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991.
Thomas Bak Angus Graham Alla Sapronova Mihai Florian John Dalsgaard Sørensen Torben Knudsen Peng Hou Zhe Chen 《风能》2017,20(9):1665-1683
The paper presents a model of a reference wind farm. The model considers the wind and wave climatologies for a specific site from which two different wind farm layouts are derived. These layouts are examined through the effective wake‐enhanced turbulence intensity at the hub height for a given climatology, and a simple model for the influence on capital expenditures is proposed. An electrical design is presented, the cable losses are calculated and the energy yield is determined. An operation and maintenance model is established, and the associated operating expenditure is obtained. All of the models are then summarized in terms of a levelized cost of energy using a numerical simulation tool, which allows the layouts to be compared. The data and models are freely available online for others to use and may serve as a baseline for benchmarking and allow researchers to compare and discuss their results. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
992.
Cold plates, devices used for the thermal management of electronic equipment, consist of a fluid flow space that is bounded by metallic walls. The fluid passages are designed to optimize the heat extraction from the electronics. This paper deals with the fluid flow and heat transfer in cold plates in which both the fluid flow and heat transfer experience periodic variations in the streamwise direction. The motivation for the work was to devise a methodology for dealing with problems that are highly complex and also computationally demanding. The first goal of the work was to transform the combined problems of fluid flow and conjugate heat transfer into one in which the wall heat transfer can be solved separately. The decoupling was achieved by first focusing on the solution of the full conjugate heat transfer problem for a portion of the periodic array. From this solution, heat transfer coefficients were extracted and subsequently employed for the solution of the wall heat conduction problem for the entire cold plate. The second focus was the development of enhancements of the heat transfer performance of cold plates. Consideration was given to manufacturing as well as thermal and fluid flow issues. 相似文献
993.
John M. E. Storey C. Scott Sluder Michael J. Lance Daniel J. Styles Steven J. Simko 《传热工程》2013,34(8-9):655-664
This article reports on the results of experimental efforts aimed at improving the understanding of the mechanisms and conditions at play in the fouling of exhaust gas recirculation coolers. An experimental apparatus was constructed to utilize simplified surrogate heat exchanger tubes in lieu of full-size heat exchangers. The use of these surrogate tubes allowed removal of the tubes after exposure to engine exhaust for study of the deposit layer and its properties. The exhaust used for fouling the surrogate tubes was produced using a modern medium-duty diesel engine fueled with both ultra-low-sulfur diesel and biodiesel blends. At long exposure times, no significant difference in the fouling rate was observed between fuel types and hydrocarbons levels. Surface coatings for the tubes were also evaluated to determine their impact on deposit growth. No surface treatment or coating produced a reduction in the fouling rate or any evidence of deposit removal. In addition, microstructural analysis of the fouling layers was performed using optical and electron microscopy in order to better understand the deposition mechanism. The experimental results are consistent with thermophoretic deposition for deposit formation, and van der Waals attraction between the deposit surface and exhaust-borne particulate. 相似文献
994.
995.
Jiadong Liu Lifen Liu Bo Gao Fenglin Yang John Crittenden Nanqi Ren 《International Journal of Hydrogen Energy》2014
A microbial fuel cell (MFC) was integrated with flat sheet membrane bioreactor (MBR) and studied for electricity generation, membrane fouling mitigation and artificial wastewater treatment. The cell potential was ∼0.2 V with 100 Ω external load during closed circuit operation. Batch tests identified that the sludge properties and aeration in cathodic chamber were the main affecting factors on electricity generation. Integration of microbial fuel cell can significantly alleviate membrane fouling, under closed circuit condition, membrane filtration lasted 21 days – 27 days and under the open circuit condition it lasted only 13 days - 15 days, before the transmembrane pressure (TMP) reached 0.03 MPa. The calculated electrostatic repulsion force between membrane surface and membrane foulant was about 2.5 × 10−14 N in this integrated reactor. The chemical oxygen demand (COD), ammonia nitrogen, phosphorus and offensive smell could be effectively removed by the sequential anaerobic-aerobic treatment system. The effluent pH was neutral and turbidity was very low. 相似文献
996.
997.
Xue Li Xianjun Lyu Xiaohan Zhao Yan Zhang Stephen Nyabire Akanyange John C. Crittenden Huaqing Zhao Tianlin Jiang 《International Journal of Hydrogen Energy》2021,46(35):18376-18390
In this study, GO and Fe2P were used as co-catalysts to improve the separation efficiency of photogenerated electron-hole pairs in an In2S3 photocatalyst. The metallic character of Fe2P provided a cheap substitute for traditional noble metal co-catalyst for H2 production in aqueous media. The GO/Fe2P/In2S3 composite demonstrated significantly enhanced photocatalytic activity compared to pure In2S3, delivering a H2 production rate of 483.35 μmol h?1 g?1 and a quantum yield was 22.68% under visible light irradiation. The design of the photocatalyst was optimized using “Design Expert” software. The analysis showed that a GO loading of 1.18 wt%, a Fe loading of 5.36 wt%, and a calcination temperature of 180 °C were optimal. 相似文献
998.
John D. Rodney S. Deepapriya M. Cyril Robinson C. Justin Raj Suresh Perumal Byung Chul Kim S. Krishnan S. Jerome Das 《International Journal of Hydrogen Energy》2021,46(54):27585-27596
The production of hydrogen, a favourable alternative to an unsustainable fossil fuel remains as a significant hurdle with the pertaining challenge in the design of proficient, highly productive and sustainable electrocatalyst for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, the dysprosium (Dy) doped copper oxide (Cu1-xDyxO) nanoparticles were synthesized via solution combustion technique and utilized as a non-noble metal based bi-functional electrocatalyst for overall water splitting. Due to the improved surface to volume ratio and conductivity, the optimized Cu1-xDyxO (x = 0.01, 0.02) electrocatalysts exhibited impressive HER and OER performance respectively in 1 M KOH delivering a current density of 10 mAcm?2 at a potential of ?0.18 V vs RHE for HER and 1.53 V vs RHE for OER. Moreover, the Dy doped CuO electrocatalyst used as a bi-functional catalyst for overall water splitting achieved a potential of 1.56 V at a current density 10 mAcm?2 and relatively high current density of 66 mAcm?2 at a peak potential of 2 V. A long term stability of 24 h was achieved for a cell voltage of 2.2 V at a constant current density of 30 mAcm?2 with only 10% of the initial current loss. This showcases the accumulative opportunity of dysprosium as a dopant in CuO nanoparticles for fabricating a highly effective and low-cost bi-functional electrocatalyst for overall water splitting. 相似文献
999.
The National Energy Strategy of the U.S. is designed to expand through federal policies the fuel and technology choices available to industry, utilities, and other energy users. It also promotes policies to encourage balanced integration of energy, economic, and environmental options in the selection of technologies for application in the marketplace. Consideration of each of these factors, separately and together, favors geothermal energy in many industrial applications. It is the policy of the Department of Energy to support growth in all uses of geothermal energy through focused R & D to improve technologies for its economic exploitation. 相似文献
1000.
James P. Coleman Anne T. Lynch Puttanachetty Madhukar John H. Wagenknecht 《Solar Energy Materials & Solar Cells》1999,56(3-4)
We describe herein some of our initial studies in pursuit of a simple, economical method of mass producing electrochromic displays. The approach we have taken is to print the display on polymer film utilizing commercially available conductive inks in an interdigitated electrode structure with a conductive metal oxide powder, dispersed in a polymer binder, as the electrode surface. A range of electrochromic materials suitable for use with an aqueous gel electrolyte have been explored and examples presented. 相似文献