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Coupled interactive effects of ammonia and hydrogen additions on ethylene diffusion flames: A detailed kinetic study

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Science China(Technological Sciences) 2024年第3期67卷 930-948页

作者： XIAO JiaYi XU TingTing SHU ZhiMei DENG QiGe ZHAO Xuan ying yaoyao LI TianJiao LIU Dong MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing210094China

In order to create effective combustion technologies and fuels with low or no carbon emissions,the research was conducted to assess the coupled interactive effects of NH_(3) and H_(2) additions on ethylene counterflow diffusion flames from a kinetic *** effects of the NH_(3)/H_(2) combination on flame temperatures,major species,key radicals,important intermediate species,representative oxygenated species and NO_xwere *** results of the study utilizing fictitious inert NH_(3) and/or H_(2) revealed the chemical effects of the two *** was found that the NH_(3)/H_(2) coupled effects had a more effective inhibitory effect on soot precursors than the effects of corresponding sum of single NH_(3) or H_(2) *** production of soot precursors was promoted by the coupled chemical effects of NH_(3) and H_(2),but the coupled dilution and thermal effects were observed to have a greater impact,resulting in a decrease of the mole fractions of soot *** for the interaction of NH_(3) and H_(2) effects,the presence of H_(2) decreased the chemical effects of NH_(3) on the augmentation of C_(2)H_(2),A1,A2,and CH_(3)CHO mole *** NH_(3) addition alleviated the H_(2) chemical effects on increasing C_(2)H_(2),C_(3)H_(3),A1 and A2 ***,the NH_(3)chemical effects on C_(3)H_(3),OH and CH_(3)CHO were enhanced when H_(2) was *** presence of NH_(3) augmented the chemical effects of H_(2) on the growth of OH mole ***,the H_(2) chemical effects hindered the production of NO and NO_(2) in the presence of NH_(3).

关键词： NH_(3)/H_(2)addition kinetic analysis coupled interactive effects chemical effects

Comprehensive kinetic study on ammonia/ethylene counter-flow diffusion flames:influences of diluents

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International Journal of Coal Science & Technology 2024年第1期11卷 232-249页

作者： Zhimei Shu Tingting Xu Jiayi Xiao Qige Deng Xuan Zhao Tianjiao Li yaoyao ying Dong Liu MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing210094China

This study aimed to investigate the effects of ammonia addition on ethylene counter-flow diffusion flames with different diluents on the fuel or oxidizer side,using kinetic analyses.A special emphasis was put on assessing the coupled chemical effects of NH_(3) and CO_(2) on C2H4 combustion *** chemical effects could be evaluated by comparing fictitious inert NH_(3) or CO_(2) with normal active NH_(3) or CO_(2).The results revealed that the addition of NH_(3) decreased the mole fractions and production rates of key soot precursors,such as acetylene,propynyl,and *** CO_(2) was used as the dilution gas,the coupled chemical effects of NH_(3) and CO_(2) were affected by the chemical effects of CO_(2) to varying *** the oxidizer-side CO_(2) addition,the coupled chemical effects of NH_(3) and CO_(2) reduced the mole fractions of H,O,OH radicals,acetylene,propynyl,and benzene,while the effects differed from the fuel-side CO_(2) *** coupled chemical effects of NH_(3) and CO_(2) also promoted the formation of aldehyde contaminants,such as acetaldehyde,to some extent,particularly with CO_(2) addition on the oxidizer side.

关键词： Ammonia addition Diluents Coupled chemical effects Kinetic analysis

Fuel type recognition of ester isomer additives in flames by optical diagnostics coupled with machine learning method

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Science China Technological Sciences 2024年

作者： HE Jiaying CHEN MengFei WU BingKun ying yaoyao YAN WeiJie LI TianJiao LIU Dong MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power Engineering Nanjing University of Science and Technology Advanced Combustion Laboratory School of Energy and Power Engineering Nanjing University of Science and Technology

Based on machine learning models, an approach for the type recognition of oxygenated additives(ester isomers, i.e., methyl butyrate, methyl crotonate, ethyl acrylate, and ethyl acrylate) via optical diagnostics was proposed. By utilizing optical diagnostic methods flame features were extracted, and three models including random forest(RF), artificial neural network(ANN),and support vector machine(SVM), were employed to establish the relationship between flame images and oxygenated additives. Moreover, the impact of multiple factors on model performance, including image compression, dataset size, and feature number was also investigated. The images of flame obtained from inverse diffusion flame under four different oxygenated additives and various combustion conditions were used as examples to examine the effectiveness of the proposed approach. Results indicated that the accuracy of the recognition of ester isomers by the proposed approach exceeded 90%.Furthermore, it is observed that image compression had minimal impact on prediction accuracy but significantly reduced processing time. Different types of features contributed to predicting the type of ester isomers variously, and all models exhibited improved accuracy with an increased number of features. The number of samples significantly affected model accuracy. The investigation of feature missing and insufficient training samples suggested that ANN and RF models were more suitable for cases with many missing features, while SVM was more suitable for dealing with small samples.

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Kinetic Analysis on Pyrolysis Characteristics of Butene Isomer Fuels with CO_(2) Additions

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Journal of Thermal Science 2022年第5期31卷 1604-1621页

作者： CHEN Chen ZHAO Rui ying yaoyao LIU Dong MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing210094China

This article compared the pyrolysis characteristics of butene isomer fuels(n-butene,trans-2-butene,isobutene)under CO_(2) *** focus of the study was on the impacts of fuels isomerization and CO_(2) chemistry on the formation of important pyrolysis intermediate products under two temperature conditions(at 1273 K and 1573 K).The results demonstrated that at 1273 K,the concentrations of all products in isobutene pyrolysis were significantly lower than those of the corresponding products formed by the pyrolysis of n-butene and trans-2-butene in the process of fuels *** generation or consumption rate of each species was arranged from high to low as n-butene>trans-2-butene>*** 1573 K,the chemical effect of CO_(2) could inhibit the consumption of ethylene(C_(2)H_(4)),promote the formation of diacetylene(C_(4)H_(2)),and inhibit the formation of acetylene(C_(2)H_(2))and benzene(A_(1)).During the pyrolysis of n-butene at 1573 K,the chemical effect of CO_(2) was mainly reflected in changes of the consumption paths of C_(2)H_(2) and benzyl(A_(1)CH_(2)).For trans-2-butene pyrolysis at 1573 K,CO_(2) addition could change the main consumption paths of methyl(CH_(3)),which then inhibited C_(2)H_(2) *** addition,CO_(2) chemical action significantly changed the consumption paths of C_(4)H_(2) and A_(1) in trans-2-butene pyrolysis at 1573 *** for isobutene pyrolysis at 1573 K,the chemical effect of CO_(2) significantly inhibited the production of A_(1) by changing the main consumption paths of C_(2)H_(2) and propargyl(C_(3)H_(3)).

关键词： butene isomers pyrolysis CO_(2) chemical effect

Soot reduction by addition of dimethyl carbonate in normal and inverse ethylene diffusion flames:Nanostructural evidence

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Journal of Environmental Sciences 2018年第10期30卷 107-117页

作者： Chutikarn Paladpokkrong Dong Liu yaoyao ying Wei Wang Rui Zhang MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power Engineering Nanjing University of Science & Technology Advanced Combustion Laboratory School of Energy and Power Engineering Nanjing University of Science & Technology

Oxygenated fuel represents an attractive alternative as an additive for reducing soot *** carbonate（DMC） is an oxygenated compound which is a good option to reduce soot,but the detailed characteristics of soot produced from combustion of hydrocarbon fuels blended with DMC are still lacking. The present research studied the nanostructure and reactivity of soot particles in ethylene/DMC normal and inverse diffusion flames. High resolution transmission electron microscopy（HRTEM）, X-ray diffraction（XRD）, and thermogravimetric analysis（TGA）were used to analyze the nanostructure and reactivity of soot. It was found that DMC addition was effective in decreasing the average weights of soot formed in flames. The results of HRTEM images showed that soot particles obtained with DMC addition showed liquid-like material and tight bonding, and exhibited more highly disorganized layers, which give it higher reactivity than soot obtained without DMC addition. Furthermore, HRTEM was used to analyze soot fringe characteristics consisting of fringe tortuosity, fringe length, and fringe separation. XRD was used to crosscheck the results for fringe separation, and was consistent with HRTEM results. In addition, the mass loss curve of TGA experiments showed that DMC addition could enhance the reactivity of soot particles.

关键词： Soot particles Dimethyl carbonate addition Reduction Nanostructure Reactivity

Nanostructure and reactivity of soot from biofuel 2,5-dimethylfuran pyrolysis with CO_(2) additions

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Frontiers in Energy 2022年第2期16卷 292-306页

作者： Lijie ZHANG Kaixuan YANG Rui ZHAO Mingfei CHEN yaoyao ying Dong LIU MIIT Key Laboratory of Thermal Control of Electronic Equipment Advanced Combustion LaboratorySchool of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China

This paper investigated the nanostructure and oxidation reactivity of soot generated from biofuel 2,5-dimethylfuran pyrolysis with different CO_(2) additions and different temperatures in a quartz tube flow *** morphology and nanostructure of soot samples were characterized by a low and a high resolution transmission electron spectroscopy(TEM and HRTEM)and an X-ray diffraction(XRD).The oxidation reactivity of these samples was explored by a thermogravimetric analyzer(TGA).Different soot samples were collected in the tail of the *** the increase of temperature,the soot showed a smaller mean particle diameter,a longer fringe length,and a lower fringe tortuosity,as well as a higher degree of ***,the variation of soot nanostructures resulting from different CO_(2) additions was not *** with 0%,50%,and 100%CO_(2) additions at one fixed temperature,the soot collected from the 10%CO_(2) addition has the highest degree of graphization and *** three temperatures of 1173 K,1223 K,and 1273 K,the mean values of fringe length distribution displayed a ranking of 10%CO_(2)>100%CO_(2)>50%CO_(2) while the mean particle diameters showed the same ***,the oxidation reactivity of different soot samples decreased in the ranking of 50%CO_(2) addition>100%CO_(2) addition>10%CO_(2) addition,which was equal to the ranking of mean values of fringe tortuosity *** result further confirmed the close relationship between soot nanostructure and oxidation reactivity.

关键词： 2 5-dimethylfuran pyrolysis soot CO_(2)addition nanostructure reactivity

Continuous synthesis of N,N-dicyanoethylaniline in microreactors:Reaction kinetics and process intensification

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Chinese Journal of Chemical Engineering 2024年第8期72卷 95-105页

作者： Pengcheng Lu yaoyao Li Jianjun Zhang Yuchao Zhao Qingqiang Wang ying Chen Nan Jin Xiugang Yu Shandong Provincial Key Laboratory of Chemical Engineering and Process College of Chemistry and Chemical EngineeringYantai UniversityYantai 264005China Shandong ANOKY Chemical Technology Research Co. Ltd.Yantai 265601China Yantai Guobang Chemical Machinery Technology Co. Ltd.Yantai 264000China

Cyanoethylation of phenylamine is one of the important steps for the production of dicyanoethyl-based disperse ***,the exothermic nature of this reaction and the inherent instability of intermittent dynamic operation pose challenges in achieving both high safety and reaction *** this study,a continuous cyanoethylation of phenylamine for synthesizing N,N-dicyanoethylaniline in a microreactor system has been *** optimizing the reaction conditions,the reaction time was significantly reduced from over 2 h in batch operation to approximately 14 min in the microreactor,while high conversion and selectivity were *** on the reaction network constructed,the reaction kinetics was established,and the kinetic parameters were then *** findings provide valuable insights into a controllable cyanoethylation reaction,which would be helpful for the design of efficient processes and optimization of reactors.

关键词： Cyanoethylation Microreactor Kinetics N,N-dicyanoethylaniline Optimization Safety

A Novel Method for Forecasting Freak Wave Occurrence in A Short Crested Coastal Sea

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China Ocean Engineering 2024年第1期38卷 104-116页

作者： WANG ying-guang State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Ocean and Civil Engineering Shanghai Jiao Tong UniversityShanghai 200240China

In order to forecast the distribution of crest amplitudes and the occurrence of freak waves in a short crested coastal sea,a novel transformed linear simulation method is initially proposed in this paper.A Hermite transformation model expressed as a monotonic cubic polynomial serves as the foundation for the novel simulation *** wave crest amplitude exceedance probabilities of two sea states-one with a directional wave spectrum based on the measured wave elevation data at the Yura coast and the other with a typical directional JONSWAP wave spectrum-have been predicted using the novel simulation method that has been *** likelihood that a particular critical wave crest amplitude will be exceeded is directly correlated with the probability that freak waves will *** is shown that the novel simulation approach suggested can provide predictions that are more precise than those obtained from the Rayleigh crest amplitude distribution model,the Jahns and Wheeler crest amplitude distribution model,or the conventional linear simulation *** study also demonstrated that the nonlinear simulation method is less effective than the novel simulation method in terms of efficiency.

关键词： wave crest amplitude freak waves short crested sea transformed linear simulation

Classification of knowledge graph completeness measurement techniques

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Journal of Systems Engineering and Electronics 2024年第1期35卷 154-162页

作者： ZHANG ying XIAO Gang Institute of Systems Engineering Academy of Military SciencesBeijing 100107China

At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissions and *** assessment and control,as an important means to ensure the quality of knowledge,can make the applications based on knowledge graphs more complete and more accurate by reasonably assessing the knowledge graphs and fixing and improving the quality problems at the same ***,as an indispensable part of the knowledge graph construction process,the results of quality assessment and control determine the usefulness of the knowledge *** them,the assessment and enhancement of completeness,as an important part of the assessment and control phase,determine whether the knowledge graph can fully reflect objective phenomena and reveal potential connections among *** this paper,we review specific techniques of completeness assessment and classify completeness assessment techniques in terms of closed world assumptions,open world assumptions,and partial completeness *** purpose of this paper is to further promote the development of knowledge graph quality control and to lay the foundation for subsequent research on the completeness assessment of knowledge graphs by reviewing and classifying completeness assessment techniques.

关键词： quality assessment completeness assessment closed world assumptions open world assumption partial completeness assumption