Modelling of the Low-Pressure Gas Injector Operation

Abstract

In recent years, there has been a growing interest in alternative sources of power supply for internal combustion engines. Liquefied petroleum gas injection systems are among the most popular. It becomes necessary to know mathematical descriptions of the operation of individual components. The article presents a mathematical model that describes the operation of the low-pressure gas injector. Valtek plunger injector was chosen as the test object. The mathematical description includes three parts, i.e. electric, mechanical and pneumatic. The electrical part describes the generation of electromagnetic force by a circuit with a coil, in the mechanical equilibrium equation of forces acting on the plunger, and in the pneumatic part the air pressure on the plunger. The calculations were performed in the Matlab/Simulink environment, creating current waveforms, acting forces and plunger displacement. Correctness of mathematical description and determined in the course of opening and closing time calculations were related to the values declared by the manufacturer, showing differences below 3%. The presented mathematical model can be modified for other injector design solutions.

Performance Evaluation of a Single Cylinder Compressed Air Engine: An Experimental Study

“…The important design parameters and the calculated performance parameters of the thermodynamic analysis are given in Tab. 4 [19].…”

Model Evaluation of the Influence of the Plunger Stroke on Functional Parameters of the Low-Pressure Pulse Gas Solenoid Injector

“…Data related to the spring stiffness of the injector are taken from [ 65 ]. The characteristics of the spring were approximated by a linear function, from which the derivative was used to determine its stiffness equal to k = 832.83 N⋅mm −1 ( R 2 = 99.9%).…”

“…The biggest problem boils down to determining the inductance of a coil with a moving core. The simplest method is to experimentally determine the inductance as a function of the displacement of a movable core [ 65 ]. Such an approach allows for differences in opening and closing times of the injector of 2.05% and 2.27% according to the manufacturer’s declaration.…”

Computational Evaluation of the Effect of Plunger Spring Stiffness On Opening and Closing Times of the Low-Pressure Gas-Phase Injector

“…The calculations support the design and manufacturing process as well as are able to evaluate the influence of selected input features of a virtual product on its output parameters. In the case of gas injectors, the output (functional) parameters are mainly opening and closing times and maximum mass flow rate [5,8,9].…”