ESTiG - Resumos em Proceedings Não Indexados à WoS/Scopus
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- Acorn pre-drying: implications for the food industryPublication . Farrero, Bernardo; Ribeiro, Luís Frölén; Famiglietti, Antonio; Babo, PedroIn industry, 74% of the energy consumed is used in the form of heat. The food sector is characterised by a high share of processes that rely on industrial heat [1]. However, 90% of this thermal energy currently comes from fossil fuels, and only 9% is supplied by renewable sources [2]. The adoption of solar thermal technologies in the food industry offers multiple benefits that support its viability as an energy alternative to overcome this caveat. Firstly, by relying on a renewable and stable source. Manufacturers can reduce production costs and limit their exposure to the volatility of fossil fuel prices, thereby ensuring greater long-term price stability and predictability [3]. These reductions in energy costs may also be reflected in lower prices for the end consumer. Solar-assisted dehydration enables a decrease in moisture content, thereby limiting microbial growth and food spoilage [3]. In this regard, Solar Heat for Industrial Processes (SHIP) may also address food security concerns as storage losses are estimated to reach up to 20%, posing a critical challenge to food security [4]. The installation of in-situ pre-dehydration systems near harvesting zones provides clear benefits for energy efficiency and product quality. The Iberian Peninsula, notably, benefits from very high solar radiation, with many clear-sky days and extended sunlight periods, making it particularly suitable for solar-based pre-dehydration systems. By lowering produce weight and moisture before transportation, these systems decrease fossil energy demand during both industrial drying and large-scale transport [5]. This approach reduces the final product cost, as demonstrated by an in-situ solar dryer used for acorns in Alentejo holm oak groves. The passive, indirect mobile dryer, fitted with hanging bags, reduces acorn moisture content by 15% after 72 hours of drying, delays fruit spoilage, and cuts large-scale industrial heat input [6,4]. Thermal energy data from a factory case at Landratech, an acorn food producer involved in the MEDACORNET project, indicate that 15% in-situ pre-dehydration cuts thermal energy use by 52% during both initial and final drying stages of acorn flour manufacture [3]. This combined method lowers fossil fuel use, reduces losses, improves energy efficiency, and supports sustainability in the food processing sector.
- Austenitic hollow stainless steel beams at elevated temperatures: experimental and numerical validationPublication . Piloto, Paulo A.G.; Mesquita, Luís M.R.; Cruz, Áureo; Lopes, Nuno; Arrais, Flávio; Vila Real, Paulo
- Modelling techniques for the fire performance of empty cavities in LSF wallsPublication . Piloto, Paulo A.G.; Gomes, Stephan; Torres, Leonardo; Couto, Carlos; Vila Real, PauloThree different solution models were used to compare the fire performance of LSF walls with void cavities. The first solution method considers the air-structure interaction in the cavity region. The second solution method considers the existence of interface elements for the radiation heat transfer in the cavity region allowing the bulk temperature prediction. The third solution method considers the convection and radiation in the cavity region with a prescribed bulk temperature from experiments (hybrid). Solution methods 1 and 3 give a smaller root mean square error (RMSE), when compared with solution method 2. Solution method 3 gives a better approximation because can capture the main fire events during fire testing, such as the cracks and fall off.