234 research outputs found
Performance assessment of thermal bridge elements into a full scale experimental study of a building façade
In this paper, an experimental and numerical approach to the characterization of thermal bridges is presented. The need for this characterization was found within an experimental study in a 2 floor high facade. This facade was constructed with 3 concrete elements which were placed in it to produce a similar thermal bridge effect to the one created by floor slabs traditional building construction in Spain. Commonly applied thermal assessments perform one-dimensional heat transfer analysis over planar elements such as the facades studied in this experiment. However, it is well known that thermal bridges are locations in buildings where one-dimensional heat transfer analysis cannot be applied. This problem was approached by creating a numerical 2D thermal model which was calibrated against experimental data from several temperature and heat flux sensors which were located at specific points in the thermal bridge elements.Government of the Basque Countr
Assessing the economics of large Energy Storage Plants with an optimisation methodology
Power plants, such as wind farms, that harvest renewable energy are increasing their share of the energy portfolio in several countries, including the United Kingdom. Their inability to match demand power profiles is stimulating an increasing need for large ESP (Energy Storage Plants), capable of balancing their instability and shifting power produced during low demand to peak periods. This paper presents and applies an innovative methodology to assess the economics of ESP utilising UK electricity price data, resulting in three key findings. Firstly the paper provides a methodology to assess the trade-off âreserve capacity vs. profitabilityâ and the possibility of establishing the âoptimum size capacityâ. The optimal reserve size capacity maximizing the NPV (Net Present Value) is smaller than the optimum size capacity minimizing the subsidies. This is not an optimal result since it complicates the incentive scheme to align investors and policy makers' interests. Secondly, without subsidies, none of the existing ESP technologies are economically sustainable. However, subsidies are a relatively small percentage of the average price of electricity in UK. Thirdly, the possibility of operating ESP as both as a reserve and do price arbitrage was identified as a mean of decreasing subsidies for the ESP technologies
Silicon oxycarbide glass for the immobilisation of irradiated graphite waste
© 2015 Elsevier B.V. Silicon oxycarbide glass has been investigated as a potential immobilisation medium for irradiated graphite waste from nuclear power generation. The glass was synthesised via sol-gel techniques using alkoxysilane precursors. Attempts to produce a wasteform via conventional sintering were unsuccessful, but dense wasteforms were achieved by spark plasma sintering (SPS). Microstructural investigations showed that the addition of graphite to the glass did not alter the structure of the matrix; no reaction between the graphite and the glass matrix was observed. Silicon oxycarbide glass is a viable candidate for encapsulation of graphite waste prior to disposal
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