ガスエンジンの高出力化に関する研究 : EGRを用いた実験的研究  [in Japanese] Improvement of Natural-Gas-Fueled Spark Ignition Engine Performance : Experimental Study on Effect of EGR Utilization  [in Japanese]

An experimental study was conducted to investigate the effect of EGR on combustion and exhaust emission characteristics of a spark-ignited supercharged stoichiometric gas engine in order to achieve a high BMEP equivalent to that of diesel engines. A single-cylinder test engine of 4-stroke-cycle was used. EGR gas was completely mixed with intake air before being introduced into the compressor. The results indicate that the dry EGR utilizing drained exhaust gas improved the maximum mean effective pressure as well as the specific fuel consumption over the whole load due to improved knock characteristics of the unburnt mixture, increased specific heat ratio (x), and reduced heat loss. Further experiments were conducted to identify the effect of humidity in the mixture on the engine performance.