A experimental study of characteristics of NO reduction by a simulating production gas of biomass gasification was performed in a ceramic flow reactor heated by an electric furnace.The gas was composed of CO,CO2,CH4,H...A experimental study of characteristics of NO reduction by a simulating production gas of biomass gasification was performed in a ceramic flow reactor heated by an electric furnace.The gas was composed of CO,CO2,CH4,H2 and N2,and the temperature used in the experiments ranged from 1 000 ℃ to 1 400 ℃.The influence of the inlet concentration of oxygen(0%～5%),the local equivalence ratio,φ(0.5～2.28),and the reactor temperatures was studied to analyse the characteristics of biomass gasification-reburning.The results indicate that more consumption of reducting agent is needed to increase the NO reduction efficiency in pyrolysis condition.The suitable values of the local equivalence ratio,φ,could make the NO reduction efficiency in oxidation condition higher than that in pyrolysis condition.The local equivalence ratio is an important parameter for NO reduction,and higher NO reduction efficiency can be obtained when φ varies between 0.8 and 1.1.The reduction of NO is favored at high temperatures.展开更多
通过实验和数值模拟的方法研究了甲烷/空气预混低旋流燃烧的流场结构及当量比对甲烷低旋流燃烧的影响．结果表明，甲烷/空气预混低旋流气流在喷嘴出口处扩张，形成有利于燃烧稳定的低速区；预混火焰“悬浮”于喷嘴上方，在剪切区的内侧...通过实验和数值模拟的方法研究了甲烷/空气预混低旋流燃烧的流场结构及当量比对甲烷低旋流燃烧的影响．结果表明，甲烷/空气预混低旋流气流在喷嘴出口处扩张，形成有利于燃烧稳定的低速区；预混火焰“悬浮”于喷嘴上方，在剪切区的内侧，火焰呈 W 型；富燃时，随着当量比的增加，火焰的推举高度略有增加；甲烷/空气预混低旋流流场具有自相似性，无量纲轴向速度的径向分布几乎不受当量比的影响．同时，燃烧室出口的温度随着当量比的增加而增加，并且在当量比为0.8～1.4时变化较为明显，当量比超过1.4后，增加趋势变缓．展开更多
In this paper,the kerosene/air rotating detonation engines(RDE)are numerically investigated,and the emphasis is laid on the effects of total pressures and equivalence ratios on the operation characteristics of RDE inc...In this paper,the kerosene/air rotating detonation engines(RDE)are numerically investigated,and the emphasis is laid on the effects of total pressures and equivalence ratios on the operation characteristics of RDE including the initiation,instabilities,and propulsive performance.A hybrid MPI t OpenMP parallel computing model is applied and it is proved to be able to obtain a more effective parallel performance on high performance computing(HPC)systems.A series of cases with the total pressure of 1 MPa,1.5 MPa,2 MPa,and the equivalence ratio of 0.9,1,1.4 are simulated.On one hand,the total pressure shows a significant impact on the instabilities of rotating detonation waves.The instability phenomenon is observed in cases with low total pressure(1 MPa)and weakened with the increase of the total pressure.The total pressure has a small impact on the detonation wave velocity and the specific impulse.On the other hand,the equivalence ratio shows a negligible influence on the instabilities,while it affects the ignition process and accounts for the detonation velocity deficit.It is more difficult to initiate rotating detonation waves directly in the lean fuel operation condition.Little difference was observed in the thrust with different equivalence ratios of 0.9,1,and 1.4.The highest specific impulse was obtained in the lean fuel cases,which is around 2700 s.The findings could provide insights into the understanding of the operation characteristics of kerosene/air RDE.展开更多
文摘A experimental study of characteristics of NO reduction by a simulating production gas of biomass gasification was performed in a ceramic flow reactor heated by an electric furnace.The gas was composed of CO,CO2,CH4,H2 and N2,and the temperature used in the experiments ranged from 1 000 ℃ to 1 400 ℃.The influence of the inlet concentration of oxygen(0%～5%),the local equivalence ratio,φ(0.5～2.28),and the reactor temperatures was studied to analyse the characteristics of biomass gasification-reburning.The results indicate that more consumption of reducting agent is needed to increase the NO reduction efficiency in pyrolysis condition.The suitable values of the local equivalence ratio,φ,could make the NO reduction efficiency in oxidation condition higher than that in pyrolysis condition.The local equivalence ratio is an important parameter for NO reduction,and higher NO reduction efficiency can be obtained when φ varies between 0.8 and 1.1.The reduction of NO is favored at high temperatures.
文摘通过实验和数值模拟的方法研究了甲烷/空气预混低旋流燃烧的流场结构及当量比对甲烷低旋流燃烧的影响．结果表明，甲烷/空气预混低旋流气流在喷嘴出口处扩张，形成有利于燃烧稳定的低速区；预混火焰“悬浮”于喷嘴上方，在剪切区的内侧，火焰呈 W 型；富燃时，随着当量比的增加，火焰的推举高度略有增加；甲烷/空气预混低旋流流场具有自相似性，无量纲轴向速度的径向分布几乎不受当量比的影响．同时，燃烧室出口的温度随着当量比的增加而增加，并且在当量比为0.8～1.4时变化较为明显，当量比超过1.4后，增加趋势变缓．
基金The authors would like to acknowledge the National Natural Science Foundation of China(Grant Nos.11802137,11702143)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX19_0292)+1 种基金the Natural Science Foundation for Young Scientists of Jiangsu Province of China(Grant No.BK20190468)the Fundamental Research Funds for the Central Universities(Grant Nos.30918011343,30919011259,309190112A1).
文摘In this paper,the kerosene/air rotating detonation engines(RDE)are numerically investigated,and the emphasis is laid on the effects of total pressures and equivalence ratios on the operation characteristics of RDE including the initiation,instabilities,and propulsive performance.A hybrid MPI t OpenMP parallel computing model is applied and it is proved to be able to obtain a more effective parallel performance on high performance computing(HPC)systems.A series of cases with the total pressure of 1 MPa,1.5 MPa,2 MPa,and the equivalence ratio of 0.9,1,1.4 are simulated.On one hand,the total pressure shows a significant impact on the instabilities of rotating detonation waves.The instability phenomenon is observed in cases with low total pressure(1 MPa)and weakened with the increase of the total pressure.The total pressure has a small impact on the detonation wave velocity and the specific impulse.On the other hand,the equivalence ratio shows a negligible influence on the instabilities,while it affects the ignition process and accounts for the detonation velocity deficit.It is more difficult to initiate rotating detonation waves directly in the lean fuel operation condition.Little difference was observed in the thrust with different equivalence ratios of 0.9,1,and 1.4.The highest specific impulse was obtained in the lean fuel cases,which is around 2700 s.The findings could provide insights into the understanding of the operation characteristics of kerosene/air RDE.
