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Articoli di riviste sul tema "C5F10O/N2/O2 gas mixture":

1

Li, Yalong, Xiaoxing Zhang, Yalong Xia, Yi Li, Zhuo Wei, Yi Wang e Song Xiao. "Study on the Compatibility of Eco-Friendly Insulating Gas C5F10O/N2 and C5F10O/Air with Copper Materials in Gas-Insulated Switchgears". Applied Sciences 11, n. 1 (28 dicembre 2020): 197. http://dx.doi.org/10.3390/app11010197.

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Sulfur hexafluoride (SF6) is widely used in the power industry because of its excellent insulation and arc extinguishing performance. However, the high greenhouse effect of this material is being restricted by many countries around the world, thereby discouraging its usage. As a potential alternative to SF6, the compatibility of C5F10O with conductive copper materials used in electrical equipment is of great significance in ensuring the safe and stable operation of environmentally friendly gas-insulated equipment. In this paper, the interaction among C5F10O/N2, C5F10O/air gas mixture, and copper was studied via experiments and simulations. When the C5F10O/N2 (or air) gas mixture comes in contact with copper at the gas–solid interface, a small portion of C5F10O is decomposed to form C3F6 (or C3F6 and C3F6O) at high temperatures. Meanwhile, at low temperatures (120 °C), the C5F10O/air gas mixture becomes more compatible with copper than with the C5F10O/N2 gas mixture. When the experiment temperatures range between 170 °C and 220 °C, the compatibility of the C5F10O/air gas mixture with copper is significantly inferior to its compatibility with copper. Under high temperatures, the C5F10O/air gas mixture shows severe corrosion on the copper surface due to the presence of O2, forms a thick cubic grain, and emits irritating gases. The simulations show that the carbonyl group in C5F10O is chemically active and can be easily adsorbed on the copper surface. An anti-corrosion treatment must be performed on copper materials in manufacturing equipment. The findings provide an important reference for the application of C5F10O gas mixture.
2

Nechmi, Houssem Eddine, Michail Michelarakis, Abderrahmane (Manu) Haddad e Gordon Wilson. "Clarifications on the Behavior of Alternative Gases to SF6 in Divergent Electric Field Distributions under AC Voltage". Energies 14, n. 4 (18 febbraio 2021): 1065. http://dx.doi.org/10.3390/en14041065.

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Negative and positive partial discharge inception voltages and breakdown measurements are reported in a needle-plane electrode system as a function of pressure under AC voltage for natural gases (N2, CO2, and O2/CO2), pure NovecTM gases (C4F7N and C5F10O) and NovecTM in different natural gas admixtures. For compressed 4% C4F7N–96% CO2 and 6% C5F10O–12% O2–82% CO2 gas mixtures, the positive-streamer mode is identified as the breakdown mechanism. Breakdown and negative partial discharge inception voltages of 6% C5F10O–12% O2–82% CO2 are higher than those of 4% C4F7N–96% CO2. At 8.8 bar abs, the breakdown voltage of 6% C5F10O–12% O2–82% CO2 is equal to that of 12.77% O2–87.23% CO2 (buffer gas). Synergism in negative partial discharge inception voltage/electric field fits with the mean value and the sum of each partial pressure individually component for a 20% C4F7N–80% CO2 and 6% C5F10O–12% O2–82% CO2, respectively. In 9% C4F7N–91% CO2, the comparison of partial discharge inception electric fields is Emax (CO2) = Emax(C4F7N), and Emax (12.77% O2–87.23% CO2) = Emax(C5F10O) in 19% C5F10O–81%(12.77% O2–87.23% CO2). Polarity reversal occurs under AC voltage when the breakdown polarity changes from negative to positive cycle. Polarity reversal electric field EPR was quantified. Fitting results show that EPR (CO2) = EPR(9% C4F7N–91% CO2) and EPR(SF6) = EPR (22% C4F7N–78% CO2). EPR (4% C4F7N–96% CO2) = EPR (12.77% O2–87.23% CO2) and EPR (6% C5F10O–12% O2–82% CO2) < EPR (4% C4F7N–96% CO2) < EPR (CO2).
3

Zhang, Yue, Xiaoxing Zhang, Yi Li, Yalong Li, Qi Chen, Guozhi Zhang, Song Xiao e Ju Tang. "Effect of oxygen on power frequency breakdown voltage and decomposition characteristics of the C5F10O/N2/O2 gas mixture". RSC Advances 9, n. 33 (2019): 18963–70. http://dx.doi.org/10.1039/c9ra03275d.

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C5F10O gas mixture is a SF6 potential substitute with high insulation strength and is a new type of environmentally friendly insulating gas. By adding oxygen to C5F10O gas mixture, insulation strength can be improved and carbon deposition can be suppressed.
4

She, Congdong, Fuping Zeng, Liangjun Dai, Long Li, Qiang Yao e Ju Tang. "Degradation Behaviors and Mechanism of Nitrile Butadiene Rubber Caused by Insulating Medium C5F10O". Polymers 15, n. 10 (12 maggio 2023): 2282. http://dx.doi.org/10.3390/polym15102282.

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C5F10O is a promising insulating medium in the manufacturing of environmentally friendly gas-insulated switchgears (GISs). The fact that it is not known whether it is compatible with sealing materials used in GISs limits its application. In this paper, the deterioration behaviors and mechanism of nitrile butadiene rubber (NBR) after prolonged exposure to C5F10O are studied. The influence of C5F10O/N2 mixture on the deterioration process of NBR is analyzed through a thermal accelerated ageing experiment. The interaction mechanism between C5F10O and NBR is considered based on microscopic detection and density functional theory. Subsequently, the effect of this interaction on the elasticity of NBR is calculated through molecular dynamics simulations. According to the results, the polymer chain of NBR can slowly react with C5F10O, leading to deterioration of its surface elasticity and loss of inside additives, mainly ZnO and CaCO3. This consequently reduces the compression modulus of NBR. The interaction is related to CF3 radicals formed by the primary decomposition of C5F10O. The molecular structure of NBR will be changed in the molecular dynamics simulations due to the addition reaction with CF3 on NBR’s backbone or branched chains, resulting in changes in Lame constants and a decrease in elastic parameters.
5

Liu, Wei Long, Shu Huei Hsieh e Wen Jauh Chen. "Manufacture and Characterization of TiO2 Nanowires by CVD". Advanced Materials Research 415-417 (dicembre 2011): 697–700. http://dx.doi.org/10.4028/www.scientific.net/amr.415-417.697.

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Under the catalysis of Co metal, the nanosized titania could be grown on Ti substrate at elevated temperature under a gas mixture of N2, O2, CH4 , and H2O. The nanosized titania was characterized by scanning electron microscope for its morphology, and by an energy dispersion spectrometer for its composition. The results showed that the straight and long titania nanowire could be formed at 900°C under a gas mixture of N2, O2, and CH4. When H2O vapor was added to the gas mixture, the titania nanowire became somewhat curved. The tiania nanowire was oxygen deficient, i.e. TiO2-X.
6

Wu, King Kung, e Wen Chung Chang. "High-Quality Polysilicon Thin Film Recrystallization by Laser Annealing". Advanced Materials Research 382 (novembre 2011): 26–29. http://dx.doi.org/10.4028/www.scientific.net/amr.382.26.

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Amorphous silicon (a:Si) recrystalized to poly-silicon (poly:Si) in different gas environments by excimer laser annealing (ELA) is studied. Variations of threshold laser power for the generation of surface ablation in pure N2 gas and the mixture of N2:98% and O2:2% environments are also investigated, respectively. From experiments, it is found the combination of N2:98% and O2:2% gas can enhance the threshold laser power from 320mJ/cm2 to 390mJ/cm2 for the suppressing of surface ablation phenomenon. In the condition of average grain over 0.25um, the process window (i.e. laser power for processing ability) is 30mJ/cm2 for pure N2 only, but is 50mJ/cm2 for the combination of N2:98% and O2:2%.
7

Pramanik, B. K., Somlal Das, K. Subrata Pr e A. Hatta. "Effect of Rare Gas Admixture on N2 /O2 Gas Mixture Discharge". Journal of Engineering and Applied Sciences 5, n. 5 (1 maggio 2010): 347–53. http://dx.doi.org/10.3923/jeasci.2010.347.353.

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8

Chen, F. J., A. S. Menon, S. V. Lichtenstein, N. Zamel e A. S. Slutsky. "Mechanisms of gas exchange with different gases during constant-flow ventilation". Journal of Applied Physiology 68, n. 1 (1 gennaio 1990): 88–93. http://dx.doi.org/10.1152/jappl.1990.68.1.88.

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To investigate the mechanisms responsible for the difference in gas exchange during constant-flow ventilation (CFV) when using gases with different physical properties, we used mixtures of 70% N2-30% O2 (N2-O2) and 70% He-30% O2 (He-O2) as the insufflating gases in 12 dogs. All dogs but one had higher arterial PCO2 (PaCO2) with He-O2 compared with N2-O2. At a flow of 0.37 +/- 0.12 l/s, the mean PaCO2's with N2-O2 and He-O2 were 41.3 +/- 13.9 and 53.7 +/- 20.3 Torr, respectively (P less than 0.01); at a flow rate of 0.84 +/- 0.17 l/s, the mean PaCO2's were 29.1 +/- 11.3 and 35.3 +/- 13.6 Torr, respectively (P less than 0.01). The chest was then opened to alter the apposition between heart and the lungs, thereby reducing the extent of cardiogenic oscillations by 58.4 +/- 18.4%. This intervention did not significantly alter the difference in PaCO2 between N2-O2 and He-O2 from that observed in the intact animals, although the individual PaCO2 values for each gas mixture did increase. When the PaCO2 was plotted against stagnation pressure (rho V2), the difference in PaCO2 between N2-O2 and He-O2 was nearly abolished in both the closed- and open-chest animals. These findings suggest that the different PaCO2's obtained by insufflating gases with different physical properties at a fixed flow rate, catheter position, and lung volume result mainly from a difference in the properties of the jet.
9

Xiao, Dezhi, Cheng Cheng, Jie Shen, Yan Lan, Hongbing Xie, Xingsheng Shu, Yuedong Meng, Jiangang Li e Paul K. Chu. "Characteristics of atmospheric-pressure non-thermal N2 and N2/O2 gas mixture plasma jet". Journal of Applied Physics 115, n. 3 (21 gennaio 2014): 033303. http://dx.doi.org/10.1063/1.4862304.

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10

Pramanik, Bimal Kumar, e AKM Akhtar Hossain. "UV Emission from N2/O2 Pulse Microwave Plasma". Rajshahi University Journal of Science 38 (10 ottobre 2013): 1–8. http://dx.doi.org/10.3329/rujs.v38i0.16543.

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The emission spectrum from pulse microwave discharge of N2/O2 gas mixture in the UV range (from 200 – 400 nm) was studied in a cylindrical quartz tube aiming to apply it as a mercury free UV light source. The UV light in the 200-280 nm range has germicidal effect which can be used for water purification. In our previous work we used continuous microwave power to produce UV emission from N2/O2 discharge. In the present work we used pulse microwave power instead of continuous microwave power. We studied the dependence of pulse width and pulse interval on the intensity of the UV emission from N2/O2 discharge. Experimental results showed that the UV emission intensity emitted from N2/O2 gas discharge in 200- 400 nm region does not vary with pulse width and pulse interval but depends on applied average power. DOI: http://dx.doi.org/10.3329/rujs.v38i0.16543 Rajshahi University J. of Sci. 38, 01-08 (2010)

Tesi sul tema "C5F10O/N2/O2 gas mixture":

1

Li, Yalong. "Research on the decomposition characteristics and biosafety of C5F10O/N2/O2 mixed insulating gas". Electronic Thesis or Diss., Orléans, 2023. http://www.theses.fr/2023ORLE1050.

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Dans ce travail de thèse de doctorat, des études expérimentales et théoriques sont réalisées sur les caractéristiques de décomposition du mélange gazeux C5F10O/N2/O2 à l'interface gaz-solide de matériaux métalliques et sous l'action d'une décharge électrique dans un appareil de coupure électrique. La faisabilité et la sécurité de son utilisation sont évaluées en combinaison avec la biosécurité du gaz C5F10O et des produits de décomposition du gaz plasmagène. Compte tenu du contact long entre le mélange gazeux C5F10O/N2/O2 et les matériaux internes de l'équipement de coupure électrique pendant son fonctionnement, la stabilité de l'interaction gaz-solide du mélange gazeux avec les métaux couramment utilisés (cuivre, aluminium et argent), à l'intérieur de l'équipement est caractérisé, et le mécanisme d'interaction gaz-solide entre le mélange gazeux C5F10O et les matériaux métalliques est précisé. Un défaut thermique peut également se produire pendant le fonctionnement de l'équipement. Les caractéristiques typiques de la décharge et de la décomposition par défaut thermique du mélange gazeux C5F10O/N2/O2 contenant différentes concentrations d'oxygène sont identifiées. La composition et les processus de création des produits de décomposition du mélange gazeux sont obtenues, et la corrélation entre les types et le contenu des produits de décomposition caractéristiques et les types de défaut, ainsi que la réaction de l'oxygène vers les produits de décomposition du mélange gazeux C5F10O et le mécanisme d'inhibition de la précipitation des produits solides sont analysés. Sur la base de ce travail, nous proposons un schéma d'optimisation de la stabilité de la couche protectrice argent- cuivre est proposé pour le cuivre avec une faible stabilité gaz-solide du gaz C5F10O/N2/O2. Nous avons défini les produits caractéristiques de la décharge et du défaut thermique du mélange gazeux, ce qui constitue une référence pour la surveillance en ligne des défauts. Nous avons testé la biosécurité du C5F10O et des produits de décomposition par arc. Sa sécurité d'application a été évaluée en fonction des caractéristiques de décharge et de décomposition thermique du mélange gazeux, et des mesures et de protection ciblées et des suggestions sont proposées
In this doctoral thesis work, experimental and theoretical studies are carried out on the decomposition characteristics of C5F10O/N2/O2 gas mixture at the gas-solid interface of metal materials and under the discharge and thermal action, and the feasibility and safety of its application are evaluated in combination with the biosafety of C5F10O gas and arc decomposition products of C5F10O/N2/O2. Considering the long-term contact between C5F10O/N2/O2 gas mixture and the internal materials of the equipment during normal operation, the gas-solid interaction stability of C5F10O/N2/O2 gas mixture with commonly used metal copper, aluminum and silver inside the equipment is evaluated, and the mechanism of gas-solid interface interaction between C5F10O gas mixture and metal materials is clarified. Discharge and thermal fault may also occur during the long-term operation of the equipment. The failure decomposition mechanism of C5F10O/N2/O2 gas mixture is studied through experiments and simulations. The typical discharge and thermal fault decomposition characteristics of C5F10O/N2/O2 gas mixture containing different concentrations of oxygen are revealed. The composition and generation rules of decomposition products of the gas mixture under the faults are obtained, and the correlation between the types and contents of characteristic decomposition products and the fault types, as well as the regulation of oxygen to C5F10O gas mixture decomposition products and the inhibition mechanism of solid product precipitation are analyzed. In conclusion, based on the simulation and experimental results, we proposed the stability optimization scheme of silver-plated protective layer on copper surface for metal copper material with poor gas-solid stability of C5F10O/N2/O2 gas. We extracted the characteristic products characterizing the discharge and thermal fault of C5F10O/N2/O2 gas mixture, which provided a reference for the on-line fault monitoring based on the decomposition components. We tested the biosafety of C5F10O and its arc decomposition products, and evaluated its application safety based on the discharge and thermal fault decomposition characteristics of C5F10O/N2/O2 gas mixture, and proposed targeted safety protection measures and suggestions

Capitoli di libri sul tema "C5F10O/N2/O2 gas mixture":

1

Bell, David, Jean-François Doussin e Thorsten Hohaus. "Preparation of Simulation Chambers for Experiments". In A Practical Guide to Atmospheric Simulation Chambers, 113–27. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-22277-1_3.

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AbstractWhen setting up a simulation chamber experiment it is essential, in order to ensure meaningful results, to start with a well-controlled chemical system. Coming after the chapter dealing with the requested careful characterization of the simulation chamber, the present chapter describes the preparation of the chamber before running an experiment. It includes various chamber cleaning protocols, the preparation of a clean chamber atmosphere (the reacting mixture) and a series of protocols for blank experiments. Indeed, having a clean atmosphere in a simulation chamber, as free as possible from both particulate and gaseous impurities, is essential to ensure high quality experimental results. As it may not be possible to have a perfectly clean chamber, blank experiments are crucial to both assess chamber cleanliness, account for impurities and establish uncertainties of the observed phenomena. In the present chapter, various cleaning protocols which involve the oxidation of the impurities, dilution, temperature degradation/evaporation, but the evacuation or manual cleaning are described as well. The various techniques to generate clean gas mixture—mostly clean O2, N2 or water vapor, are discussed. Finally, complementarily to the reference experiments proposed in Chap. 2, blank experiments to characterize walls chemical inertia, chamber-dependent radical sources or the presence of water-soluble species are also described.

Atti di convegni sul tema "C5F10O/N2/O2 gas mixture":

1

Xia, Yalong, Fan Liu, Yalong LI, Xiaoxing Zhang, Shijun Xie, Chenmeng Zhang, Ju Tang e Song Xiao. "Study on the Thermal Decomposition Characteristics of C5F10O/N2 Gas Mixture". In 2020 IEEE 4th Conference on Energy Internet and Energy System Integration (EI2). IEEE, 2020. http://dx.doi.org/10.1109/ei250167.2020.9346950.

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2

Jing, Yi, Haoyong Song, Ran Zhuo, Mingli Fu, Dibo Wang e Wei Wang. "Breakdown and decomposition characteristics of environmentally friendly C4F7N/N2/O2 gas mixture at high pressure". In 2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE). IEEE, 2020. http://dx.doi.org/10.1109/ichve49031.2020.9279546.

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3

Chen, W., S. S. Thanapal, K. Annamalai e R. J. Ansley. "Comparative Evaluation of CO2-O2 and Air (N2-O2) Gasification of Agricultural Biomass Fuels". In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-69324.

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Biomass gasification is being considered as one of the most promising technologies for converting biomass into gaseous fuel. Here we present the results of gasification, using an adiabatic fixed bed updraft gasifier with air and carbon dioxide as gasification medium, for redberry juniper (Juniperus pinchotii), one of the woody species that dominate uncultivated lands in the Southern Great Plains, U.S.A., that may have potential for bioenergy utilization. The effect of gasifying the woody fuels with carbon dioxide (oxy fuel gasification) was carried out to study for increased production of carbon monoxide through Boudouard reaction. The effect of three different moisture contents: 5–6%, 11–12%, and 23–24%, on the tar yield was investigated for juniper using air as the gasification medium since the amount of tar in the gas produced impacts the way the gas is utilized for different applications. It was observed that oxy fuel gasification of juniper resulted in increased production of carbon monoxide at higher peak temperatures and hence increased heating value of the resulting gas mixture (6264 kJ/ Nm3 with inerts CO2 and N2, 19750 kJ/Nm3 inert free). It was found that the tar yield was more than 100 g/Nm3 of the gas produced using air as gasification medium for juniper fuels with moisture content between 5–6% and 11–12%. Also, the tar yield increased with the increase of equivalence ratio (ER). At a fixed ER, tar increased with the increasing moisture content. However, when the fuel moisture content reached 23–24%, the tar yield reduced significantly due low gasification temperature which reduced the pyrolysis and other gas phase reaction rates within the gasifier.
4

Schildberg, Hans-Peter. "Experimental Determination of the Static Equivalent Pressures of Detonative Explosions of Ethylene/O2/N2-Mixtures and Cyclohexane/O2/N2-Mixtures in Long and Short Pipes". In ASME 2018 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/pvp2018-84493.

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In the recent past (PVP2013-97677, PVP2014-28197, PVP2015-45286, PVP2016-63223) we had started to determine the static equivalent pressures (pstat) of the eight detonative pressure scenarios in long and short pipes for different detonable gas mixtures. The pstat-values are of vital importance for process design: by assigning static equivalent pressures to the highly dynamic detonative pressure peaks it is possible to apply the established pressure vessel guidelines, which can only cope with static loads, in the design of detonation pressure resistant pipes. In the previous publications the parameter R was defined as the ratio between pstat at the location where transition from deflagration to detonation occurs and pstat in the region of the stable detonation. One important finding was that R depends on the reactivity of the gas mixture. So far, R cannot be predicted from first principles or from combustion parameters, but can only be determined experimentally. The ratio R has a special significance, because it not only determines pstat for the Deflagration to Detonation Transition (DDT) in long pipes (first detonative pressure scenario), but also gives a good estimate for two of the three scenarios relevant in the design of short pipes: DDT and the coalescence of DDT and reflection. The present paper concludes the test series conducted at BASF during the last 4 years. It presents additional experimental data showing the variation of R over the entire detonative range of Ethylene/O2/N2 mixtures and along the stoichiometric line of Cyclohexane/O2/N2 mixtures. Based on the variation of R for these ternary mixtures and for the mixtures presented in the preceding publications, a typical variation of R for a general combustible/O2/N2-mixture is estimated over the entire explosive range. By means of this estimation the static equivalent pressures of the six design-relevant detonative pressure scenarios of any combustible/O2/N2-mixture can now be derived combining the parameter R with the Chapman-Jouguet pressure ratio, which can be calculated in a straightforward manner from thermodynamic properties.
5

Komatsu, K., T. Shirai, A. Toyama, T. Iseki, D. Y. Enkin, A. Nakamura, Y. Li, S. Ohshio, H. Muramatsu e H. Saitoh. "Densification of Metal Oxide Films Synthesized from a Metal Complex by Flame Apparatus". In ITSC 2016, a cura di A. Agarwal, G. Bolelli, A. Concustell, Y. C. Lau, A. McDonald, F. L. Toma, E. Turunen e C. A. Widener. DVS Media GmbH, 2016. http://dx.doi.org/10.31399/asm.cp.itsc2016p1088.

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Abstract In this study, metal oxide films were synthesized from an EDTA·Er·H complex by flame spraying. The erbium oxide (Er2O3) layers were deposited on stainless steel using N2, air, or O2 as the carrier gas and a H2-O2 mixture as the combustion gas. Test results indicate that the carrier gas has a significant effect on film thickness and porosity and that O2 is the ideal carrier gas for producing dense metal oxide films.
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Mazas, A. N., D. A. Lacoste e T. Schuller. "Experimental and Numerical Investigation on the Laminar Flame Speed of CH4/O2 Mixtures Diluted With CO2 and H2O". In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-22512.

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The effects of CO2 and H2O addition on premixed oxy-fuel combustion are investigated with experiments and numerical simulations on the laminar flame speed of CH4/O2/CO2/H2O(v) and CH4/O2/N2/H2O(v) mixtures, at atmospheric pressure and for a reactants inlet temperature Tu = 373 K. Experiments are conducted with steady laminar conical premixed flames over a range of operating conditions representative of oxy-fuel combustion with flue gas recirculation. The relative O2-to-CO2 and O2-to-N2 ratios, respectively defined as O2/(O2+CO2) (mol.) and O2/(O2+N2) (mol.), are varied from 0.21 to 1.0. The equivalence ratio of the mixtures ranges from 0.5 to 1.5, and the steam molar fraction in the reactive mixture is varied from 0 to 0.45. Laminar flame speeds are measured with the flame area method using a Schlieren apparatus. Experiments are completed by simulations with the PREMIX code using the detailed kinetic mechanism GRI-mech. 3.0. Numerical predictions are found in good agreement with experimental data for all cases explored. It is also shown that the laminar flame speed of CH4/O2/N2 mixtures diluted with steam H2O(v) features a quasi-linear decrease when increasing the diluent molar fraction, even at high dilution rates. Effects of N2 replacement by CO2 in wet reactive mixtures are then investigated. A similar quasi-linear decrease of the flame speed is observed for CH4/O2/CO2 H2O-diluted flames. For a similar flame speed in dry conditions, results show a larger reduction of the burning velocity for CH4/O2/N2/H2O mixtures than for CH4/O2/CO2/H2O mixtures, when the steam molar fraction is increased. Finally, it is observed that the laminar flame speed of weakly (CO2, H2O)-diluted CH4/O2 mixtures is underestimated by the GRI-mech 3.0 predictions.
7

Schildberg, Hans-Peter. "Experimental Determination of the Static Equivalent Pressures of Detonative Explosions of Stoichiometric CH4/O2/N2-Mixtures and CH4/O2-Mixtures in Long Pipes". In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63223.

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In the recent past (PVP2013-97677, PVP2014-28197, PVP2015-45286) we had started to determine the static equivalent pressures pstat of the eight detonative pressure scenarios in long and short pipes for different detonable gas mixtures. The pstat-values are of vital importance for process design: by assigning static equivalent pressures to the highly dynamic detonative pressure peaks it is possible to apply the established pressure vessel guidelines, which can only cope with static loads, for the design of detonation pressure resistant pipes. One important finding was that the ratio R between pstat at the location where transition from deflagration to detonation occurs and pstat in the region of the stable detonation strongly depends on the reactivity of the gas mixture. In this paper we present experimental data showing the variation of R over the entire explosive range of Methane/O2/N2 mixtures. Qualitatively, the results should be representative for all other combustible/O2/N2-mixtures. Furthermore, recommendations for estimating pstat values of short pipe scenarios on basis of the long pipe scenarios are given.
8

Briottet, Laurent, e Hamza Ez-Zaki. "Influence of Hydrogen and Oxygen Impurity Content in a Natural Gas / Hydrogen Blend on the Toughness of an API X70 Steel". In ASME 2018 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/pvp2018-84658.

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The European Union is intending to reduce their carbon emissions by up to 80–95% by 2050. This will imply the increase of electricity coming from variable renewable energy sources. Producing hydrogen from this electricity is one way to facilitate the integration of such intermittent sources. Currently, there is no consensus in the world on the allowed amount of hydrogen in the natural gas with the aim to use the natural gas existing transportation grid to transport such mixture. The object of the present study is to provide additional experimental data concerning the effect of the hydrogen content in a N2/H2 mixture on the toughness of an API X70 steel dedicated to gas transport. The toughness has been measured in terms of Crack Tip Opening Displacement under a total pressure of 85 bar. The mechanical results are compared to existing results. It is confirmed that 1% H2 induces a significant decrease of the material toughness. Moreover, the content of O2 impurity in the N2/H2 mixture has been considered and its effect on HE mitigation has been quantified for an O2 content ranging between 10 vol. ppm and 100 vol. ppm. Finally, several approaches to take into account the effect of H2 in the NG/H2 blend on the design or on the service life of gas pipelines will be discussed.
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Matkovskii, A., A. Durygin, A. Suchocki, D. Sugak e F. Wallrafen. "Stable and Transient Colour Centers in YAlO3-ND Laser Crystals". In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1998. http://dx.doi.org/10.1364/cleo_europe.1998.ctua8.

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The result of investigation of the UV, gamma irradiation, annealing in air (700-1300 K) and N2+H2 gas mixture (1700 K) on optical and lasing properties of Nd-doped YAlO3 (YAP-Nd) laser crystals are presented The crystals were grown by the Czochralski technique from iridium crucibles in 98% Ar+2% O2 atmosphere.
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Chakravarthy, Vijayaraghavan, Joe Weber, Abdul-Aziz Rashad, Arun Acharya e Dante Bonaquist. "Oxygen Liquefier Using a Mixed Gas Refrigeration Cycle". In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-42124.

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This paper presents the design, selection of equipment, testing, and analysis of a 2 TPD (76 kg/hr) prototype oxygen liquefier that employs a mixed gas refrigeration cycle. Small scale oxygen plants (30–60 TPD) based on VPSA systems (Vapor Pressure Swing Adsorption) periodically require liquid back-up to provide uninterrupted supply of O2 gas to customers during planned plant maintenance. Supply of liquid for back-up, especially to customers in remote locations, is expensive and difficult. Economically designed MGR liquefiers will fulfill this market need. The 2 TPD prototype O2 liquefier is based on the dual loop MGR Rankine cycle (see Figure 1). The forecooler loop provides refrigeration at the warm end (233K). R507 is used as a refrigerant for the forecooler in the warm end loop. The main refrigeration loop uses a mixture of R218, R14 and N2. The main advantage of separating the refrigerants into two different loops is to avoid freezing of high boiling point refrigerants at liquid O2 temperatures in the main refrigeration loop. The process and mixture composition were optimized using the HYSYS process simulation package. Very useful insights were gained in terms of reducing the irreversibilities in the heat exchanger. Low cost innovative designs were adopted for the heat exchangers. For example: (1) plate-and-frame heat exchangers were successfully used for multiple gas streams, (ii) a spirally wound coiled heat exchanger was used to liquefy oxygen. Similarly, the compressors used in the forecooler and main cycle were low cost, off-the-shelf items used in conventional refrigeration systems. The liquefier unit was initially demonstrated and a liquid making capacity of 1.5 TPD at a unit power of 44 kW/TPD was achieved. Subsequent modifications to the heat exchangers resulted in meeting the design expectations at a unit power of 37 kW/TPD.

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