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31.
A review of integration strategies for solid oxide fuel cells 总被引:1,自引:0,他引:1
Due to increasing oil and gas demand, the depletion of fossil resources, serious global warming, efficient energy systems and new energy conversion processes are urgently needed. Fuel cells and hybrid systems have emerged as advanced thermodynamic systems with great promise in achieving high energy/power efficiency with reduced environmental loads. In particular, due to the synergistic effect of using integrated solid oxide fuel cell (SOFC) and classical thermodynamic cycle technologies, the efficiency of the integrated system can be significantly improved. This paper reviews different concepts/strategies for SOFC-based integration systems, which are timely transformational energy-related technologies available to overcome the threats posed by climate change and energy security. 相似文献
32.
The rapid advances in technology and improved living standard of the society necessitate abundant use of fossil fuels which poses two major challenges to any nation. One is fast depletion of fossil fuel resources; the other is environmental pollution. The porous medium combustion (PMC) has proved to be one of the feasible options to tackle the aforesaid problems to a remarkable extent. PMC has interesting advantages compared with free flame combustion due to the higher burning rates, the increased power dynamic range, the extension of the lean flammability limits, and the low emissions of pollutants. This article provides a comprehensive picture of the global scenario of applications of PMC so as to enable the researchers to decide the direction of further investigation. The works published so far in this area are reviewed, classified according to their objectives and presented in an organized manner with general conclusions. 相似文献
33.
A review on the mechanical and electrical properties of graphite and modified graphite reinforced polymer composites 总被引:1,自引:0,他引:1
Rajatendu SenguptaMithun Bhattacharya S. BandyopadhyayAnil K. Bhowmick 《Progress in Polymer Science》2011,36(5):638-670
Carbon materials particularly in the form of sparkling diamonds have held mankind spellbound for centuries, and in its other forms, like coal and coke continue to serve mankind as a fuel material, like carbon black, carbon fibers, carbon nanofibers and carbon nanotubes meet requirements of reinforcing filler in several applications. All these various forms of carbon are possible because of the element's unique hybridization ability. Graphene (a single two-dimensional layer of carbon atoms bonded together in the hexagonal graphite lattice), the basic building block of graphite, is at the epicenter of present-day materials research because of its high values of Young's modulus, fracture strength, thermal conductivity, specific surface area and fascinating transport phenomena leading to its use in multifarious applications like energy storage materials, liquid crystal devices, mechanical resonators and polymer composites. In this review, we focus on graphite and describe its various modifications for use as modified fillers in polymer matrices for creating polymer-carbon nanocomposites. 相似文献
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The present work demonstrates the structure-rheology relationship of novel polyvinylidene fluoride/hydrogenated nitrile rubber blends with special reference to the effect of mixing time, which has not been amply discussed in the literature. In between 50 and 70 wt% rubber content, a yield in complex viscosity and secondary plateau in storage modulus were discerned due to interconnected droplets-matrix morphology manifesting the thermoplastic elastomeric nature of the blends (TPEs). Such network-like structure altered the rheological properties like relaxation time, capillary viscosity, die swell, elastic responses of the TPE with respect to the trend as expected according to the rule of mixing. Interestingly, in the early stages of mixing, when the dispersed size was bigger, the effect of physical network on the rheological properties was suppressed. During dynamic vulcanization (TPV), both lower and higher frequency responses in oscillatory shear flow, steady shear rheological properties, recoverable strain etc. have changed notably with mixing time. For example, although the complex viscosity of the TPV was higher at a lower frequency as compared to its TPE, it was significantly lower at a higher frequency at the beginning of dynamic curing; however, viscosity increased appreciably with time. Temperature-dependendent rheological properties were also influenced with mixing time of the compositions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48758. 相似文献
36.
Generation of electricity using InGaAsSb and GaSb TPV cells in combustion-driven radiant sources 总被引:4,自引:0,他引:4
Electric power generation using InGaAsSb and GaSb thermophotovoltaic (TPV) cells was investigated in a gas-fired heating furnace. Electric output characteristics of the TPV cells in the combustion-driven radiant sources are presented. For the InGaAsSb cells, open circuit voltage was higher than 300 mV at a short circuit current density above 1 A/cm2. The short circuit current of the InGaAsSb cells increased more rapidly than that of the GaSb cells in radiator temperature range 930–1215 °C. A mathematical model for the TPV devices was developed to describe the effect of cell bandgap and radiator temperature on electric power output and cell efficiency. Also, the design aspects of the combustion-driven TPV systems are discussed. 相似文献
37.
《International Journal of Hydrogen Energy》2019,44(42):23741-23749
In recent years, there has been increasing interest in fuel cell hybrid systems. In this paper, a novel multi-generation combined energy system is proposed. The system consists of a molten carbonate fuel cell (MCFC), a thermally regenerative electro-chemical cycle (TREC), a thermo photovoltaic cell (TPV), an alkaline electrolyzer (AE) and an absorption refrigerator (AR). It has four useful outputs, namely electricity, hydrogen, cooling and heating. The overall system is thermodynamically modeled in a detailed manner while its simulation and modeling are done through the TRNSYS software tool. Power output, cooling-heating and produced hydrogen rates are determined using energetic and exergetic analysis methods. Results are obtained numerically and plotted. The maximum power output from the system is 16.14 kW while maximum energy efficiency and exergy efficiency are 86.8% and 80.4%,. The largest exergy destruction is due to the MCFC. 相似文献
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S. Dakshinamurthy S. Shetty I. Bhat C. Hitchcock R. Gutmann G. Charache M. Freeman 《Journal of Electronic Materials》1999,28(4):355-359
The GaInSb material system is attractive for application in therm ophotovoltaic (TPV) cells since its band gap can be tuned
to match the radiation of the emitter. At present, most of the TPV cells are fabricated using epitaxial layers and hence are
expensive. To reduce the cost, Zn diffusion using elemental vapors in a semiclosed diffusion system is being pursued by several
laboratories. In this paper, we present studies carried out on Zn diffusion into n-type (Te-doped) GaSb substrates in an open
tube diffusion furnace. The dopant precursor was a 2000 ? thick, zinc doped spin-on glass. The diffusion was carried out at
temperatures ranging from 550 to 600°C, for times from 1 to 10 h. The diffused layers were characterized by Hall measurements
using step-and-repeat etching by anodic oxidation, secondary ion mass spectrometry measurements, and TPV device fabrication.
For diffusion carried out at 600°C, the junction depth was 0.3 μm, and the hole concentration near the surface was 5 × 1019/cm3. The external quantum efficiency, measured without any anti-reflection coating of the TPV cells fabricated using mesa-etching
had a maximum value of 38%. Masked diffusion was also carried out by opening windows in a Si3N4 coated, GaSb wafer. TPV cells fabricated on these structures had similar quantum efficiency, but lower dark current. 相似文献
40.
Shiquan SHAN Chuyang CHEN Peter G. LOUTZENHISER Devesh RANJAN Zhijun ZHOU Zhuomin M. ZHANG 《Frontiers in Energy》2020,14(3):482
Micro/nanostructures play a key role in tuning the radiative properties of materials and have been applied to high-temperature energy conversion systems for improved performance. Among the various radiative properties, spectral emittance is of integral importance for the design and analysis of materials that function as radiative absorbers or emitters. This paper presents an overview of the spectral emittance measurement techniques using both the direct and indirect methods. Besides, several micro/nanostructures are also introduced, and a special emphasis is placed on the emissometers developed for characterizing engineered micro/nanostructures in high-temperature applications (e.g., solar energy conversion and thermophotovoltaic devices). In addition, both experimental facilities and measured results for different materials are summarized. Furthermore, future prospects in developing instrumentation and micro/nanostructured surfaces for practical applications are also outlined. This paper provides a comprehensive source of information for the application of micro/nanostructures in high-temperature energy conversion engineering. 相似文献