Fundamental Study of Spray and Partially Premixed Combustion of Methane/Air Mixture

Effects of Structural Parameters on Operating Characteristics of a Solenoid Injector

This study presents fundamentals of spray and partially premixed combustion characteristics of directly injected methane inside a constant volume combustion chamber (CVCC). The constant volume vessel is a cylinder with inside diameter of 135 mm and inside height of 135 mm. Two end of the vessel are equipped with optical windows. A high speed complementary metal oxide semiconductor (CMOS) camera capable of capturing pictures up to 40,000 frames per second is used to observe flow conditions inside the chamber. The injected fuel jet generates turbulence in the vessel and forms a turbulent heterogeneous fuel–air mixture in the vessel, similar to that in a compressed natural gas (CNG) direct injection engine. The fuel–air mixture is ignited by centrally located electrodes at a given spark delay timing of 1, 40, 75 and 110 milliseconds after fuel injection has been completed to reflect different turbulence intensities. For comparative study, by increasing the spark delay timing to five minutes, a homogeneous premixed mixture is also prepared in the vessel which provides information on laminar homogeneous mixture combustion.Spray development and characterization including spray tip penetration, spray cone angle and overall equivalence ratio were investigated under 30–90 bar fuel pressures and 1–5 bar chamber pressure. Flame propagation images and combustion characteristics were determined via pressure-derived parameters and analyzed at a fuel pressure of 90 bar and a chamber pressure of 1 bar at different stratification ratios (from 0% to 100%) at overall equivalence ratios of 0.6, 0.8 and 1.0. Shorter combustion duration and higher combustion pressure were observed in direct injection-type combustion at all fuel air equivalence ratios compared to those of homogenous combustion.Copyright © 2012 by ASME

Purpose of this study is to develop a solenoid actuator that can be used for natural gas injector. Operation of the solenoid injector is described by two mathematical models including an electrical...

https://journals.sagepub.com/doi/pdf/10.1177/1687814018817421

A simulation and experimental study on the operating characteristics of a solenoid gas injector

This paper develops a superior injector driving circuit for a 500c.c. motorcycle GDI engine. The POWER MOSFET component is introduced in the design of the three-pulse injector driving circuit. Experiments for the designed electric driving circuit are investigated to verify its feasibility. The experiments of the H.P. injector driving circuit are conducted for the fuel injection quantity of the H.P. injector under 80~100 bar fuel pressure, 1200~2000 μs injection pulse duration and DC 55~65V power supply voltage. PWM control is introduced to the last pulse 3A holding current for fast cut-off response time of the H.P. injector. Next, Taguchi method was used to lead the design of experiments (DOE). The fuel injection quantities were measured in the various control parameters as engine speeds, power supply voltages, injector driving currents, and fuel supply pressures by the designed injector driving circuit. Effect of these control parameters of the high-pressure (H.P.) injector driving circuit on the fuel injection quantity are analyzed in the paper. Taguchi orthogonal array optimizes the operating parameters of the H.P. fuel injecting system. Results show that the three-pulse POWER MOSFET injector driving circuit is capable of operating stably and assure the accurate injection quantity of the H.P. injector.

Use of Taguchi Method to Optimize the Operating Parameters of a High-Pressure Injector Driving Circuit

Mathematical models of the electronically controlled injector are given based on the characteristics of the system. The models have included solenoid, valve and injector. Then simulation program was built with matlab simulink. The influences of structure parameters on the system performance are studied with simulation program. The approximation model of injector was established based on the regression function, which had considered responsibility and economy. The parameters of the system configuration are optimized with mutiobject program. The whole injector was designed based on the optimized results. The dynamic response characteristic of optimized injector was tested on testing equipment. Testing results were the same with simulation results. The optimized injector, who's open and close response time are both 0.2ms, has a very good injection wave shape which is similar to that of the control signal.

Jingqiu Zhang

Papers

Optimization design of the electronically controlled injector