基于GT-Power的天然气发动机爆震分析与研究

Study and Analysis on Knock of Natural Gas Engine Based on GT-Power

为了改善增压天然气发动机的燃烧状况、提高发动机的性能,对某发电用增压天然气发动机爆震现象进行研究。利用GT-Power软件建立了增压天然气发动机整机仿真模型,通过模拟数据与试验数据的对比验证了模型的准确性,然后在仿真模型中利用自主建立的爆震预测模型对天然气发动机的性能和爆震现象进行了模拟计算,并对得到的数值结果进行分析。结果表明:随着压缩比的增加,发动机发生爆震的可能性增大,爆震开始时刻提前,爆震强度增大,燃气消耗率呈现先减小后增大的趋势,压缩比为13时,燃气消耗率最小;随着点火提前角的增加,发动机发生爆震的可能性增大,爆震开始时刻提前,爆震强度基本不变,燃气消耗率变化趋势是先减小后增大,当点火提前角为-21°时,燃气消耗率最小。

In order to improve the engine combustion status and performance ,the knock phenomenon of turbocharged natural gas engine for power generation was researched .The simulation model of the whole engine was built with GT‐Power software and verified by comparing the simulation data and test data ,then the simulation and calculation of engine performance and knock phenomenon were conducted with the self‐built knock prediction model ,and the numerical results were finally analyzed . The results show that the possibility of knock increases ,the knock timing advances ,the knock intensity increases ,the specific gas consumption first decreases and then increases with the increase of compression ratio .The specific gas consumption is the minimum when the compression ratio is 13 .With the increase of ignition advance angle ,the knock characteristics keep the same changes as with the compression ratio except the knock intensity .The specific gas consumption is the minimum at the ignition advance angle of - 21° .