Il mercato dell'efficienza energetica

L'ltalia e storicamente un Paese dalla bassa intensita energetica, essenzialmente per la struttura industriale poco energivora e dalla tassazione da sempre gravosa su molti prodotti energetici. ll Legislatore ha quindi deciso di intervenire allo scopo di migliorare l 'efficienza energetica del Paese introducendo un meccanismo di mercato per incentivare l'utilizzo di tecnologie efficienti, basato sullo scambio di titoli che attestino il risparmio energetico conseguito (Titoli di Efficienza Energetica, TEE, di dimensione unitaria pari a 1 tep). ll meccanismo e stato implementato attraverso i Decreti M.A.P. 20 luglio 2004

Pompe di calore a terreno: diffusione nel mondo e prospettive future

ll risparmio energetico, ta riduzione delle emissioni e to sviluppo delle fonti rinnovabili hanna portato ad una sempre maggiore attenzione per la tecnologia delle pompe di calore, e fra queste anche queUe a terrene (GHP). ll Paese leader per densita di impianti net territorio e la Svizzera, gli Stati Uniti contano il maggior numero di installazioni, mentre in ltalia non esiste ancora un vera e proprio mercato, anche se negli uttimi anni sono aumentati gti installatori: le ragioni di questa scarsa diffusione sono motteplici e sono strettamente connesse alta struttura energetica

COMPARISON OF BOREHOLE HEAT EXCHANGERS RESPONSE BASED ON DIFFERENT HOURLY LOAD MODELS

Borehole heat exchangers (BHE) are the most frequently adopted solution for ground coupled heat pump applications. In most installations, BHEs also represent the most important cost item, and a careful design analysis is needed to either assure long time performance or reduce the payback period, both parameters related to overall BHE length. The most efficient way, from a computational point of view, to predict the temperature evolution in time and space of a ground volume in contact with a system of BHE, is the recursive calculation of a basic thermal response factor, evaluated at different time steps and for given different heat pulses representing the building energy demand. Hourly load simulations, along multiyear periods, are considered the most reliable approach for simulating the thermal interactions between the ground and a system of BHEs and thus simulating the ground coupled heat pump (GCHP) behaviour during the expected lifetime of the whole system. Among the literature models, the DST one is often used as the reference analysis tool. The DST model is based on a description of the ground/BHE system in terms of interacting cylindrical volumes, arranged in a regular geometry. In this paper, the DST solution, in terms of hourly temperatures of the heat carrier fluid, is compared with the correspondent results obtained by implementing the MLAA approach of Bernier et Al. into a model able to employ suitable g-functions generated starting from the Finite Line Source solution of Lamarche and Beauchamp. The study is aimed at comparing the predicted temperature values by the DST and MLAA models with reference to different BHE configurations, having the same number of ground heat exchangers but different geometrical distribution (e.g. square configurations vs in-line configurations

Pompe di calore a terreno del tipo a compressione e ad assorbimento nella climatizzazione ambientale

Le pompe di calore possono consentire la climatizzazione ambientale estate-inverno e attraverso una progettazione attenta degli impianti riescono a garantire un risparmio energetico ed economico notevoli. L\u2019accoppiamento con il terreno sfrutta in maniera intelligente le caratteristiche delle pompa di calore, aumentando le potenzialit\ue0 di prestazione a fronte di costi che sono per\uf2 piuttosto elevati. Il presente lavoro valuta le prestazioni energetiche di pompe di calore, a compressione e ad assorbimento, per la climatizzazione ambientale, rivolgendo una particolare attenzione all\u2019accoppiamento con il terreno nei due casi e alle potenzialit\ue0 applicative per il raffrescamento anche passivo. Un\u2019analisi economica le confronta infine con i generatori di calore tradizionali

Historical and recent evolution of the Reno river mouth and adjacent areas.

The Reno river mouth and the adjacent areas are characterized by sandy beaches, wide brackish lagoons and extended salt marshes. The study area belongs to the Po Delta Park of the Emilia Romagna Region. The study consists in a reconstruction of the coastal evolution from the beginning of the 19th century to the present. It is an analysis of the historical and geodetic cartography and of the photogrammetry. At the beginning of the XIX century the river mouth was oriented eastward but, after some human modifications to its terminal stretch, the river mouth showed a gradually northward shift, inducing the growth of a spit; in the last century the spit entered in an erosive phase, which caused the reduction and the thinning of its shape. At the same time the northward movement of the sediment coming from the Reno river caused the occlusion of the outlet of the Bellocchio Channel inducing a decrease of water exchange between the \u201cSacca di Bellocchio\u201d and the Adriatic sea. From a naturalistic point of view, the \u201cSacca di Bellocchio\u201d is one of the most important area of the Po Delta Park; the worrying forecasts for the next decades give uncertain expectation for this esteemed, sensitive ecosystem. The territorial setting suggests the possibility of increased intensification of flooding events, the amplifications of beach erosion, an instability in the water circulation and an enhanced intrusion of the saline wedge into the channels and into the coastal aquifers. Even in a short-term scale, all the above factors will be able to significantly modify this ecosystem

Misure sperimentali delle prestazioni di caldaie a condensazione per il riscaldamento centralizzato

The condensing boiler technology has been known for at least two decades and its energy saving potential is nowadays acknowledged. Taking advantage from the additional heat recovered from the condensation of the water vapour contained in the exhaust flow, condensing boilers achieve, during test operations, efficiencies up to 108% on the LHV of natural gas. However, the yearly global performance of such boilers strongly depends on the type of heating system installed downstream. Due to the operating temperature ranges of the device, the radiant floor seems to be the most suitable heating system for such boilers. The present study evaluates the experimental data collected from a centralised plant, coupled to radiator and fan coil heating systems, over two years of operation. Although these medium/high temperature devices are not expected to fit at best to the condensing boiler, the yearly average performance reaches very high values

Prestazioni delle caldaie a condensazione. Misure sperimentali per il riscaldamento centralizzato

Misure sperimentali per il riscaldamento centralizzato. Il presente lavoro valuta le prestazioni di un impianto di riscaldamento centralizzato che opera con terminali a radiatore. Lo schema idraulico adottato consente un funzionamento del sistema che da un lato ottimizza la resa dei corpi scaldanti e dall\u2019altro minimizza la temperatura di ritorno in caldaia, requisito fondamentale per un buon funzionamento di quest\u2019ultima

The role of dunes in coastal hydrology and integrated coastal zone management.

Dune characterization in coastal zones is important for planning coastal defenses, groundwater management, and tourism development. Dune protection should be one of the main goals of any Integrated Coastal Zone Management Plan (ICZM). Coastal dunes efficiently oppose saltwater intrusion: their topographic elevation and their excellent infiltration capacity provide freshwater recharge and a hydraulic head that protect from saline intrusion according to the Ghyben-Herzberg principle (Fetter, 2001). The lateral continuity of the dunes system is also important for creating a continuous freshwater lens along the coast. As part of the Interreg IIIc Beachmed – “PosiDune project”, a monitoring campaign for groundwater levels and quality is being conducted on some test sites along stretches of the Ravenna coast: P.to Corsini, Marina Romea, Marina di Ravenna, Bevano river mouth. Dunes are still preserved in these areas and they act as natural defenses against storms, erosion and wave attack (Caruso et al., 2004; Caruso et al. 2006). A monitoring network has been established in each test site by placing piezometers both on the back and the crest of the dune and by carrying out a VES (Vertical Electri Sounding) geophysical campaign. The two methods (giving the chance to compare direct – piezometers - and indirect – geoelectric - data) has allowed to characterize the thickness of the fresh groundwater lens and the depth of the freshwater-saltwater interface. These actions have been integrated using: 1. a G.I.S. for data management; 2. a topographic and bathymetric reconstruction of the area using a LIDAR (Light detection and Ranging) survey; 3. a systematic seasonal update of the topography base and geomorphology using DGPS and theodolite surveys; 4. a survey of the geomorphologic evolution of the area through the periodical (monthly) acquisition of aerial images (flight height at 300m). The techniques employed are aimed at a precise charactetrization of the morphologic and hydrogeologic framework of the study areas. In addition, the maintenance of the monitoring system in future years will allow a better understanding of the effects of vegetation, dune restoration, and climate change to coastal hydrology and to ecosystem development (Gabbianelli & Sangiorgi, 2004; Ranjan et al. 2006). A clear comprehension of the role of dunes, achieved with this project, will be helpful for the management of the sites studied, especially considering their naturalistic values and peculiarities (they all belong to the Ramsar Zones list, SIC/ZPS sites list, Regional Po Delta Park – Emilia Romagna Region areas)

Fifteen years of research in innovative HVAC plants at DTG

At the Department of Management and Engineering (DTG) of the University of Padova (Italy), the research team led by Prof. Renato Lazzarin, formed by the au-thors, worked during the first fifteen years of the millennium on different topics fo-cused on innovative HVAC technologies. Both experimental and theoreti-cal/modelling studies were carried on: condensing boilers performances were eval-uated in different climates; a liquid desiccant system for the air conditioning of one of the DTG buildings, operating both in winter and in summer mode, was designed, realized and tested; a self-regenerating liquid desiccant cooling system able to de-humidify, heating or cooling the ambient air by an electric heat pump was installed in a new building of the Vicenza hospital, and a data logging system was set up to monitor several parameters; a Gas Engine Heat Pump plant for the air conditioning of another building of the DTG was designed, realized and monitored for a long pe-riod; a multi-source heat pump system for a school building was modelled and dy-namically simulated, and then designed and monitored; hybrid water/phase change materials tanks were modelled, designed and tested for thermal energy storage; fi-nally, thermal and electric solar cooling plants were modelled and dynamically simulated for evaluating energy performance. The paper summarizes the main ideas and results of the research during the fifteen years period of work together

Caratterizzazione idrologico-idrogeologica delle dune costiere

Le dune costiere, grazie alle loro caratteristiche di alta porosit\ue0 e permeabilit\ue0, possono rappresentare un buon serbatoio di acqua dolce, facilmente ricaricabile dalle precipitazioni meteoriche. Date la topografia rilevata e la buona capacit\ue0 infiltrante, l\u2019accumulo d\u2019acqua piovana porta la superficie freatica sopra il livello del mare, inducendo un controllo idrostatico sull\u2019intrusione di acque marine