Promotion and inhibition of the combustion of methane in oxidative gases with various oxygen concentrations by fluorinated hydrocarbons
25 Nov 2010-Russian Journal of Physical Chemistry B (SP MAIK Nauka/Interperiodica)-Vol. 4, Iss: 5, pp 760-768
TL;DR: In this article, the properties of fluorinated hydrocarbons (HFC and FC) exhibited both flame inhibitors and promoters for near-limit methane-oxidative gas (O2 + N2)-inhibitor (CHF3, C2HF5, and C4F10) mixtures.
Abstract: Experimental data on the combustion characteristics of methane-oxidative gas (O2 + N2)-inhibitor (CHF3, C2HF5, and C4F10) mixtures and an analysis thereof show that fluorinated hydrocarbons (HFC and FC) exhibit the properties of both flame inhibitors and promoters. The flammability concentration limits, maximum explosion pressure ΔP
max, maximum explosion pressure rise rate (dP/dt)max, and laminar flame speed S
u
are measured for near-limit methane-oxidative gas-fluorinated hydrocarbon mixtures. It is demonstrated that, when added to lean near-limit mixtures, HFC and FC behave as an additional fuel. Calculations of the thermodynamic characteristics of reactions involving fluorinated hydrocarbons capable of acting as both an inhibitor and oxidizer show that such reactions have significant heat effects, 150–700 kJ/mol, with the respective adiabatic temperatures being as high as 900–1800 K. The results of the present study suggest that the procedure of selecting fluorinated hydrocarbons for practical applications as fire and explosion suppressants should include careful tests of their promoting effect.
Citations
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TL;DR: In this paper, a kinetic mechanism for hydrocarbon flame inhibition by the potential halon replacement 2-BTP (2-Bromo-3, 3,3-trifluoropropene) has been assembled, and is used to study its effects on premixed methane-air flames.
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TL;DR: In this article, the combustion properties of pure mixtures of fire suppressants and air/oxygen were studied, and the results showed that the fluorinated agents possess sufficient energy to participate in combustion processes, and can support combustion with burning velocities which should be measurable (for some of the systems) at slightly elevated initial temperatures.
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TL;DR: In this paper, the suppression effectiveness of fluorinated species CHF3 and C2HF5 on premixed hydrogen-air explosions was examined experimentally and numerically. And the results demonstrate that as for stoichiometric and rich hydrogen air mixtures, both CHF 3 and C 2HF5 can effectively reduce thermal expansion ratio and increase flame thickness, and then reduce the influence of hydrodynamic instability on the flame acceleration.
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TL;DR: In this paper, the influence of the flame suppressants CCl4, CF3H, and C2F4Br2 on the ignition of hydrogen and acetylene behind shock waves was investigated, and the results showed that the chemical stability of the suppressants molecules is essential for successive chemical suppression of ignition under given conditions.
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References
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Book•
01 Jan 1977
TL;DR: In this article, the authors estimate physical properties of pure components and Mixtures and show that the properties of these components and mixtures are similar to those of ideal gases and liquids.
Abstract: Chapter 1: The Estimation of Physical Properties. Chapter 2: Pure Component Constants. Chapter 3: Thermodynamic Properties of Ideal Gases. Chapter 4: Pressure-Volume-Temperature Relationships of Pure Gases and Liquids. Chapter 5: Pressure-Volume-Temperature Relationships of Mixtures. Chapter 6: Thermodynamic Properties of Pure Components and Mixtures. Chapter 7: Vapor Pressures and Enthalpies of Vaporization of Pure Fluids. Chapter 8: Fluid Phase Equilibria in Multicomponent Systems. Chapter 9: Viscosity. Chapter 10: Thermal Conductivity. Chapter 11: Diffusion Coefficients. Chapter 12: Surface Tension.
14,380 citations
01 Jan 1965
TL;DR: In this article, a summary of the available limit of flammability, autoignition, and burning rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as empirical rules and graphs that can be used to predict similar data for thousands of other combustibles under a variety of environmental conditions are given.
Abstract: : A summary is given of the available limit of flammability, autoignition, and burning-rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as of empirical rules and graphs that can be used to predict similar data for thousands of other combustibles under a variety of environmental conditions. Specific data are presented on the paraffinic, unsatuarted, aromatic, and alicyclic hydrocarbons, alcohols, ethers, aldehydes, ketones, and sulfur compounds, and an assortment of fuels, fuel blends, hydraulic fluids, engine oils, and miscellaneous combustible gases and vapors.
829 citations
TL;DR: For downwardly propagating flames in pyrex tubes at atmospheric pressure and intial temperature of 295°K, measurements were made of the nitrogen dilution required for quenching as a function of the hydrogen-oxygen ratio, as well as of flame temperatures, flame speeds, temperature gradients behind the flame, unburnt hydrogen, and cell sizes as mentioned in this paper.
142 citations
TL;DR: In this paper, the effects of a number of flame retardants (CF 3 I, CF 3 Br, and CF 3 H) on the high-temperature reactions of methane with air in a plug flow reactor are studied by numerical simulations using the Sandia Chemkin Code.
130 citations
TL;DR: In this paper, the burning velocity of premixed hydrocarbon flames inhibited by the three one-carbon fluorinated species CH 2 F 2, CF 3 H, and CF 4 was determined using the total area method from a schlieren image of the flame.
123 citations