An experimental system that consisted was of gas mixing equipment,a sensor detection flame system,a data and acquisition quenching device,and an electric spark ignition device set in up to investigate fuel/air deflagr...An experimental system that consisted was of gas mixing equipment,a sensor detection flame system,a data and acquisition quenching device,and an electric spark ignition device set in up to investigate fuel/air deflagration propagation suppression processes through when a crimped-ribbon concentration flame arrester an was enclosed close horizontal the pipe.Deflagration ratio,experiments showed that the the four of and flammable ethylene-air combustion,gas to stoichiometric pipe the evolution processes of and explosion could pressure divided for propane-air stages:premixed slow gases in the diameter(DN32–DN400)and were similar be into isobaric pressure was rise,quick pressure and rise,pressure oscillation.However,high.the explosion duration quickly of the the hydrogen-air premixed gas stage.relatively short,the peak be explosion pressure three was The pipe pressure diameter rose after isobaric combustion speed Therefore,the the process can divided into stages increased in the and(DN15–DN150).Deflagration increases results indicated that propane-air flame speed initially eventually decreased along with in the pipe diameter(DN32–DN400);however,the of ethylene-air flame speed gradually flame increased with the increase the of the pipe diameter(DN80–DN400).No notable pattern change speed in the hydrogen-air at speed was observed in pipe diameter(DN15–DN150).The maximum happened propane-air when flame occurred 5%concentration.The the maximum conditions flame of speed same for size ethylene-air of and hydrogen-air tube the mixture ignition was close to but stoichiometric different ratio.Under or the experimental configuration experimental and the same distance flame pipe lengths,stopped the same flames pipe length high but different ignition low distances,results showed that the arrester successfully the at flame speed and explosion pressure,but failed at low flame speed and high explosion pressure.展开更多
Crimped ribbon flame arresters are important safety devices in the chemical industry, especially for the dangerous situations. Although proper design of arresters by the numerical simulation method is promising, its r...Crimped ribbon flame arresters are important safety devices in the chemical industry, especially for the dangerous situations. Although proper design of arresters by the numerical simulation method is promising, its reliability and accuracy are dependent upon the mathematical model. In this work, an integrated mathematical model for the microchannel in the crimped ribbon flame arresters was set up; the fluid flow behavior and the sensitivities of four chemical kinetics mechanisms of propane-air on the accuracy were analysed. It is shown that turbulence is predominant in the microchannel of the crimped ribbon flame arresters under the deflagration and detonation conditions, and a new quenching criterion for the numerical simulation is proposed. The kinetics mechanism of Mansouri et al. among the four ones is the most accurate due to the best agreement of the predicted outlet temperature at the experimental flameproof velocity with the autoignition temperature of propane-air. The species mass fraction profiles and the temperature distribution, which are too difficult to measure due to the tiny dimension of the microchannel in experiments, are captured. The fundamental insights into chemical reactions and heat loss are well portrayed. It can be concluded that the integrated mathematical model established in this work can be used as a reliable tool for modeling, selecting and designing such type of crimped ribbon flame arresters with the propane-air medium in the future.展开更多
基金supported by General Administration of Quality Supervision,Inspection and Quarantine of China Scientific Project(Grant No.2011QK083)Shenyang Science and Technology Project(Grant No.F14-048-2-00)
文摘An experimental system that consisted was of gas mixing equipment,a sensor detection flame system,a data and acquisition quenching device,and an electric spark ignition device set in up to investigate fuel/air deflagration propagation suppression processes through when a crimped-ribbon concentration flame arrester an was enclosed close horizontal the pipe.Deflagration ratio,experiments showed that the the four of and flammable ethylene-air combustion,gas to stoichiometric pipe the evolution processes of and explosion could pressure divided for propane-air stages:premixed slow gases in the diameter(DN32–DN400)and were similar be into isobaric pressure was rise,quick pressure and rise,pressure oscillation.However,high.the explosion duration quickly of the the hydrogen-air premixed gas stage.relatively short,the peak be explosion pressure three was The pipe pressure diameter rose after isobaric combustion speed Therefore,the the process can divided into stages increased in the and(DN15–DN150).Deflagration increases results indicated that propane-air flame speed initially eventually decreased along with in the pipe diameter(DN32–DN400);however,the of ethylene-air flame speed gradually flame increased with the increase the of the pipe diameter(DN80–DN400).No notable pattern change speed in the hydrogen-air at speed was observed in pipe diameter(DN15–DN150).The maximum happened propane-air when flame occurred 5%concentration.The the maximum conditions flame of speed same for size ethylene-air of and hydrogen-air tube the mixture ignition was close to but stoichiometric different ratio.Under or the experimental configuration experimental and the same distance flame pipe lengths,stopped the same flames pipe length high but different ignition low distances,results showed that the arrester successfully the at flame speed and explosion pressure,but failed at low flame speed and high explosion pressure.
基金Supported by the National Key Research and Development Program of China(2016YFB0301701)the National Natural Science Foundation of China(21706268+4 种基金9143411421376254)the Postdoctoral Science Foundation of Qingdao Municipal Government(Y7330419DM)the Instrument Developing Project of the Chinese Academy of Sciences(YZ201641)State Key Laboratory of Safety and Control for Chemicals of China
文摘Crimped ribbon flame arresters are important safety devices in the chemical industry, especially for the dangerous situations. Although proper design of arresters by the numerical simulation method is promising, its reliability and accuracy are dependent upon the mathematical model. In this work, an integrated mathematical model for the microchannel in the crimped ribbon flame arresters was set up; the fluid flow behavior and the sensitivities of four chemical kinetics mechanisms of propane-air on the accuracy were analysed. It is shown that turbulence is predominant in the microchannel of the crimped ribbon flame arresters under the deflagration and detonation conditions, and a new quenching criterion for the numerical simulation is proposed. The kinetics mechanism of Mansouri et al. among the four ones is the most accurate due to the best agreement of the predicted outlet temperature at the experimental flameproof velocity with the autoignition temperature of propane-air. The species mass fraction profiles and the temperature distribution, which are too difficult to measure due to the tiny dimension of the microchannel in experiments, are captured. The fundamental insights into chemical reactions and heat loss are well portrayed. It can be concluded that the integrated mathematical model established in this work can be used as a reliable tool for modeling, selecting and designing such type of crimped ribbon flame arresters with the propane-air medium in the future.
