Swirl combustion serves as a helpful flame stabilization method,which also affects the combustion and emission characteristics.This article experimentally investigated the effects of CO_(2)microjets on combustion inst...Swirl combustion serves as a helpful flame stabilization method,which also affects the combustion and emission characteristics.This article experimentally investigated the effects of CO_(2)microjets on combustion instability and NO_(x)emissions in lean premixed flames with different swirl numbers.The microjets’control feasibility was examined from three variables of CO_(2)jet flow rate,thermal power,and swirl angles.Results indicate that microjets can mitigate the combustion instability and NO_(x)emissions in lean premixed burners with different swirl numbers and thermal power.Still,the damping effect of microjets in low swirl intensity is better than that in high swirl intensity.The damping ratio of pressure amplitude can reach the maximum of 98%,and NO_(x)emissions can realize the maximum reduction of 10.1×10^(−6)at the swirl angle of 30°.Besides,the flame macrostructure switches from an inverted cone shape to a petal shape,and the flame length reduction at low swirl intensity is higher than that of high swirl intensity.This research clarified the control differences of mitigation of combustion instability and NO_(x)emissions by microjets in lean premixed flames with different swirl numbers,contributing to the optimization of microjets control and the construction of high-performance burners.展开更多
N (Trans 4 isopropylcyclohexyl 1 carbonyl) D phenylalanine,nateglide,is an effective drug to decrease blood sugar,which is under clinical trials in China.This compound has been reported to have two crystal types,of wh...N (Trans 4 isopropylcyclohexyl 1 carbonyl) D phenylalanine,nateglide,is an effective drug to decrease blood sugar,which is under clinical trials in China.This compound has been reported to have two crystal types,of which the one is more suitable to prebare the drug.We have studied the preparation of different crystal types and discovered a new one that has not been reported in the literature.Their melting points,TGA DTA and DSC spectral data,IR and X ray powder diffraction spectra of all samples have been investigated with different crystal types,some have been compared with the commercial drug from abroad.Suggestions have been made to control the crystal type.展开更多
基金This work was supported by the National Science Fund for Distinguished Young Scholars(Grant 51825605).
文摘Swirl combustion serves as a helpful flame stabilization method,which also affects the combustion and emission characteristics.This article experimentally investigated the effects of CO_(2)microjets on combustion instability and NO_(x)emissions in lean premixed flames with different swirl numbers.The microjets’control feasibility was examined from three variables of CO_(2)jet flow rate,thermal power,and swirl angles.Results indicate that microjets can mitigate the combustion instability and NO_(x)emissions in lean premixed burners with different swirl numbers and thermal power.Still,the damping effect of microjets in low swirl intensity is better than that in high swirl intensity.The damping ratio of pressure amplitude can reach the maximum of 98%,and NO_(x)emissions can realize the maximum reduction of 10.1×10^(−6)at the swirl angle of 30°.Besides,the flame macrostructure switches from an inverted cone shape to a petal shape,and the flame length reduction at low swirl intensity is higher than that of high swirl intensity.This research clarified the control differences of mitigation of combustion instability and NO_(x)emissions by microjets in lean premixed flames with different swirl numbers,contributing to the optimization of microjets control and the construction of high-performance burners.
文摘N (Trans 4 isopropylcyclohexyl 1 carbonyl) D phenylalanine,nateglide,is an effective drug to decrease blood sugar,which is under clinical trials in China.This compound has been reported to have two crystal types,of which the one is more suitable to prebare the drug.We have studied the preparation of different crystal types and discovered a new one that has not been reported in the literature.Their melting points,TGA DTA and DSC spectral data,IR and X ray powder diffraction spectra of all samples have been investigated with different crystal types,some have been compared with the commercial drug from abroad.Suggestions have been made to control the crystal type.
