scholarly journals Simulation Study on the Influence of Injector Coupling Leakage on Fuel Injection

2021 ◽  
Vol 2097 (1) ◽  
pp. 012014
Author(s):  
Ziwei Zhang
Keyword(s):  
Fuel Injection ◽  
Control Valve ◽  
Simulation Method ◽  
Slide Valve ◽  
Injection Rate ◽  
Needle Valve ◽  
Start Time ◽  
Injection Duration ◽  
Common Rail Injector ◽  
Fuel Leakage

Abstract In order to study the effect of fuel leakage of an ultra-high pressure common rail injector control valve coupling on fuel injection performance, a simulation model was established by AMESim and the accuracy was verified by fuel injection test data. The leakage law of couples with different clearances was analyzed by using numerical simulation method and then the influence of control valve coupling on fuel injection performance was analyzed. The results demonstrate that the increase of the matching clearance of the slide valve coupling makes the start time of needle valve advanced and delay its end time. The injection rate and injection duration increase with the increase of the matching clearance of slide valve coupling. The increase of the matching clearance of the control plunger coupling keeps the start time of the needle valve unchanged at first, and then delay slightly, while the end time remains unchanged at first, and then show the trend of advance. The injection rate and injection duration decrease with the increase of the matching clearance of plunger coupling.

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.

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.

scholarly journals A Study of Combustion Characteristics of Two Gasoline–Biodiesel Mixtures on RCEM Using Various Fuel Injection Pressures

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3265
Author(s):  
Ardhika Setiawan ◽  
Bambang Wahono ◽  
Ocktaeck Lim
Keyword(s):  
Heat Release ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Fuel Mixture ◽  
Injection Rate ◽  
Injection Duration ◽  
Late Start ◽  
Fuel Injection Rate ◽  
Injection Pressures

Experimental research was conducted on a rapid compression and expansion machine (RCEM) that has characteristics similar to a gasoline compression ignition (GCI) engine, using two gasoline–biodiesel (GB) blends—10% and 20% volume—with fuel injection pressures varying from 800 to 1400 bar. Biodiesel content lower than GB10 will result in misfires at fuel injection pressures of 800 bar and 1000 bar due to long ignition delays; this is why GB10 was the lowest biodiesel blend used in this experiment. The engine compression ratio was set at 16, with 1000 µs of injection duration and 12.5 degree before top dead center (BTDC). The results show that the GB20 had a shorter ignition delay than the GB10, and that increasing the injection pressure expedited the autoignition. The rate of heat release for both fuel mixes increased with increasing fuel injection pressure, although there was a degradation of heat release rate for the GB20 at the 1400-bar fuel injection rate due to retarded in-cylinder peak pressure at 0.24 degree BTDC. As the ignition delay decreased, the brake thermal efficiency (BTE) decreased and the fuel consumption increased due to the lack of air–fuel mixture homogeneity caused by the short ignition delay. At the fuel injection rate of 800 bar, the GB10 showed the worst efficiency due to the late start of combustion at 3.5 degree after top dead center (ATDC).

Effects of fuel temperature on injection performance of an EUP system

2017 ◽  
Vol 233 (3) ◽  
pp. 671-686
Author(s):  
Fushui Liu ◽  
Ruo Hu ◽  
Yikai Li ◽  
Ziming Yang ◽  
Hongming Xu
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Great Influence ◽  
Injection Rate ◽  
Needle Valve ◽  
Engine Fuel ◽  
Fuel Temperature ◽  
Closing Time ◽  
Fuel Supply ◽  
Injection Quantity

The fuel temperature has a great influence on the characteristics of an electronic unit pump (EUP) system, especially on the injection performance. This paper studies the regularity of the high-pressure fuel supply system performance at different fuel temperatures. The injection quantity, the injection rate, the fuel pressure, and the needle lift were measured by the EUP system test bench. Investigation results showed that, with the increase of fuel temperature, the injection quantity and maximum injection rate decreased, the time of start injection was delayed, and the peak fuel pressure value decreased. For the needle valve, as the temperature was raised its closing time was advanced at low speed conditions but delayed at high speed conditions. In addition, the empirical equations for the fuel temperature effects on the circulating fuel injection quantity and peak pressure are proposed by the experimental test and simulation data. This study will help to further apply and study the engine, and provide a reference for engine fuel supply control system design.

scholarly journals Study on Influencing Factors and Laws of Fuel Injection Consistency of Common Rail Injector

2021 ◽  
Vol 2097 (1) ◽  
pp. 012001
Author(s):  
Ziwei Zhang ◽  
Chunlong Xu
Keyword(s):  
Fuel Injection ◽  
Solenoid Valve ◽  
Hole Diameter ◽  
Operating Conditions ◽  
Nozzle Diameter ◽  
Common Rail ◽  
Valve Lift ◽  
Needle Valve ◽  
Inlet Hole ◽  
Common Rail Injector

Abstract In order to study the influence of parameters of common rail injector internal components on cycle injection consistency, its simulation model is established by AMESim, and the model is validated by the experimental injection rate data. The effects of solenoid valve spring preload, gag bit lift, fuel discharge hole diameter, fuel inlet hole diameter, needle valve lift, needle valve preload and nozzle diameter on the change of injection quantity under different operating conditions are studied by simulation method, and the impact weight of each parameter on fuel injection consistency is analyzed. The results show that the preload of solenoid valve, fuel discharge hole diameter, oil inlet hole diameter, needle valve lift and nozzle diameter are the main parameters affecting the consistency of cycle injection. The percentages of five parameters influencing on the consistency of cyclic injection are 8.68-16.84%, 11.41-23.68%, 17.2086-37.74%, 12.772-18.34% and 9.69-37.27% respectively.

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

The Investigation of Geometric Parameters on the Injection Characteristic of the High Pressure Common-Rail Injector

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Ling Wang ◽  
Guo-Xiu Li ◽  
Chun-Long Xu ◽  
Xing Xi ◽  
Xiao-Jun Wu ◽  
...  
Keyword(s):  
Injection Rate ◽  
Common Rail ◽  
Needle Valve ◽  
Fuel Injector ◽  
Pressure Injection ◽  
Common Rail Pressure ◽  
Outlet Hole ◽  
Common Rail Injector ◽  
The Common ◽  
Injection Pulse

According the actual structure and working principle of a fuel injector to build a model of the common-rail injector, including the control valve, the solenoid valve, and the needle valve of the injector. The model includes the leakage model for the control piston and needle valve that takes into account increasing leakage at high pressure. The performance of the fuel injector is investigated using a one-dimensional numerical model. Analyzing the effect of the system and structure parameters including common-rail pressure, injection pulse width, inlet and outlet hole diameter, and the injection nozzle on the injection characteristics of the fuel injector. Results show that the geometric parameter is the main property affecting the flow characteristic of the injector, which includes the flow rate of inlet and outlet hole, pressure waves in the control chamber and injection rate. The common-rail pressure, injection pulse width and the geometric parameters mainly affect the injection performance, such as the injection rate and injected volume. The investigation result can provide some useful information to improve the injection characteristic in follow-up studies.

Mass and Momentum Flux Measurements With a High Pressure Common Rail Diesel Fuel Injector

2010 ◽  
Author(s):  
Samuel E. Johnson ◽  
Jaclyn E. Nesbitt ◽  
Jeffrey D. Naber
Keyword(s):  
High Pressure ◽  
Momentum Flux ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Injection Rate ◽  
Common Rail ◽  
Fuel Injector ◽  
Injection Duration ◽  
Wide Range ◽  
High Pressure Common Rail

The combined optimization of diesel engine power, fuel consumption, and emissions output significantly drives the development and tuning of engines. One leading subsystem that continues to receive major development and advancement is the fuel system. High pressure common rail systems lead fuel injection technology and utilize both solenoid and piezoelectric actuated injectors with a wide range of pressure and injection scheduling control. To optimize engine operation the fuel system’s capability is implemented through complex fuel scheduling coupled with charge preparation. With the number of parameters to control, fuel delivery (including dynamic flow characteristics) is one that must be well understood. Most rate of injection systems provide mass flow rate; however, studies have shown that momentum flux is a critical parameter controlling spray entrainment and penetration. To obtain the mass flow rate and momentum flux for a high pressure common rail diesel fuel injector, a rate of injection meter was designed, constructed, and tested allowing for the dynamic measurement of fuel injection with the capability of in-situ operation in a combustion vessel. Measurements were obtained by recording the force signal from a fuel spray jet impinging on the anvil of a force transducer. Combining the force signal with a measure of cumulative injected mass enables calculation of mass and momentum dynamics. The injection system consisted of a Bosch Generation 2 CRIP 2.2 solenoid controlled fuel injector with a single hole 0.129 mm diameter injector nozzle, driven by a custom programmable injector driver from Southwest Research Institute. Testing control variables were injection pressure and injection duration while using #2 ULSD fuel. Initial results showed high repeatability with a COV of less than 1.1 percent for all injection parameters with an average Cd of 0.92 and Ca of 0.97 for a mean injection pressure of 852 bar. A six point injection pressure sweep from 1000 to 1810 bar showed a 1.74 mg/ms overall increase in injection rate and a 0.16 ms overall decrease in fuel discharge duration. A six point injection duration sweep from 0.25 ms to 1.50 ms showed a 3.36 mg/ms total injection rate increase and a 0.68 ms overall increase in fuel discharge time while maintaining a consistent start-of-injection delay. The results show that this injection rate apparatus provides needed information on injection characteristics to assist engine manufacturers with achieving goals of high power with minimal emissions. Furthermore, it has been shown that this system is versatile for future injector characterizations over a wide range of pressures and durations, along with fuel type and injector parameters including nozzle hole diameter.

Study on Wear-Preventing of Needle Valve in Fuel Injection System Mounted on DME Engine

2011 ◽  
Vol 228-229 ◽  
pp. 1057-1062
Author(s):  
Xin Rong Wen ◽  
Guang De Zhang ◽  
Wei Hua Wang ◽  
Xie Lu ◽  
Sun Jing
Keyword(s):  
Dynamic Stability ◽  
Structural Design ◽  
Fuel Injection ◽  
Dynamic Instability ◽  
Calculation Model ◽  
The Other ◽  
Injection System ◽  
Needle Valve ◽  
Fuel Injection System ◽  
Theoretical Support

The purpose of this paper is to provide theoretical support for the structural design to prevent the wear of needle. The actual wear of the orientation part of the needle in scrapped needles was researched. The presented results showed that the main reason to the wear of the orientation part of needle was the dynamic instability and the abrasives enter into the surface of orientation part which increases the wear, and that the calculation model of dynamic stability was proposed to prevent the wear of needle. This model was a pressure rod, one end of which was fixed, the other was free, and the two ends were pressed on axial force which changes with time. Besides, the classic formula of dynamic stability of pressure rod was changed rationally, so as to correspond with the calculation model. It will play a part in preventing the wear of needle.

The Influence of Needle Eccentric Motion On Hole-to-Hole Injection Characteristics of a Two-Layered 8-Hole Diesel Injector

2021 ◽  
Author(s):  
Tianyu Jin ◽  
Yu Sun ◽  
Chuqiao Wang ◽  
Adams Moro ◽  
Xiwen Wu ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Lateral Displacement ◽  
Three Dimensional ◽  
Injection Rate ◽  
Hole Injection ◽  
Three Dimensional Model ◽  
Maximum Displacement ◽  
Fuel Flow ◽  
Diesel Injection ◽  
Eccentric Motion

Abstract The stringent emission regulations diesel engines are required to meet has resulted in the usage of multi-hole and ultra-multi-hole injectors, nowadays. In this research study, a double layered 8-hole diesel injection nozzle was investigated both numerically and experimentally. A three-dimensional model of the nozzle which was validated with experimental results was used to analyze the injection characteristics of each hole. The validation was conducted by comparing experiment and simulation injection rate results, acquired simultaneously from all the holes of the injector and the model. The fuel flow rates of the lower layered holes are higher than those of the upper layered holes. Two different needle eccentricity models were established. The first model only included the lateral displacement of the needle during needle lift. The needle reached maximum displacement at full needle lift. The second model considered the needle inelastic deformation into consideration. The needle radially displaces and glides along with the needle seat surface during needle lift. When the eccentricity reached maximum in the radial direction, the needle began to lift upwards vertically. The differences in injection characteristics under the different eccentricity models were apparent. The results indicated that the cycle injection quantity, fuel injection rate and cavitation of each hole were affected during the initial lifting stages of the needle lift. As the eccentricity of the needle increases, the injection rate uniformity from the nozzle hole deteriorates. The result showed that the upper layered holes were affected by the needle eccentricity during needle lift.

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