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.

scholarly journals Experimental study on the performance of ultra high pressure common rail system

2021 ◽  
Vol 39 (4) ◽  
pp. 883-890
Author(s):  
Kun Yang ◽  
Lei Zhou ◽  
Gang Wang ◽  
Tao Nie ◽  
Xin Wu
Keyword(s):  
High Pressure ◽  
Fuel Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Common Rail System ◽  
Ultra High Pressure ◽  
Rail System ◽  
Pressure Peak ◽  
Fuel Injection Rate ◽  
High Pressure Common Rail

In order to overcome the difficulties of high pressure source design and parts integration in the injector, realizing the ultra high pressure injection and controllable fuel injection rate, an ultra high pressure common rail system based on domestic basic materials and manufacturing technology level was proposed and designed. The working principle of this system was first introduced; the performance test bench of ultra high pressure common rail system was built. Then, the influence of pressure-amplifier device structure parameters on the pressurization pressure peak was analyzed quantitatively, and on the basis of selecting the most appropriate combination of parameters, the pressure and fuel injection rate control characteristics were conducted. The results show that ultra high pressure common rail system can magnify fuel pressure to ultra high pressure state (more than 200 MPa) and by changing the control signal timing of pressure-amplifier device and injector solenoid valve, the flexible and controllable fuel injection rate can be achieved. Under the condition of the same pressurization ratio, the peak value of pressurization pressure increases gradually, and with the increase of pressurization ratio, the increasing trend of the pressurization pressure peak value is nonlinear. At the same time, under the same condition of spring preload, the greater of the spring stiffness, the higher of the rail base pressure can bear, that means the pressure-amplifier device can achieve pressurization at a higher base pressure. But if the spring stiffness is too large, the solenoid valve of pressure-amplifier device will not be opened due to insufficient electromagnetic force, so the specific selection should be considered in a compromise.

scholarly journals A calculation method and experiment study of high-pressure common rail injection rate with solenoid injectors

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Ziguang Gao ◽  
Guoxiu Li ◽  
Chunlong Xu ◽  
Hongmeng Li ◽  
Min Wang
Keyword(s):  
High Pressure ◽  
Input Data ◽  
Fuel Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Common Rail System ◽  
Rail System ◽  
Rate Profile ◽  
Fuel Injection Rate ◽  
High Pressure Common Rail

The high-pressure common rail system has been widely used owing to its precise control of fuel injection rate profile, which plays a decisive role in cylinder combustion, atomization, and emission. The fuel injection rate profile of high-pressure common rail system was studied, and a fuel injection rate profile calculation model is proposed. The model treats the injector as a black box. Some measured data are needed to calculate the parameters in the model. The rise and fall of injection rate is regarded as trigonometric function to reduce the complexity and increase the accuracy. The model was verified using two different types of fuel injectors. The model calculation results were evaluated under various data input conditions. The results show that the model has good applicability to different input data and injectors. In addition, because the model building requires a large amount of experimental data, a comprehensive analysis of various input data was also conducted. The injection profile was analyzed from a new perspective and the regularity of injection rate profile was established.

scholarly journals Experiment investigation of injection parameters effects on injection stability of a high pressure common rail system

2021 ◽  
Vol 104 (1) ◽  
pp. 003685042098362
Author(s):  
Ziguang Gao ◽  
Guoxiu Li ◽  
Hongmeng Li ◽  
Chunlong Xu ◽  
Yanhong Kang
Keyword(s):  
High Pressure ◽  
Pressure Fluctuation ◽  
Injection Pressure ◽  
Injection Rate ◽  
Common Rail ◽  
Common Rail System ◽  
Stability Parameters ◽  
Rail System ◽  
The Stability ◽  
High Pressure Common Rail

High pressure common rail system can precisely control the injection time and injection pressure to improve the thermal efficiency of the engine. The injection characteristics of the system can affect the combustion and emission process of the engine. Injection stability is defined as variation characteristics of injection. This could have an unignored influence on combustion and engine output, while few study has been published. The primary objective is to establish evaluation systems and methods for injection stability. Then to study injection stability of the high pressure common rail system. Firstly, several parameters that have an important influence on the emission and combustion are identified. Based on the characteristics data obtained, it is verified that the stability parameters are in accordance with the normal distribution. Then, the five characteristic stability parameters of close speed of injection, cycle injection mass, injection delay, maximum injection rate and open speed of injection were quantitatively analyzed by using range, relative range, kurtosis and variance. It is found that the close speed of injection is greatly depend on injection pressure, the range of close speed varies from 1.8 to 5.1 mg/ms when rail pressure varies from 60 MPa to 160 MPa at 0.6 ms energizing time. The stability of injection mass depends on energizing time, the relative range in short energizing time can be four times than long energizing time. The maximum injection rate has similar characteristics with injection mass, it is also depends on energizing time. The range of maximum injection rate is reduced from the average of 0.6–0.7 mg/ms to 0.3 or even 0.2 mg/ms with the increase of energizing time. The injection delay and open speed of injection seems to be greatly affected by pressure fluctuation, since the observed data present complex rules. Pressure fluctuation in common rail can affect injection stability a lot.

scholarly journals Simulation of the Effect of Fuel Injection Rate that Matches Fuel Injection Advanced Angle on the Performance of Ultra High Pressure Common Rail Diesel Engine

2019 ◽  
Vol 37 (2) ◽  
pp. 417-423
Author(s):  
Lei Zhou ◽  
Kun Yang ◽  
Zhenming Liu ◽  
Yin Wang ◽  
Miao Chi
Keyword(s):  
High Pressure ◽  
Diesel Engine ◽  
Fuel Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Ultra High Pressure ◽  
Pressure Cylinder ◽  
Temperature Heat ◽  
Fuel Injection Rate ◽  
High Pressure Common Rail

On the basis of introducing the implementation method of variable fuel injection rate, the calculation model of a single-cylinder ultra high pressure common rail diesel engine was built, and the accuracy of this model was verified with experiments; then the effects of different fuel injection rates and fuel injection advanced angles on the performance of the ultra high pressure common rail diesel engine were analyzed with this model. The results show that the variable fuel injection rate can be realized by adjusting the opening time of electric-controlled pressure amplifier and injector solenoid valve in the ultra high pressure common rail system. With the lagging of pressurization time, the cylinder pressure, cylinder temperature, heat release rate and NOx emissions of the diesel engine decrease, while the soot emission rises. The ultra high pressure rectangle injection rate can make the diesel engine acquire best power and economy performance. With the increasing of fuel injection advanced angle, the cylinder pressure, cylinder temperature, heat release rate and NOx emission of the diesel engine rise, while the soot emission decreases first and then rises, the too small or too large fuel injection advanced angle can both reduce the power and economy performance of the diesel engine. The high fuel injection rate that matches small fuel injection advanced angle can improve power output and reduce fuel consumption of the diesel engine, and there is an optimal fuel injection advanced angle for each fuel injection rate to make the diesel engine performance achieve the best.

Experimental Study of Spray Penetration under High Pressure Common Rail Condition

2011 ◽  
Vol 347-353 ◽  
pp. 66-69
Author(s):  
Jian Xin Liu ◽  
Song Liu ◽  
Hui Yong Du ◽  
Zhan Cheng Wang ◽  
Bin Xu
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Injection Pressure ◽  
Electronic System ◽  
Common Rail ◽  
Spray Penetration ◽  
Jet Breakup ◽  
Secondary Breakup ◽  
Breakup Time ◽  
High Pressure Common Rail

The fuel spray images were taken with an equipment (camera-flash-injection) which has been synchronized with a purpose made electronic system under the condition of the high pressure common rail in two injection pressure has been expressed in this paper. It is discovered when fitting spray tip penetration that after jet breakup for a period of time, the spray tip begin to slow down rapidly, and the speed of spray tip running becomes smooth. Hiroyasu and other traditional tip penetration fitting formula are fitting larger to this phase. This is because that after jet breakup, the secondary breakup of striker particles will occur under the influence of the aerodynamic, surface tension and viscosity force. Therefore, a spray penetration fitting formula containing secondary breakup time to fit penetration in three sections was proposed in this paper. Results show that when pressure difference increase, both first and second breakup time become earlier. The former is because of gas-liquid relative velocity increasing, while the latter is due to high speed interface movement acceleration increasing.

scholarly journals Diagnostics of common rail components based on pressure curves in the fuel rail

2018 ◽  
Vol 173 (2) ◽  
pp. 3-8
Author(s):  
Mirosław KARCZEWSKI ◽  
Krzysztof KOLIŃSKI
Keyword(s):  
High Pressure ◽  
Fuel Injection ◽  
Dynamic Pressure ◽  
Common Rail ◽  
Injection System ◽  
Fuel Injector ◽  
Labview Software ◽  
Cr System ◽  
Data Acquisition Module ◽  
Pressure Changes

Majority of modern diesel engines is fitted with common-rail (CR) fuel systems. In these systems, the injectors are supplied with fuel under high pressure from the fuel rail (accumulator). Dynamic changes of pressure in the fuel rail are caused by the phenomena occurring during the fuel injection into the cylinders and the fuel supply to the fuel rail through the high-pressure fuel pump. Any change in this process results in a change in the course of pressure in the fuel rail, which, upon mathematical processing of the fuel pressure signal, allows identification of the malfunction of the pump and the injectors. The paper presents a methodology of diagnosing of CR fuel injection system components based on the analysis of dynamic pressure changes in the fuel rail. In the performed investigations, the authors utilized LabView software and a µDAC data acquisition module recording the fuel pressure in the rail, the fuel injector control current and the signal from the camshaft position sensor. For the analysis of the obtained results, ‘FFT’ and ‘STFT’ were developed in order to detect inoperative injectors based on the curves of pressure in the fuel rail. The performed validation tests have confirmed the possibility of identification of malfunctions in the CR system based on the pressure curves in the fuel rail. The ‘FFT’ method provides more information related to the system itself and accurately shows the structure of the signal, while the ’STFT’ method presents the signal in such a way as to clearly identify the occurrence of the fuel injection. The advantage of the above methods is the accessibility to diagnostic parameters and their non-invasive nature.

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).

An on-line measurement method of injection rate of high pressure common rail system

Measurement ◽  
2021 ◽  
Vol 170 ◽  
pp. 108716
Author(s):  
Quan Dong ◽  
Xiyu Yang ◽  
Hao Ni ◽  
Jingdong Song ◽  
Changhao Lu ◽  
...  
Keyword(s):  
High Pressure ◽  
Measurement Method ◽  
Injection Rate ◽  
Common Rail ◽  
Common Rail System ◽  
Rail System ◽  
Line Measurement ◽  
On Line ◽  
High Pressure Common Rail
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