Search results for "Q40"
showing 10 items of 21 documents
Thermoeconomic optimization of a renewable polygeneration system serving a small isolated community
2015
During the last years, special attention has been paid to renewable polygeneration technologies, able of simultaneously producing thermal, cooling, electrical energy and desalinated water from seawater. This paper focuses on an innovative polygeneration system driven by renewable energy sources, including the following technologies: hybrid photovoltaic/thermal collectors, concentrating parabolic trough (CPVT), a biomass heater, a single-stage absorption chiller and a multiple-effect distillation desalination system. The system is designed to cover the base load of an isolated small community. In previous papers, the dynamic simulation model about plant operation is discussed. In this paper,…
A Self-Adapting Approach for Forecast-Less Scheduling of Electrical Energy Storage Systems in a Liberalized Energy Market
2013
In this paper, an original scheduling approach for optimal dispatch of electrical Energy Storage Systems (ESS) in modern distribution networks is proposed. The control system is based on fuzzy rules and does not use forecasts since it repairs the past history according to the real time data on the electrical energy cost, renewable energy production and load. When the system detects a worsening of performances, the fuzzy logic rule-based control system self-adapts its membership functions using an economic indicator. The common use, in the relevant literature, of forecasted values in such systems can lead to large errors and economic losses. Moreover the speed of calculation guaranteed by th…
Spectra for Semiclassical Operators with Periodic Bicharacteristics in Dimension Two
2014
We study the distribution of eigenvalues for selfadjoint $h$--pseudodifferential operators in dimension two, arising as perturbations of selfadjoint operators with a periodic classical flow. When the strength $\varepsilon$ of the perturbation is $\ll h$, the spectrum displays a cluster structure, and assuming that $\varepsilon \gg h^2$ (or sometimes $\gg h^{N_0}$, for $N_0 >1$ large), we obtain a complete asymptotic description of the individual eigenvalues inside subclusters, corresponding to the regular values of the leading symbol of the perturbation, averaged along the flow.
Banki-Michell Optimal Design by Computational Fluid Dynamics Testing and Hydrodynamic Analysis
2013
In hydropower, the exploitation of small power sources requires the use of small turbines that combine efficiency and economy. Banki-Michell turbines represent a possible choice for their simplicity and for their good efficiency under variable load conditions. Several experimental and numerical tests have already been designed for examining the best geometry and optimal design of cross-flow type machines, but a theoretical framework for a sequential design of the turbine parameters, taking full advantage of recently expanded computational capabilities, is still missing. To this aim, after a review of the available criteria for Banki-Michell parameter design, a novel two-step procedure is de…
About the link between the detailed description of transitions in an ion and the average-ion models
2009
We study the link which exists between microscopic (detailed) models for the evolution of the electronic configurations in a population of ions and the macroscopic (average ion) models. Rigorous asymptotics are presented in situations where they exist (large temperature; almost empty or almost full shells), and numerical simulations are presented.
The Impact of the Poland Foreign Trade On Its Real CO2 Emissions
2017
CO2 emissions are a global problem. This means that nothing or very little will change if only particular countries are involved. The purpose of this paper is the attempt to show the real CO2 emissions of the Poland as well as the impact of its trade on CO2 emissions in other countries in the world and in the EU in 2015. This study was conducted on the group of countries that are the major emitters of CO2 in the world including most of the EU members. Actual CO2 emissions were achieved by applying the actual emission factor. This takes into account the transfer of CO2 in export products and services as well as those imported by particular countries. It has turned out that the real CO2 emiss…
Biogas production from the perspective of sustainable development
2020
One of the basic aspects of sustainable development strategy involves investments in green technologies, including energy production from renewable sources. Biomass, special organic waste which belongs to “green sources” of energy can be used in the methane fermentation process of biogas production to generate heat and electricity.Biogas power plants have functioned in the Polish energy industry for many years now. On the basis of the data available from Central Statistical Office, in 2014 the ratio of biogas accounted for 7.6% of the structure of primary energy derived from renewable sources in the EU and 2.6% in Poland. An important consideration related to the production of biogas is ass…
$PT$-symmetry and Schrödinger operators. The double well case
2016
International audience; We study a class of $PT$-symmetric semiclassical Schrodinger operators, which are perturbations of a selfadjoint one. Here, we treat the case where the unperturbed operator has a double-well potential. In the simple well case, two of the authors have proved in [6] that, when the potential is analytic, the eigenvalues stay real for a perturbation of size $O(1)$. We show here, in the double-well case, that the eigenvalues stay real only for exponentially small perturbations, then bifurcate into the complex domain when the perturbation increases and we get precise asymptotic expansions. The proof uses complex WKB-analysis, leading to a fairly explicit quantization condi…
Energy Management and Smart Grids
2013
The paper outlines energy management concepts and the smart grid evolution. The necessity of considering energy management as a crucial innovation in load supplying to permit a more powerful penetration of renewable energy usage at the building and city level and to perform energy savings and CO2 emissions reduction is pointed out. The driving factors to enhance the current power distribution are presented, and the benefits concerning smart grids are underlined. In the paper, a specific energy management analysis is reported by considering all the electric value chain, and the demand-side management and distributed on site control actions are described. To verify the benefit of energy manag…
Are Energy Market Integrations a Green Light for FDI?
2015
This paper studies the effect of energy market integration (EMI) on foreign direct investment (FDI). EMIs diminish energy uncertainty and price volatility in the host country and affect FDI through two channels: first, by harmonizing energy prices and, second, by reducing price dispersion. FDI may, as a result, increase both within and outside the EMI area, through energy stability mechanisms and price mechanisms, respectively. An empirical application on a global dataset including bilateral FDI data, during 2003-2012, using the gravity equation, shows that the integration of Portugal and Spain's electricity market in 2007 increased the amount of FDI's participants. Additionally, a positive…