Development and Study of a Low-Cost Mass Flow Characterization Technique for Port Fuel Injector

Abstract

Liquid fuel injection in the intake manifold is the source of fuel supply in the case of a gasoline engine equipped with a port fuel injection (PFI) system. The injected fuel breaks into small droplets which increases the vaporization rate and leads to proper mixing with the intake air. The amount of the injected fuel significantly influences the air–fuel ratio and as a result controls the combustion and emission formation. In the present work, a low-cost system is developed to measure the fuel flow rate of a PFI injector. The effect of fuel injection pressure, injection pulse width, off time between pulses, and fuel properties on the mass flow rate are studied. A solenoid-operated port fuel injector is taken for the study. A high-pressure chamber is designed and manufactured to control the injection pressure. An Arduino Uno board is used to control the pulse duration of the solenoid valve of the PFI Injector. Two fuels, diesel and petrol, and three different injection pressures (2, 4, and 6 bar) are considered for the study. The solenoid opening timings or the pulse width is varying from 2 to 10 ms. The off time between the two pulses is also varied. The experimental results show that increasing the injection pressure or opening time of the solenoid (pulse duration) increases the mass flow rate, but there is no effect of the off time between the two pulses on the mass flow rate. It is also noticed that different fuels show different mass flow rates at the same injection pressure and pulse duration.