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- Parametric Numerical Study of the Airflow and Thermal Performance in a Real Data Center for Improving SustainabilityPublication . Macedo, Diogo Gonçalves Costa e Silva de; Godina, Radu; Gaspar, Pedro Dinis; Silva, Pedro Dinho da; Covas, Miguel TrigueirosIn recent years, reducing energy consumption has been relentlessly pursued by researchers and policy makers with the purpose of achieving a more sustainable future. The demand for data storage in data centers has been steadily increasing, leading to an increase in size and therefore to consume more energy. Consequently, the reduction of the energy consumption of data center rooms is required and it is with this perspective that this paper is proposed. By using Computational Fluid Dynamics (CFD), it is possible to model a three-dimensional model of the heat transfer and air flow in data centers, which allows forecasting the air speed and temperature range under diverse conditions of operation. In this paper, a CFD study of the thermal performance and airflow in a real data center processing room with 208 racks under di erent thermal loads and airflow velocities is proposed. The physical-mathematical model relies on the equations of mass, momentum and energy conservation. The fluid in this study is air and it is modeled as an ideal gas with constant properties. The model of the e ect of turbulence is made by employing a k–" standard model. The results indicate that it is possible to reduce the thermal load of the server racks by improving the thermal performance and airflow of the data center room, without a ecting the correct operation of the server racks located in the sensible regions of the room.
- Controlo estatístico do processo: um estudo de caso numa empresa na área da indústria automóvelPublication . Godina, Radu; Matias, João Carlos de OliveiraNo quadro de crescente globalização, a economia confronta as empresas com inúmeros desafios, já não chega produzir, as premissas actuais assentam na qualidade como condição para se atingir a produtividade e a competitividade. E, dado que a qualidade não é estática, está constantemente a ser alterada, porque os clientes são cada vez mais exigentes, qualquer organização empresarial, que queira ser competitiva, tem que inovar. No ambiente competitivo em que vivemos as organizações procuram cada vez mais produzir com qualidade com o menor custo possível, ao garantir assim a sua própria sobrevivência. Uma das respostas a essa procura é o Controlo Estatístico do Processo (CEP) – um poderoso método de gestão que permite a melhoria da qualidade e a eliminação de desperdícios. Este trabalho propõe-se a melhorar a qualidade de um processo através do uso do CEP numa empresa da indústria automóvel, bem como efectuar um estudo dos conceitos associados à metodologia e pretende demonstrar todas as vantagens associadas à sua utilização, como forma de melhoria de qualidade e redução de desperdícios. Para o efeito, foi estudada a metodologia existente da implantação do CEP nesse mesmo processo, e procurou-se uma maneira de a adaptar à realidade da empresa após ter sido efectuada a recolha de amostras e as interpretações das cartas de controlo, ou seja, as análises.
- Influence of Orchard Cultural Practices during the Productive Process of Cherries through Life Cycle AssessmentPublication . Gaspar, Pedro Dinis; Godina, Radu; Barrau, RuiThis study describes the influence of orchard cultural practices during the productive process of cherries on the environmental impact in terms of energy, air, soil and water through a “farm to market” Life Cycle Assessment (LCA). The results were used to identify the orchard cultural practices that contribute significantly to the environmental impact and to find solutions to reduce those impacts, serving as best practices guide to improving the environmental performance and as benchmarks for other national and international cherry and fruit growers. Primary data for production, harvest and post-harvest periods were gathered experimentally. The openLCA 1.10.2 software and the ecoinvent 3.5 database were used for modelling. Test case scenarios are modelled to identify the influence of cultural practices in low and high cherry production campaigns depending on climatic conditions and consequently diseases and plagues. Moreover, results are compared with other studies, not only covering cherries but also other fruits. The energy consumption per hectare in the production phase is similar in test scenarios. The energy consumption of orchard cultural practices related to tractor use, fertilizers and fungicides application are the main hotspots in terms of global warming, freshwater ecotoxicity and eutrophication, and terrestrial acidification. The use of electric vehicles, change the warehouse location or redefine transportation routes can reduce this impact, along with the optimization of the cherry’s quantity transported in each trip. In addition, the use of plant protection products, fertilizers and herbicides with less environmental impact will contribute to this objective. For that, the use of agriculture and precision systems to predict the need for fertilizers (nutrients), herbicides and fungicides, the use of decision support systems to define the dates of cultural practices, as well as innovative and emerging food and by-products processing methods are suggested. Thus, this study identifies and quantifies the environmental impacts associated with the production system of cherries and their main hotspots. It provides a best-practices guide for sustainable solutions in orchard management that contributes to the competitiveness and sustainability of fruit companies.
- Smart operation of transformers for sustainable electric vehicles integration and model predictive control for energy monitoring and managementPublication . Godina, Radu; Catalão, João Paulo da Silva; Matias, João Carlos de OliveiraThe energy transmission and distribution systems existing today are stillsignificantly dependent on transformers,despite beingmore efficient and sustainable than those of decadesago. However, a large numberof power transformers alongwith other infrastructures have been in service for decades and are considered to be in their final ageing stage. Anymalfunction in the transformerscouldaffect the reliability of the entire electric network and alsohave greateconomic impact on the system.Concernsregardingurban air pollution, climate change, and the dependence on unstable and expensive supplies of fossil fuels have lead policy makers and researchers to explore alternatives to conventional fossil-fuelled internal combustion engine vehicles. One such alternative is the introduction of electric vehicles. A broad implementation of such mean of transportation could signify a drastic reduction in greenhouse gases emissions and could consequently form a compelling argument for the global efforts of meeting the emission reduction targets. In this thesis the topic of a high penetration of electric vehicles and their possible integration in insular networksis discussed. Subsequently, smart grid solutions with enabling technologies such as energy management systems and smart meters promote the vision of smart households, which also allows for active demand side in the residential sector.However, shifting loads simultaneously to lower price periods is likely to put extra stress on distribution system assets such as distribution transformers. Especially, additional new types of loads/appliances such as electric vehicles can introduce even more uncertaintyon the operation of these assets, which is an issue that needs special attention. Additionally, in order to improve the energy consumption efficiencyin a household, home energy management systems are alsoaddressed. A considerable number ofmethodologies developed are tested in severalcasestudies in order to answer the risen questions.
- Improving airflow and thermal distribution in a real data centre room through Computational Fluid Dynamics modelingPublication . Macedo, Diogo Gonçalves Costa e Silva de; Gaspar, Pedro Dinis; Silva, Pedro Dinho da; Godina, RaduA Data Centre is a physical space that groups together computer equipment such as servers, storage arrays, among other equipment. It can be used for storage, processing and data protection. The majority of data centres operate 24 hours a day, and must provide the user with guarantees in terms of security and performance. Energy consumption is therefore permanent and the level of assistance and maintenance high. Data Centres have an ecological impact that is almost invisible to many users. In this paper a computational fluid dynamics (CFD) model of the airflow and thermal distribution of a real data centre room with 208 racks is proposed. Two case studies are presented and simulated with a high thermal load subjected to the minimum and maximum air flow velocity, respectively. The objective is to assess if the computer room air conditioning unit (CRAC) can cool the racks of the data centre in order to efficiently refrigerate all the hot spots.
- Life-Cycle Assessment of Dairy Products - Case Study of Regional Cheese Produced in PortugalPublication . Nunes, Óscar Soares; Gaspar, Pedro Dinis; Nunes, José; Quinteiro, Paula; Dias, Ana Cláudia; Godina, RaduNowadays, there is a growing promotion to label products ecologically in European markets. Knowing that daily products have relevant environmental impact associated with their production, it is of utmost importance to analyse all the related production processes for a better understanding of each process impact. The present study analysed the potential environmental impacts of a Portuguese regional product, the Beira Baixa cheese, coming from the largest national sheep milk region. So, a life cycle assessment (LCA) methodology is used from -cradle-to -gate, including the supplying of the animal feedstock. Impact calculations are performed using the ReCiPe midpoint 2008 method, allowing an analysis of the environmental impacts contributing to climate change, terrestrial acidification, freshwater and marine eutrophication of all productive processes. The results have shown that the greatest impacts occur within the milk production process for all four selected impact categories. This happens mainly due to the fodder cultivation process, also necessary to produce animal feed, which contain processes of fertilization and land preparation. The enteric fermentation and manure management processes have also shown relevant contributions. The impact assessment also showed that the cheesemaking industry has practically insignificant impacts. Nonetheless, the cheesemaking industry can promote their business with these results, by advertising and marketing their product as environmentally friendly, with production processes causing reduced impacts, and therefore also their products.
- Parametric study by means of 3D CFD to improve the airflow pattern and temperature distribution in data center roomsPublication . Macedo, Diogo Gonçalves Costa e Silva de; Godina, Radu; Gaspar, Pedro Dinis; Silva, Pedro Dinho da; Covas, Miguel TrigueirosThe processing efficacy and energy efficiency of data centers (DC) is directly related with the cooling performance of the air-conditioning systems. The cooling effectiveness depends on airflow pattern and temperature distribution. This paper presents the parametric study of three-dimensional (3D) computational fluid dynamics (CFD) models to improve these technical characteristics. In this case study the most suitable thermal load, as deemed by the organization, of the heat flow boundary condition is simulated and studied for maximum and minimum airflow. The analysis of the numerical results provides a prediction of the thermal performance, i.e., the lower values and spatial gradients (hot spots) of air temperature and velocity while maintaining the computational processing requirements. These results allow the development of an optimized CFD model for setting up the operational parameters of CRAC systems for DC rooms.