Common Rail System Research Articles

Advanced Methods for Monitoring and Fault Diagnosis of Control Loops in Common Rail Systems

Common rail systems are a key component of modern diesel engines and highly increase their performance. During their working lifetime, there could be critical damages or failures related to aging, like backlash or friction, or out-of-spec operating conditions, like low-quality fuel with, e.g., the presence of water or particles or a high percentage of biodiesel. In this work, suitable data-driven methods are adopted to develop an automatic procedure to monitor, diagnose, and estimate some types of faults in common rail systems. In particular, the pressure control loop operating within the engine control unit is investigated; the system is described using a Hammerstein model composed of a nonlinear model for the control valve behavior and an extended linear model for the process dynamics, which also accounts for the presence of external disturbances. Three different sources of oscillations can be successfully detected and quantified: valve stiction, aggressive controller tuning, and external disturbance. Selected case studies are used to demonstrate the effectiveness of the developed methodology.

ТЕСТОВЫЙ КОНТРОЛЬ ТОПЛИВНЫХ НАСОСОВ СОВРЕМЕННОЙ АВТОТРАКТОРНОЙ ТЕХНИКИ

The article presents the results of a study of the energy balance when the technical condition of the fuel pump of agricultural machines changes. Over 30% of internal combustion engine failures occur in the fuel system. Timely diagnostics, repairs and maintenance work (the latter is often not provided for or not performed) of electric fuel pumps can increase the service life and service life. Calculation of the energy balance is a prerequisite for developing a new or upgrading an existing method for diagnosing a fuel pump. The importance of using current strength as a diagnostic parameter (when determining the technical condition) of the pump in the mode of creating maximum pressure in the fuel system is emphasized. Based on the research results, an additional diagnostic parameter can be the rate of increase in the pump supply current. Research has shown that with an increase in the hydraulic resistance of the fuel system by 90%, the average rate of current increase was 7.6 A/s. When the hydraulic resistance of the fuel supply system decreased by less than 10%, the average rate of current increase was 19.2 A/s. Current is a sensitive parameter that increases or decreases depending on the level of increase in hydraulic resistance or leaks in the fuel system. The pump power expended on hydraulic losses did not change significantly due to the constant value of the pump operating voltage. The ideas (methods, techniques) developed in the article are in good agreement with the issues of modeling processes in hydrodynamic tribocouplings of high-pressure fuel pumps, in particular for Common Rail systems. The research was carried out at the expense of the Russian Science Foundation grant No. 23-29-10042, Topic: Numerical modeling of processes in hydrodynamic tribocouplings of high-pressure fuel pumps for advanced high-pressure diesel engines https://rscf.ru/project/23-29-10042/.”

Study on precise fuel injection under multiple injections of high pressure common rail system based on deep learning

The fluctuation of fuel injection quantity under multiple injections of high pressure common rail system leads to a decline in engine economy and emission performance, the precise injection control is the key problem in current research. In this study, a deep learning data-driven model of injection quantity under multiple injections was established based on generalized regression neural network (GRNN), and the particle swarm optimization (PSO) was introduced to optimize the smoothing factor in the model, thereby improving its prediction accuracy. An injection quantity correction method based on the data-driven model was proposed and applied to actual common rail fuel injection system for experimental verification. The results demonstrate that the proposed data-driven model has excellent prediction performance and generalization ability for the predicted main injection quantity with mean absolute percentage error of 1.10 % and determination coefficient of 0.997. Through the experimental verification of the correction method under 144 groups of operating conditions, it was observed that the maximum deviation of main injection quantity decreased from −25.83～17.91 mm3 to −9.81～7.64 mm3, and the maximum absolute deviation reduced by 62.02 %. The precise of injection control under multiple injections is improved.

Modifying Injection Equipment Components for Their Adaptation to Work with Greener Hydrogen-Containing Fuels for Non-Road Vehicle Engines

This article presents the authors’ considerations regarding the possibilities of developing fuel equipment for modern compression ignition engines used in special and non-road vehicles. The paper discusses the process of fuel combustion and atomization in the chamber of a piston combustion engine. The paper then presents the concept of modifying the atomizer of a modern fuel injector for operation using hydrogen-containing fuels of plant origin. The authors present a review of tests performed using an engine dynamometer on a modern engine with a Common Rail system running on biofuel. The CI engine operated with standard and modified fuel injectors. During the tests, the external ecological characteristics of the engine were analyzed as a function of rotational speed; the values of injection doses at individual rotational speeds and their effects on the characteristics were read from the current parameters, and the pressure and temperature in the engine’s combustion chamber were measured. The research results show that implementing the changes proposed by the authors of this work is a good direction for the development of compression ignition engines.

Model-free adaptive full-order sliding mode control with time delay estimation of high-pressure common rail system

Model-free adaptive full-order sliding mode control with time delay estimation of high-pressure common rail system

Real-time estimation of fuel injection rate and injection volume in high-pressure common rail systems

The injection rate and injection volume are essential parameters for the combustion process, which greatly affect the engine efficiency and emission performance. However, at the current time the injection information cannot be obtained in real time during the actual operation of engine. This paper presents a novel real-time estimation method for the injection rate and injection volume based on the measurable rail pressure. A comprehensive dynamic model is derived by considering both the effect of fuel injection and supply process on the pressure fluctuation. Then a linear time-varying state space model is constructed by choosing three appropriate state variables. On this basis, considering the measurement noise and model uncertainty, a Kalman filter-based estimation method of the injection information is investigated. And the noise covariance matrix Q is optimally designed to adapt to a wide range of operating conditions. The proposed estimation method is validated on the different conditions, and the results show the injection rate estimation errors are within 4.5 %, the injection volume estimation errors are within 4 %. And on the situation with overlap of injection and supply process, the injection rate and injection volume estimation errors are all within 4.5 %.

Investigation of the effect of injection rate shaping on combustion and emissions in heavy-duty diesel engine under steady and transient conditions

The fuel injection rate (ROI) is a crucial factor that affects the combustion and emissions of diesel engines. This study focuses on the injection pressure in a common rail system, which is divided into a high-pressure section and a low-pressure section. A control-oriented ROI shaping (ROIs) model is developed based on the switching strategy between high and low injection pressure. Three types of ROI were generated, namely ROIB (conventional ROI), boot-ROI (low followed by high injection pressure), and anti-boot-ROI (high followed by low injection pressure) respectively. The 1-D and 3-D numerical simulations are conducted to analyze the impact of the shaped ROI on combustion and emissions for steady condition and transient condition. In terms of overall results, boot-ROI shows significant advantage among the three types of ROI. For the steady condition, the boot-ROI was able to increase the IMEP (indicated mean effective pressure) (1.57 bar) at high load conditions with almost unchanged NOx emission. For low load conditions with delayed SOI (start of injection), the exhaust temperature is close to that of the ROIB with a reduction of 0.51 g/kW·h in NOx emissions. For transient condition, the boot-ROI also shows its advantage. It was found to improve the BSFC (brake specific fuel consumption) with almost unchanged NOx emission during load-down process. And in load-up process, the BSFC and soot emission also could be improved with slightly increase in NOx emission through advance of SOI when boot-ROI was adopted. The one-dimensional model using boot-ROI reduces fuel consumption by 2 g/kW·h in experiment with WHTC cycles, with slightly higher soot emission and similar NOx emission.

Zero-Dimensional Modeling of the Rate of Injection with a Diesel Common Rail System Using Single-Hole Nozzles with Neat Low-Carbon Fuels

This paper presents a fuel injection rate predictive model based on zero-dimensional correlations from experimental results. This model estimates the fuel injection rate behavior with varying parameters such as fuel injection pressure-injector energizing, the injection nozzle geometrical characteristics, and fuel viscosity. The model approach was carried out with diesel fuel. Then, the model was applied to the use of two alternative low-carbon fuels without diesel. An experimental methodology was used under controlled conditions, employing an injection rate indicator to measure the injection parameters in real time. The setup was carried out on a pump test bench using a common rail injection system. The results show that the model can be adapted to different injection conditions and fuels.

Fuel injection performance and spray characteristic of high‐pressure common rail systems at low temperatures

AbstractThe fuel injection performance and spray characteristics of the high‐pressure common rail (HPCR) system at low temperatures are investigated with experiment. The effects of environmental temperature, common rail pressure, and fuel injection pulse width on the injection quantity and spray characteristics are discussed. The fuel injection quantity at −30°C decreases by about 10% compared to the target fuel quantity. For the different target fuel quantity, the decrease of fuel injection quantity with temperature is the same under different rail pressures. The impact of temperature change on fuel injection quantity is relatively greater when the fuel injection pulse width is small. At the same common rail pressure and injector control pulse width, the injection quantity of −35# diesel is greater than that of −10# diesel for the same temperature condition. The low‐temperature fluidity can ensure normal diesel supply and injection in the fuel supply system. When the viscosity of diesel fuel rises and fluidity deteriorates in a low‐temperature environment, the spray beam produced by the same spray pressure becomes difficult to spread, and the spray penetration distance and cone angle decrease. The spray penetration distance differs by about 2.2 mm between the two temperatures. At low temperatures, the viscosity of diesel fuel rises and the fluidity deteriorates. The minimum injection pressure of the spray increases, and the spray angle is relatively small.

Matching analysis on flow limiting valve of marine diesel engine common rail system

The flow limiting valve (FLV) designed for the high pressure common rail fuel system (CRS) was designed, the simulation model of the FLV and electronic controlled injector is established and the injector’s model was verified by experiment data. Through simulation, the maximum cycle injection quantity (CIQ) and close flow quantity (CFQ) of the CRS matched with the FLV are verified, and the influence of key FLV’s parameters on the matching performance was analysed. The maximum CIQ is 722mm3 and the CFQ is 1194.2mm3, which can satisfy the technical requirements of the CRS under overload conditions. The closing lift and orifice diameter of the FLV has a significant impact on the CFQ, which should be carefully designed according to the technical requirements, and the dimensional tolerance and processing accuracy should be guaranteed in the production and assembly process to ensure the consistency of the CFQ.

Research on fuel injection characteristics of common rail system based on high pressure pipeline integration and matching

AbstractThe modular prediction model of high pressure common rail system was established to study the influence of high‐pressure pipeline integration matching on the fuel injection characteristics of common rail system. The influence of common rail volume on pressure building and pressure fluctuation in common rail tubes was analyzed. The influence of common rail volume on the matching of fuel injection frequency (number of fuel injectors) and fuel supply frequency (number of plunger pumps) was studied by using the control variable method, and the basic optimal solution of the system was obtained. The influence of the common rail structure on the fuel flow characteristics of the system was also studied. The matching relationship between high pressure tubing and common rail system is studied by introducing dimensionless numbers such as length‐diameter ratio of pipeline. The results demonstrate that the increase of the storage space of the accumulator can effectively reduce the fluctuation in the system, so that the injection volume increases slowly and then decreases rapidly, with a slope of −5.70 × 10−3 mm3. The increase of the diameter of the common rail makes the fuel flow characteristics become good first and then bad, and the increase of the length of the common rail can soothe the pressure fluctuations. The increase of the diameter of the link tube (LT) makes the fuel injection volume of the injector increase first and then decrease. The optimal VR solution for the LT is 0.0249 and the optimal ratio of the length to diameter of a pipeline solution is 55.10. The structure of the distribution tube and its matching to the common rail have little effect on the fuel flow characteristics. When the diameter and length of the injection tube are too large, the influence on the injection pressure of the injector is negatively correlated.

Design and Evaluation of a Throttle Controller for Common Rail Diesel Engines

Currently, engine remapping is widely utilized to enhance the performance of diesel and petrol engines. Given that a substantial amount of data must be collected during the optimization process, a data acquisition system is necessary to organize and retrieve data automatically. This research focuses on the design, development, and testing of a data acquisition system for controlling and measuring the throttle pedal in diesel vehicles equipped with a common rail system. The system is designed to manage the Throttle Position Sensor (TPS) and monitor vehicle operational parameters in real-time. The proposed device employs Arduino as the primary hardware, with TechStream software for vehicle data acquisition, and a web-based application developed using the Python programming language, and displays data in real-time in the form of graphs and tables. From the test results, it can be concluded that the developed acquisition system produces precise and sensitive throttle position settings. Its operation is also straightforward, safe, and requires a relatively short amount of time.

Statistical analysis of the results of studies of the routes of garbage trucks with a hybrid power plant based on the Ural vehicle chassis

This work explores the possibility of creating a hybrid power plant based on the chassis of Ural vehicle equipped with a bunker for collecting municipal solid waste (MSW). The purpose of the work is to statistically analyze the existing routes of garbage trucks in the city of Chelyabinsk to identify the most loaded operating mode and to develop on its basis a test route for the garbage truck being created with a hybrid power plant based on the chassis of the Ural C26 and C18. Statistical processing of source data was carried out based on methods for processing large amounts of source data using the SPSS computer program. The methodology discussed in the article is also supposed to be used when modeling processes in hydrodynamic tribocouplings of high-pressure fuel pumps, in particular for Common Rail systems. Keywords garbage truck, hybrid power plant, driving routes, statistical processing, generalized cycle, ydrodynamic tribocouplings, fuel pumps

Evaluation of Ecological Parameters of a Compression Ignition Engine Fueled by Diesel Oil with an Eco Fuel Shot Liquid Catalyst

This article discusses the potential applications of the Fuel Shot liquid catalyst in compression ignition (CI) engines for reducing toxic substances in exhaust gases. Incorporating catalysts into fuel can optimize the combustion process, consequently reducing the emission of toxic substances into the atmosphere. Toxic compounds, such as nitrogen oxides, particulate matter, and hydrocarbons, adversely affect flora and fauna. Various methods are known for reducing their concentration in engine exhaust gases, one of which is the Fuel Shot liquid catalyst. The authors conducted experiments on a Fiat 1.3 JTD engine with a Common Rail system. The results indicate that the application of the liquid catalyst reduces the content of nitrogen oxides and hydrocarbons in the exhaust gases and slightly decreases fuel consumption. Additionally, investigations were carried out on the engine’s injection apparatus, which was fueled with modified fuel. The findings demonstrate that the fuel additive does not affect the wear of precision parts of fuel injectors and high-pressure pumps.

Effect research of fuel injection and pressurization pulse width on injection characteristics of ultra high pressure common rail system

Ultra high pressure common rail system can realize adjustable injection rate by controlling the relationship between fuel injection and pressurization timing, and then affect the fuel injection characteristics of diesel engine. In order to ascertain the effect law and its formation mechanism of the fuel injection and pressurization pulse width on the fuel injection characteristics of ultra high pressure common rail system, on the basis of introducing the mathematical model of the system, the simulation model of ultra high pressure common rail system was established, and the accuracy of the model was verified by performance experiment, the effect of fuel injection and pressurization pulse width on the fuel injection characteristics of the system under different common rail pressure were analyzed. The results show that with the increase of fuel injection pulse width, the shape of fuel injection rate curve is similar to saddle shape and the proportion of large fuel injection rate range in the whole injection process increases gradually. At the same time, the fuel injection opening delay remains unchanged, but the fuel injection closing delay increases significantly when the fuel injection pulse width is small (0.6~1 ms), while it remains basically unchanged when the fuel injection pulse width is large (1~1.4 ms). With the increase of pressurization pulse width, the shape of fuel injection rate curve is similar to saddle shape and remains unchanged under the condition of small injection pulse width, while the fuel injection rate curve shape may appear similar to the "inverted saddle-shaped" under the condition of large injection pulse width, this is due to the rapid decrease of pressurization pressure caused by the closing of the solenoid valve control signal in the pressure-amplifier device before the end of fuel injection.

Combustion of raw Camelina sativa oil in CI engine equipped with common rail system

During the world energy transformation, using some vegetable oils as fuel enables the production of clean and inexpensive energy with the application of the well-known technology of the CI engine. The common rail (CR) fuel system gives many opportunities related to creating an air–fuel mixture and its efficient combustion. Can the system dedicated to diesel oil be used to inject vegetable oil and control its combustion effectively? This paper presents some results of the application of the injection strategy for raw Camelina sativa (CS) oil fueling. The test was conducted on the AVL single-cylinder CI engine equipped with a CR system for engine speed n = 1500 rpm and different excess air coefficients (1.1 < λ < 2.1). The engine parameters and performance obtained for raw CS oil were compared with the results obtained for diesel oil fueling for the same and slightly modified injection strategy. The experiment demonstrated how much the combustion process and its effects differ for these two fuels. In addition, several aspects related to the cultivation and use of Camelina sativa oil as a renewable energy source are presented.

Research on the influential factors related to the fuel leakage rate in the plunger-sleeve clearance of high pressure common rail system

In this study, a numerical model of the fuel leakage rate in the plunger-sleeve clearance of high-pressure common rail system was established based on graph theory. The transient clearance changes caused by the elastic deformation and the physical properties of the fuel along the flow direction within the plunger-sleeve were considered. This model realized the fluid–structure–thermal transient coupling during the leakage, and the accuracy was verified by comparing the calculated fuel leakage rate with the experimental data. Based on the main structural parameters of the plunger-sleeve, a three-level five-factor experimental calculation matrix was proposed using the D-optimal design method. The fuel leakage rates of all groups in the calculation matrix were obtained based on the fuel leakage rate numerical model, and the significant influencing parameters of the fuel leakage rate were determined using analysis of variance (ANOVA). The results indicate that the plunger diameter, sleeve external diameter, plunger-sleeve initial clearance and sealing length are significant parameters that affect the fuel leakage rate. In case of interaction between parameters, the interaction between the plunger diameter and sleeve external diameter, plunger diameter and plunger-sleeve initial clearance, and plunger diameter and plunger-sleeve sealing length contributed to a significant change in the fuel leakage rate. The influencing behavior of significant single parameters and significant interactions between parameters on the fuel leakage rate were revealed. The research outcomes can provide theoretical support for the optimization of the design of plunger-sleeve.

Evaluation of the influence of fuel pressure pulsation in the Common Rail system on the economic and environmental performance of a diesel engine

BACKGROUND: At present, all the worlds diesel engine manufacturers have directed their development strategy towards reducing harmful emissions, improving fuel efficiency and increasing power per liter. To achieve this, using only the Common Rail system is not sufficient. It is necessary to apply new additional devices, such as an exhaust gas converter, an exhaust gas recirculation system, the injection of additional fluids together with diesel fuel, as well as to improve existing ones. Increasing the accuracy of fuel delivery for an injector will make it possible to adjust the engine fuel system more precisely, leading to a positive effect on all areas of development of the diesel industry.&#x0D; In this article, the possibility of increasing fuel efficiency and reducing harmful emissions through exhaust gases of a diesel engine with a decrease in pressure pulsation in the accumulator of the Common Rail system is considered on the example of the D-442-59I-1 (4ChN 13/14) experimental four-cylinder diesel engine with a two-valve gas distribution system manufactured by Altai Motor Plant.&#x0D; AIMS: Study of the effect of fuel pressure pulsation in the Common Rail fuel system on the economic and environmental performance of a diesel engine.&#x0D; METHODS: On a non-motorized test rig, the dependence of the fuel delivery of the injector on the pressure in the accumulator was determined. To assess the effect of fuel pressure at the injector inlet on the performance of a diesel internal combustion engine, experimental designs of diesel engines were simulated using the specialized software. Theoretical studies have been carried out to assess the influence of fuel pressure in the fuel system.&#x0D; RESULTS: Data have been obtained on the effect of fuel pressure fluctuations in the high-pressure line on the injector cycling, harmful emissions and fuel efficiency.&#x0D; CONCLUSIONS: As a result of the study of the process of fuel supply and combustion in a 4CHN 13/14 diesel engine, it was found that with a pressure fluctuation range of 50 bar in the fuel accumulator, the concentration of wet NOx decreases by 11%. The concentration of solid particles increases to 13.4%, fuel efficiency deteriorates to 0.5% when the operating pressure of the fuel deviates 160 MPa in any direction from the set value.

Study of the Optimization of Rail Pressure Characteristics in the High-Pressure Common Rail Injection System for Diesel Engines Based on the Response Surface Methodology

This paper establishes a mathematical model of the high-pressure common rail injection system used in diesel engines according to the parameters of its key components, and AMESim 2020 software was used to establish a simulation model of the common rail injection system used in diesel engines. The simulation model mainly includes a high-pressure oil pump model, a common rail pipe model, and a model of four injectors. This paper also describes an experimental analysis of the accuracy of the established simulation model. Through a simulation analysis of the system rail’s pressure fluctuation and pressure characteristics, it was concluded that the length of the common rail pipe, the diameter of the common rail pipe, and the inner diameter of the high-pressure fuel pipes are important influencing parameters for the rail pressure characteristics of the system. In this study, according to the original common rail pipe and high-pressure fuel pipe model, a response surface methodology was used to optimize and analyze the parameters of the common rail pipe and high-pressure fuel pipes, and the optimal size parameters for the common rail pipe and high-pressure fuel pipes were obtained with the minimum rail pressure fluctuations and the average rail pressure setpoint. After the optimization, the pressure for the common rail pipe of the high-pressure common rail system was increased by 0.82%, the pressure fluctuation was reduced by 21.66%, the injection pressure was increased by 1.15%, the single injection volume was increased by 0.86%, and its fuel injection characteristics were significantly improved.

Compound control of rail pressure in dual common rail injection system based on a dual regulating valve

To improve the performance of fuel injection in high power diesel engines, high pressure dual common rail system (HPDCRS) is made to match high power diesel engine, proportional-integral-derivative (PID) compound control for rail pressure is proposed based on dual regulating valve: pressure balance valve (PBV) and pressure control valve (PCV), a PID hybrid neural network (PID-HNN) is provided to complete tuning and match of PID coefficient automatically, simulation control modelling of rail pressure is made by MATLAB software, pressure control comparison of dual common rail is made with PID compound control method. The pressure control effects illustrated that PID compound control of dual regulating valves can rapidly trace different target pressure and reduce rails pressure wavelet, and feasibility of compound control is verified in dual common rail pressure.