Study on ether spray combustion and its products under sub- and super-critical environments

Abstract

In order to explore the combustion process of fuel and its products under sub- and super-critical environments, the constant volume combustion bomb system was used. The high-pressure common rail system and single injection instrument were used to supply fuel. Images of spray and combustion processes were recorded by high speed video camera using shadow photographic method, and combustion products were measured with a gas analyzer. The experimental results show that the ether flame presents a bright spherical shape. At the critical pressure point, the spray combustion penetration is the shortest, and the overall flame area is the smallest. The combustion duration of ether increases with increasing ambient pressure, reaches the maximum at the critical pressure, and then decreases with further increasing pressure. The amount of CO emitted from the combustion of the ether continuously decreases with the increase of ambient pressure. The amount of HC changes abruptly at the critical pressure. The differences between combustion characteristics and products formation are mainly due to the differences in fuel physical parameters and its break-up and evaporation mechanisms under sub- and super-critical conditions.