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The Italian industrial sector contains 22% of the final energy demand due to the poor energy performance of manufacturing buildings. This proposed study aimed to evaluate retrofit interventions for existing industrial buildings integrating photovoltaic solutions into the external envelope to improve both the environmental sustainability and the facade performance. The methodology is based on an innovative procedure including BIM and generative design tools. Starting from the Revit model of a representative case study, interoperability with energy analysis plugins via Grasshopper were exploited to optimize the differently oriented facade layout of photovoltaic modules to maximize the electricity production. In the case of comparable facade sizes, the building orientation had a minor impact on the results, although a southern exposure was preferable. The optimized configuration involved the installation of PV panels with a tilt angle ranging from −35° to −75°. The best compromise solution between the panel surface area and energy production during the summer solstice involves 466 m2 of PV modules. The design-optioneering approach was used to define possible alternatives to be explored for the possible installation of solar shading systems on existing windows. In this case, the impact on visual comfort within the working environment was chosen as a reference parameter, along with the value of the indoor air temperature. A decrease in this parameter equal to 0.46 was registered for the solution with horizontal (or nearly horizontal) shaders and a spacing ranging between 0.2 and 0.4. The integration of the BIM environment with generative design tools effectively assists decision-making processes for the selection of technological solutions in the building sector. [ABSTRACT FROM AUTHOR]

As the energy efficiency is at the heart of the integrated European Union energy policy, which aims to protect the environment through various research projects, the application of the Stirling engine for diffused electricity generation is one of the possible paths for low-carbon application. That is today particularly topical, just looking at the major interest paid at European level at the energy communities, also in terms of incentives and policies facilitating and supporting such initiatives. Although the tested engine V-160 runs on natural gas, its emissions can be neglected in comparison with the internal combustion engines, due to the much more favourable external combustion under the lower pressures and temperatures, as well as to the working medium, which is helium. Next step, becoming every day more and more relevant, will be using hydrogen as a clean (and green) fuel. A major advantage of the proposed engine for use in power generation is the constant speed under different loads. According to the thorough parametric analysis after 200 hours of operation of the engine at the University of Rome La Sapienza, new evidence of the possibilities of performance improvement was obtained. Compared to the Stirling engine with low temperature difference, it has a much lower Schmidt factor of about 21%, which means that a real thermodynamic efficiency of the cycle could be improved. The scope of the analysis was to determine the power that is changed due to the mass of helium and the power that is changed due to the temperature difference. Based on the experimental data, it is found that the temperature difference and the mass of the working medium have a reciprocal relationship. In such a working condition, the engine power is simultaneously increased due to the greater mass of helium, but at the same time decreased due to the decrease in the temperature difference, which is not valid for other types of Stirling engines. The resulting power can be optimized according to a new expression, presented in the paper.

Industrial buildings in Italy are currently highly energy intensive. Their old age prevents them from complying with current environmental and energy requirements; consequently, redevelopment initiatives should therefore be considered in order to improve the overall performances of these facilities. Within this framework, this research aims to evaluate the results achievable by introducing indirect green façades as retrofitting solutions. Starting from a real case study building located in central Italy, energy simulations were carried out using DesignBuilder, varying buildings' geometry, dimensions and windows-to-wall ratios as well as greenery coverage percentage. The evidence shows an appreciable potential for green walls to improve the summer performance of industrial buildings, as they resulted in a reduction in cooling energy demand during the summer season of about 14%. Moreover, external surface temperature was reduced by 8 °C during the hottest days, ensuring higher durability in building components. Furthermore, indoor air temperature during the summer design week decreased by 0.6 °C. During the winter season, the green façades avoid exploiting free solar gains due to incident solar radiation, and a slight increase of about 4% occurred in heating energy needs. For this reason, the implementation of deciduous vegetation species should be evaluated for industrial buildings located in Mediterranean latitudes. [ABSTRACT FROM AUTHOR]

Precast reinforced concrete technology has been widely applied in Italy for industrial facilities throughout the years and nowadays older buildings show structure and energy-related deficiencies. In order to promote integrated redevelopment interventions, the research sets a methodological framework to investigate such a vast building stock and proposes a classification of the different typological variants registered according to structural, architectural, and technological aspects. This paper focuses on the industrial building stock realized recurring to prefabrication techniques in the geographical cluster of Casentino, in Tuscany. The research involved 675 buildings intended for production activities whose specifications were collected in a GIS database as alphanumerical parameters. Data, obtained through digital surveys, aerial views, and on-field recognitions, were postprocessed to provide a general overview of the most recurring characteristics and highlight evolutionary trends over years. Seven typological declinations were identified for prefabricated reinforced concrete industrial buildings and their diffusion was related to the different periods of constructions. Roofing systems, structural solutions, and external wall components were chosen as key parameters for the classification procedures. The definition of recurrent typological solutions in industrial buildings is meant as a preparatory operation that will facilitate the assessment of their current architectural, technological, structural, and specifically energy and environmental performances. This research paves the way toward the development of protocols and guidelines containing integrated retrofitting strategies and solutions tailored on the specific issues of each variant. [ABSTRACT FROM AUTHOR]

The high efficiency of concentrated solar power (CSP) in energy conversion makes it a very attractive device for using solar energy as a substitute of nonrenewable energy sources. The open volumetric receiver plays an important role in the performance of a CSP. The optimized design of solar receiver implies the thorough knowledge of the heat transfer between the air and the foam and of the temperature distribution in the receiver. Heat transfer in the cylindrical SiC porous volumetric receiver of a solar tower, undergoing the impact of concentrated solar radiation, is investigated numerically in this paper. Governing equations are written with the volume averaging technique. A two-equation model for the energy equation, under the local thermal nonequilibrium assumption, is used. Numerical simulations are carried out through the commercial code COMSOL Multiphysics. The solid and fluid temperatures, the fluid velocity and the pressure drop, for various boundary and morphological conditions, are predicted and discussed. The receiver efficiency is finally maximized carrying out an extended parametric analysis of process parameters. [ABSTRACT FROM AUTHOR]

Byline: Graham Walker, Philipp Wagner, Vincenzo Naso, Lorenzo Fedelo Stirling engines are heat engines that operate on a closed thermodynamic regenerative cycle and are used as power systems, refrigerators or heat pumps. Recent developments in Stirling technology allow the use of low temperature heat sources including flat plate solar collectors. New concepts for low-cost, low ΔT Stirling engines that may be made by village craftsmen using locally available materials are presented. It is anticipated that the machines will be used for water pumping, low capacity refrigerators for food and vaccine preservation, for air conditioning and for low level electric power generation (trickle charging an automobile battery to illuminate a 20/40 W bulb for a few hours during the dark hours).

An experimental investigation on air natural convection in a vertical channel asymmetrically heated at uniform heat flux with downstream unheated parallel extension is performed. Results are obtained for different values of wall heat flux and geometrical parameters.

In Italy, a large stock of public housing was built during the 1970s and 1980s with industrialized/prefabricated techniques. These buildings have envelopes characterized by the presence of many thermal bridges and low transmittance values. In addition, they feature inefficient single heating systems in residential units and no cooling/ventilation systems. As a result, these buildings require urgent energy retrofitting actions, and it is therefore necessary to define procedures that will guarantee effective results. The possible interventions must be compatible with building construction techniques as well as be minimally invasive and inexpensive. There are only a limited number of technical solutions, considering that residents should not have to move out during the renovations. In most Italian climatic zones, current interventions are usually linked to external insulation and window replacement, leading to an improvement in energy performance and comfort only during winter. Internal comfort conditions tend to worsen in summer months because seasonal temperatures tend to increase by a few degrees. Therefore, solutions should be proposed that will improve both summer and winter conditions. This work proposes an energy recovery procedure applied to a representative building from the abovementioned period located in the Florence area and constructed with an industrialized system named the "tunnel system" (great panels structure). The procedure used in this study provides for the redevelopment of the envelope and the application of a simple mechanical ventilation system to achieve substantial energy savings and improved indoor comfort conditions. [ABSTRACT FROM AUTHOR]

This work studies the teenage pedestrian–sport utility vehicle (SUV) crash; injury to the vital parts of the body, such as the head and chest, and to the femur is evaluated. More advanced injury criteria are applied, as provided in the rules. The multibody technique is applied by making use of SimWise software and of the teenager anthropomorphic model, the use of which is now consolidated. Head injury criterion (HIC) is used for the head, thoracic trauma index (TTI) criterion for the thorax in the case of side impact and 3 ms criterion in the case of frontal impact, while the force criterion is used for the femur. Both the TTI and femur load evaluation require non-substantial modifications of the dummy, by insertion of sensors for the measurement of the acceleration of the 4th rib and the 12th vertebra and two very thin plates at the knees for the correct individuation of the contact point with the vehicle bumper. Particular attention is paid to the front shape of the vehicle, concluding that the SUV examined in this paper is less dangerous than the sedan studied in a previous work, since its frontal dimensions (bonnet angle, bumper height and bonnet height) are more advantageous. However the teenage pedestrian in a lateral position is less prone to injuries in the head and chest, with respect to the frontal position; the pedestrian's position has little influence on femur damage. Furthermore, the braking of the vehicle reduces the possibility of crash fatality. In conclusion, a theoretical approach is shown, to highlight the influence of the vehicle mass on the pedestrian speed after the impact. [ABSTRACT FROM AUTHOR]

The effect of the distance between an inclined plate, partially heated and downward facing and a parallel shroud on natural convection is investigated. Nusselt number exhibited minor discrepancies due difference of some conditions and of heat conduction in the channel walls.