1,721,250 research outputs found
Coroncina, mignola e piantone di Mogliano storia di sapori
No full textCoroncina, Mignola e Piantone di Mogliano storia di sapori
Oli tipici tra economia e paesaggio
Caldarola 11 Novembre 2012
Atti del convegno di studi
organizzato da
Università degli Studi di Camerino, Comune di Caldarola, Comunità Montana dei Monti Azzurri
con il patrocinio di
Camera di Commercio Industria Agricoltura e Artigianato di Macerata
A cura di: Berrettoni Mario, Conti Paolo, Zamponi Silvia
ISBN: 978-88-67680-00-
Vittorio Conti : Paolo Maria Dora. Della repubblica dei togati alla repubblica dei notabili, 1978. («Biblioteca dell'Archivio Storico Italiano », 20.)
No full textGeorgelin Jean. Vittorio Conti : Paolo Maria Dora. Della repubblica dei togati alla repubblica dei notabili, 1978. («Biblioteca dell'Archivio Storico Italiano », 20.). In: Dix-huitième Siècle, n°13, 1981. Juifs et judaïsme. pp. 491-492
La Falda Austroalpina dell'Ortles e l'evoluzione tettonica delle Dolomiti dell'Engadina (Svizzera-Italia)
No full text
Second-law analysis of GSHP systems: a case study
No full textGround source heat pump (GSHP) systems are globally recognized as one of the most promising generation technologies in terms of economic and energy savings. However, operative performances can be lower than expected. The reasons can be ascribed to: i) an incomplete technological development; b) a not-optimized sizing and control strategies. A comprehensive approach to the optimal sizing and control methodologies has been discussed in previous works: remarkable economic and energy savings can be achieved with an optimized synergy between geothermal source and back-up generators. Furthermore, additional technological developments are required to improve current GSHPs performance. As well known, GSHP systems involve different subsystems: ground source, ground-coupled heat exchangers, heat pump unit, and back-up generators: this work aims at identifying the one that mainly affects the overall efficiency
The Impact of Hydraulic Sizing on the Performance of Ground-Coupled Heat Pump Systems
No full textA novel approach to the hydraulic sizing of borehole heat exchangers (BHEs) is presented. The choice of flow rate and operating temperature of fluids and their impact on the following elements are investigated: heat transfer performance, head losses, pumping energy consumption, and the performance of coupled heat pump. Up to now, sizing methodologies investigate principally the ground behavior when heat flux is applied: desired results consist mainly in number and length of BHEs necessary to meet the thermal load. Hydraulic analysis is often rough performed. Here, an integrate modeling of the overall system are considered through an innovative set of equations. It includes main elements that determine the performance of a GSHP system: ground thermal modeling, heat transfer effectiveness of BHEs, sensitivity of the heat pump to the sources temperatures. Results shows how an approximate hydraulic sizing of a BHE field, and a decoupled choice of the heat pumps device can conduct the operating point of GSHP system far from planning condition: overall coefficient of performance is consequentially reduced
A novel evaluation criterion for GSHP systems based on operative performances
No full textThis work proposes an innovative approach to the ground source evaluation for heat pump systems. The initial characterization of the soil (e.g. thermo-physical properties, temperature.) is integrated with classical considerations about HVAC design. In particular, we propose to analyze the viability of a ground source project through the evaluation of its final operative performances. The achievable savings with respect to alternative technologies become the key-parameter for project viability and system design. The proposed methodology aims to investigate the best level of exploitation of the ground source according to soil thermo-physical properties, local external climate, building thermal load, and back-ups efficiency. Through a plain test case, we show how the utilization of the sole GSHP technology, even if technically feasible, might not be the best design solution: indeed, the large number of required ground heat exchangers could make the project unfavorable. On the contrary, a proper synergy among GSHP and back-up generators leads to notable energetic and economic benefits, ensuring higher energetic performances, lower installation costs, and a sustainable exploitation of the ground-source
Dimensionless Maps for the Validity of Analytical Ground Heat Transfer Models for GSHP Applications
Full text linkThis article provides plain and handy expressions to decide the most suitable analytical model for the thermal analysis of the ground source in vertical ground-coupled heat pump applications. We perform a comprehensive dimensionless analysis of the reciprocal deviation among the classical infinite, finite, linear and cylindrical heat source models in purely conductive media. Besides, we complete the framework of possible boreholes model with the “hollow” finite cylindrical heat source solution, still lacking in the literature. Analytical expressions are effective tools for both design and performance assessment: they are able to provide practical and general indications on the thermal behavior of the ground with an advantageous tradeoff between calculation efforts and solution accuracy. This notwithstanding, their applicability to any specific case is always subjected to the coherence of the model assumptions, also in terms of length and time scales, with the specific case of interest. We propose several dimensionless criteria to evaluate when one model is practically equivalent to another one and handy maps that can be used for both design and performance analysis. Finally, we found that the finite line source represents the most suitable model for borehole heat exchangers (BHEs), as it is applicable to a wide range of space and time scales, practically providing the same results of more complex models
Numerical simulation of geothermal resources: a critical overlook
No full textThe numerical simulation is a challenging part of the study of the geothermal resources. In this paper some of the main problems, criticalities and issues related to both simulation of reservoirs and ground thermal analysis are treated. Numerical simulation is successfully applied in several scientific fields and to solve a great number of engineering problems. Several applications in geothermal energy are possible, like reservoir engineering, ground heat exchange for HVAC (Heating, Ventilation and Air Conditioning) applications, environmental impact, hydrogeology.
An interdisciplinary approach is necessary to pursue an aware and reliable utilization of the numerical models, due to the great complexity of the geothermal phenomenon. The different backgrounds involved are Numerical Analysis, Earth Sciences, Energy Engineering, Geochemistry. In this paper the authors discuss about the numerical simulation of the resource (generally considered): large spatial scale (reservoir engineering) and small spatial scale (shallow systems)
examples are both illustrated. Particular attention is paid on these aspects: thermophysical parameters, boundary conditions, physical equations of the model, potential assessment, coupling of the “plant-reservoir” system. All of them are important to elaborate a critical and engineering point of view. For example, physical hypothesis and assumptions about the system are two of the main criticalities in the application of numerical approach; they have to be clear and reliable and their consequences should be known before the simulation is set up. The principle “trash in, trash out” should be known since the accuracy level of the input data is not always dealt as a problem, but it has a great influence on the results. The industry and market operators sometimes look at numerical models in a wrong way. Models should be related to the decisions about the utilization plant (heat/power) size. If the sustainability of a utilization project is seen from a global point of view, in which Environment, Economy, Technology are merged, the
numerical models can be seen as the synthetic instrument to elaborate industrial strategies in relation to the resource durability. A discussion about when and why numerical models should be successfully implemented is carried on, also taking into account case studies and practical examples
Energy balance of the Italian hydrothermal spa system
No full textAfter heating and cooling, thermal balneology was in 2010 the second most important sector of direct uses in Italy, with 149 thermal localities using hot water for balneotherapy, with no combination with other direct uses. This is why, in 2009 and 2010, UGI conducted regional studies on their water and energy balance to investigate the possible optimization of the heat consumption by coupling thermal bathing with other upstream and downstream direct uses. Moreover, since two thirds of the spas utilize water in part artificially heated, the studies also evaluated the energy consumption of the heating process and compared the result with the geothermal fraction of the energy used.
After an overview of the geological and hydrogeological settings of low-temperature geothermal resources, the paper describes the situation of thermal balneology in Italy at Dec. 2010, estimating the volume of hot water consumed, and the amount of heat used by the overall spa system at the regional and national level. The methodology devised to analyze the various components of the water and energy balance and its conceptual flow diagrams are described in the paper.
The paper also reviews the different types of direct uses which, depending on the temperature of the water available upstream (T > 38°C) and downstream (T < 28°C) of the thermal establishments, might be associated with the thermal balneotherapy.
Finally, the paper pinpoints the benefits that might arise from the development of multiple uses combined with the thermal balneology, in terms of: i) oil saved; ii) displaced CO2 emissions; iii) higher number of spa users; iv) increased tourist activity in the spa areas; and v) creation of new production activities and jobs in the same areas
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