Experimental study on improving cold start performance of diesel engines at extremely low ambient temperatures with diethyl ether

Abstract

How to achieve a fast and reliable cold start of diesel engines at extremely low temperatures is a significant and longstanding problem. In this study, a precise amount of diethyl ether was premixed in the intake to facilitate the starting at extremely low ambient temperatures down to −40 °C. The study investigated the effects of diesel fuel injection strategies, diethyl ether concentration, and ambient temperature on the cold-start performance. Additionally, an analysis was conducted on energy consumption and heat loss during the cold start period. The test engine could start quickly and steadily when diethyl ether was premixed in the intake. This was achieved by optimizing the diesel injection quantity to 60% of the original quantity and retarding the injection timing from 6 oCA BTDC to 2 oCA BTDC. The engine exhibited reliable starting at −40 °C when 2.0% v/v diethyl ether was premixed. However, excessive direct injection of diesel had an adverse effect on fuel ignition at such extremely low temperatures. Moreover, the electricity consumption was much lower with diethyl ether premixed in the intake than that with an electric intake heater, greatly reducing the requirements for starting batteries during the cold start under extremely low-temperature conditions.