Experimental Study on the Performance of RT 25 to be Used as Ambient Energy Storage

AbstractThe proposed experimental work intends to analyse the thermal performance of a TES unit incorporated into a ventilation system under different working conditions. The influences of the air inlet temperature and velocity on the air outlet temperature and heat transfer rate were investigated The air inlet temperature used for the solidification of RT25 were 10°C, 12°C and 14°C and for the melting 34°C, 36°C and 38°C. The selected air inlet velocities were the same for the melting and solidification process: 0.5 m/s, 1.4 m/s and 2.5 m/s. The results suggest that an increase of the air inlet velocity reduces linearly the temperature difference between the air inlet and outlet for the solidification process of the RT25. Contrary, for the melting of the RT25, increasing the air inlet velocity does not reduce the temperature difference linearly, increasing the air inlet temperature furthermore from 36°C to 38°C did not affect the melting time. The air inlet temperature plays a significant role on the melting process, reducing linearly the air inlet and outlet temperature difference and the heat transfer rate, however does not influence the solidification process, similar air inlet and outlet temperature difference and the heat transfer rate were obtained for all condition.Thus, air inlet velocity and air inlet temperature have to be carefully balanced to optimize the whole running cycle of both melting and solidification processes

A Portuguese study on building renovation towards a nearly zero energy building (nZEB)

The social and environmental urgency of large-scale integrated retrofitting of the European residential building stock is widely acknowledged and supported by all Member States. However, the European building sector is currently still not able to offer an integral solution for deep renovation toward nearly Zero Energy Building (nZEB) for reasonable costs. MORE-CONNECT project aims to tackle this issue by developing cost optimal solutions to renovate buildings towards nZEB. In this project, the optimal solutions include the development of prefabricated, multifunctional renovation elements for the total building envelope (façade and roof) and installation/building services. This paper presents the first stage of the project, namely the analysis and comparison of three scenarios following the current national requirements in Portugal i) 80% reduction of the current primary energy consumption of the building, ii) cost optimal solution (nZEB) and iii) net zero energy (NZEB). The optimization of the building envelope will be the main driver for the three scenarios as well as the inclusion of renewable energy strategies. Overall, results suggest that it is possible to achieve cost-effective solutions for the renovation of Portuguese residential buildings. Moreover, the cost-optimal solution (scenario ii) matches approximately with the 80% reduction of energy scenario (scenario i).MORE-CONNECT is funded by the European Commission within the framework of the Horizon 2020 progra

Soluções de reabilitação de fachadas como contributo para assegurar os nZEB – um caso de estudo em Portugal

O sector dos edifícios é o maior consumidor de energia final na União Europeia. Isto deve-se ao facto de a maioria dos edifícios apresentar um fraco desempenho térmico da envolvente. O parque edificado da União Europeia é, na sua maioria, anterior a 1960, de uma época pautada pela ausência de regulamentos de eficiência energética e em que as questões relacionadas com o consumo de energia e as emissões de carbono não assumiam a premência que apresentam na atualidade. A reabilitação energética apresenta-se hoje como a ferramenta mais eficaz para fazer face ao desafio de melhorar o desempenho energético do parque edificado existente. Servirá não só para atingir as ambiciosas metas de redução de consumo energético até 2020 e 2050 como para garantir um ambiente construído de qualidade e sustentável. Com taxas de construção nova muito reduzidas, a reabilitação é uma solução alternativa que apresenta inúmeras vantagens e é cada vez mais reconhecida como o futuro no sector dos edifícios. A revisão da diretiva Europeia relativa ao desempenho energético dos edifícios introduziu o conceito de edifício de necessidades quase nulas de energia (nZEB) e a obrigatoriedade de todos os edifícios novos após 2020 serem nZEB. Da mesma forma, também o conceito deverá ser aplicado aos edifícios existentes, adaptando-os para nZEB, através da reabilitação energética. Estes edifícios apresentam um desempenho energético muito elevado, sendo que as reduzidas necessidades energéticas que apresentam devem ser asseguradas em grande parte por energia proveniente de fontes renováveis, produzida no local ou nas proximidades. Complementarmente, as soluções nZEB devem obedecer a critérios de racionalidade económica. Para tal, a Comissão Europeia desenvolveu um quadro metodológico aplicável a todos os Estados Membros, que permite a identificação e análise dos níveis ótimos de rentabilidade do desempenho energético dos edifícios. O presente estudo enquadra-se no âmbito do projeto Europeu More-Connect que se centra no desenvolvimento de elementos modulares prefabricados de reabilitação energética para atingir edifícios nZEB. É apresentada a análise preliminar de três cenários de reabilitação energética aplicados ao caso de estudo em Portugal e o desenvolvimento inicial de um elemento prefabricado de reabilitação de fachada.Projeto Europeu H2020-EE-2014-2015/H2020-EE-2014-1-PPP, grant agreement no 633477, “MORE-CONNECT – Development and advanced prefabrication of innovative, multifunctional building envelope elements for Modular Retrofitting and smart CONNECTions

An innovative window heat recovery (WHR) system with heat pipe technology: Analytical, CFD, experimental analysis and building retrofit performance

This paper addresses the numerical and experimental performance analysis of a windows heat recovery system made of heat pipes. For modelling, the heat pipe is considered as a pseudo solid material with high value of effective thermal conductivity. An experimental investigation using a window heat recovery prototype was carried out to predict the value of effective thermal conductivity of the heat pipes and to validate the numerical model. After validation, a parametric analysis was conducted to investigate the performance of the recovery system for different working conditions (mass flow rate and temperature difference between exhausted and supplied air). Based on the performance obtained in the parametric analysis, energy performance in building and the impact on velocity and pressure distributions are also evaluated with the support of CFD analysis. It is found that the effectiveness of window heat recovery made of heat pipes depends on ventilation rate and temperature difference between exhausted and supplied air. Increasing ventilation rates and temperature differences decrease the effectiveness. For ventilation rate between 10–60 m 3/h and temperature difference 10–30 °C, effectiveness between 65%–95% and pressure drop 4–80 Pa are obtained. For performance in building, the power consumption can be reduced between 3%–24% and the thermal comfort increased

Guidelines for Industrial Symbiosis—a Systematic Approach for Content Definition and Practical Recommendations for Implementation

AbstractThe increase of industrial symbiosis (IS) activities around the world has strongly contributed to promote awareness among companies on the benefits of this business model and, consequently, their interest to apply/incorporate dedicated IS actions in their activities. In most cases, companies assume self-learning and ongoing approaches for the adaption of synergies, ignoring some fundamental aspects as the full spectrum of considerations regarding these processes. Unexpected barriers frequently appear during the implementation process and become hardly overcome due to incomplete systematic approaches and the lack of information. In this context, it is important to promote effective and sequential guidance procedures regarding IS implementation processes to support companies in their transition to full IS processes implementation. This paper aims to advance the synergy implementation emerging process, through the identification, promotion, and definition of the core steps to be considered in an IS implementation process. This study is based on a comprehensive perspective for the definition of contents to be considered in a step-by-step guideline that includes the different theoretical, technical, and strategic approaches for large-scale IS promotion. The main outputs of this paper are a final set of independent and sequential information clusters, their associated contents identification process, and a comprehensive description of the systematic approach used to support companies in the implementation of their pre-identified stages. The guideline methodology proposed in this study is an important support tool for companies, practitioners, and agents intending to initiate IS synergies implementation and also a strong contribution to the development of complementary guidance activities regarding IS implementation process.</jats:p