The gasoline/natural gas dual-fuel combustion mode has been found to have unique advantages in combustion. The ignition timing has a significant impact on the combustion characteristics of gasoline engines. Thus, here we study the combustion characteristics of gasoline/natural gas dual-fuel combustion mode to determine the details of their respective advantages under cooperative combustion. A direct-injection turbocharged gasoline engine was modified, and an engine experimental platform was built for the coordinated control of gasoline direct-injection and natural gas port injection. A low-speed and low-load operating point was selected, and the in-cylinder pressure, heat release rate, pressure rise rate, combustion temperature, ignition delay, and combustion duration under the coordinated combustion of gasoline and natural gas dual fuel at the ignition moment were studied through bench tests among other typical combustion parameters. The results show that with the increase of the ignition advance angle, the maximum cylinder pressure, heat release rate, pressure rise rate, and maximum combustion temperature increase. The ignition advance angle is 28°CA-BTDC, and PES40 has the best fuel synergy effect and the best power performance improvement. The effect of the advance of the ignition advance angle on the ignition delay and the combustion duration reaches the peak at 20°CA-BTDC–22°CA-BTDC, and the improvement of the two periods is more significant at PES60.

中文翻译：

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点火正时对部分负荷工况下加有压缩天然气的汽油直喷发动机燃烧特性的影响

已经发现汽油/天然气双燃料燃烧模式在燃烧中具有独特的优势。点火正时对汽油发动机的燃烧特性有重大影响。因此，在这里我们研究汽油/天然气双燃料燃烧模式的燃烧特性，以确定它们在协同燃烧下各自优点的细节。改造了直喷涡轮增压汽油机，建立了发动机直喷与天然气进气口喷油协调控制的发动机实验平台。选择了低速和低负载工作点，并确定了缸内压力，放热率，压力上升率，燃烧温度，点火延迟，通过台架试验和其他典型燃烧参数研究了汽油和天然气双燃料在点火时刻协调燃烧下的燃烧持续时间。结果表明，随着点火提前角的增加，最大气缸压力，放热率，压力上升率和最高燃烧温度升高。点火提前角为28°CA-BTDC，PES40具有最佳的燃料协同效应和最佳的动力性能提升。点火提前角提前对点火延迟和燃烧持续时间的影响在20°CA-BTDC–22°CA-BTDC达到峰值，在PES60，这两个周期的改善更为显着。结果表明，随着点火提前角的增加，最大气缸压力，放热率，压力上升率和最高燃烧温度升高。点火提前角为28°CA-BTDC，PES40具有最佳的燃料协同效应和最佳的动力性能提升。点火提前角提前对点火延迟和燃烧持续时间的影响在20°CA-BTDC–22°CA-BTDC达到峰值，在PES60，这两个周期的改善更为显着。结果表明，随着点火提前角的增加，最大气缸压力，放热率，压力上升率和最高燃烧温度升高。点火提前角为28°CA-BTDC，PES40具有最佳的燃料协同效应和最佳的动力性能提升。点火提前角提前对点火延迟和燃烧持续时间的影响在20°CA-BTDC–22°CA-BTDC达到峰值，在PES60，这两个周期的改善更为显着。