56 research outputs found

    Towards Integration of Energy Storage Systems for Carbon Neutral Buildings : A Review of Multi-Criteria Decision Making Approaches

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    Building sector consumes about 40% of the global energy consumption and emits over 30% of the global energy-related CO2 emissions. It is one of the most resource-intensive sectors and the main contributor of the environmental emissions. Additionally, the amount of greenhouse gas emissions is increasing remarkably due to the rapid growth in urbanization. Distributed energy resources (DERs) offer opportunities to support the deployment of large shares of renewable energy sources (RES) in order to meet the sustainability goals of reducing carbon emissions and increasing building resilience. DERs consist primarily of energy generation and energy storage systems (ESS) which are located near to the end-users of buildings, allowing easily integration of RES and realization of carbon neutrality. However, widespread adoption of renewable energy is challenging because of its intermittent nature. Energy supply does not satisfy with the demand, back-up supply from ESS is therefore required to solve the problems. ESS are of great importance for balancing supply and demand mismatches and offering the opportunity to replace fossil fuels with large shares of renewable penetration on DERs to eventually achieve zero-carbon emissions in buildings. Due to numerous factors that influence ESS, selection of the suitable energy storage technologies for specific building applications presents a challenge. In the literature, different criteria have been suggested to contrast ESS’ strengths and weaknesses for different applications. Methodologically, multi-criteria decision making (MCDM) has been widely employed in planning ESS. This paper aims to provide a critical review of MCDM for the deployment solutions of RES and ESS in carbon neutral building applications. A conceptual illustration is also presented to synthesize the literature review and explain the key methodologies of MCDM.© 2023 The Author(s). Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.fi=vertaisarvioitu|en=peerReviewed

    Hygrothermal performance of highly insulated external walls subjected to indoor air exfiltration

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    The study comprises three laboratory tests in which typical Finnish highly insulated (HI) walls were exposed to concentrated leakages of indoor air under steady outdoor temperatures of 1–5°C. Airflows with a relative humidity of 50% and at rates of 1–3 L/min were directed close to the wooden frames inside the walls. The thermal resistance ratios between the exterior sheathing(s) and the whole wall (Γ) were 20%–22% and 1%–10% for the HI and baseline (BL) walls. The HI walls that presented Γ values of at least 20% were observed to be resistant to air exfiltration, and their durability was not affected by the addition of a gypsum sheathing outside the wooden frame or a more permeable vapor retarder. This is related to the negative linear correlation that exists between the moisture accumulation rate in wood-based material and the dew point depression (DPD) value. The developed approach, called the DPD method, shows that a significant degree of moisture accumulation does not occur even for DPD values of as low as −2°C if the exterior sheathing is vapor permeable. The airflow does not penetrate into the rigid mineral wool sheathing, which helps to avoid interstitial condensation. Regardless of thermal transmittance, the HI and BL walls with maximum Γ values of 1% were exposed to a high relative humidity and even interstitial condensation because the DPD values were often below −2°C. For these walls, the mold index analysis and visual observations confirmed the local risk for mold growth on the opposite side of the leakage point. In practice, long-term mold growth may be limited if the seasonal periods during which the outdoor temperature is 1–5°C last for a maximum of about 1 month every year.©The Author(s) 2022. https://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).fi=vertaisarvioitu|en=peerReviewed

    Release Mechanism of Volatile Products from Oil Shale Pressure-Controlled Pyrolysis Induced by Supercritical Carbon Dioxide

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    The compactness of the oil shale reservoir and the complexity of the pore structure lead to the secondary reaction of kerogen in the process of hydrocarbon expulsion, which reduces the effective recovery of shale oil. In this paper, supercritical carbon dioxide was used as a heat carrier and a displacement medium. In a self-designed fluidized bed experimental system for pressure-controlled pyrolysis of oil shale, the experiments of oil shale pyrolysis under standard atmospheric pressure and 7.8–8.0 MPa pressure in nitrogen and carbon dioxide atmospheres were completed. The extraction efficiency of supercritical carbon dioxide at low temperature is obvious, but with the increase of temperature, the effect of extraction on pyrolysis is lower than that of temperature. Under a nitrogen atmosphere, the secondary reaction of shale oil is mainly secondary pyrolysis and aromatization. However, in a supercritical carbon dioxide atmosphere, the main reactions are secondary addition and aromatization. In addition, compared with that in the standard atmospheric pressure, it was found that the olefin synthesis reaction was obviously inhibited under a high-pressure nitrogen or supercritical carbon dioxide atmosphere.© 2022 The Authors. Published by American Chemical Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.fi=vertaisarvioitu|en=peerReviewed

    Experimental Study on the Factors of the Oil Shale Thermal Breakdown in High-Voltage Power Frequency Electric Heating Technology

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    We conducted an experimental study on the breakdown process of oil shale by high-voltage power frequency electric heating in-situ pyrolyzing (HVF) technology to examine the impact mechanisms of the electric field intensity, initial temperature, and moisture content on a breakdown, using Huadian oil shale samples. A thermal breakdown occurred when the electric field intensity was between 100 and 180 V/cm. The greater the electric field intensity, the easier the thermal breakdown and the lower the energy consumption. The critical temperature of the oil shale thermal breakdown ranged from 93 to 102 °C. A higher initial temperature increases the difficulty of breakdown, which is inconsistent with the classical theory of a solid thermal breakdown. The main factor that affects the electrical conductivity of oil shale is the presence of water, which is also a necessary condition for the thermal breakdown of oil shale. There should be an optimal moisture content that minimizes both the breakdown time and energy consumption for oil shale’s thermal breakdown. The thermal breakdown of oil shale results from heat generation and dissipation. The electric field intensity only affects the heat generation process, whereas the initial temperature and moisture content impact both the heat generation and dissipation processes, and the impacts of moisture content are greater than those of the initial temperature.© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

    An Urban Traffic Flow Fusion Network Based on a Causal Spatiotemporal Graph Convolution Network

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    Traffic flow prediction is an important part of intelligent transportation systems. In recent years, most methods have considered only the feature relationships of spatial dimensions of traffic flow data, and ignored the feature fusion of spatial and temporal aspects. Traffic flow has the features of periodicity, nonlinearity and complexity. There are many relatively isolated points in the nodes of traffic flow, resulting in the features usually being accompanied by high-frequency noise. The previous methods directly used the graph convolution network for feature extraction. A polynomial approximation graph convolution network is essentially a convolution operation to enhance the weight of high-frequency signals, which lead to excessive high-frequency noise and reduce prediction accuracy to a certain extent. In this paper, a deep learning framework is proposed for a causal gated low-pass graph convolution neural network (CGLGCN) for traffic flow prediction. The full convolution structure adopted by the causal convolution gated linear unit (C-GLU) extracts the time features of traffic flow to avoid the problem of long running time associated with recursive networks. The reduction of running parameters and running time greatly improved the efficiency of the model. The new graph convolution neural network with self-designed low-pass filter was able to extract spatial features, enhance the weight of low-frequency signal features, suppress the influence of high-frequency noise, extract the spatial features of each node more comprehensively, and improve the prediction accuracy of the framework. Several experiments were carried out on two real-world real data sets. Compared with the existing models, our model achieved better results for short-term and long-term prediction.© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

    Electromagnetic-Thermal Analyses of Distributed Antennas Embedded into a Load Bearing Wall

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    The importance of indoor mobile connectivity has increased during the last years, especially during the Covid-19 pandemic. In contrast, new energy-efficient buildings contain structures like low-emissive windows and multi-layered thermal insulations which all block radio signals effectively. To solve this problem with indoor connectivity, we study passive antenna systems embedded in walls of low-energy buildings. We provide analytical models of a load bearing wall along with numerical and empirical evaluations of wideband back-to-back antenna spiral antenna system in terms of electromagnetic- and thermal insulation. The antenna systems are optimized to operate well when embedded into load bearing walls. Unit cell models of the antenna embedded load bearing wall, which are called signal-transmissive walls in this paper, are developed to analyze their electromagnetic and thermal insulation properties. We show that our signal-transmissive wall improves the electromagnetic transmission compared to a raw load bearing wall over a wide bandwidth of 2.6-8 GHz, covering most of the cellular new radio frequency range 1, without compromising the thermal insulation capability of the wall demanded by the building regulation. Optimized antenna deployment is shown with 22 dB improvement in electromagnetic transmission through the load bearing wall.Comment: 9 pages, 13 figures, submitted to IEEE Transactions on Antennas and Propagatio

    3D Object Detection Algorithm Based on the Reconstruction of Sparse Point Clouds in the Viewing Frustum

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    In response to the problem that the detection precision of the current 3D object detection algorithm is low when the object is severely occluded, this study proposes an object detection algorithm based on the reconstruction of sparse point clouds in the viewing frustum. The algorithm obtains more local feature information of the sparse point clouds in the viewing frustum through dimensional expansion, performs the fusion of local and global feature information of the point cloud data to obtain point cloud data with more complete semantic information, and then applies the obtained data to the 3D object detection task. The experimental results show that the precision of object detection in both 3D view and BEV (Bird’s Eye View) can be improved effectively through the algorithm, especially object detection of moderate and hard levels when the object is severely occluded. In the 3D view, the average precision of the 3D detection of cars, pedestrians, and cyclists at a moderate level can be increased by 7.1p.p., 16.39p.p., and 5.42p.p., respectively; in BEV, the average precision of the 3D detection of car, pedestrians, and cyclists at hard level can be increased by 6.51p.p., 16.57p.p., and 7.18p.p., respectively, thus indicating the effectiveness of the algorithm.© 2022 Xing Xu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.fi=vertaisarvioitu|en=peerReviewed

    The air temperature change effect on water quality in the Kvarken Archipelago area

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    The Kvarken Archipelago is Finland's World Heritage site designated by UNESCO. How climate change has affected the Kvaken Archipelago remains unclear. This study was conducted to investigate this issue by analyzing air temperature and water quality in this area. Here we use long-term historical data sets of 61 years from several monitoring stations. Water quality parameters included chlorophyll-a; total phosphorus; total nitrogen; coliform bacteria thermos tolerant; temperature; nitrate as nitrogen; nitrite-nitrate as nitrogen, and Secchi depth and correlations analysis was conducted to identify the most relevant parameters. Based on the correlation analysis of weather data and water quality parameters, air temperature showed a significant correlation with water temperature (Pearson's correlations = 0.89691, P < 0.0001). The air temperature increased in April (R2 (goodness-of-fit) = 0.2109 & P = 0.0009) and July (R2 = 0.1207 & P = 0.0155) which has indirectly increased the chlorophyll-a level (e.g. in June increasing slope = 0.39101, R2 = 0.4685, P < 0.0001) an indicator of phytoplankton growth and abundance in the water systems. The study concludes that there might be indirect effects of the likely increase in air temperature on water quality in the Kvarken Archipelago, in particular causing water temperature and chlorophyll-a concentration to increase at least in some months.© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

    A carbonation and chloride induced corrosion model for hot-dip galvanised reinforcement bar material in concrete

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    This paper focuses on methodological issues relevant to corrosion risk prediction models. A model was developed for the prediction of corrosion rates associated with hot-dip galvanised reinforcement bar material in concrete exposed to carbonation and chlorides in outdoor environment. One-year follow-up experiments, over five years, were conducted at various carbonation depths and chloride contents. The observed dependence of corrosion rate on the depth of carbonation and chloride content is complex indicating that the interaction between the carbonation and chloride influencing the corrosion. A non-linear corrosion model was proposed with statistical analysis to model the relationship between the corrosion rate and the test parameters. The main methodological contributions are (i) the proposed modeling approach able to take into account the uncertain measurement errors including unobserved systematic and random heterogeneity over different measured specimens and correlation for the same specimen across different measuring times, which best suits the measurement data; (ii) the developed model in which an interaction parameter is introduced especially to account for the contribution and the degree of the unobserved carbonation-chloride interaction. The proposed model offers greater flexibility for the modelling of measurement data than traditional models

    Pyrolysis treatment of nonmetal fraction of waste printed circuit boards : Focusing on the fate of bromine

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    Advanced thermal treatment of electronic waste offers advantages of volume reduction and energy recovery. In this work, the pyrolysis behaviour of nonmetallic fractions of waste printed circuit boards was studied. The fate of a bromine and thermal decomposition pathway of nonmetallic fractions of waste printed circuit boards were further probed. The thermogravimetric analysis showed that the temperatures of maximum mass loss were located at 319°C and 361°C, with mass loss of 29.6% and 50.6%, respectively. The Fourier transform infrared Spectroscopy analysis revealed that the spectra at temperatures of 300°C–400°C were complicated with larger absorbance intensity. The nonmetallic fractions of waste printed circuit boards decomposed drastically and more evolved products were detected in the temperature range of 600°C–1000°C. The gas chromatography–mass spectrometry analysis indicated that various brominated derivates were generated in addition to small molecules, such as CH4, H2O and CO. The release intensity of CH4 and H2O increased with temperature increasing and reached maximum at 600°C–800°C and 400°C–600°C. More bromoethane (C2H5Br) was formed as compared with HBr and methyl bromide (CH3Br). The release intensity of bromopropane (C3H7Br) and bromoacetone (C3H5BrO) were comparable, although smaller than that of bromopropene (C3H5Br). More dibromophenol (C6H4Br2O) was released than that of bromophenol (C6H5BrO) in the thermal treatment. During the thermal process, part of the ether bonds first ruptured forming bisphenol A, propyl alcohol and tetrabromobisphenol A. Then, the tetrabromobisphenol A decomposed into C6H5BrO and HBr, which further reacted with small molecules forming brominated derivates. It implied debromination of raw nonmetallic fractions of waste printed circuit boards or pyrolysis products should be applied for its environmentally sound treating.© 2020 Sage. The article is protected by copyright and reuse is restricted to non-commercial and no derivative uses. Users may also download and save a local copy of an article accessed in an institutional repository for the user's personal reference.fi=vertaisarvioitu|en=peerReviewed
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