液化天然气与RP-3航空煤油燃烧特性对比试验

Comparison on combustion characteristics test for LNG and RP-3 kerosene

采用定容燃烧器和激波管分别对RP-3航空煤油、液化天然气(LNG)的燃烧特性进行了试验研究,对相同条件下RP-3航空煤油和LNG的着火延迟时间和层流火焰传播速度进行了比较,并深入研究了当量比、温度、压力等参数对LNG着火延迟时间和层流火焰传播速度的影响。试验结果表明,相同条件下LNG的着火延迟时间近似为CH4的一半,但为RP-3航空煤油的20倍,最大层流火焰传播速度比CH4高约5%,但仅为RP-3航空煤油的63%。低压条件下LNG/空气混合气的着火延迟时间对当量比不敏感,但随初始温度和压力的升高,着火延迟时间逐渐缩短;当量比影响LNG火焰前锋面稳定性,在当量比为1.1时,层流火焰传播速度最大;初始压力的增加会降低LNG/空气混合气的层流火焰传播速度,初始温度的增加会促进层流火焰传播速度。

Combustion characteristics of RP-3 aviation kerosene and liquefied natural gas （LNG） were studied using a constant volume burner and a shock tube. Ignition delay time （IDT） and laminar flame propagation velocity （LFPV） of RP-3 aviation kerosene and LNG were compared under the same experimental conditions. The effects of equivalence ratio, temperature, pressure on IDT and LFPV of LNG were further studied. The experimental results show that IDT of LNG is approximately half of that of CH4 and 20 times of that of RP-3, while the maximum LFPV is about 5 % higher than that of CH4 and only 63 % of that of RP-3 under the same conditions. IDT of LNG/air mixture is not sensitive to equivalence ratio at low pressure. With the increase of initial temperature and pressure IDT gradually decreases. The equivalence ratio affects stabili- ty of the flame front surface of LNG, and the flame propagation velocity is maximum when the equivalence ratio is 1.1. The increase of initial pressure will reduce the LFPV of LNG/air mixture while the increase of initial temperature will promote the LFPV.