Investigation on Realizing Fuel Rate Shaping Using a Common Rail Injector

2003 ◽  
Author(s):  
Paolo Carlucci ◽  
Antonio Ficarella ◽  
Antonio Giuffrida ◽  
Rosario Lanzafame
Keyword(s):  
Modeling And Simulation ◽  
Computer Modeling ◽  
Injection Rate ◽  
Common Rail ◽  
Simulation Experiments ◽  
The Real ◽  
Rail Systems ◽  
Rate Shaping ◽  
Common Rail Injector ◽  
Fuel Rate

The present work deals with the first researches into the real capabilities of an electronically controlled injector for common rail systems in realizing a proper shaping of the fuel rate with particular reference to its rising profile. Injectors equipped with standard and geometrically modified control valves have been investigated in detail by means of computer modeling and simulation. Experiments have been carried out in order to validate the feasibility of such a shaping and the injection rate meter based on the method proposed by Bosch was used. The main result of this work is a noteworthy dependence of the fuel rate on geometrical modifications in the piloting stage of the injector, since a certain difference in the slope of the first part of the fuel rate has been attained. The injector model has been finally used to investigate further geometrical modifications to be realized in order to achieve the desired fuel rate shaping.

Understanding the Acoustic Oscillations Observed in the Injection Rate of a Common-Rail DI Diesel Injector

2012 ◽  
Author(s):  
Julien Manin ◽  
Alan Kastengren ◽  
Raul Payri
Keyword(s):  
Acoustic Analysis ◽  
Injection Rate ◽  
Point Of View ◽  
Common Rail ◽  
Acoustic Oscillations ◽  
Real Rate ◽  
The Real ◽  
Injection Process ◽  
Engine Combustion ◽  
Common Rail Injector

Measuring the rate of injection of a common-rail injector is one of the first steps for diesel engine development. At the same time, this information is of prime interest for engine research and modeling as it drives spray development and mixing. On the other hand, the widely used long-tube method provides results that are neither straightforward, nor fully understood. This study performed on a 0.09 mm axially drilled single-hole nozzle is part of the Engine Combustion Network (ECN) and aims at analyzing these features from an acoustic point of view to separate their impact on the real injection process and on the results recorded by the experimental devices. Several tests have been carried out for this study including rate of injection and momentum, X-ray phase-contrast of the injector and needle motion or injector displacement. The acoustic analysis revealed that these fluctuations found their origin in the sac of the injector and that they were the results of an interaction between the fluid in the chamber (generally gases) and the liquid fuel to be injected. It has been observed that the relatively high oscillations recorded by the long-tube method were mainly caused by a displacement of the injector itself while injecting. In addition, the results showed that these acoustic features also appear on the momentum flux of the spray which means that the real rate of injection should present such behavior.

Comparison of Three Types of Common Rail Systems Suited for Diesel Engines From 1 to 5 Megawatt

2006 ◽  
Author(s):  
Marco Ganser ◽  
Ulrich Moser
Keyword(s):  
Diesel Engines ◽  
Pressure Wave ◽  
Dynamic Pressure ◽  
Injection Pressure ◽  
Injection Rate ◽  
Common Rail ◽  
Wave Dynamics ◽  
Rail Systems ◽  
Heavy Duty Diesel ◽  
The Individual

The basic physical law governing the injection in Common Rail Systems is the compressibility of the fuel. The effects of pressure wave dynamics, the layout of the system volume and its geometrical distribution strongly affect the injection events at every injector. In this Paper, three different arrangements of system volumes and their effect upon the performance of the individual injectors are compared using the hydraulics simulation tool AMESim. Two systems are known in the passenger car and the heavy duty diesel engine domains. The third system is new and takes advantage of pressure wave dynamics to tailor the injection event. This system is best suited for Diesel Engines with a power from 1 to 5 MW, as used in locomotives, ships, power generation and heavy earthmoving machinery. It produces a more favorable pattern of the injection pressure and injection rate shape during any injection event by hydraulically interconnecting the individual injector’s accumulators during the injection and taking advantage of pressure wave dynamics. Right after the end of each injection, dynamic pressure pulsations are evened out with a dampening device. A multi-cylinder system provides equal conditions for all injections. Its very simple design and increased performance makes the novel system of very attractive use in the above mentioned fields.

scholarly journals Providing Boot-Type Injection Rate Shape by Electric Impulse Control of the Common Rail Injector

2020 ◽  
pp. 32-42
Author(s):  
A.Y. Dunin ◽  
M.G. Shatrov ◽  
L.N. Golubkov ◽  
A.L. Yakovenko
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Control Valve ◽  
Road Construction ◽  
Injection Rate ◽  
Common Rail ◽  
Oxide Content ◽  
Common Rail Injector ◽  
Electric Impulse ◽  
The Common

For effective reduction of noise level and nitrogen oxide content in exhaust fumes of diesel engines, multistage fuel injection is used in combination with control of the front edge shape of the main injection. At the Moscow Automobile and Road Construction State Technical University (MADI), a method of control of the injection rate shape using an electric impulse was proposed, which was applied to the electromagnet of the control valve of the injector of the common rail fuel system. A computational and experimental analysis of the possibility of boot-type injection rate shape was carried out. The studies involved three most used designs of the common rail injector (CRI): CRI 1 featuring a control valve with shut-off cone and piston; CRI 2 consisting of a flat-lock control valve and a needle, which does not overlap the drain when the needle is in the highest position; CRI 3 with an injector that partially overlaps the drain. It was established that friction in the control valve piston and the guide surface pair of CRI 1 complicated the implementation of the boot-type injection rate due to its smoothing. CRI 2 and CRI 3 provide boot-type injection rate at different pressures in the fuel accumulator. The CRI 3 example shows that the instability of fuel supply during boot-type injection rate is comparable with that of fuel pre-injection, which is widely used in the organization of the common rail diesel engines working process.

Dynamic rate shaping – one diesel common-rail injector for all combustion strategies

2019 ◽  
pp. 335-357
Author(s):  
David Needham ◽  
Dan Mellors ◽  
Tony Williams ◽  
Thomas Cawkwell ◽  
Simon Tullis
Keyword(s):  
Common Rail ◽  
Rate Shaping ◽  
Common Rail Injector

scholarly journals INFLUENCE OF PRESSURE OSCILLATIONS IN COMMON RAIL INJECTOR ON FUEL INJECTION RATE

2020 ◽  
pp. 579
Author(s):  
Mikhail G. Shatrov ◽  
Andrey U. Dunin ◽  
Pavel V. Dushkin ◽  
Andrey L. Yakovenko ◽  
Leonid N. Golubkov ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Fuel Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Needle Valve ◽  
Rail Pressure ◽  
Pressure Oscillations ◽  
Multiple Injections ◽  
Double Injection ◽  
Common Rail Injector

Fuel injection causes considerable oscillations of fuel pressure at the injector inlet. One of the reasons is hydraulic impact when the needle valve closes. For multiple injections, the previous injections affect the following. As both the fuel pressure in rail pac and the injection rate grow, the oscillations increase. The pressure oscillation range at the common rail injector inlet at pac=1500 bar is up to 350 bar, and at the rail pressure pac=500 bar, the amplitude decreases to 80 bar. Physical properties of the fuel are also important. As the viscosity of the fuel increases, its hydraulic friction grows which results in a rapid damping of pressure oscillations. The data for an injector operating on sunflower oil is presented. As compared with diesel fuel, the oscillations range decreases from 400 to 250 bar at the same operating mode. The influence of the interval between the impulses of a double injection on the injection rate of the second fuel portion was investigated. Superposition of two waves during multiple injections may result in amplification and damping of the oscillations. Simulation was performed to estimate the influence of fuel type and time interval Δτ between control impulses of a double injection on the injection quantity of the second portion at pressures of 2000-3000 bar. When the rail pressure pac grows, the oscillations and their impact on the injection process increase. For diesel fuel at pressure of pac=2000 bar, the variation in injection rates of the second portion is 2.36-4.62 mg, and at pac=3000 bar – 1.58-6.63 mg.

Understanding the Acoustic Oscillations Observed in the Injection Rate of a Common-Rail Direct Injection Diesel Injector

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
Julien Manin ◽  
Alan Kastengren ◽  
Raul Payri
Keyword(s):  
Acoustic Analysis ◽  
Direct Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Acoustic Oscillations ◽  
Acoustic Features ◽  
Injection Process ◽  
Engine Combustion ◽  
Common Rail Injector ◽  
Engine Development

Measuring the rate of injection of a common-rail injector is one of the first steps for diesel engine development. The injected quantity as a function of time is of prime interest for engine research and modeling activities, as it drives spray development and mixing, which, in current diesel engines, control combustion. On the other hand, the widely used long-tube method provides results that are neither straightforward nor fully understood. This study, performed on a 0.09-mm axially drilled single-hole nozzle, is part of the Engine Combustion Network (ECN) and aims at analyzing the acoustic oscillations observed in the rate of injection signal and measuring their impact on the real injection process and on the results recorded by the experimental devices. Several tests have been carried out for this study, including rate of injection and momentum, X-ray phase-contrast of the injector, and needle motion or injector displacement. The acoustic analysis revealed that these fluctuations found their origin in the sac of the injector and that they were the results of an interaction between the fluid in the chamber (generally gases) or in the nozzle sac and the liquid fuel to be injected. It has been observed that the relatively high oscillations recorded by the long-tube method were mainly caused by a displacement of the injector itself while injecting. In addition, the results showed that these acoustic features are also present in the spray, which means that the oscillations make it out of the injector, and that this temporal variation must be reflected in the actual rate of injection.

scholarly journals Experimental study of the influence of pressure oscillations in common rail injector on fuel injection rate

2016 ◽  
pp. 304-304
Author(s):  
Mikhail Shatrov ◽  
Leonid Golubkov ◽  
Andrey Dunin ◽  
Pavel Dushkin ◽  
Andrey Yakovenko
Keyword(s):  
Experimental Study ◽  
Fuel Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Pressure Oscillations ◽  
Common Rail Injector ◽  
Fuel Injection Rate
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