211 research outputs found
Uncertainty Analysis of Feature Extraction from Expired Gas Traces
No full textNoninvasive medical analyses are a convenient method to study several pathologies even though their indirect nature often requires a complex processing to determine the relevant health "indicators". The usefulness of such indicators depends on the employed model, but also on the uncertainty that is connected to the complex processing involved in the indicator determination. This paper deals with the problems related to the estimation of the uncertainty when the indicators are computed by means of a nontrivial processing on recorded traces of clinical parameters. The paper is focused on the analysis of expired gas traces, but the procedure can also be applied to many other cases where the processing involves manual or automatic selection of suitable "key points" on repetitive traces
Energy-Exergy, Environmental and Economic Criteria in Combined Heat and Power (CHP) Plants: Indexes for the Evaluation of the Cogeneration Potential
No full textIn the first part of this work, combined heat and power (CHP) criteria pertaining to energy, exergy, environmental (pollutant emission) and economic aspects, have been investigated and compared. Although the constraints in legislation usually refer to energy efficiency, primary energy savings and greenhouse gas savings, other criteria should also be taken into account in order to obtain a better evaluation of a cogeneration plant. Here particular attention has been paid to saving indexes for both an individual CHP-unit and for a CHP-system, that is the complete system with all the cogeneration units and the auxiliary plants necessary to cover the users’ demand. Five indexes, named potential indexes, have been introduced to evaluate the cogeneration potential: one for energy saving, one for exergy, two for environmental aspects (global and local scale) and one for economic aspects. Finally, some indexes analysed in the paper have been applied to a case study concerning a district heating cogeneration system, and the different behaviour of the energy-exergy, environmental and economic aspects has been discussed
TABELLE di Termodinamica Applicata e Trasmissione del Calore. Proprietà delle sostanze di uso frequente
No full textSi tratta di un volume didattico di supporto agli insegnamenti di Termodinamica applicata, Trasmissione del calore e Fisica Tecnica per gli allievi dei corsi di ingegneria. Nel volume sono raccolte le proprietà termodinamiche e termofisiche per una selezione di materiali utili per affrontare un significativo numero di casi applicativi all'interno dei sopracitati insegnament
Studio dei campi termici in dispositivi di piccola e media potenza
No full textTesi di Dottorato di Ricerc
Distributed Generation-CHP or District Heating-CHP? A comparison between available technologies
No full textL'impiego dei superelementi nella soluzione accoppiata fem e problemi inversi per la stima delle proprietà termofisiche
No full textAnalisi del tipo di impulso da fornire per la stima della conduttività termica con generazione interna di calore
No full textESERCIZI SVOLTI DI TERMODINAMICA PER INGEGNERI - Metodologia e applicazioni sui concetti di base
No full textComparison of district heating CHP and distributed generation CHP with energy, environmental and economic criteria for Northern Italy
No full textDistrict heating CHP (combined heat and power) and distributed generation CHP have been compared in
this paper on the basis of energy, environmental and economic criteria, and a deviation index has been
proposed to establish, in aggregate form, what the improvement margins are for a given design choice.
Three technologies that are suitable for both district heating and distributed generation have been cho-
sen: a mature market technology, internal combustion engines, and recent entry market technologies,
that is, microturbines, and fuel cells. The calculations have been based on the real heating load curve
of a town in Northern Italy at the current market conditions: power and fuel prices, tax exemptions
relative to cogeneration, white certificates, etc. Two scenarios have been considered: maximum energy
saving and maximum present value saving. In the first scenario, district heating obtained better energy
and CO
2
savings than distributed generation, but critical values have been observed for local nitrogen
oxides (NO
x
) and particulate matter emissions, when internal combustion engines are adopted. In the
second scenario, all the options offer positive energy, environmental and economic savings, and the
payback times are significantly reduced compared to the previous scenario. The district heating options
show the best present value savings and payback times, while distributed generation is only economi-
cally viable when internal combustion engines are adopted. Microturbines leads to the best NO
x
savings.
Finally, the comparison with an alternative separate production of heat and power has shown that there
are scenarios where none of the analysed technologies leads to a significant improvement. All this
information, analysed together, provides a sort of map for policy makers through which they can better
orientate themselves among the different scenarios
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