Laminar Burning Velocities of Hydrogen-Blended Methane–Air and Natural Gas–Air Mixtures, Calculated from the Early Stage of <i>p</i>(<i>t</i>) Records in a Spherical Vessel
The flammable hydrogen-blended methane–air and natural gas–air mixtures raise specific safety and environmental issues in the industry and transportation; therefore, their explosion characteristics such as the explosion limits, explosion pressures, and rates of pressure rise have significant importa...
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2021-11-01
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| Online Access: | https://www.mdpi.com/1996-1073/14/22/7556 |
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| author | Maria Mitu Domnina Razus Volkmar Schroeder |
| author_facet | Maria Mitu Domnina Razus Volkmar Schroeder |
| author_sort | Maria Mitu |
| collection | DOAJ |
| description | The flammable hydrogen-blended methane–air and natural gas–air mixtures raise specific safety and environmental issues in the industry and transportation; therefore, their explosion characteristics such as the explosion limits, explosion pressures, and rates of pressure rise have significant importance from a safety point of view. At the same time, the laminar burning velocities are the most useful parameters for practical applications and in basic studies for the validation of reaction mechanisms and modeling turbulent combustion. In the present study, an experimental and numerical study of the effect of hydrogen addition on the laminar burning velocity (LBV) of methane–air and natural gas–air mixtures was conducted, using mixtures with equivalence ratios within 0.90 and 1.30 and various hydrogen fractions <i>r<sub>H</sub></i> within 0.0 and 0.5. The experiments were performed in a 14 L spherical vessel with central ignition at ambient initial conditions. The LBVs were calculated from <i>p</i>(<i>t</i>) data, determined in accordance with EN 15967, by using only the early stage of flame propagation. The results show that hydrogen addition determines an increase in LBV for all examined binary flammable mixtures. The LBV variation versus the fraction of added hydrogen, <i>r<sub>H</sub></i>, follows a linear trend only at moderate hydrogen fractions. The further increase in <i>r<sub>H</sub></i> results in a stronger variation in LBV, as shown by both experimental and computed LBVs. Hydrogen addition significantly changes the thermal diffusivity of flammable CH<sub>4</sub>–air or NG–air mixtures, the rate of heat release, and the concentration of active radical species in the flame front and contribute, thus, to LBV variation. |
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| issn | 1996-1073 |
| language | English |
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| spelling | doaj.art-d119038ed9f4433da9a5ce35fc5318202023-11-22T23:10:03ZengMDPI AGEnergies1996-10732021-11-011422755610.3390/en14227556Laminar Burning Velocities of Hydrogen-Blended Methane–Air and Natural Gas–Air Mixtures, Calculated from the Early Stage of <i>p</i>(<i>t</i>) Records in a Spherical VesselMaria Mitu0Domnina Razus1Volkmar Schroeder2“Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, 202 Spl. Independentei, 060021 Bucharest, Romania“Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, 202 Spl. Independentei, 060021 Bucharest, RomaniaFormerly Bundesanstalt fuer Materialforschung und-Pruefung (BAM), Unter den Eichen 87, 12205 Berlin, GermanyThe flammable hydrogen-blended methane–air and natural gas–air mixtures raise specific safety and environmental issues in the industry and transportation; therefore, their explosion characteristics such as the explosion limits, explosion pressures, and rates of pressure rise have significant importance from a safety point of view. At the same time, the laminar burning velocities are the most useful parameters for practical applications and in basic studies for the validation of reaction mechanisms and modeling turbulent combustion. In the present study, an experimental and numerical study of the effect of hydrogen addition on the laminar burning velocity (LBV) of methane–air and natural gas–air mixtures was conducted, using mixtures with equivalence ratios within 0.90 and 1.30 and various hydrogen fractions <i>r<sub>H</sub></i> within 0.0 and 0.5. The experiments were performed in a 14 L spherical vessel with central ignition at ambient initial conditions. The LBVs were calculated from <i>p</i>(<i>t</i>) data, determined in accordance with EN 15967, by using only the early stage of flame propagation. The results show that hydrogen addition determines an increase in LBV for all examined binary flammable mixtures. The LBV variation versus the fraction of added hydrogen, <i>r<sub>H</sub></i>, follows a linear trend only at moderate hydrogen fractions. The further increase in <i>r<sub>H</sub></i> results in a stronger variation in LBV, as shown by both experimental and computed LBVs. Hydrogen addition significantly changes the thermal diffusivity of flammable CH<sub>4</sub>–air or NG–air mixtures, the rate of heat release, and the concentration of active radical species in the flame front and contribute, thus, to LBV variation.https://www.mdpi.com/1996-1073/14/22/7556hydrogenmethanenatural gaslaminar burning velocity (LBV)closed vessel combustion |
| spellingShingle | Maria Mitu Domnina Razus Volkmar Schroeder Laminar Burning Velocities of Hydrogen-Blended Methane–Air and Natural Gas–Air Mixtures, Calculated from the Early Stage of <i>p</i>(<i>t</i>) Records in a Spherical Vessel Energies hydrogen methane natural gas laminar burning velocity (LBV) closed vessel combustion |
| title | Laminar Burning Velocities of Hydrogen-Blended Methane–Air and Natural Gas–Air Mixtures, Calculated from the Early Stage of <i>p</i>(<i>t</i>) Records in a Spherical Vessel |
| title_full | Laminar Burning Velocities of Hydrogen-Blended Methane–Air and Natural Gas–Air Mixtures, Calculated from the Early Stage of <i>p</i>(<i>t</i>) Records in a Spherical Vessel |
| title_fullStr | Laminar Burning Velocities of Hydrogen-Blended Methane–Air and Natural Gas–Air Mixtures, Calculated from the Early Stage of <i>p</i>(<i>t</i>) Records in a Spherical Vessel |
| title_full_unstemmed | Laminar Burning Velocities of Hydrogen-Blended Methane–Air and Natural Gas–Air Mixtures, Calculated from the Early Stage of <i>p</i>(<i>t</i>) Records in a Spherical Vessel |
| title_short | Laminar Burning Velocities of Hydrogen-Blended Methane–Air and Natural Gas–Air Mixtures, Calculated from the Early Stage of <i>p</i>(<i>t</i>) Records in a Spherical Vessel |
| title_sort | laminar burning velocities of hydrogen blended methane air and natural gas air mixtures calculated from the early stage of i p i i t i records in a spherical vessel |
| topic | hydrogen methane natural gas laminar burning velocity (LBV) closed vessel combustion |
| url | https://www.mdpi.com/1996-1073/14/22/7556 |
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