1,721,006 research outputs found
Heat recovery steam generator performance and degradation in a 400MWcombined cycle
No full textThis article presents a research project carried out by the Thermochemical Power Group of the University of Genoa and is concerned with the monitoring of a three pressure level heat recovery steam generator (HRSG). The work consists of the development of an original computer code using Matlab software that calculates the performance of heat exchangers, at different power plant operating conditions. This kind of software was developed with a twofold objective: to calculate the actual gas path inside the HRSG starting from the available measurements, thus obtaining the current effectiveness of all the heat exchangers in the HRSG, and to estimate the expected performance of each heat exchanger to be compared with the actual ones. Once the actual effectiveness and the expected effectiveness of the heat exchanger are defined, non-dimensional performance parameters suitable for degradation assessment can be defined. As a result of the sensitivity analysis, each performance parameter is coupled with an accuracy factor. The developed methodology has been successfully applied to historical logged data (3 years) of an existing large size (400 MW) combined cycle, showing good capabilities in estimating the degradation of the HRSG throughout plant life
Emulatore celle a combustibile: controllo dinamico temperature e pressione stack, monitoraggio remoto impianto ibrido con microturbina
No full textQuesto articolo presenta l'utilizzo di NI Compact FieldPoint e LabVlEW per il monitoraggio ed il controllo di un impianto emulatore di sistemi ibridi con microturbina a gas recuperata (Turbec T100) da 100 kW elettrici, accoppiata con un volume modulare di 4 m3 per l'emulazione di sisterni ibridi con cella a combustibile ad alta temperatura. L'impianto sperimentale, installato presso il laboratorio dell'Università di Genova, DIMSET-TPG, a Savona è il primo esempio in Europa ed il secondo al mondo del suo tipo, in quanto si propone di studiare sperimentalmente l'accoppiamento di una microturbina a gas con un volume modulare, al fine di verificare il funzionamento della macchina e del suo controllo in condizioni di forte off-design tipiche di tali sistemi ibridi e durante i transitori
Le contromisure adottate da Stati non materialmente lesi nel diritto internazionale
Full text linkSince 2014, many scholars have drawn renewed attention to the subject concerning unilateral coercive measures adopted by States. Due to the annexation of Crimea and to the conflict broke out in the Eastern regions of Ukraine, the Russian Federation has been accused of committing serious breaches of international law. As a response to them, several States, such as the United States, Japan, Australia and the members of the European Union, have adopted so called economic sanctions against Russia, in particular, against Russian officials and enterprises. International practice, far from being limited just to this case, shows how the adoption of economic restrictive measures as a reaction to serious breaches of international law has turned to be a relevant phenomenon in recent years.
The object of the present analysis is part of one of the most controversial field in international law: reaction of States against violation of international law and enforcement of international rules. Notably, the international Community is made up of sovereign, equal and independent States and, as a consequence, coercive measures may be implemented only through self-help measures. Such a decentralized reaction system need to be framed in a judicial architecture which seems necessary in order to avoid the primacy of power-based, instead of law-based, relations. Moreover, the complexity of the present subject has increased due to the emergence of the erga omnes obligations which are meant to protect fundamental values and basic principles of the international Community. All States have to comply with this kind of rules, thus entailing an overcoming in the classical bilateral structure of international relations. As a consequence, new questions have been raised by scholars concerning the possibility for States, not directly affected by the wrongful act, of reacting against violations of erga omnes obligations through the adoption of countermeasures. Violations of erga omnes obligations are deeply linked to the most serious breaches of international law which represent a threat to international peace and security and thus to the stability of international relations. This is the reason why it is possible to affirm that the central point this work aims at assessing concerns conditions of States’ reaction “between words and war”.
In particular, the present research will be focused on the lawfulness of countermeasures adopted by States not directly affected by the wrongful act in case of violations of erga omnes obligations. Indeed, the solution proposed by the Draft Articles on State Responsibility for internationally wrongful act, adopted in 2001, is deemed to be a compromise not setting out any clear regime. In view of the above, the first part of the work will be focused on the analysis of preliminary concepts considered as fundamental for a comprehensive understanding of the matter, and on the theoretical debate developed by scholars. The second part will be devoted to the exhaustive study of international practice and opinio of States in order to assess the emergence of a new international rule allowing the adoption of countermeasures by all States to enforce erga omnes obligations.
The third part will deal with the analysis of possible legal basis other than countermeasures which could justify unilateral coercive measures. The fourth and final part of the work will eventually discuss about the limits of countermeasures, steering the attention at proportionality and protection of economic, social and cultural human rights
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Bottoming cycle performance in large size combined cycle power plants. Part A: health monitoring system
No full textMonitoring of the thermoeconomic performance in an actual combined cycle power plant bottoming cycle
No full textThis paper presents a research project carried out by TPG (Thermochemical Power Group) of University of Genoa to develop innovative monitoring and diagnostics procedures and software tools for software-aided maintenance and customer support. This work is concerned with preliminary outcomes regarding the thermoeconomicmonitoring of the bottomingcycle of a combinedcyclepowerplant, using real historical data. The software is able to calculate functional exergy flows (y), their related costs (c) (using the plant functional diagram); after that non dimensional parameters for the characteristic exergonomic indexes (Δc, Δc*, Δk*) are determined.
Through a plant optimization (not described here) the reference conditions of the plant at each operating condition can be determined. Then, non dimensional indexes related to each thermoeconomic parameter are defined, in order to depict a “cost degradation”, and thus a significant rise in the production cost of the main products of the bottomingcycle (steam and power).
The methodology developed has been successfully applied to historical logged data of an existing 400 MW powerplant, showing the capabilities in estimating the “cost degradation” of the elements of the BC over the plant life, and trends in the thermoeconomic indexes
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