Piezo-actuated common rail injector structure and efficient design

Abstract

Piezo-actuated common rail injectors are often utilized in today's automobile engines' fuel systems. This high-tech instrument decreases fuel consumption, thereby harmful exhaust emissions are also lowered especially in diesel ignition engines. Owing to ultra-high pressure in piezo-injection systems, fuel droplets are scaled down into a smaller particle form and thus provided more efficient combustion. Pulverized fuel droplets are evaporated and oxidized in a very short time and they provide exact combustion inside the combustion chamber. In this study, numerical simulation of a piezo-actuated common rail injector fluid-mechanical model with detail is demonstrated. The hydraulic and mechanical component interaction is modeled through the fluid-mechanical components. Thus, the piezo injector dynamics are predicted based on the geometry and the physical quantities describing the equipment. Input voltage in the entrance is used to describe the piezo actuator force for piezo-electric material. In model, fuel flows from the common rail to a tee that separates the flow into two paths: fuel gallery and valve with the inlet orifice. Using this detailed model, behavior of the piezo injector, effects of the injector parameters on the fuel flow were investigated numerically and results were represented.

Problems of regeneration of modern piezoelectric fuel injectors

“…This is due to the optimal shaping of the high-pressure direct fuel injection strategy, implemented with a highly flexible and multiple division of the dosed fuel during a single diesel engine cycle. This is essential from the point of view of reducing fuel consumption as well as reducing noise emissions and the toxicity of exhaust fumes [13,21,22]. Due to the above considerations, piezoelectric fuel injectors are offered by all major manufacturers of fuel injection equipment.…”

Method for testing modern common rail piezoelectric fuel injectors

“…The main reason for the popularisation of piezoelectric fuel injectors, which gradually replace solutions with a classic electromagnetic coil, is the possibility of multiple division of fuel doses and obtaining very small time intervals between them during one cycle of diesel engine operation [2,3,13]. Optimal shaping of the injection process, and thus the preparation of the combustible mixture and the combustion process, allows for the improvement of its dynamic parameters as well as measurable benefits in terms of reducing fuel consumption, exhaust gas toxicity and noise emissions [11,15,16]. Meeting these conditions required the introduction of next generations of fuel injectors with a stack of piezoelectric crystals, modified for more flexible control of the multiphase fuel atomisation process and adapted to higher and higher operating pressures [4,9].…”

Simulation of Internal Pipe Flows in Gasoline Port Fuel Injection System under Steady State Condition

“…Numerical simulation of a piezo-actuated common rail injector fluid-mechanical model was employed by Koten et al [17] to investigate the effects of injector parameters on fuel flow. Injection cycle took place in nearly 1 millisecond while poppet movement and velocity formed within this interval.…”