Effect of Natural Gas Composition and Rail Pressure on Injector Performance

The demand for Compressed Biogas (CBG) as an alternative fuel to Compressed Natural Gas (CNG) is rapidly increasing due to its renewable nature and environmental benefits. However, CBG and H-CNG has variations in gas composition standards as compared to CNG, which may require hardware changes in fuel system to adapt to these variations while ensuring the same performance. Fuel delivery system of CNG vehicle comprises of fuel storage tank, fuel delivery circuit, pressure regulator, fuel rail and injector. Performance of a fuel injector and pressure regulator are critical factors in the efficient and effective delivery of gaseous fuel to engine. This paper theoretically examines fuel flow requirement of injectors with different gas compositions such as CNG, CBG, G25, G20, H-CNG and taking in consideration other factors impacting overall performance. This paper defines one of the approaches to accommodate the variation in fuel composition and rail pressure while targeting same engine performance.