Search

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.