the first time in Polish, that addresses the problem of a relationship between the image of the author and his/her work
Introduzione a: G. F. Cromaz Pagine goriziane. Liberal-nazionali e cattolici popolari italiani al Comune di Gorizia (1851-1914)
No full textThe author describes the activity of the communal administration in Gorizia from 1848 to 1918. He uses documents of the communal archive and of a former communal adviser, Luigi Faidutti, leader of christian-social party in the austrian Friuli. The essay gives an important place to discussion about the creation of a public water service
Securing XML documents with author-X
No full textAuthor-X is a Java-based system that addresses the security issues of access control and policy design for XML document administration. Author-X supports the specification of policies at varying granularity levels and the specification of user credentials as a way to enforce access control. Access control is available according to both push and pull document distribution policies, and document updates are distributed through a combination of hash functions and digital signature techniques. The Author-X approach to distributed updates allows a user to verify a document's integrity without contacting the document server
Le lettere di Francesco Paolo Como a Ettore Ferrari.
No full textIn 1923 the sculptor Francesco Paolo Como (Taranto, 1888-Rome, 1973) wins the contest for the Monumento ai caduti in Taranto. As known, the realization of this work suffers many delays because of tension between the author and the various committees. Only in 1953, the last group, the Aquilifero, can be set up. The article analyses the sequence of events related to the monument through a series of missives between Como and his mentor Ettore Ferrari (Rome, 1845-1929). Through this correspondence is possible to write a clearer history of the monument and his author, explaining the reasons of Como’s anxiety, his relationship with Ferrari and his social role into the ‘fascistissima’ Taranto
Il Naxiǰewan di Luigi Villari.
No full textLuigi Villari’s book Fire and Sword in the Caucasus, published in London in 1906, is
widely quoted by the scholars who study the history of South Caucasus at the time
of the first Russian Revolution in 1905. After a short introduction about the interest-
ing figure of this author, the first part of the article will take into consideration Villari’s
peculiar attitude toward the Armenians. The larger part of the article will consider his
first-hand description of the massacres perpetrated by the Azeris (Tartars) in the region
of Nakhichevan. As a matter of fact, Luigi Villari’s testimony of the tragic events of 1905
is more interesting than ever to understand the origins of a contrast that continues—
even if in a deeply different situation—to stain with blood the relationship between Armenians and the South Caucasian Turks
Rhétorique et compréhension
No full text@incollection{OL-FERRARI-2006, author = {St{é}phane Ferrari}, title = {{Rh{é}torique et compr{é}hension}}, chapter = {7}, pages = {195-224}, booktitle = {Compr{é}hension des langues et interaction}, editor = {G{é}rard Sabah}, series = {Trait{é} IC2, s{é}rie Cognition et traitement de l'information}, publisher = {Herm{è}s Sciences, Lavoisier}, year = {2006}
Le texte évaluatif : de la phraséologique à l'analyse du discours
No full text@inproceedings{AC-FERRARI-2006, author = {St{é}phane Ferrari and Dominique Legallois}, title = {{Le texte {é}valuatif : de la phras{é}ologique {à} l'analyse du discours}}, year = {2006}, booktitle = {Actes du 25e Colloque international sur le lexique et la grammaire}, organization = {September}, address = {Palerme, Italie} }International audienc
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