scholarly journals Evaluation of changes in fuel delivery rate by electromagnetic injectors in a common rail system during simulated operation

2021 ◽  
Vol 23 (2) ◽  
pp. 352-358
Author(s):  
Mariusz Kamiński ◽  
Piotr Budzyński ◽  
Jacek Hunicz ◽  
Jerzy Józwik

The objective of this study was to determine changes in fuel delivery rate by common rail system injectors during their simulated operation on a test stand. Four Bosch injectors used, among others, in Fiat 1.3 Multijet engines were tested. The injectors were operated on a test rig at room temperature for 500 hours (more than 72 million work cycles). During the test, pressure and injection frequency were changed. Changes in the operating parameters were estimated based on obtained injection characteristics and effective flow area determined thereby. The observed changes in fuel delivery rate were compared with results of the surface analysis of control valves and nozzle needles. Despite the stated lack of wear, significant changes in the dynamics of injector operation were observed, particularly at short injection times. Small pilot injections do not have to be corrected by the fuel injection control system because they do not affect the changes in torque; however, they do affect the combustion process. This creates conditions for increased emission of toxic exhaust components.

2013 ◽  
Vol 210 ◽  
pp. 136-141 ◽  
Author(s):  
Sławomir Wierzbicki ◽  
Michał Śmieja

The electromagnetic injector in the Common Rail system is the actuator directly responsible for fuel injection. Its proper operation is enabled by ensuring appropriately shaped changes of the electric signal worked out by the output stage of the controller. This paper determines the repeatability of the control signal and the possibility of using this signal for the diagnostics of the electrical part of the injector.


2013 ◽  
Vol 21 (4) ◽  
pp. 89-95
Author(s):  
Yunsub Sin ◽  
Geesoo Lee ◽  
Hyunchul Kim ◽  
Sangshin Kwak ◽  
Suk Shin Shin ◽  
...  

2021 ◽  
Vol 2 (143) ◽  
pp. 12-20
Author(s):  
Dmitriy A. Galin ◽  
◽  
Nikolay V. Rakov ◽  
Aleksandr M. Davydkin ◽  
Leonid O. Krush

Analysis of technical condition of diesels with accumulator Common Rail power supply system shows that the largest share of fuel equipment failures is associated with malfunction of high-pressure fuel injectors. The electronic engine control unit generates commands for biphasic fuel injection from each injector. Due to the wear of the injector elements, there is an uneven fuel supply to the engine cylinders and, as a rule, deterioration of its operation. (Research purpose) The research purpose is in studying the process of adjusting the fuel supply in the Common Rail system when diagnosing the engine of a Ford Transit vehicle. (Materials and methods) The most relevant method of commissioning Common Rail fuel system injectors are various service procedures, such as the Low Injection Training procedure. Authors used a scanner and appropriate software to estimate total fuel delivery at idle mode. Authors performed the study on a 2.4 liter Duratorq diesel engine. (Results and discussion) The article presents the engine parameters before and after adjustment (Small Injection Procedure). Before adjustment, two cylinders of the engine received more fuel than the other cylinders. It manifests in an increase in crankshaft speed. After the adjustment, the fuel supply to the cylinders was equalized, resulting in an equalization of crankshaft RPM, reduced vibration and noise. (Conclusions) The study showed that fuel adjustment and Low Injection Training should be a must for engine diagnostics. Correction is effective if the value of injection discrepancy is no more than 5 mg/stroke.


Author(s):  
Kun Yang ◽  
Lei Zhou ◽  
Gang Wang ◽  
Tao Nie ◽  
Xin Wu

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.


2020 ◽  
pp. 146808742092161
Author(s):  
Ying Hu ◽  
Jianguo Yang ◽  
Nao Hu

The structure and performance of the common-rail system for the marine diesel engine are different from those used for automobile applications, resulting from the larger accumulator volume and the single injection volume. According to the characteristics of the distributed structure of the accumulator volume, a novel optimisation idea to improve the steady-state performance of the high-pressure common-rail fuel injection system designed for a marine engine retrofitting is proposed. The study concentrates on the optimisation in the hydraulic layouts and the structure parameters to manage the energy stored in the pressure waves. First, the test rig was established to study and evaluate the steady-state performance of the high-pressure common-rail system. Second, the experiments of rail orders and injection sequences were carried out to study the influence of different hydraulic layouts on the energy distribution of pressure waves in the system. Meanwhile, a comprehensive and detailed model of the high-pressure common-rail system was built to investigate the structural parameters of a rail-to-injector pipe. Based on the high-pressure common-rail system model, the modified multi-objective genetic algorithm was employed to seek the trade-off between the consistency of the injection volume and the reduction of the rail pressure fluctuation. Results show that a uniform distribution of multiple rails in one cycle contributed to reducing the amplitude of the rail pressure oscillation. In the parameter ranges of this study, a longer length and larger diameter of the rail-to-injector pipe could reduce the standard deviation of the injection volume and the rail pressure fluctuation rate simultaneously.


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