Experimental study on the influence of high temperature and high pressure on the upper limit of explosion of ethane in oxygen
-
摘要: 获得高温、高压下可燃介质爆炸极限数值,对完善复杂工况下可燃介质燃爆安全理论、构建可燃介质爆炸防护技术提供支持。搭建了适用于开展高温、高压工况的20 L球形爆炸实验装置,测量了初始温度为20~270 ℃,初始压力为0.5~2.6 MPa下乙烷在氧气中的爆炸极限,分析温度、压力单因素对乙烷在氧气中的爆炸极限的影响以及温度和压力双因素的耦合影响。结果表明,随着初始压力和初始温度的提高,乙烷在氧气中的爆炸极限逐渐扩大。在温度小于140 ℃时,在高压和低压两种情况下,压力对乙烷爆炸上限的影响基本一致。在温度高于140 ℃时,压力的升高使乙烷爆炸上限升高,但其影响的效果逐渐减小。在初始压力小于1.6 MPa时,温度的升高使乙烷的爆炸上限升高,但其影响的效果变化很小。在压力大于1.6 MPa,温度高于140 ℃时,温度的升高使乙烷的爆炸上限升高,且其影响的效果逐渐增大。温度和压力的升高均使乙烷的爆炸下限降低,但其影响较小。初始温度和初始压力对乙烷在氧气中爆炸极限的耦合作用略小于两个因素作用的和,但大于单个因素的作用。通过拟合得到了C2H6/O2爆炸极限随初始压力、初始温度变化的定量规律。Abstract: The explosion limits of combustible material at elevated temperatures and pressures provide support for perfecting fire and explosion safety theory and improving explosion protection technology. A closed 20 L spherical vessel was designed to measure the explosion limits under abnormal conditions. The explosion limits of ethane/oxygen mixtures at temperatures ranging from 20 to 270 °C and pressures ranging from 0.5 to 2.6 MPa were measured. The influence of temperature, pressure and their coupling effect on the explosion limits in oxygen were analyzed. The results showed that the range of the explosion limits of ethane in oxygen gradually widened as the initial pressures and temperatures increased; the UELs in oxygen changed almost linearly when the initial temperatures were below 140 °C; as the temperature continues to rise, its effect gradually decreased; the UELs in oxygen changed almost linearly when the initial temperatures were below 140 °C; the UELs in oxygen linearly increased when the initial pressures were below 1.6 MPa; the rising rate of UEL increased above 1.6 MPa and 140 °C; the elevated temperatures and pressures decreased the LELs of ethane in oxygen, but their effect was reduced; the coupling effect of the initial temperatures and pressures on the explosion limits of ethane/oxygen mixtures was found slightly less than the sum of the two factors, but far greater than the effect of each individual factor; and the quantitative rules of explosion limits varying with the initial pressures and temperatures were obtained using the fitting formula.
-
Key words:
- explosion limit /
- elevated temperatures and pressures /
- ethane /
- oxygen
-
表 1 乙烷在氧气中爆炸上限随初始温度和初始压力变化拟合函数参数
Table 1. Fitting function parameters of temperature and pressure dependence of upper explosion limits of ethane in oxygen
z0 B C D E F R2 72.59 0.003 9 1.45 8.19 0.57 −0.001 4 0.99 -
[1] SCHOOR F V D, VERPLAETSEN F, BERGHMANS J, et al. Experimental and numerical study of the influence of pressure and temperature on the flammability limits of combustible gases in air [C] // 3rd European Combustion Meeting. Greece, 2007. [2] 高娜, 张延松, 胡毅亭. 温度、压力对甲烷-空气混合物爆炸极限耦合影响的实验研究 [J]. 爆炸与冲击, 2017, 37(3): 453–458. DOI: 10.11883/1001-1455(2017)03-0453-06.GAO Na, ZHANG Yansong, HU Yiting. Experimental study on methane-air mixtures explosion limits at normal and initial temperatures and pressures [J]. Explosion and Shock Waves, 2017, 37(3): 453–458. DOI: 10.11883/1001-1455(2017)03-0453-06. [3] VAN D S F, VERPLAETSEN F, BERGHMANS J. Calculation of the upper flammability limit of methane/air mixtures at elevated pressures and temperatures [J]. International Journal of Hydrogen Energy, 2008, 33(4): 1399–1406. DOI: 10.1016/j.ijhydene.2008.01.002. [4] CUI G, YANG C, LI Z L, et al. Experimental study and theoretical calculation of flammability limits of methane/air mixture at elevated temperatures and pressures [J]. Journal of Loss Prevention in the Process Industries, 2016, 41(5): 252–258. DOI: 10.1016/j.jlp.2016.02.016. [5] WAN Xin, ZHANG Qi, SHEN Shilei. Theoretical estimation of the lower flammability limit of fuel-air mixtures at elevated temperatures and pressures [J]. Journal of Loss Prevention in the Process Industries, 2015, 36(7): 13–19. DOI: 10.1016/j.jlp.2015.05.001. [6] SCHOOR F V D. Influence of pressure and temperature on flammability limits of combustible gases in air[D]. Katholieke University. 2007. [7] MENDIBURU A Z, CARVALHO J A D, CORONADO C R, et al. Determination of lower flammability limits of C-H-O compounds in air and study of initial temperature dependence [J]. Chemical Engineering Science, 2016, 144: 188–200. DOI: 10.1016/j.ces.2016.01.031. [8] CATOIRE L, NAUDET V. Estimation of temperature-dependent lower flammability limit of pure organic compounds in air at atmospheric pressure [J]. Process Safety Progress, 2005, 24(2): 130–137. DOI: 10.1002/prs.10072. [9] HUSTAD J E, SØNJU O K. Experimental studies of lower flammability limits of gases and mixtures of gases at elevated temperatures [J]. Combustion and Flame, 1988, 71(3): 283–294. [10] 刘振翼, 李浩, 邢冀, 等. 不同温度下原油蒸气的爆炸极限和临界氧含量 [J]. 化工学报, 2011, 62(7): 1998–2004. DOI: 10.3969/j.issn.0438-1157.2011.07.032.LIU Zhenyi, LI Hao, XING Ji, et al. Explosion limits and critical oxygen content of crude oil vapor at different ambient temperatures [J]. Journal of Chemical Industry and Engineering, 2011, 62(7): 1998–2004. DOI: 10.3969/j.issn.0438-1157.2011.07.032. [11] HOLMSTEDT G S. The upper limit of flammability of hydrogen in air, oxygen, and oxygen-inert mixtures at elevated pressures [J]. Combustion and Flame, 1971, 17(3): 295–301. [12] CUI G, LI Z, YANG C. Experimental study of flammability limits of methane/air mixtures at low temperatures and elevated pressures [J]. Fuel, 2016, 181(1): 1074–1080. DOI: 10.1016/j.fuel.2016.04.116. [13] CRAVEN A D, FOSTER M G. The limits of flammability of ethylene in oxygen, air and air-nitrogen mixtures at elevated temperatures and pressures [J]. Combustion and Flame, 1966, 10(2): 95–100. [14] SHEBEKO Y N, TSARICHENKO S G, KOROLCHENKO A Y, et al. Burning velocities and flammability limits of gaseous mixtures at elevated temperatures and pressures [J]. Combustion and Flame, 1995, 102(4): 427–437. [15] 李刚, 李玉峰, 苑春苗. 高温和高压下CBM的爆炸极限 [J]. 东北大学学报(自然科学版), 2012(4): 580–583.LI Gang, LI Yufeng, YUAN Chunmiao. Explosion limits of CBM at elevated pressure and temperature [J]. Journal of Northeastern University (Natural Science), 2012(4): 580–583. [16] Determination of explosion limits of gases and vapours [S]. Brussels: European Committee for Standardisation, 2012. [17] LEWIS B. Selected combustion problems [R]. Butter-worths, London, 1954.