Search Results

The authors have been developing a ceramic heat insulated natural gas engine, in which cooling losses are greatly reduced by using heat insulation structure on the combustion chamber walls. High thermal efficiency is achieved by being able to operate this engine at high compression ratios. This engine is intended to use in co-generation systems and hybrid vehicles. In the engine, a new combustion system has been developed to enable the use of compressed natural gas (CNG) as fuel supplied at low pressure. The system consists of a pre-chamber and a throat valve on the passage between the pre- and main- chambers in order to make the engine ignite smoothly. This system uses low-pressure fuel, injected into the pre-chamber when the throat valve is closed. A homogeneous charge and large amounts of EGR are used in the main chamber.

This paper is the part II of the report of IDIS (Isuzu Dual Fuel Injection System) IDIS was applied to 5.8 liter L-6 DI diesel engine. The outlines of improved and simplified system, rate of alcohol blend, exhaust emission and performance of the engine were shown in the case of methanol blend as well as ethanol blend. For preventing the torque deviation just after start and end of alcohol blend caused by difference of calorific values between alcohol and diesel fuel, improved system with additional check valve was developed. It was confirmed that replacement of about 30% of diesel fuel by alcohol was possible without any fundamental problems. Basically no modification of the engine was required except the adoptions of new fuel tank and fuel line with low pressure pump for alcohol, some check valves and magnetic valves, a microswitch on the fuel lever and the new delivery valves with increased retraction volume.