メイン噴射分割によるディーゼル機関の熱効率向上

Abstract

This study aims to establish a strategy for improving thermal efficiency of diesel engines by using multi-stage main injection. A series of experiment was conducted using a single cylinder diesel engine varying the injection pressure and the proportion of multi-stage main injection. As a result, the thermal efficiency was improved by the combination of increase in injection pressure, advanced injection timing, and multi-stage main injection with large proportion of laterpart. According to the analysis of heat balance, lower heat loss was achieved by using multi-stage main injection. The trend of cooling loss against the proportion of multi-stage injection in the CFD simulation could be reproduced by using wide spray cone angle for the small-quantity injection.