Fuel Injection Quantity Research Articles

가솔린 엔진 배출가스 제어장치에 대한 고장사례 고찰

이 논문의 목적은 승용자동차의 배출가스 제어장치에 대한 고장사례 연구이다. 첫 번째 사례의 원인은 퍼지 컨트럴 솔레노이드밸브(PCSV)가 일정한 동작조건에서 열리지 말아야 하나, 오작동 되어 열림으로써 서지탱크로 증발가스가 유입되어 이것이 연료량이 농후한 것으로 측정되었다. 이 결과 엔진의 ECU(Electronic control uint)에서 연료의 분사량을 줄임으로써 공회전시 엔진의 부조화 현상이 발생된 것으로 확인되었다. 두 번째 사례에서는, EGR 밸브를 작동하는 호스가 다른 곳으로 조립되어 진공압력이 공급되지 않았다. 이로 인해 EGR 밸브가 작동되지 않고 다른 곳에서 진공이 누설됨으로써 엔진이 부조화 현상이 발생된 것으로 확인되었다. 세 번째 사례는 두개의 센서 가운데 뒤쪽(Rear side) 산소센서가 다른 자동차의 산소센서로 오장착됨으로 인해 산소량을 감지하지 못해 감속시 급격하게 속도가 줄어든 것으로 확인되었다. 따라서, 배출가스 제어 장치에 관련된 시스템은 최적의 상태로 작동되어 배출가스를 저감하는 역할을 할 수 있도록 철저한 관리가 요구된다. The purpose of this paper is to study for the emission gas control of passenger car. The first example, the PCSV never open when operating condition, but it opened by causing malfunction because of trouble. As a result, the purge gas entered into surge tank, a mount of fuel was displayed with excessive supply on tester. Therefore, it certified the bad-condition of the engine when idling by decreasing of fuel injection quantity from engine ECU. The second example, the hose activating a EGR valve didn't supply the vacuum pressure because of assembling the other part. Thus, it knew the bad-condition of engine that the EGR valve would not work normally by leaking with the other port. The third example, as the rear oxygen sensor of two sensor were fault-installing by changing the sensor of other a car it could not detect of oxygen quantity. Finally, it found the phenomenon of abruptly decreasing vehicle speed when braking a car. Therefore, the system including with emission control has to drastically manage by maximizing condition to role decreasing the emission gas.

Anatomy of the cooled EGR effects on soot emission reduction in boosted spark-ignited direct-injection engines

It has been extensively examined that cooled exhaust gas recirculation (EGR) is effective not only to reduce NOx emissions but also to improve fuel conversion efficiency in spark ignition (SI) engines. Recently, the benefit of cooled EGR on soot particle emission reduction in SI direct injection (DI) gasoline engines attracts increased attention. However, the mechanism behind the phenomena needs to be further clarified. The objective of this study is to anatomize the cooled EGR effects on soot emission reduction in SIDI gasoline engines by the experiments along with the computational fluid dynamics (CFD) simulation. The soot emission reductions up to 48% by cooled EGR are firstly demonstrated at three typical high load conditions of a 2.0L boosted SIDI engine. Since the engine-out soot emissions are the combined results of soot particle formation and oxidation, the effects of cooled EGR on these two processes are respectively considered. It is found that cooled EGR plays adverse effects on soot oxidation, owing to the reduced in-cylinder oxygen availability and lowered reaction temperature. Although the increased intake boost pressure and reduced fuel injection quantity with cooled EGR can help reduce remarkably the wall wetting during the intake stroke, the quantity of liquid fuel on the wall is only slightly lower than the case without EGR during the combustion processes. The in-cylinder mixture distribution and equivalence ratio (ϕ)-temperature (T) plots obtained by the CFD simulations show that the lowered temperature of “pool fire” is the primary contributor to the reduced soot formation with cooled EGR, while improvement of the local rich pockets in the cylinder and the dilution effect of EGR may also play positive roles in suppressing the soot formation.

Dynamic characteristics of the nozzle opening pressure based on the fluid–structure interaction for a double-solenoid-valve fuel injection system

The nozzle opening pressure of fuel injection systems affects the initial fuel atomization, the fuel injection quantity, the emission characteristics and the operation stability of diesel engines. This paper presents an investigation on the dynamic characteristics of the nozzle opening pressure for a double-solenoid-valve fuel injection system. A numerical model for the nozzle opening pressure based on the fluid–structure interaction theory is established, including the models for the physical properties of the fuel, the leakage rate of the piston pair and the elastic deformation of the piston chamber and the piston pair. Also, experiments were carried out to validate the proposed model. Good agreement was found between the simulated results and the measured results. Based on this model, the effects of some factors on the nozzle opening pressure are analysed. The results show that the rotational speed of the cam, the initial clearance of the piston pair and the sealing length of the piston pair have slight effects on the nozzle opening pressure but that the diameter of the piston, the initial fuel temperature and the residual volume greatly influence the nozzle opening pressure.

Effect of exhaust gas recirculation (EGR) and multiple injections on diesel soot nano-structure and reactivity

The physio-chemical characteristics of soot particles are of importance with regard to performance of diesel after-treatment systems. In this study, the soot particles generated in a single-cylinder heavy-duty diesel engine are examined in terms of nanostructure, oxidative reactivity and volatile organic fraction (VOF), using thermogravimetric analysis (TGA), X-ray diffraction (XRD), Raman micro-spectroscopy, and high resolution transmission electron microscopy (HRTEM). Five different injection strategies including single injection and multiple injections with various pilot injection amounts and dwell times were tested with and without exhaust gas recirculation (EGR), while combustion phasing, engine speed, and fuel injection quantity was matched for all cases. Results indicate that for the soot produced under EGR condition, nano-structural order (indicated by crystallite size obtained from XRD and AD1/AG resulted from the Raman Analysis) can explain the soot reactivity. However, in the absence of EGR, the reactivity trend cannot be explained by the structural order. It is discussed that a possible reason can be a higher level of in-cylinder oxidation in non-EGR cases (indicated by higher level of surface functional groups) which roughens the soot surface, and enhances the oxidation by increasing the specific soot surface area. It is also found that in the absence of EGR, different injection strategies impact the soot reactivity and VOF content, which can be explained mainly through the level of charge premixed-ness and the in-cylinder soot oxidation, and the consequent effect on the soot surface roughness. Results also show that the influence of injection strategy on the soot reactivity and VOF content tends to vanish as EGR is added.

Lean hydrous and anhydrous bioethanol combustion in spark ignition engine at idle

The applications of anhydrous bioethanol to substitute or replace gasoline fuel have shown to attain benefits in terms of engine thermal efficiency, power output and exhaust emissions from spark ignition engines. A hydrous bioethanol has also been gained more attention due to its energy and cost effectiveness. The main aim of this work is to minimize fuel quantity injected to the intake ports of a four-cylinder engine under idle condition. The engine running with hydrous ethanol undergoes within lean-burn condition as its combustion stability is analyzed using an engine indicating system. Coefficient of variation in indicated mean effective pressure is an indicator for combustion stability with hydrocarbon and carbon monoxide emission monitoring as a supplement. Anhydrous ethanol burns faster than hydrous ethanol and gasoline in the uncalibrated engine at the same fuel-to-air equivalence ratio under idle condition. The leaner hydrous ethanol combustion tends to elevate the coefficient of variation in indicated mean effective pressure. The experimental results have found that the engine consumes greater hydrous ethanol by 10% on mass basis compared with those of anhydrous ethanol at the lean limit of fuel-to-air equivalence ratio of 0.67. The results of exhaust gas analysis were compared with those predicted by chemical equilibrium analysis of the fuel-air combustion; the resemble trends were found. Calibrating the alternative fueled engine for fuel injection quantity should be accomplished at idle with combustion stability and emissions optimization.

Exergy analysis of biodiesel combustion in a direct injection compression ignition (CI) engine using quasi-dimensional multi-zone model

In the present work, the exergy analysis was carried out for a diesel engine fueled with waste cooking oil (WCO) and its blends in four-stroke DI (direct injection) diesel engine at full load operation. To model the combustion process, a computerized version of Shahed's quasi-dimensional multi-zone was used. Moreover, a FORTRAN-based code, which includes 12 species (CO2, H2O, N2, O2, CO, H, OH, H2, N, NO, O, Ar) associated with combustion products was employed to study the exergy analysis. The fuel injection amount was kept constant and five different fuel mixtures (B0, B5, B20, B50 and B100) were employed during a closed cycle. The computational in-cylinder pressures for neat diesel fuel were compared with those of calculated experimentally in the literature, and they showed a good agreement. Various rate and accumulative exergy components were computed with crank position at five fuel compositions. The results showed that as biodiesel increases by volume blends from 0% to 100%, the exergy efficiency increases slightly. The accumulative irreversibility decreased by 4.7%. From the viewpoint of the exergy analysis, for considered biodiesel blends the biodiesel fuel could be used as an alternative fuel without any considerable penalty on converting the fuel exergy to thermal energy in order to produce useful work. Moreover, the exergetic performance coefficient showed that B20 was the optimum biodiesel blend to present the best combustion performance.

Experimental study of hydraulic electronic unit injector in a hydraulic free piston engine

The fuel injection system in two stroke engine is very important, therefore the hydraulic electronic unit injector system is developed and the injection characteristics of hydraulic electronic unit injector are investigated. Firstly the HFPE and the hydraulic electronic unit injector working principle are analyzed, and then PID control strategy is built by engine demand. In order to validate the feasibility of hydraulic electronic unit injector, the prototype test bench is established. The specific measurement principle is presented. Further the injection characteristics, such as the effect of injection pressure on injection delay and the effect of engine frequency on injection delay, are analyzed. In order to optimize the engine stability performance, the BDC control based on fuel injection control is investigated. The load control based on fuel injection is also discussed and the BDC feedforward control with the load variation is investigated. Experiment results of stead engine operation shows that the hydraulic electronic unit injector system based on PID control can be satisfied with the engine operation demand. In addition, cycle fuel injection quantity is tested online and off-line engine operation. It is obvious that the fuel injection quantity is affected by the hydraulic pressure. The fuel injection quantity variation can be improved with decreasing the fluctuation of drive pressure or adopting more suitable oil common rail instead of connected with exhaust valve hydraulic drive oil-way. The energy flow in HFPE is analyzed and the hydraulic output energy can be optimized by selecting suitable hydraulic valves parameters. The fuel injection quantity should be designed by the energy balance and the stable operation requirement in spite of the higher thermal efficiency.

Analysis upon fuel injection quantity variation of common rail system for diesel engines

Fuel injection quantity variation of common rail system has effect on the stability and reliability of diesel engines. For purpose of investigating the influence rule and mechanism of fuel injection quantity variation caused by parameters, taking account of the influence of fuel physical properties on dynamic injection characteristics of the system, a bond graph model of common rail injector has been proposed based on bond graph methodology and the state equations of the system are obtained. Comparisons between calculated fuel injection quantities by the numerical model and experimental measurements at different rail pressures and injection pulse widths indicate that the developed model can reasonably predict the fuel injection quantity characteristic of the system. Fuel injection quantity variation characteristics caused by the parameters of common rail injector have been analyzed in entire operating conditions. The selected parameters are delivery chamber diameter, needle seat semi-angle, needle cone semi-angle, ball valve seat semi-angle, nozzle hole diameter, inlet orifice diameter and outlet orifice diameter. The variation rules of quantitative percentages are obtained by quantitative analysis upon fuel injection quantity variation influential factors. It is concluded that ball valve seat semi-angle, nozzle hole diameter, inlet orifice diameter and outlet orifice diameter have the most significant effect on fuel injection quantity variation, and the followed are delivery chamber diameter and needle seat semi-angle. In addition, needle cone semi-angle also results in the variation of fuel injection quantity, but the effect is insignificant.

Effect of injector parameters on the injection quantity of common rail injection system for diesel engines

In this paper, the bond graph model of common rail injector was proposed in consideration of the effects of variable liquid capacitance and fuel physical property on the injection characteristics of the injector. State equations were derived based on the model, which were numerically solved by programming in Matlab. Comparisons between the simulation results and the experimental data show that the numerical model can effectively predict the injection quantity of the system. Effect of variation of delivery chamber diameter, needle seat semi-angle, needle cone semi-angle, ball valve seat semi-angle, nozzle hole diameter, inlet orifice diameter and outlet orifice diameter on fuel injection quantity had been analyzed. The influence rules of various parameters on the fuel injection quantity had been established. The experiments were conducted using face centered central composite design. A second order polynomial response surface model had been developed for predicting fuel injection quantity, as a function of the independent variables. Analysis of variation was used to determine the significance interactions which primarily affect the fuel injection quantity. It had been concluded that six interaction factors including delivery chamber diameter with nozzle hole diameter, needle seat semi-angle with needle cone semi-angle, needle seat semi-angle with nozzle hole diameter, needle cone semi-angle with nozzle hole diameter, nozzle hole diameter with inlet orifice diameter, and nozzle hole diameter with outlet orifice diameter have significant effect on the fuel injection quantity of the system.

Modeling of pressure line behavior of a common rail diesel engine due to injection and fuel variation

Common rail diesel engines with electronic fuel injection can accurately meter the fuel injection quantity with more accurate fuel injection control capability. In this work a common rail fuel injection system of a single cylinder diesel engine has been proposed and the important parameters like injection pressure, energizing time and high pressure pipes diameter and length are designed such that to be compatible with the engine basic design in case of pressure waves and injected mass variations. A one-dimensional approach has been used to model the injector using AMESim code in which Adiabatic models have been used to model injector system. Injected mass quantity has been calculated for different working point of fuel injection system that can be utilized as engine electronic control maps as inlet parameters. Results indicated that pressure fluctuation at the injector inlet is increased by decreasing pipe diameter while tube length has no significant effect on pressure waves. It is also shows that using biodiesel as fuel will lead to decrease in injection quantity but there is no significant impact on pressure fluctuations.

Measurements and analyses on the transient discharge coefficient of each nozzle hole of multi-hole diesel injector

The objective of this paper is to propose a measuring method based on the spray momentum flux measurement of each nozzle hole that could be used to determine the transient discharge coefficient of each nozzle hole of a multi-hole diesel injector. For this purpose, a measurement system for the transient discharge coefficient of each nozzle hole was established utilizing a conventional injection system of pump-line-nozzle and a dedicated constructed experimental rig. By measuring the spray momentum flux of each nozzle hole of the multi-hole fuel injector and injection pressure of the pump-pipe-injector fuel delivery system, the discharge coefficient of each nozzle hole was obtained, and analyzed throughout the injection duration and with different injection pump speeds and cycle fuel injection quantities. The results show that the transient discharge coefficient of each nozzle hole changes constantly, meanwhile, the variations of the transient discharge coefficient of the nozzle holes were similar. However, the discharge coefficient of the nozzle holes were not uniform at the same operating condition and that of the No.5 was apparently lower than that of the others. With increasing cam speed, the fluctuations of the discharge coefficients were variably stable at the maximum needle position.The fluctuations of the discharge coefficients of the nozzle holes were higher for the smaller cycle fuel injection quantity, but as the fluctuation gradually became smaller, the mean discharge coefficient of each nozzle hole increased slightly with increasing cycle fuel injection quantity.

Model-Based Gain Scheduling Strategy for an Internal Model Control-Based Boost Pressure Controller in Variable Geometric Turbocharger System of Diesel Engines

This paper proposes a model-based gain scheduling strategy of a Skogestad internal model control (SIMC)-based boost pressure controller for passenger car diesel engines. This gain scheduling strategy is proposed with a new scheduling variable to handle the nonlinear variable geometric turbocharger (VGT) plant characteristics. The scheduling variable is derived from the pressure ratio between the exhaust and intake manifolds and the exhaust air-to-fuel ratio to estimate the static gain of the VGT plant, which varies widely with change in the engine operating conditions. The proposed static gain model was designed with the scheduling variable, engine speed, and fuel injection quantity. Compared to the steady-state experimental data, the static gain model showed an R-squared value of 0.91. The boost pressure controller had the proportional-integral (PI) structure to allow for online calibration, and the PI gains were determined using the SIMC method. The proposed static gain model for the VGT plant was integrated into the SIMC control structure to obtain the appropriate control gains under wide engine operating area. The proposed control algorithm was compared with a fixed gain boost pressure controller through various step tests of the desired boost pressure. The fixed gain controller showed a large overshoot of 64% when the exhaust gas recirculation (EGR) operating condition was changed. In contrast, the proposed gain scheduled boost pressure controller reduced the overshoot to 12%. The model-based gain scheduling strategy successfully adjusted the control gains to achieve consistent control performance under various engine operating conditions.

A Study on the Influence of Fuel Pipe on Fuel Injection Characteristics of Each Nozzle Hole in Diesel Injector

The inner diameter of high pressure fuel pipe has a significant effect on the fuel injection process and the performance of a diesel engine. The spray impact force of each nozzle hole of a conventional injection system of pump-line-nozzle for diesel engine (based on the spray momentum flux) and the injection pressure (on a fuel injection pump test rig) were measured. With varying fuel injection quantities and pump speed, the effects of the inner diameter of the high pressure fuel pipe on fuel injection process and the fuel injection characteristics of each nozzle hole were analyzed. It was noted from experimental results that the fuel injection pressure changes with variations in the inner diameter of the high pressure fuel pipe and also the injection duration gradually increases with increase in the inner diameter. At low injection pump speed, even with the same geometric fuel deliver rate, the injection duration also increases gradually. Due to throttling effect and reduction in injection pressure, the fuel injection quantities of the injection nozzle were relatively minimal when the inner diameters of the high pressure fuel pipe were respectively small and large. The optimum injection pipe inner diameter for the right quantity for fuel injection falls between the two cases (between small and large). In addition, the injection rate of each nozzle hole increases with the decrease in angle between the needle axis and each of the nozzle hole axis. The fuel injection quantity of each nozzle hole increases while their relative difference decreases with increasing pump speed.

DDVC方式燃料噴射装置による舶用ディーゼルエンジンの噴射量制御

DDVC方式燃料噴射装置による舶用ディーゼルエンジンの噴射量制御

Design and Evaluation for Target Indicated Torque Based Engine Starting Control Strategy in a High Pressure Common Rail Diesel Engine

The diesel engine power demand of the start condition can be separated into two parts including resistance overcoming and acceleration realization for the reason that there is no power output during the starting process. The present paper mainly focuses on the fuel injection quantity control based on the engine power demand especially the acceleration demand for the resistance force is fixed for a specific engine, and the starting acceleration velocity is set as a target curve so that the acceleration process can also be fixed. The feasibility of the start control strategy proposed in this paper was verified by a comparison of the traditional starting control with a constant fuel quantity, and starting performance of the target acceleration based control shows predominance to the constant quantity control. And then the comparison between various starting acceleration processes, which was realized by the settings of acceleration curve slope factor, was conducted and results showed that the acceleration processes with higher slope factors perform better.

Flatness-based Feedforward and Feedback Control for Fuel Rail System of Gasoline Direct Injection Engine

For gasoline direct injection (GDI) engines, obtaining desired rail pressure has become a key prerequisite of fuel injection quantity precise control. Since improved control performance and robustness will translate into better combustion stability, fuel economy and emissions. This paper develops a feedforward-feedback controller based on a nonlinear model of fuel rail system, where nominal feedforward control is derived by differential flatness and fuel rail pressure is selected as flat output. In feedback part, to simplify the design, the system is linearized on equilibrium point using Taylor series expansion, and Lyapunov method is used to ensure stability of closed-loop error system. Finally, the proposed controller is verified by fuel rail system simulation model established in AMESim software package, the simulation results in different pressure references demonstrate the effectiveness of the control system.

승용디젤엔진의 과도구간 입자상물질 저감 및 운전성능 향상을 위한 연료분사량 및 커먼레일압력 제어전략

This study proposes a control strategy of the common rail pressure with a fuel injection limitation algorithm to reduce particulate matter (PM) emissions under transient states. The proposed control strategy consists of two parts: injection quantity limitation and rail pressure adaptation. The injection limitation algorithm determines the maximum allowable fuel injection quantity to avoid rich combustion under transient states. The fuel injection quantity is limited by predicting the burned gas rate after combustion; however, the reduced injection quantity leads to deterioration of engine torque. The common rail pressure adaptation strategy is designed to compensate for the reduced engine torque. An increase of the rail pressure under transient states contributes to enhancement of the engine torque as well as reduction of PM emissions by promoting atomization of the injected fuel. The proposed control strategy is validated through engine experiments. The rail pressure adaptation reduced the PM emission by 5-10% and enhanced the engine torque up to 2.5%.

Optimizing the Quantity of Diesel Fuel Injection by Using 25HHOCNG Gas Fuel Mixture

Injection behaviors of internal combustion engines are very substantial fact that provides developments to future strategies about optimizing the engine and fuel parameters. During the combustion process, pilot diesel injection technique is more preferable option while using alternative gas fuels in a diesel engine. In this experimental study, a 3.6 L commercial, four stroke, four cylinders and mechanical fuel pump non-modified diesel test engine operated with hydroxy (HHO) and compressed natural gas (CNG) fuel mixtures under 25% and 75% (vol/vol), respectively. Diesel fuel injection quantities were reduced with the help of steeping motor devices which mounted on mechanical fuel pump plunger pin. Sensitive removes of steeping motor, plunger pin twisted clockwise 360°, 720° and 1080°, respectively. Comparisons of engine performance and exhaust emissions were explained briefly and illustrated via graphs. As a result, 720° clockwise twisted pin is the optimum point for experimental fuel pump plunger while using 25HHOCNG fuel mixtures.

A Comprehensive Study on Fuel Injector Test Bench for Heavy Duty Engine

Abstract This study discusses a fuel injector test bench containing a mechanical type fuel supply system for heavy duty dieselengine. The main focus of this study was to evaluate the design stability of the test bench, which basically measures theinjector durability of a multi-hole heavy duty injector by using pure diesel as a test fuel. In this experiment, diesel spraywas controlled by a specially designed control box and all the experiments were carried out to measure e.g. fuel injectionpressure and fuel injection quantity to understand the injection status which is interlinked with the stability factor of totaltest bench design. Also, the durability test was performed to understand the heavy duty operation lastingness of thedesigned system and the flow rate of the installed distributor pump in the fuel supply system of this studying test benchwas compared with LO-1 and LO-2 pump. The results of the above mention tests revealed that the injector test benchdesign and control system can serve the purpose for heavy duty injector.

Investigation on the fuel injection quantity fluctuation of a common-rail fuel injection system using response surface methodology

Variations in the parameters affect the injection characteristics of a common-rail injection system and leads to fluctuation in the fuel injection quantity. This paper is aimed at combining the numerical modelling and design of experiments to investigate the significant effects of the interactions between the common-rail injector parameters on the fluctuation in the fuel injection quantity using response surface methodology. A numerical model of a common-rail injector was developed. The model was validated by comparing simulation results with experimental measurements, which showed that it can accurately predict the fuel injection quantity of the system. The design of experiments was performed using a two-level five-factor D-optimal design. The factors studied were the pre-tension of the control valve spring, the diameter of the outlet orifice, the diameter of the inlet orifice, the needle lift and the diameter of the nozzle holes. A quadratic response surface model was suggested by means of partial least-squares regression analysis. The distribution of the standardized residuals, the relation between the predicted fluctuation and the observed fluctuation in the fuel injection quantity, the coefficient R2 of determination and the adjusted coefficient [Formula: see text] of determination for the response surface model were analysed, which demonstrated the significance of the model. Analysis of the F value and the p value for the model terms at the 95% confidence level revealed that the interactions between the control valve spring pre-tension and the nozzle hole diameter, between the outlet orifice diameter and the nozzle hole diameter, between the inlet orifice diameter and the nozzle hole diameter and between the needle lift and the nozzle hole diameter had significant effects on the fluctuation in the fuel injection quantity of the system. Furthermore, the significant effects of the interactions between these parameters were analysed in detail.