The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Jinhui Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Hydrogen Pressure drop characteristics in a fuel cell stack
International Journal of Hydrogen Energy, 2006Co-Authors: Ming Gao Ouyang, Haiyan Huang, Wei Feng, Languang Lu, Jinhui ZhangAbstract:Research on Hydrogen Pressure characteristics was performed for a fuel cell stack to supply a rule of Hydrogen Pressure drop for flooding diagnostic systems. Some experiments on the Hydrogen Pressure drop in various operating Pressure, temperature, flowrate and stack current conditions were carried out, and hydrodynamic calculation was managed to compare with the experiment results. Results show that the Hydrogen Pressure drop is strongly affected by liquid water content in the flow channel of fuel cells, and it is not in normal relation with flowrate when the stoichiometric ratio is inconstant. The total Pressure drop can be calculated by a frictional Pressure loss formula accurately, relating with mixture viscosity, stack temperature, operating Pressure, stoichiometric ratio and stack current. The Pressure drop characteristics will be useful for predicting liquid water flooding in fuel cell stacks before flow channels have been jammed as a diagnostic tool in electric control systems.
-
Hydrogen Pressure drop characteristics in a fuel cell stack
International Journal of Hydrogen Energy, 2006Co-Authors: Pucheng Pei, Ming Gao Ouyang, Haiyan Huang, Wei Feng, Languang Lu, Jinhui ZhangAbstract:Research on Hydrogen Pressure characteristics was performed for a fuel cell stack to supply a rule of Hydrogen Pressure drop for flooding diagnostic systems. Some experiments on the Hydrogen Pressure drop in various operating Pressure, temperature, flowrate and stack current conditions were carried out, and hydrodynamic calculation was managed to compare with the experiment results. Results show that the Hydrogen Pressure drop is strongly affected by liquid water content in the flow channel of fuel cells, and it is not in normal relation with flowrate when the stoichiometric ratio is inconstant. The total Pressure drop can be calculated by a frictional Pressure loss formula accurately, relating with mixture viscosity, stack temperature, operating Pressure, stoichiometric ratio and stack current. The Pressure drop characteristics will be useful for predicting liquid water flooding in fuel cell stacks before flow channels have been jammed as a diagnostic tool in electric control systems. ?? 2005 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.
Eric Andrieu - One of the best experts on this subject based on the ideXlab platform.
-
Fatigue crack initiation and growth in a CrMo steel under Hydrogen Pressure
International Journal of Hydrogen Energy, 2015Co-Authors: L. Briottet, M. Escot, G. M. Tamponi, J. Solin, Paolo Bortot, Isabelle Moro, Grégory Odemer, Jader Furtado, Christine Blanc, Eric AndrieuAbstract:Along the Hydrogen supply chain, metallic components, such as Pressure vessels, compressors and valves, are facing high Pressure Hydrogen gas. The object of this paper is to address microstructural as well as mechanical aspects of fatigue crack initiation and growth at room temperature in a quenched and tempered (Q&T) low alloy steel under Hydrogen Pressure in the range 0.5e35 MPa. For such steel, the need to perform tests in-situ under Hydrogen Pressure is required. The influence of Hydrogen gas on the total life in terms of crack initiation and crack propagation is analyzed. The experimental techniques developed to detect crack initiation in a Pressure vessel under Hydrogen Pressure are presented. Thanks to these technical developments the influence of Hydrogen gas on the total life duration including crack initiation and crack propagation is analyzed. It is shown that the effect of Hydrogen Pressure on crack initiation is important. At constant load ratio, the Hydrogen Pressure effect on fatigue crack growth (FCG) is dependent on the loading amplitude (in terms of DK). These results related to cracking behavior are enriched with information on fracture surfaces appearance. The results presented have been achieved within the European project MATHRYCE [1] dedicated to Material Testing and Recommendations for Hydrogen Components under fatigue. They are part of a process necessary to give a scientific background to the development of a design methodology where Hydrogen enhanced fatigue damage is taken into account.
-
Fatigue crack initiation and growth in a CrMo steel under Hydrogen Pressure
International Journal of Hydrogen Energy, 2015Co-Authors: L. Briottet, M. Escot, G. M. Tamponi, J. Solin, Christophe Blanc, Paolo Bortot, Isabelle Moro, Grégory Odemer, Jader Furtado, Eric AndrieuAbstract:Along the Hydrogen supply chain, metallic components, such as Pressure vessels, compressors and valves, are facing high Pressure Hydrogen gas. The object of this paper is to address microstructural as well as mechanical aspects of fatigue crack initiation and growth at room temperature in a quenched and tempered (Q&T) low alloy steel under Hydrogen Pressure in the range 0.5-35 MPa. For such steel, the need to perform tests in-situ under Hydrogen Pressure is required. The influence of Hydrogen gas on the total life in terms of crack initiation and crack propagation is analyzed. The experimental techniques developed to detect crack initiation in a Pressure vessel under Hydrogen Pressure are presented. Thanks to these technical developments the influence of Hydrogen gas on the total life duration including crack initiation and crack propagation is analyzed. It is shown that the effect of Hydrogen Pressure on crack initiation is important. At constant load ratio, the Hydrogen Pressure effect on fatigue crack growth (FCG) is dependent on the loading amplitude (in terms of ΔK). These results related to cracking behavior are enriched with information on fracture surfaces appearance. The results presented have been achieved within the European project MATHRYCE [1] dedicated to Material Testing and Recommendations for Hydrogen Components under fatigue. They are part of a process necessary to give a scientific background to the development of a design methodology where Hydrogen enhanced fatigue damage is taken into account.
M Tkacz - One of the best experts on this subject based on the ideXlab platform.
-
dihydride formation in the palladium rhodium alloys under high Hydrogen Pressure
International Journal of Hydrogen Energy, 2017Co-Authors: M A Kuzovnikov, M TkaczAbstract:Abstract Palladium, rhodium and their alloys were studied in a diamond anvil cell in a high Pressure Hydrogen atmosphere up to 20 GPa by X-ray diffraction at room temperature. Formation of a monohydride with H/(Rh + Pd) = 1 ratio was observed for each alloy at Hydrogen Pressures less than 3 GPa. The corresponding volume expansion of the metal lattice was 2.2–2.8 A3 per metal atom. A formation of the dihydride with H/(Rh + Pd) = 2 was observed at a Hydrogen Pressure around 10 GPa for the alloys with rhodium content Rh/(Rh + Pd) ≥ 50 at.%. The dihydride formation is accompanied by a volume expansion of metal lattice by 3.2–3.9 A3 per metal atom. For Pd-rich alloys with Rh/(Rh + Pd) ≤ 25 at.% and pure Pd the dihydride formation was not observed up to maximum reached Hydrogen Pressure. All observed phases had a fcc structure of metal lattice.
-
Dihydride formation in the palladium–rhodium alloys under high Hydrogen Pressure
International Journal of Hydrogen Energy, 2017Co-Authors: M A Kuzovnikov, M TkaczAbstract:Abstract Palladium, rhodium and their alloys were studied in a diamond anvil cell in a high Pressure Hydrogen atmosphere up to 20 GPa by X-ray diffraction at room temperature. Formation of a monohydride with H/(Rh + Pd) = 1 ratio was observed for each alloy at Hydrogen Pressures less than 3 GPa. The corresponding volume expansion of the metal lattice was 2.2–2.8 A3 per metal atom. A formation of the dihydride with H/(Rh + Pd) = 2 was observed at a Hydrogen Pressure around 10 GPa for the alloys with rhodium content Rh/(Rh + Pd) ≥ 50 at.%. The dihydride formation is accompanied by a volume expansion of metal lattice by 3.2–3.9 A3 per metal atom. For Pd-rich alloys with Rh/(Rh + Pd) ≤ 25 at.% and pure Pd the dihydride formation was not observed up to maximum reached Hydrogen Pressure. All observed phases had a fcc structure of metal lattice.
B. Dam - One of the best experts on this subject based on the ideXlab platform.
-
Fiber optic Hydrogen sensor for a continuously monitoring of the partial Hydrogen Pressure in the natural gas grid
Sensors and Actuators B: Chemical, 2014Co-Authors: R.j. Westerwaal, H. Darmeveil, J. Middelkoop, Peter Ngene, H. Schreuders, Sander Gersen, B. DamAbstract:The development of reliable Hydrogen sensors will facilitate the introduction of Hydrogen to the natural gas infrastructure. One of the most promising configurations for such a device is a thin film based fiber optic sensor. We demonstrate that with such a device not only the measurement of a specific threshold partial Pressure is possible, but also allows for a quantitative determination of the partial Hydrogen Pressure measured real-time and in-situ in the gas stream. The changing Hydrogen Pressure, up to 200 mbar partial Pressure, can be measured optically using a Pd-Au alloy thin film. However for the daily use of the sensor in the natural gas infrastructure it is important to determine the Hydrogen sensing abilities under non-ideal conditions i.e. in gas mixtures containing high concentrations of CH4, C2H6, and C3H8. It is found that, the type of carrier gas (i.e. Ar (clean-conditions), CH4, C2H6, and C3H8) has hardly any influence on the measured Hydrogen concentration and switching kinetics of the sensor. The sensor response times (Hydrogenation kinetics) are comparable to those for clean H2flows. © 2014 Elsevier B.V.
-
Nanostructured Pd-Au based fiber optic sensors for probing Hydrogen concentrations in gas mixtures
International Journal of Hydrogen Energy, 2013Co-Authors: R.j. Westerwaal, J. S.a. Rooijmans, D. G. Gheorghe, T. Radeva, L. Mooij, Tw Mak, Laurent Leclercq, M. Slaman, Lisa Polak, B. DamAbstract:We demonstrate that with a thin film based fiber optic sensor it is possible to quantitatively determine the Hydrogen concentration over a wide Pressure range using a Pd-Au alloy as H2sensitive layer. The optical properties of the Pd-Au sensing layer change in an almost one-to-one relation with the Hydrogen Pressure when the Au concentration is varied between 18 at.% and 36 at.%. Thus we measure the Hydrogen Pressure continuously and quantitatively up to ∼250 mbar in reflection mode at room temperature. The response time during absorption and desorption is typically less than 15 s, which is fast enough for sensing applications. The addition of O2(up to 2%) and CH4(up to 5%) to the feed flow has little or no influence on the measured Hydrogen Pressure. In contrast, CO affects the sensor's response even at concentrations as low as 19 ppm. The Pd-Au fiber optic sensor shows a high reproducibility and remains optically and mechanically stable up to at least ∼250 Hydrogenation cycles without any indication of degradation. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Jader Furtado - One of the best experts on this subject based on the ideXlab platform.
-
Fatigue crack initiation and growth in a CrMo steel under Hydrogen Pressure
International Journal of Hydrogen Energy, 2015Co-Authors: L. Briottet, M. Escot, G. M. Tamponi, J. Solin, Paolo Bortot, Isabelle Moro, Grégory Odemer, Jader Furtado, Christine Blanc, Eric AndrieuAbstract:Along the Hydrogen supply chain, metallic components, such as Pressure vessels, compressors and valves, are facing high Pressure Hydrogen gas. The object of this paper is to address microstructural as well as mechanical aspects of fatigue crack initiation and growth at room temperature in a quenched and tempered (Q&T) low alloy steel under Hydrogen Pressure in the range 0.5e35 MPa. For such steel, the need to perform tests in-situ under Hydrogen Pressure is required. The influence of Hydrogen gas on the total life in terms of crack initiation and crack propagation is analyzed. The experimental techniques developed to detect crack initiation in a Pressure vessel under Hydrogen Pressure are presented. Thanks to these technical developments the influence of Hydrogen gas on the total life duration including crack initiation and crack propagation is analyzed. It is shown that the effect of Hydrogen Pressure on crack initiation is important. At constant load ratio, the Hydrogen Pressure effect on fatigue crack growth (FCG) is dependent on the loading amplitude (in terms of DK). These results related to cracking behavior are enriched with information on fracture surfaces appearance. The results presented have been achieved within the European project MATHRYCE [1] dedicated to Material Testing and Recommendations for Hydrogen Components under fatigue. They are part of a process necessary to give a scientific background to the development of a design methodology where Hydrogen enhanced fatigue damage is taken into account.
-
Fatigue crack initiation and growth in a CrMo steel under Hydrogen Pressure
International Journal of Hydrogen Energy, 2015Co-Authors: L. Briottet, M. Escot, G. M. Tamponi, J. Solin, Christophe Blanc, Paolo Bortot, Isabelle Moro, Grégory Odemer, Jader Furtado, Eric AndrieuAbstract:Along the Hydrogen supply chain, metallic components, such as Pressure vessels, compressors and valves, are facing high Pressure Hydrogen gas. The object of this paper is to address microstructural as well as mechanical aspects of fatigue crack initiation and growth at room temperature in a quenched and tempered (Q&T) low alloy steel under Hydrogen Pressure in the range 0.5-35 MPa. For such steel, the need to perform tests in-situ under Hydrogen Pressure is required. The influence of Hydrogen gas on the total life in terms of crack initiation and crack propagation is analyzed. The experimental techniques developed to detect crack initiation in a Pressure vessel under Hydrogen Pressure are presented. Thanks to these technical developments the influence of Hydrogen gas on the total life duration including crack initiation and crack propagation is analyzed. It is shown that the effect of Hydrogen Pressure on crack initiation is important. At constant load ratio, the Hydrogen Pressure effect on fatigue crack growth (FCG) is dependent on the loading amplitude (in terms of ΔK). These results related to cracking behavior are enriched with information on fracture surfaces appearance. The results presented have been achieved within the European project MATHRYCE [1] dedicated to Material Testing and Recommendations for Hydrogen Components under fatigue. They are part of a process necessary to give a scientific background to the development of a design methodology where Hydrogen enhanced fatigue damage is taken into account.
-
effects of Hydrogen Pressure and test frequency on fatigue crack growth properties of ni cr mo steel candidate for a storage cylinder of a 70 mpa Hydrogen filling station
Engineering Fracture Mechanics, 2011Co-Authors: Arnaud Macadre, Jader Furtado, Maxim Artamonov, Saburo MatsuokaAbstract:Abstract Experiments to investigate the effect of Hydrogen Pressure and test frequency on the fatigue crack growth properties of a Ni–Cr–Mo steel for the storage cylinder of a 70 MPa Hydrogen storage station were conducted. Compact tension specimens were cut out from the storage cylinder. The crack growth properties obtained in Hydrogen gas were compared with those obtained in air. Higher Hydrogen Pressures and lower loading frequencies lead to faster crack growth. However, there is an upper limit to the acceleration of the fatigue crack growth rate in Hydrogen gas, which can be used for the design of the Hydrogen cylinder. The effect of long and large inclusions present in the steel was also verified. The observations carried out on specimen fracture surfaces showed that the low population of inclusions did not influence the fatigue crack growth rate.
