ASME 2018 12th International Conference on Energy Sustainability最新文献

{"title":"Experimental Performance Evaluation of a Rechargeable Lithium-Air Battery With Hyper-Branched Polymer Electrolyte","authors":"S. Das, K. J. Berry","doi":"10.1115/ES2018-7262","DOIUrl":"https://doi.org/10.1115/ES2018-7262","url":null,"abstract":"Synthesis of hyper branched polymer (HBP) based electrolyte has been examined in this study. A real world lithium-air battery cell was fabricated using the developed HBP electrolyte, oxygen permeable air cathode and lithium metal as anode material. Detailed synthesis procedures of hyper branched polymer electrolyte and the effect of different operation conditions on the real-world lithium-air battery cell were discussed in this paper. The fabricated battery cells were tested under dry air with 0.1mA∼0.2mA discharge current to determine the effect of different operation conditions such as carbon source, electrolyte types and cathode processes. It was found that different processes affect the battery cell performance significantly. We developed optimized battery cell materials upon taking into account the effect of different processes. Several battery cells were fabricated using the same optimized anode, cathode and electrolyte materials in order to determine the battery cells performance and reproducibility. Experimental results showed that the optimized battery cells were able to discharge over 55 hours at over 2.5V. It implies that the optimized battery cell can hold charge for more than two days at over 2.5V. It was also shown that the lithium-air battery cell can be reproduced without loss of performance with the optimized battery cell materials.","PeriodicalId":298211,"journal":{"name":"ASME 2018 12th International Conference on Energy Sustainability","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132724541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Changes in Alloy Anodes for Li-Ion Batteries","authors":"Jacob N. Adams, Logan J. Ausderau, G. Nelson","doi":"10.1115/ES2018-7539","DOIUrl":"https://doi.org/10.1115/ES2018-7539","url":null,"abstract":"Tin (Sn) alloy electrodes show great potential for advancing battery performance due to the high capacity of tin. To realize this potential, the volumetric expansion during the lithiation process must be mitigated. One means of mitigating volumetric expansion of tin is to alloy it with copper to create Cu6Sn5. Such alloy electrodes retain some of the high capacity of tin, while attempting to accommodate volumetric changes with the addition of the malleable copper. Lithiation and delithiation tests were conducted with the Cu6Sn5 pellet electrodes to produce microstructural changes at the electrode surface. To observe and quantify these microstructural changes, x-ray microtomography was performed on electrode samples after electrochemical testing. The microtomography data was reconstructed into a 3D image, segmented, and the continuous phase size distribution (PSD) of each electrode sample was analyzed. The electrodes lithiated to 0 V vs Li/Li+ and then delithiated to 0.2 V vs. Li/Li+ showed the most substantial reduction in overall PSD compared to the other samples. This suggests that full lithiation of the Sn present in the alloy electrodes followed by partial delithiation of the Li4.4Sn to Li2CuSn can cause substantial microstructural changes related to volume expansion on lithiation and structural collapse upon delithiation. The electrodes fully lithiated to 0 V vs Li/Li+ and not delithiated show a higher overall phase size distribution, including all solid phases, than the pristine sample and the electrode samples that were partially lithiated to 0.2 V vs. Li/Li+ and delithiated to 1.5 V vs. Li/Li+. The higher overall phase size distribution that is shown by the sample that was fully lithiated and not delithiated is evidence of the significant volumetric expansion of the Cu6Sn5 compound due to lithiation. During this process of volumetric expansion, the phase size distribution of the Cu6Sn5/Sn phase is shown to decrease. When the volumetric expansion of the lithiated electrode samples and the volumetric contraction of the delithiated electrode sample are considered together, it can be inferred that the microstructural changes that are observed, such as the decrease in phase size distribution of the Cu6Sn5/Sn phase, can be attributed to the volumetric expansion and contraction of the compound during the lithiation and delithiation process.","PeriodicalId":298211,"journal":{"name":"ASME 2018 12th International Conference on Energy Sustainability","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123633436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accurate and Data-Limited Prediction for Smart Home Energy Management","authors":"Baris Aksanli","doi":"10.1115/ES2018-7461","DOIUrl":"https://doi.org/10.1115/ES2018-7461","url":null,"abstract":"Residential energy applications have become an important domain of cyber-physical systems. These applications provide significant opportunities for end-users to reduce their electricity costs and for the utilities to balance their supply and demand in the most effective way. One of the most important applications is predicting the total energy usage of a house. However, an accurate time-series prediction may require significant amount of data, e.g. per appliance energy consumption values, that need costly installations, data storage units, and computation and communication devices. In this paper, we propose a framework that uses a forward-selection-based input filtering mechanism for residential prediction applications. Our framework can effectively reduce the amount of data required for residential energy prediction without sacrificing prediction performance. We demonstrate that 94% of the houses can leverage our method, which leads to up to 80% reduction in required data, greatly reducing the system cost and overhead.","PeriodicalId":298211,"journal":{"name":"ASME 2018 12th International Conference on Energy Sustainability","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115625978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FluxTracer: A 3D-Partitioning and Radiant Flux Computer Tool to Analyse the Optical Behaviour of Light Collection and Concentration Subsystems Using High Performance Computers","authors":"Manuel Blanco, E. Votyakov, C. Christou, C. Papanicolas, Clotilde Corsi, John Pye","doi":"10.1115/ES2018-7415","DOIUrl":"https://doi.org/10.1115/ES2018-7415","url":null,"abstract":"The light collection and concentration subsystem (LCCS) of any concentrating solar thermal (CST) system is composed of the surfaces that collect and concentrate the sunlight and of the input surfaces of the receivers, or receivers’ envelopes, where the light is concentrated. For all commercial CST technologies the LCCS is, together with the power block, the subsystem that has more influence in the overall performance and cost. Thus, its optimization is critical to increase the cost-competitiveness of these systems. This optimization requires, in many cases, the optimization of the position, geometry and size of a very large number of solar collecting and concentrating surfaces as well as the optimization of the shape and size of the input surfaces of the receivers where the sunlight is concentrated. Because a full optimization requires the exploration of a configuration space with a very large number of dimensions, the traditional approach consist in making many initial assumptions to drastically reduce the number of dimensions of the configuration space to a handful, so that the optimization can be carried out using conventional high-end workstations in a matter of hours.\u0000 However, to achieve relevant breakthroughs and to substantially increase the cost-competitiveness of CST systems a bolder approach is needed, where sophisticated design and analysis tools, engineered from the start to be used in High Performance Computers (HPC), will be combined with sophisticated optimization strategies targeted to explore and find optimal solutions in very high dimensional configuration spaces.\u0000 This paper presents the first of a series of such design and analysis tools. The tool, call Flux Tracer, partitions the three-dimensional space in which the LCC subsystem under analysis is immersed into volumetric pixels (voxels) and computes the radiant energy flux that traverses each voxel as a function of time. It integrates the energy density in every voxel overtime, providing detailed information regarding how the radiant energy flows in space in a given LCC subsystem and in a given period of time. This information is the cornerstone of the highly sophisticated computational LCC subsystem optimization framework The Cyprus Institute (CYI) is developing, in collaboration with the Australian National University (ANU), targeted to be used in HPC’s.","PeriodicalId":298211,"journal":{"name":"ASME 2018 12th International Conference on Energy Sustainability","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131618230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gradient Based Soil Thermal Conductivity Optimization for Ground Source Heat Exchangers","authors":"A. DiCarlo, R. A. Caldwell","doi":"10.1115/ES2018-7418","DOIUrl":"https://doi.org/10.1115/ES2018-7418","url":null,"abstract":"In geothermal heating and cooling, there exists an opportunity to improve the efficiency by utilizing non-uniform soil properties of a ground source heat exchanger during installation. This paper presents a gradient approach based upon finite element mathematics to determine an optimal distribution of heterogeneous soils with varying thermal conductivities. The numerically simulated case studies demonstrate the good performance of this algorithm to minimize the cross-talk of heat flux between pipes and maximize the overall efficiency.","PeriodicalId":298211,"journal":{"name":"ASME 2018 12th International Conference on Energy Sustainability","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127339023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cooling of Concentrator Photovoltaic Cells Using Mini-Scale Jet Impingement Heat Sinks","authors":"A. Radwan, Meshack Hawi, Mahmoud A. Ahmed","doi":"10.1115/ES2018-7569","DOIUrl":"https://doi.org/10.1115/ES2018-7569","url":null,"abstract":"In this study, an efficient cooling technique for concentrator photovoltaic (CPV) cells is proposed to enhance the system electrical efficiency and extend its lifetime. To do this, a comprehensive three-dimensional conjugate heat transfer model of CPV cells layers coupled with the heat transfer and fluid flow model inside jet impingement heat sink is developed. Four different jet impingement designs are compared. The investigated designs are (A) central inlet jet, (B) Hypotenuse inlet jet, (C) staggered inlet jet, and (D) conventional jet impingement design with side drainage. The effect of coolant flowrate on the CPV/T system performance is investigated. The model is numerically simulated and validated using the available experiments. The performance of CPV system is investigated at solar concentration ratios of 20 and coolant flowrate up to 6000g/min. It is found that increasing the flowrate from 60 g/min to 600 g/min decrease the maximum cell temperature by 31°C for the configuration D while increasing the flowrate from 600 g/min to 6000 g/min reduce the cell temperature by 20.2°C. It is also concluded that at a higher flowrate of 6000g/min, all the investigated configurations relatively achieve better temperature uniformity with maximum temperature differences of 0.9 °C, 2.1 °C, 3.6 °C, and 3.9 °C for configurations A, B, C, and D respectively.","PeriodicalId":298211,"journal":{"name":"ASME 2018 12th International Conference on Energy Sustainability","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127498088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Extreme Climate Variability on Energy Demands for Indoor Human Comfort Levels in Tropical Urban Environments","authors":"R. Pokhrel, L. Ortiz, N. Ramirez-Beltran, Jorge E. González","doi":"10.1115/ES2018-7131","DOIUrl":"https://doi.org/10.1115/ES2018-7131","url":null,"abstract":"The main objective of this study is to identify how climate variability influences human comfort levels in tropical-coastal urban environments. San Juan Metro Metropolitan Area (SJMA) of the island of Puerto Rico was chosen as a reference point. Temperature and relative humidity are identified as key environmental variables to maintain human comfort level. A new Human Discomfort Index (HDI) using the key environmental variables based on environmental enthalpy is defined. This index is expanded to determine the energy required to maintain indoor human comfort levels and is compared to total electric energy consumption for the island of Puerto Rico. Regression analysis shows that both temperature and HDI are good indicators to predict total electrical energy consumption. Results showed that over the past 35 years the average environmental enthalpy have increased, resulting in the increase of average HDI for SJMA. Surface weather station data further shows clear indication of urbanization biases ramping up the HDI. Long-term local scale (weather station; 30-years record) data shows a decreasing rate of maximum cooling per capita at −11.41 kW-h/years, and increasing of minimum cooling per capita of 10.64 kW-h/years. This contrasts with regional scale data for the whole Caribbean where increasing trends are observed for both minimum and maximum energy per capita. To estimate human comfort levels under extreme heat wave events conditions, an event of 2014 in the San Juan area was identified. The analysis is complemented by data from the National Center for Environmental Prediction (NCEP) at 250km spatial resolution, North American Regional Reanalysis (NARR) at 32 km spatial resolution, and simulations of the Weather Research and Forecasting model (WRF) at a resolution of 1 km, and by weather station data for San Juan. Model results were evaluated against observations showing good agreement for both temperature and relative humidity and improvements from the NCEP input. It also shows that Energy Per Capita (EPC), required to maintain indoor space at human comfort level, in urban areas during a heat wave event can increase to 21% as compared to normal day.","PeriodicalId":298211,"journal":{"name":"ASME 2018 12th International Conference on Energy Sustainability","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123691864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the Impact of Free-Stream Turbulence on Convective Cooling of Overhead Conductors Using Large Eddy Simulations (LES)","authors":"M. Abdelhady, D. Wood","doi":"10.1115/ES2018-7322","DOIUrl":"https://doi.org/10.1115/ES2018-7322","url":null,"abstract":"This study uses Large Eddy Simulation in the ANSYS Fluent software to assess the accuracy of the forced cooling term for the overhead conductor codes, IEEE 738 [1] and CIGRÉ 207 [2], for Real Time Thermal Rating of a wind farm power line. The analysis is done for low wind speed, corresponding to Reynolds Number of 3,000. The primary goal is to calculate Nusselt Number for cylindrical conductors with free-stream turbulence. Calculations showed an increase in convective heat transfer from the low turbulence value by ∼ 30 % at turbulence intensity of 21% and length scale to diameter ratio of 0.4; and an increase of ∼ 19 % at turbulence intensity of 8% and length scale to diameter ratio of 0.4.","PeriodicalId":298211,"journal":{"name":"ASME 2018 12th International Conference on Energy Sustainability","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124740283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effective Thermal Conductivity of Wall-Adjacent Layer in Gravity-Driven Vertical Dense Granular Flows","authors":"Megan F. Watkins, Yesaswi N. Chilamkurti, R. Gould","doi":"10.1115/ES2018-7464","DOIUrl":"https://doi.org/10.1115/ES2018-7464","url":null,"abstract":"Particle-based heat transfer fluids for concentrated solar power (CSP) tower applications offer a unique advantage over traditional fluids as they have the potential to reach very high operating temperatures. Our work studies the heat transfer behavior of dense granular flows through cylindrical tubes as a potential system configuration for CSP towers. Thus far, we have experimentally investigated the heat transfer to such flows. Our results corroborate the observations of other researchers; namely, that the discrete nature of the flow limits the heat transferred from the tube wall to the flow due to an increased thermal resistance in the wall-adjacent layer. The present study focuses on this near-wall phenomenon, examining how it varies with system configuration and flow rate. A correlation to predict the thermal resistance, in the form of an effective thermal conductivity, was developed based on the underlying physics controlling the heat transfer. The model developed focuses on heat transfer via conduction, considering the heat transfer to particles in contact with the wall, heat transfer to particles not in contact with the wall, and heat transfer through the void spaces. Discrete Element Method simulations were used to examine the flow parameters necessary to understand the heat transfer in the wall-adjacent layer, in particular the packing fraction in the wall-adjacent layer and the number of particle-wall contacts. Incorporation of the model into the single-resistance model developed by Sullivan & Sabersky [1] showed good agreement with their experimental results and those of Natarajan & Hunt [2].","PeriodicalId":298211,"journal":{"name":"ASME 2018 12th International Conference on Energy Sustainability","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132540050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Study on Thermoelectric Performance of Cross-Flow Planar Solid Oxide Fuel Cell","authors":"Haibin Lu, C. Xie, Xiuwen Hua, Taosif Iqbal, Xiongwen Zhang, Guojun Li, Di Zhang","doi":"10.1115/ES2018-7351","DOIUrl":"https://doi.org/10.1115/ES2018-7351","url":null,"abstract":"This paper investigates the thermoelectric characteristics of cross-flow planar type solid oxide fuel cell (SOFC) with natural gas as fuel by using a three-dimensional numerical model. The results reveal that temperature and reactant concentration increase gradually along the direction of fuel gas flow, and the reactant concentration increases in the first and subsequently decreases. In addition, the lower the temperature, the higher ideal electromotive force is as well as the less actual output electromotive force. The hydrogen concentration is positively correlated with the current density and the ideal electromotive force. However, increasing the mass flow continuously beyond the reasonable range can decrease the current and electrochemical reaction intensity. Variation in wall thickness was also simulated and found that increasing the thickness would result in higher intensity of electrochemical reaction and increased current density but at the cost of low efficiency in SOFC. Thus an optimal design can make a balance between fuel utilization and output power of SOFC.","PeriodicalId":298211,"journal":{"name":"ASME 2018 12th International Conference on Energy Sustainability","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133126884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}