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- Numerical experimental evaluation of the aerodynamic drag of the air curtain in Vertical Open Refrigerated Display CabinetsPublication . Nascimento, Samuel Mariano do; Heidinger, Gustavo Galdi; Gaspar, Pedro Dinis; Silva, Pedro Dinho daThis paper presents the experimental and numerical results of a set of air curtain evaluations in a Vertical Open Refrigerated Display Cases (VORDC) when subjected to external disturbances due to the transfer of people in front of the air curtain. Previous experimental studies identified that the stability of the air curtain depends on the climatic conditions and ambient air movement inside the stores. The ambient air and VORDC air curtain can be disturbed during the movement of people in front of the VORDC, causing a certain amount of cold air to flow out of the VORDC and consequently hot and humid air entering. It is not possible to quantify exclusively the increase in energy consumption due to the transfer of people in the real case, due to the other variables involved in the process. Thus, a robot (Automated Mannequin for Interference Reproduction in the Air Curtain - MARIA) was mounted on a rail placed around the VORDC, in a climate chamber with controlled environment according to climatic class (n. º 3: T=25°C; =60%). MARIA performed clockwise and counterclockwise movements around the VORDC, with velocities of 0.2 m.s-1 at 0.8 m.s-1, with a pitch of 0.2 m.s-1. For the numerical evaluation, a 3D CFD model was developed to predict and analyze the air flow and heat transfer in the air curtain and outside both ways, refrigerated space and ambient air due to transfer of a body parallel to the air curtain.
- Avaliação da qualidade e segurança alimentar pela previsão do crescimento microbiano em diferentes condições de conservaçãoPublication . Gaspar, Pedro Dinis; Domingues, C.; Gonçalves, Luís Carlos Carrilho; Andrade, Luís P.A segurança alimentar surge actualmente como uma das grandes preocupações das indústrias que se dedicam à conservação de produtos perecíveis. A avaliação da qualidade e segurança alimentar dos produtos evidencia as fragilidades da distribuição de produtos alimentares através da cadeia de frio, sendo um elemento crítico para a manutenção das condições adequadas de refrigeração. No presente trabalho avalia-se a segurança alimentar de produtos perecíveis armazenados em câmaras de conservação pela previsão do crescimento microbiano em diferentes condições termohigrométricas do ambiente de conservação. Com base numa ferramenta computacional, os tempos de crescimento dos principais microrganismos patogénicos encontrados nos produtos alimentares até à dose infectante são previstos e avaliados para as condições ambientais na zona de conservação de produtos. A recolha de dados decorreu durante 4 meses e os parâmetros ambientais foram medidos com uma sonda integrada de temperatura, humidade e velocidade do ar através do instrumento de precisão multi-função TESTO 400. Foram analisadas seis câmaras de frio e cada câmara foi monitorizada pelo menos durante uma jornada de trabalho. Para a previsão do crescimento microbiano foram utilizados os valores médios dos parâmetros ambientais. Os resultados indicam que variações das condições ambientais no interior das câmaras de conservação resultam no crescimento de diferentes tipos de microrganismos, alguns dos quais responsáveis por alterações nas características de qualidade dos produtos e condicionam o nível de segurança alimentar. A previsão do crescimento microbiano para as diferentes condições termohigrométricas do ambiente de conservação, possibilita estimar um período temporal durante o qual a segurança e qualidade alimentar não é assegurada.
- Experimental study of the influence of consumers movement parallel to the frontal opening of a multideck display case on the evaporator's thermal performancePublication . Heidinger, Gustavo Galdi; Nascimento, Samuel Mariano do; Gaspar, Pedro Dinis; Silva, Pedro Dinho daThis paper reports the results of experimental tests performed according to ISO 23953 (climate class n° 3: 25ºC and 60%) in an open refrigerated multideck display case (ORDC) to evaluate the influence of consumers passing in front of its opening on the thermal performance of the evaporator. The consumers’ passage in front of the ORDC is simulated by a robotic mannequin: MARIA - Mannequin for Automatic Replication of the Interference in the Air curtain. Tests are performed for MARIA velocity's ranging from 0.2 ms-1 to 0.8 ms-1, with 0.2 ms-1 velocity steps for two conditions: mannequin moving towards or against the airflow of the test room. All tests are performed in an ORDC with dual air curtain. The results quantify the influence of MARIA translational velocity on the frost formation in the evaporator coil and how this phenomenon affects the evaporator's airflow, inlet and outlet temperatures and sensible and latent heat loads. The analysis of experimental data provides valuable information for evaporator design taking into account usual in-store conditions.
- Real-Time Vital Signs Monitoring System Towards Livestock Health FurtherancePublication . Reigones, Ana Rita Runa da Silva; Gaspar, Pedro DinisThe application of information and communication technologies & electronics (ICTE) in agriculture has proved to be very efficient and revolutionary. With the adoption of increasingly efficient and modern technologies, the competitiveness and production in agriculture activities is carried out in a more sustainable way. Precise positioning and geolocation, geographic mapping, sensors and communication systems are tools that help the development of a complete and accurate system for livestock monitoring. This paper includes the proposal for a cattle or equine ICTE-based monitoring system developed as a belt. It contains a microcontroller that is used to evaluate the animal's heart rate and detect abnormal mobility. The correct evaluation of these two parameters proves very useful for the detection of many of the pathologies and anomalies that constitute economic losses for the producers. With accurate monitoring, it is possible to circumvent these events that are detrimental to animal production.
- Technological modernization and innovation of traditional agri‐food companies based on ICT solutionsPublication . Gaspar, Pedro Dinis; Soares, Vasco N. G. J.; Caldeira, João; Andrade, Luís P.; Soares, Cláudia D.This paper assesses the potential for technological modernization and innovation based on Information and Communication Technologies (ICT) in traditional agri‐food companies located in the central region of Portugal. A survey was applied to 50 agri‐food companies of cereals, cheese, olive oil, dry sausages, honey, wine, and horticultural sectors. Results analysis show that companies use computers, have internet service, and use social networks for business purposes. However, most of it have no webpage, do not use internet for advertising/selling/buying products, and have not promoted collaborators’ ICT training. Companies expect webpages to improve their productivity and/or marketing products/services. Recommendations were provided to promote the use of ICT for business purposes. Webpages, Facebook pages, and CRM systems were developed to a limited set of companies. The results of the satisfaction survey of the ICT solution confirm the company sales increase due to the web visibility gained by the company products.
- Comparing open and closed vertical refrigerated display cabinets at mild and tropical external environmentsPublication . Heidinger, Gustavo Galdi; Nascimento, Samuel Mariano do; Gaspar, Pedro Dinis; Silva, Pedro Dinho daThis paper reports the results of experimental tests performed according to ISO 23953 in vertical open and closed refrigerated display cabinets (VORDC vs. VCRDC). Tests were performed at a mild climate class (n. º 3: T=25°C; φ=60%) and a tropical one (n. º 6: T=27°C; φ=70%). The direct energy consumption is 46% higher at VCRDC due to the heated glass doors frame and defrost heaters. The product simulator temperature is higher and more stable at VORDC. The highest product simulator temperature is lower (-1.4°C) at the VCRDC and less stable (+2.7°C variation) due to the opening doors period. The total mass of condensed water at the evaporator is reduced 87% and the total heat load is 77% lower at the VCRDC. Thus, the estimated total energy consumption is reduced 42%. Given the current concerns with energy consumption and sustainability of the heat exchange processes, the VCRDC provide the best solution.
- iSensA - A System for Collecting and Integrating Sensor DataPublication . Caldeira, João; Soares, Vasco N. G. J.; Gaspar, Pedro Dinis; Rodrigues, Joel P. C.; Fontes, Ricardo; Silva, José Luís LopesThe idea of monitoring several types of parameters in various environments has been motivating significant research works in Internet of Things (IoT). This paper presents the design and construction of iSensA, a system for integrating and collecting information from sensors. The solution implements a multi-sensor monitoring system and then expands the monitoring concept to an IoT solution, by employing multi-network access, Web services, database and web and mobile applications for user interaction. iSensA system is highly configurable, enabling several monitoring solutions with different types of sensors. Experiments have been performed on real application scenarios to validate and evaluate our proposition.
- Intelligent micro-cogeneration systems for residential grids: a sustainable solution for efficient energy managementPublication . Cardoso, Daniel; Nunes, Daniel Figueira; Faria, João; Fael, Paulo; Gaspar, Pedro DinisThis paper presents an optimization approach for Micro-cogeneration systems with internal combustion engines integrated into residential grids, addressing power demand failures caused by intermittent renewable energy sources. The proposed method leverages machine learning techniques, control strategies, and grid data to improve system flexibility and efficiency in meeting electricity and domestic hot water demands. Historical residential grid data were analysed to develop a machine learning-based demand prediction model for electricity and hot water. Thermal energy storage was integrated into the Micro-cogeneration system to enhance flexibility. An optimization model was created, considering efficiency, emissions, and cost while adapting to real-time demand changes. A control strategy was designed for the flexible operation of the Micro-cogeneration system, addressing excess thermal energy storage and resource allocation. The proposed solution’s effectiveness was validated through simulations, with results demonstrating the Micro-cogeneration system’s ability to efficiently address high electricity and hot water demand periods while mitigating power demand failures from renewable energy sources. The research presents a novel approach with the potential to significantly improve grid resilience, energy efficiency, and renewable energy integration in residential grids, contributing to more sustainable and reliable energy systems.
- Inovenergy - Eficiência Energética no setor AgroIndustrial: Manual de Boas PráticasPublication . Andrade, Luís P.; Nunes, José; Silva, Pedro Dinho da; Gaspar, Pedro Dinis; Domingues, Luísa Catarina; Nobre, Telmo; Gaspar, Adélio; Feliciano, Manuel; Araújo, Alberta; Brito, Paulo; Félix, PedroNos últimos 150 anos o clima tem-se tornado progressivamente instável e mais quente. Se nada for feito, estas alterações tendem a acentuar-se e afetarem negativamente o ambiente, com efeitos a nível dos recursos hídricos, das zonas costeiras, da agricultura, da saúde humana, da energia, e da biodiversidade. Estas alterações climáticas estão diretamente relacionadas com o crescimento das emissões dos Gases de Efeito Estufa (GEE), em que se salienta o papel do dióxido de carbono (CO2). Outros gases relevantes para o efeito de estufa incluem o metano (CH4), os óxidos de azoto (NOx) e os compostos fluorados. As emissões de CO2 e de NOx produzidas pelo Homem são maioritariamente atribuídas ao setor energético e aos transportes. A solução para reduzir o excessivo consumo de energia está longe de ser conhecida, contudo devemos procurar fontes de energia alternativas e adotar medidas que promovam essa redução. É neste âmbito que se aplica a eficiência energética. A forma como a energia é utilizada é impreterivelmente uma questão chave neste processo. Como tal, é imprescindível aumentar a eficiência energética nas operações das empresas, de modo a promover a redução de custos, aumentando a competitividade, contribuindo ainda para a redução da intensidade energética global.
- Experimental analysis of the thermal entrainment factor of air curtains in vertical open display cabinets for different ambient air conditionsPublication . Gaspar, Pedro Dinis; Gonçalves, Luís Carlos Carrilho; Pitarma, R. A.The vertical open refrigerated display cabinets suffer alterations of their thermal performance and energy efficiency due to variations of ambient air conditions. The air curtain provides an aerothermodynamics insulation effect that can be evaluated by the thermal entrainment factor calculation as an engineering approximation or by the calculus of all sensible and latent thermal loads. This study presents the variation of heat transfer rate and thermal entrainment factor obtained through experimental tests carried out for different ambient air conditions, varying air temperature, relative humidity, velocity and its direction relatively to the display cabinet frontal opening. The thermal entrainment factor are analysed and compared with the total sensible and latent heats results for the experimental tests. From an engineering point of view, it is concluded that thermal entrainment factor cannot be used indiscriminately, although its use is suitable to design better cabinet under the same climate class condition.