Applications in Energy and Combustion Science
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2022
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IF 0
Bingzhi Liu,Long Zhu,Qingbo Zhu,Hao Lou,Qiang Xu,Zhandong Wang
Ozone-assisted combustion is an advanced combustion technology that is considered a promising means for the active control of combustion. Ozone addition can enhance combustion processes and extend the experimental parameters to extreme conditions. In this work, ozone-assisted low temperature oxidation of methanol and ethanol in a jet-stirred reactor (JSR) was carried out at atmospheric pressure, with a fuel initial mole fraction of 0.005, an equivalence ratio of 0.28, and in the temperature range of 330–800 K. Significant conversions of methanol and ethanol were observed in the low temperature region when ozone was added. Numerous intermediate species were analyzed and quantified by synchrotron vacuum ultraviolet photoionization mass spectrometry and gas chromatography, which are crucially important for unraveling the low temperature oxidation reaction network. The kinetic model of NUIGMech1.1 is tentatively updated to better explain the measured results, although the improvements of the C 1 –C 2 core mechanisms are difficult. Ozone addition enhances the action of the reaction channel of related radicals. Model analysis shows that the kinetics of Ö/ȮH/HȮ 2 atoms/radicals are crucial for the overall reaction progress, as well as the reaction of HȮ 2 radicals with ozone, which mainly contributes to the formation of ȮH radicals during the initial reaction stage. Inconsistency between measurements and model predictions highlights the considerable uncertainty in the C 1 -C 2 alcohols subchemistry at lower temperatures. The experimental results obtained in this work and model development will motivate further study of the low temperature oxidation chemistry of methanol and ethanol.
研究领域:
化学工程
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燃烧化学
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反应动力学
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能源化学
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大气压反应器
✓ 已验证
DOI
PROCEEDINGS OF THE COMBUSTION INSTITUTE
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2022
·Vol. 39
·期 1
·315-324
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IF 6.535
Qianjin Lin,Wanxiong Liao,Jia Cheng,Chun Zou,Bin Yang,Wenxiang Xia
Few studies on the low-temperature combustion behavior of MIPK, being a promising fuel additive , have been conducted. In this work, ignition delay times (IDTs) of MIPK were measured in the temperatures ranging between 780–910 K and pressures of 20 and 25 bar using a rapid compression machine (RCM). Oxy-fuel combustion combined with biofuel could remove CO 2 from the atmosphere. The IDTs of MIPK were measured in the temperatures ranging between 1125–1600 K under the O 2 /CO 2 atmosphere at the pressures of 1 and 10 bar using a shock tube . A low to high-temperature MIPK kinetic model (HUST-MIPK model) was proposed, in which the low-temperature sub-model consists of 19 low-temperature reaction classes and was constructed by analogy-based method, the high-temperature sub-model was adapted from the works of Cheng et al.. The predictions of HUST-MIPK model are in good agreement with the present low-temperature IDTs, high-temperature O 2 /CO 2 atmosphere IDTs, and the literature experimental data. The negative temperature coefficient (NTC) behavior was not observed in the temperature range from 790 to 910 K in the present RCM experiments, but was observed for methyl propyl ketone (MPK) and diethyl ketone (DEK) under similar conditions. The low-temperature chemistry of three pentanone isomers (MIPK, MPK, and DEK) was compared using the flux and sensitivity analysis. The comparison of the experimental high-temperature IDTs between O 2 /CO 2 and O 2 /Ar atmospheres indicates the IDTs of MIPK under O 2 /CO 2 atmosphere are longer than those under O 2 /Ar atmosphere at 1 bar, and the effects of CO 2 are almost independent of the pressure. The physical and chemical effects of CO 2 on the ignition were studied in detail.
研究领域:
燃烧化学
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燃料化学
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反应动力学
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能源工程
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大气环境影响
✓ 已验证
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2018
·Vol. 37
·期 1
·565-573
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IF 5.336
Xiaoyuan Zhang,Yuyang Li,Chuangchuang Cao,Jiabiao Zou,Yan Zhang,Wei Li,Tianyu Li,Jiuzhong Yang,Philippe Dagaut
The kinetics of propanal oxidation was studied in a jet-stirred reactor (JSR) at atmospheric pressure. The investigated temperature range is from 450 to 800 K at two different equivalence ratios (0.35 and 4.0). Thanks to the synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS), critical intermediates were identified, including methylperoxy, methyl hydroperoxide , ethylperoxy, ethyl hydroperoxide, α-lactone, β-propiolactone and ketohydroperoxides. A kinetic model for propanal oxidation was also developed and validated against the present experimental results, as well as those available from the literature. Main chain-branching pathways under the investigated conditions were analyzed based on present experimental data and kinetic model . The O 2 addition reaction to the propanoyl radical and subsequent oxidation reactions play an important role in determining the oxidation rate of propanal under fuel-lean conditions, especially in the low-temperature oxidation region. Under fuel-rich conditions, the decomposition of the propanoyl radical is predominant and C 2 H 5 relevant reactions consequently determine the kinetics of oxidation of propanal.
研究领域:
物理化学
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燃烧化学
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反应动力学
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分析化学
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能源化学
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
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2021
·
IF 4.185
Jizhen Zhu,Sixu Wang,Mohsin Raza,Yuan Feng,Jing Li,Yebing Mao,Liang Yu,Yong Qian,Xingcai Lu
Methanol is an attractive oxygenate increasingly used as primary fuel for dual-fuel combustion technology yielding beneficial thermal-efficiency and emissions in modern engines. As such, it is significant to fundamentally understand the autoignition behavior of methanol/diesel mixtures. This study measured the ignition delay times (IDTs) of methanol/diesel blends with different mixing ratios (30%, 50%, 70% methanol by mol.) on a heated shock tube and a heated rapid compression machine at temperatures of 650−1450 K, pressures of 6−20 bar, and equivalence ratios of 0.5, 1.0 and 2.0. The typical two-stage ignition characteristics with the negative temperature coefficient response were observed for dual-fuel mixtures. In general, both the total and first-stage IDTs decrease with the increment of pressure and equivalence ratio as well as diesel proportion in mixtures. The simulation results performed with a published detailed mechanism in conjunction with a tri-component diesel surrogate demonstrate generally good agreement with the experimental data at all test conditions. Moreover, a crossover of IDTs occurs at a higher temperature (~1500 K) for varying equivalence ratios, and experiment and simulation both exhibit a non-linear mixing effect of methanol addition on diesel ignition. Interestingly, simulation results clearly suggest a crossover (~940 K) for mixtures with varying methanol content at an intermediate-temperature, where the IDT of the mixture with a lower methanol ratio becomes longer as the temperature is higher than that of the crossover. Furthermore, brute-force sensitivity analyses assisted with reaction path analysis were conducted to gain deeper insights into the autoignition chemistry of dual-fuel mixtures, especially for the chemical interaction between both fuels during the low-temperature oxidation process . It is found that methanol hardly generates •OH, whereas •OH is mainly produced by the low-temperature reaction pathways of diesel. Thus, •OH is the bridge for both fuels during the ignition process. At the high methanol ratio, the H-abstraction of diesel is mainly via •HO 2 while CH 3 OH consumes a large percentage of •OH. Consequently, the competition between methanol and diesel for •OH radicals inhibits the overall reactivity of reaction network. In addition, the original data reported here lay a foundation for the development and validation of more accurate and robust dual-fuel kinetic schemes.
研究领域:
燃烧化学
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燃料科学
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化学动力学
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内燃机工程
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替代燃料技术
✓ 已验证
DOI
高影响因子
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