Determination of common rail injector flow characteristics with the use of diesel and biodiesel fuels

One of the most important requirements in the design of diesel combustion systems is to reduce emissions of harmful chemical compounds contained in exhaust gases. Solution to this problem is sought by the use of advanced engine injection systems and accurate control of mixture formation inside a cylinder via split fuel injection. The differences in physical characteristics between traditional and alternative fuels can affect fuel metering, especially at short injection durations. Thus, the aim of the current study was to identify dynamic flow parameters of the Common Rail injector with the use of different fuels. The study involved Diesel available in retail and biodiesel fuel obtained by methyl esterification of fatty acids. Measurements were performed on a test stand designed for determination of injectors and injection pumps characteristics. Studies were carried out changing the following parameters: injection pressure in the range of 30-180 MPa, injection time in the range of 200-1600 microseconds. Each fuel was tested at temperature 40 and 60°C. The obtained test results showed that injection of different fuels provided variable amounts of fuel injected at short injection durations, which can affect mixture formation process as well as combustion. Effect of the dose of the injected fuel has a viscosity of used fuel.