2021 年 16 巻 2 号 p. JTST0014
The prechamber combustion characteristics of a cogeneration system were studied using a rapid compression and expansion machine (RCEM) to improve the efficiency of cogeneration natural gas engines. The generated torch flames by the prechamber were used to investigate the effect of prechamber on the main combustion. In our previous study, we observed the correlation between the torch flame and the main flame, which is so-called “prechamber combustion.” In this study, the prechamber combustion characteristics of a gas engine were examined by visualization using a RCEM for methane and propane. In addition, the study mainly aimed to clarify the effects of the prechamber parameters, such as the equivalence ratio, initial pressure, and prechamber nozzle diameter, on the ignition and combustion in the main chamber for methane by comparing the combustion characteristics in the cases of methane and propane. Consequently, the ignitability of both fuels was improved by increasing the initial pressure and nozzle diameter. However, the effect of the equivalent ratio on the ignitability was different for the two fuels.