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

Author(s):  
Lei Zhou ◽  
Kun Yang ◽  
Zhenming Liu ◽  
Yin Wang ◽  
Miao Chi

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.

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.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Ziguang Gao ◽  
Guoxiu Li ◽  
Chunlong Xu ◽  
Hongmeng Li ◽  
Min Wang

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.


2021 ◽  
Author(s):  
Yuhua Wang ◽  
Guiyong Wang ◽  
Guozhong Yao ◽  
Lizhong Shen ◽  
Shuchao He

Abstract This paper studies the high-pressure common-rail diesel engine fuel supply compensation based on crankshaft fragment signals in order to improve the uneven phenomenon of diesel engine fuel supply and realize high efficiency and low pollution combustion. The experiments were conducted on a diesel engine with the model of YN30CR. Based on the characteristics of crankshaft fragment signals, the proportional integral (PI) control algorithm was used to quantify the engine working nonuniformity and extract the missing degree of fuel injection. The quantization method of each cylinder working uniformity and algorithm of fuel compensation control (FOC) based on crankshaft fragment signal were established, and the control strategy of working uniformity at different operating conditions was put forward. According to the principle of FOC control, a FOC control software module for ECU was designed. The FOC software module was simulated on ASCET platform. The results show that: Compared with the traditional quantization method, the oil compensation information extracted from crankshaft fragment signal has stronger anti-interference and more accurate parameters. FOC algorithm can accurately reflect the engine's working nonuniformity, and the control of the nonuniformity is reasonable. The compensation fuel amount calculated by FOC is high consistency with the fuel supply state of each cylinder set by experiment, which meets the requirement of accurate fuel injection control of common-rail diesel engine.


Author(s):  
Samuel E. Johnson ◽  
Jaclyn E. Nesbitt ◽  
Jeffrey D. Naber

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.


Measurement ◽  
2021 ◽  
Vol 170 ◽  
pp. 108716
Author(s):  
Quan Dong ◽  
Xiyu Yang ◽  
Hao Ni ◽  
Jingdong Song ◽  
Changhao Lu ◽  
...  

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