Optimiza����o energ��tica de um sistema de climatiza����o industrial

O desenvolvimento deste trabalho teve como objectivo a optimiza����o de um sistema de climatiza����o industrial, constitu��do por quatro centrais de climatiza����o adiab��ticas, que apresentam limita����es de capacidade de arrefecimento, controlo e efici��ncia. Inicialmente foi necess��ria a pesquisa bibliogr��fica e recolha de informa����o relativa �� ind��stria t��xtil e ao processo de arrefecimento evaporativo. Numa fase posterior foram recolhidos e analisados os diversos dados essenciais �� compreens��o do bin��mio edif��cio/sistema de climatiza����o, para a obten����o de poss��veis hip��teses de optimiza����o. Da fase de recolha de informa����es e dados, destaca-se, tamb��m, a realiza����o de an��lises �� qualidade do ar interior (QAI). As optimiza����es seleccionadas como pass��veis de implementa����o, foram estudadas e analisadas com o aux��lio do software de simula����o energ��tica din��mica DesignBuilder e os resultados obtidos foram devidamente trabalhados e ajustados de modo a permitir uma assimila����o amig��vel e de f��cil interpreta����o das suas vantagens e desvantagens, tendo ainda sido objecto de estudo de viabilidade econ��mica. A optimiza����o proposta reflecte uma melhoria substancial das condi����es interiores ao n��vel da temperatura e humidade relativa, resultando, ainda assim, numa redu����o de consumos energ��ticos na ordem dos 23 % (490.337 kWh), isto ��, uma poupan��a anual de 42.169 ��� aos custos de explora����o e com um per��odo de retorno de 1 ano e 11 meses.

An��lise das condi����es de utiliza����o de permutadores de calor de modo a serem economicamente rent��veis

Trabalho Final de Mestrado para obten����o do grau de Mestre em Engenharia Mec��nica Perfil Energia, Refrigera����o e Climatiza����o

Auditoria energ��tica e plano de racionaliza����o de energia

Trabalho Final de Mestrado para obten����o do grau de Mestre em Engenharia Mec��nica

Reabilita����o de edif��cios com novas tend��ncias NZEB: caso de estudo: edif��cio de servi��os em Set��bal

Trabalho Final de Mestrado para obten����o do grau de Mestre em Engenharia Civil

Reabilita����o energ��tica de um edif��cio de servi��os

Trabalho Final de Mestrado para obten����o do grau de Mestre em Engenharia Civil na ��rea de Especializa����o de Edifica����es

Nano-CF: a Coordination Framework for macro-programming in wireless sensor networks

Wireless Sensor Networks (WSN) are being used for a number of applications involving infrastructure monitoring, building energy monitoring and industrial sensing. The difficulty of programming individual sensor nodes and the associated overhead have encouraged researchers to design macro-programming systems which can help program the network as a whole or as a combination of subnets. Most of the current macro-programming schemes do not support multiple users seamlessly deploying diverse applications on the same shared sensor network. As WSNs are becoming more common, it is important to provide such support, since it enables higher-level optimizations such as code reuse, energy savings, and traffic reduction. In this paper, we propose a macro-programming framework called Nano-CF, which, in addition to supporting in-network programming, allows multiple applications written by different programmers to be executed simultaneously on a sensor networking infrastructure. This framework enables the use of a common sensing infrastructure for a number of applications without the users having to worrying about the applications already deployed on the network. The framework also supports timing constraints and resource reservations using the Nano-RK operating system. Nano- CF is efficient at improving WSN performance by (a) combining multiple user programs, (b) aggregating packets for data delivery, and (c) satisfying timing and energy specifications using Rate- Harmonized Scheduling. Using representative applications, we demonstrate that Nano-CF achieves 90% reduction in Source Lines-of-Code (SLoC) and 50% energy savings from aggregated data delivery.

Job phasing aware preemption deferral

Preemptions account for a non-negligible overhead during system execution. There has been substantial amount of research on estimating the delay incurred due to the loss of working sets in the processor state (caches, registers, TLBs) and some on avoiding preemptions, or limiting the preemption cost. We present an algorithm to reduce preemptions by further delaying the start of execution of high priority tasks in fixed priority scheduling. Our approaches take advantage of the floating non-preemptive regions model and exploit the fact that, during the schedule, the relative task phasing will differ from the worst-case scenario in terms of admissible preemption deferral. Furthermore, approximations to reduce the complexity of the proposed approach are presented. Substantial set of experiments demonstrate that the approach and approximations improve over existing work, in particular for the case of high utilisation systems, where savings of up to 22% on the number of preemption are attained.

Inter-application redundancy elimination in sensor networks with compiler-assisted scheduling

Most current-generation Wireless Sensor Network (WSN) nodes are equipped with multiple sensors of various types, and therefore support for multi-tasking and multiple concurrent applications is becoming increasingly common. This trend has been fostering the design of WSNs allowing several concurrent users to deploy applications with dissimilar requirements. In this paper, we extend the advantages of a holistic programming scheme by designing a novel compiler-assisted scheduling approach (called REIS) able to identify and eliminate redundancies across applications. To achieve this useful high-level optimization, we model each user application as a linear sequence of executable instructions. We show how well-known string-matching algorithms such as the Longest Common Subsequence (LCS) and the Shortest Common Super-sequence (SCS) can be used to produce an optimal merged monolithic sequence of the deployed applications that takes into account embedded scheduling information. We show that our approach can help in achieving about 60% average energy savings in processor usage compared to the normal execution of concurrent applications.

A case study on the eco-efficiency performance of a composite processing industry: evaluation and quantification of potential improvements

In this study, an attempt was made in order to measure and evaluate the eco-efficiency performance of a pultruded composite processing company. For this purpose the recommendations of World Business Council for Sustainable Development (WCSD) and the directives of ISO 14301 standard were followed and applied. The main general indicators of eco-efficiency, as well as the specific indicators, were defined and determined. With basis on indicators��� figures, the value profile, the environmental profile, and the pertinent eco-efficiency ratios were established and analyzed. In order to evaluate potential improvements on company eco-performance, new indicators values and eco-efficiency ratios were estimated taking into account the implementation of new proceedings and procedures, at both upstream and downstream of the production process, namely: i) Adoption of a new heating system for pultrusion die-tool in the manufacturing process, more effective and with minor heat losses; ii) Recycling approach, with partial waste reuse of scrap material derived from manufacturing, cutting and assembly processes of GFRP profiles. These features lead to significant improvements on the sequent assessed eco-efficiency ratios of the present case study, yielding to a more sustainable product and manufacturing process of pultruded GFRP profiles.

Estudo de aplica����o de coletores solares na produ����o de eletricidade e calor para uso dom��stico

O trabalho apresentado explora o aproveitamento da energia solar para suprir as necessidades energ��ticas, tanto el��tricas como t��rmicas, de uma habita����o tipo 3, recorrendo ao uso de coletores solares, em que o fluido de trabalho �� ��gua. As necessidades el��tricas ser��o supridas atrav��s da produ����o de energia com recurso a um ciclo de Rankine, em que fluido de trabalho �� um frigorig��nio aquecido atrav��s de um permutador cujo fluido quente ser�� uma mistura, de ��gua com anticongelante, aquecida pelo coletor solar. Por outro lado, as necessidades t��rmicas ser��o satisfeitas atrav��s do calor libertado no ciclo de Rankine. Na instala����o solar estar�� integrado um acumulador t��rmico com apoio energ��tico, caldeira el��trica, que funcionar�� nas situa����es em que coletor seja insuficiente para satisfazer as necessidades t��rmicas. No final ser�� feita uma avalia����o econ��mica para que possa atestar a viabilidade econ��mica do projeto, tendo em conta os seus custos totais versus as poupan��as energ��ticas que este sistema origina.

Saving energy in the GFRP pultrusion process

This study addresses to the optimization of pultrusion manufacturing process from the energy-consumption point of view. The die heating system of external platen heaters commonly used in the pultrusion machines is one of the components that contribute the most to the high consumption of energy of pultrusion process. Hence, instead of the conventional multi-planar heaters, a new internal die heating system that leads to minor heat losses is proposed. The effect of the number and relative position of the embedded heaters along the die is also analysed towards the setting up of the optimum arrangement that minimizes both the energy rate and consumption. Simulation and optimization processes were greatly supported by Finite Element Analysis (FEA) and calibrated with basis on the temperature profile computed through thermography imaging techniques. The main outputs of this study allow to conclude that the use of embedded cylindrical resistances instead of external planar heaters leads to drastic reductions of both the power consumption and the warm-up periods of the die heating system. For the analysed die tool and process, savings on energy consumption up to 60% and warm-up period stages less than an half hour were attained with the new internal heating system. The improvements achieved allow reducing the power requirements on pultrusion process, and thus minimize industrial costs and contribute to a more sustainable pultrusion manufacturing industry.

Estudo t��cnico-econ��mico para otimiza����o do projeto e implementa����o de uma bomba de calor "heat machine"

Trabalho Final de Mestrado para obten����o do grau de Mestre em Engenharia Mec��nica

An��lise energ��tica, otimiza����o e moderniza����o dos sistemas de um grande edif��cio de servi��os na ��tica da melhoria da efici��ncia energ��tica

Trabalho Final de Mestrado para obten����o do grau de Mestre em Engenharia Mec��nica Perfil Energia, Refrigera����o e Climatiza����o

Otimiza����o da torre de arrefecimento da Artlant PTA

Trabalho Final de Mestrado para obten����o de grau de Mestre em Engenharia Qu��mica e Biol��gica

Converg��ncia para NZEB de um edif��cio de servi��os em Faro

Disserta����o para obten����o do grau de Mestre em Engenharia Civil