A numerical and comparative study of the laminar combustion characteristics and kinetics of dimethyl ether and ethanol flames at elevated temperature
| Autor: | Fushui Liu, Yuxuan Xu, Zechang Liu, Fengshan Liu, Zheng Sang, Cong Liu, Xu He |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
endocrine system diseases
genetic structures 020209 energy General Chemical Engineering Analytical chemistry Energy Engineering and Power Technology 02 engineering and technology Mole fraction Combustion Chemical kinetics chemistry.chemical_compound fluids and secretions 020401 chemical engineering chemical kinetics 0202 electrical engineering electronic engineering information engineering DME Dimethyl ether 0204 chemical engineering Gasoline Ethanol Organic Chemistry Acetaldehyde humanities eye diseases Adiabatic flame temperature Fuel Technology chemistry laminar burning velocity ethanol flame instability |
| DOI: | 10.1016/j.fuel.2020.118934 |
| Popis: | Ethanol and DME are the most promising gasoline and diesel alternative fuels among biofuels. In the present study, we conducted a numerical and comparative study of the laminar burning velocity, chemical kinetics and flame instability of DME and ethanol premixed flames at P = 1 bar, T = 408 K and equivalence ratio of 0.8–1.4. The laminar burning velocity and adiabatic flame temperature of DME are higher than ethanol at all equivalence ratios. In addition, acetaldehyde and formaldehyde are the dominant intermediate product of ethanol and DME, respectively. The peak mole fraction of H + OH + CH3 radicals correlates nearly linearly with the laminar burning velocity. The rate-of-production of DME and ethanol suggests that CH3 + O = CH2O + H is the main reaction of CH3 consumption in both DME and ethanol flames. In addition, the reverse reaction of CH3 + O = CH2O + H is enhanced to inhibit the consumption of CH3 due to the high mole fraction of CH2O in DME, which is one of the reasons that the mole fraction of CH3 in DME flame is higher than in ethanol flame. Furthermore, the hydrodynamic and diffusional-thermal instability of DME are both stronger than ethanol because of thinner flame thickness, higher thermal expansion ratio and smaller effective Lewis number. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|