Explosion behavior of methane-dimethyl ether/air mixtures

FUEL

卷:157

Article

Zhang, Bo^1,2  Ng, Hoi Dick³ 

[1] E China Univ Sci & Technol, State Environm Protect Key Lab Risk Assessment &, Shanghai 200237, Peoples R China

[2] Beijing Inst Technol, State Key Lab Explos Sci & Technol, Beijing 100081, Peoples R China

[3] Concordia Univ, Dept Mech & Ind Engn, Montreal, PQ H3G 1M8, Canada

关键词: Dimethyl ether addition;    Maximum explosion pressure;    Maximum rate of pressure rise;    Flammability limits;    Laminar burning velocity;   

DOI  :  10.1016/j.fuel.2015.04.058

来源: Elsevier

【 摘 要 】

In this study, the effect of dimethyl ether (DME) addition on the explosion of methane/air mixture is investigated. In particular, the explosion and deflagration parameters of various CH4-DME/air mixtures are systematically studied. Those parameters include flammability limits, maximum explosion pressure, pmax, maximum rate of pressure rise (dp/dt)(max), and laminar burning velocity S-L. In general, the experimental results indicate that both p(max) and (dp/dt)(max) increase with increasing DME content in the total fuel. Simple correlations to evaluate the dimensionless pressure ((p) over bar) of CH4-air and DME-air mixtures with an initial pressure of 100 kPa are developed and given respectively by (p) over bar = 1/[2.81839 + 0.22424 chi(CH4) - 2.14347ln(chi(CH4))] and (p) over bar = 1/[1.04153 + 0.12637 chi(DME) - 0.94532ln(chi(DME))] where chi is the volume fraction of the fuel. The experimental results also indicate that for lean CH4 mixtures, the relationship between p(max) and DME concentration exhibits an inversely U-shaped curve. In contrast, an exponential decay of p(max) with increasing DME concentration is observed for rich CH4 mixtures. By adding DME into the CH4-air mixture, both the lower and upper flammability limits go down. The maximum amount of the total fuel for the binary blend (CH4 plus DME) below which the mixture can be initiated is approximately 15-16%. Lastly, a good agreement is found in the determination of the laminar burning velocity S-L using both a theoretical model and the CHEMKIN-PREMIX simulation. For CH4-DME/air mixtures, the S-L near the stoichiometric equivalence ratio phi(total) = 1 is larger than the fuel lean or rich side. It is found that with a slight amount of DME adding into the lean CH4 mixture, making phi(total) closer to stoichiometry, the value of S-L increases. However, with further addition of DME into lean CH4 mixture, or DME adding into rich CH4 mixture, only a decreasing behavior of S-L is observed. (c) 2015 Elsevier Ltd. All rights reserved.

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