1,721,129 research outputs found
La tecnologia narrow band imaging e high definition television nel work up diagnostico del carcinoma laringeo: studio prospettico su 279 pazienti
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Techno-economic assessment of hybrid CSP-biogas power plants
Full text linkThis study aims to investigate the performance and economic benefits arising from the integration of concentrating solar power (CSP) plants with anaerobic digestion processes. To demonstrate the capabilities of hybrid CSP-biogas plants, the CSP section of the Ottana solar facility (Italy) is considered as a case study. A simulation model for the performance analysis of the hybrid system is developed, and the effects of variation in the volume of the anaerobic digester and the biogas storage capacity on the main performance indexes are evaluated. Furthermore, two different operating strategies for energy storage management are compared and the possible requirements for energy curtailment are analysed. Finally, a preliminary economic analysis is carried out. The results demonstrate the benefits and improvements in plant capacity factor and efficiency arising from proper sizing of the biogas section. Conversely, oversizing of the biogas section results in significant curtailments in biogas and/or solar field energy production, due to the limited storage capacity. Consequently, the optimal configuration, even from an economic point of view, is achieved by a biogas section of a size that is able to supply part (in the range of 10%–65%) of the nominal thermal power input required by the power block
A multi-scenario approach for a robust design of solar-based ORC systems
Full text linkThe application of Organic Rankine cycle (ORC) units in concentrating solar power systems is a very promising solution. However, fluctuations in the available solar energy often force solar-based ORC systems to operate at off-design conditions. An innovative methodology for finding robust design solutions of such ORC systems, based on the minimization of the expected Levelized Cost of Energy (LCOE), is therefore proposed. The expected variations in the ORC heat source and heat sink are considered during the design stage by adopting a multi-scenario approach. The proposed methodology has been tested by referring to a medium-scale ORC unit and by considering different working fluids. As case studies, the direct coupling of the ORC unit with a solar field and the integration of a thermal energy storage system have been investigated. The comparison of the results obtained by using a multi-scenario and a single-scenario approach highlights a reduction of the actual LCOE. The ORC configuration obtained by adopting a multi-scenario approach is characterized by lower performance under design conditions, but it is less sensitive to variations in the main inputs during off-design operating periods. This fact is particularly noteworthy for the case with the direct coupling of the solar field
Performance of integrated gasification combined cycle power plants integrated with methanol synthesis processes, Proc. Instn Mech. Engrs, Vol 215 Part A: J. Power and Energy, pp.347-356, 2001
No full textGoing 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
Analysis and optimization of solar-pumped hydro storage systems integrated in water supply networks
No full textA new strategy for the integrated management of water and energy in large water supply networks with the aim of reducing the energy costs of the energy intensive water facilities via the installation of photovoltaic plants is proposed. To address the non-dispatchability of photovoltaic systems, the integration of pumped hydroelectric storage plants based on the upgrading of existing pumping stations is also proposed. As case study, the proposed integrated solution is applied to two different pumping stations: the “Basso Flumendosa” pumping station, which is also candidate for the conversion to a pumped hydroelectric storage section due to its low utilization factor, and the “Monteleone-Roccadoria” one. A mathematical model is developed with the objective of maximizing the energy self-consumption. Different photovoltaic and turbine sizes are investigated to assess the achievable self-sufficiency rate and economic performance. The effect of the availability of the pumping station for storage purposes and the shape of the daily demand curves on the main result parameters are also evaluated. The results demonstrate that self-sufficiency rates higher than 65% are achievable only with the integration of the pumped hydroelectric storage section. Full self-sufficiency of the two pumping stations can be reached but a reduction of the profitability occurs
Integrated coal gasification and methanol synthesis power plants. Part II. Parametric analysis and performance evaluation
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