Diesel Engine System Research Articles

Fault diagnostics and adjustment of the fuel system of a medium-speed diesel engine using heat release characteristics

Adjustment of the diesel fuel equipment is an important condition for maintaining the technical condition of the diesel engine in operation at the level declared by the manufacturer. This paper presents the results of an experimental study of the method previously proposed by the authors for tuning the fuel system of a diesel engine based on the analysis of diagrams of net heat release in the cylinder. Net heat release diagrams are calculated based on the first law of thermodynamics, written for a closed system, using only cylinder pressure and cylinder volume. The method allows some instability of the load mode during testing and does not require simultaneous measurement of in-cylinder pressure in all engine cylinders. The method is adapted for typical operating conditions and in-cylinder pressure measurement through the indicator channel. The object of the study was a medium-speed six-cylinder diesel engine with a high-pressure hydromechanical fuel pump. The article also considers the possibility of using net heat release diagrams to identify injector malfunctions that lead to poor fuel atomization.

Research on thermoeconomic fault diagnosis for marine low speed two stroke diesel engine.

To satisfy the requirements of low fuel consumption, low emission, and high efficiency of the shipping industry, marine diesel engines are developing in the direction of automation and energy-saving, which increases the possibility and complexity of marine diesel engine failures. A one-dimension thermodynamic model for the marine diesel engine is built with AVL Boost software. The model is applied to a low-speed two-stroke 6S50MC diesel engine, and the error between the main performance parameters obtained by simulation and the test bench data is less than 3% under 100% and 75% load. Based on the model, 6 typical single faults and many typical double faults concomitant phenomena of diesel are reproduced. Based on the second law of thermodynamics, the exergy flow among the components and the external environment is analyzed. The thermoeconomic model of a marine diesel engine is established where the "fuel" and "product" of the components are defined according to their function. The fault diagnosis results show that the effects of faults generally propagate through the diesel engine system and affect the behavior of several components, resulting in induced malfunction in normal components. Therefore the malfunction MFi of each component is the superposition of the intrinsic malfunction and the induced malfunction according to the malfunction and dysfunction analysis. The thermoeconomic fault diagnosis method can be used to narrow the search range of abnormal components though it cannot accurately locate the fault.

Research on adaptive diagnosis algorithm for fuel injection failure system of construction machinery diesel engine

Research on adaptive diagnosis algorithm for fuel injection failure system of construction machinery diesel engine

ИССЛЕДОВАНИЕ РАБОТОСПОСОБНОСТИ ФОРСУНОК ТРАКТОРНЫХ ДИЗЕЛЕЙ

Fuel equipment is one of the main systems of tractor diesel engines, the technical condition of which determines such power and economic indicators as reliability and stability of operation. At the present stage, the vast majority of tractors in operation have a power reduced by about 10... 15% and fuel consumption increased by more than 15%, which is explained by such reasons as imperfection of methods and means of maintenance, the "age" of machines. It is known that up to half of the failures of tractor diesels are accounted for by fuel equipment, while a decrease in power has a negative impact on the performance of machine-tractor units. In addition, as a result of downtime and fuel overspending, agricultural producers incur significant losses. At the same time, the level of technical operation often remains very low, the frequency of maintenance is not observed, high-quality regulation of agricultural machines is not provided. Energy-saturated tractors with forced diesels are more demanding on the stability of adjustments. One of the ways to improve the efficiency of the existing tractor fleet is to improve the design of the sprayer. In this regard, this article presents the results of experimental studies devoted to evaluating the effectiveness of the design solution and determining the predicted operating time of sprayers of experimental and serial injectors installed on diesel engines SMD-62. Experienced sprayers have a reverse taper, which allows you to improve the mobility of the needle and self-adjust when assembling the nozzle. Analytical dependences of technical and economic indicators of the control diesel engine with experimental and serial sprayers depending on operational operating time are obtained. It is established that the maximum predicted operating time of experimental and serial sprayers is, respectively, 4130 and 39920 motor-hours. The results of the research showed that the operating time of experimental sprayers was higher by 1000 moto-hours than serial sprayers, and the probability of trouble–free operation was 2 times greater.

A literature survey on exergy analyses of marine diesel engine and power systems

The oil crisis in the world has led countries to seek an alternative fuel that can replace fossil fuels. In addition, the fact that global warming, which is one of the most important problems for the world, has reached significant levels, has led to an increase in studies on greenhouse gas emissions and the efficient use of energy. Every effort to increase efficiency contributes to both environmental and economic improvements. Considering this situation, the study was compiled by examining the studies on energy and exergy analysis related to diesel engines and marine diesel power systems in the literature. As a result of the study, it has been seen that the use of different fuel types contributes significantly to the decrease in environmental emissions as well as the increase in efficiency in diesel engines. In addition, it is thought that there are few studies in the literature on ship diesel engines, and with the increase in the studies to be done on this subject, there may be important references to both companies engaged in maritime transport and studies that will conduct research on this subject.

Experimental Investigations on Control Strategy of Regulated Two-Stage Turbocharging System for Diesel Engine Under Transient Process

Experimental Investigations on Control Strategy of Regulated Two-Stage Turbocharging System for Diesel Engine Under Transient Process

Обоснование потенциала увеличения интервала замены моторного масла двигателя КАМАЗ Р-6

Abstract. The article is devoted to solving the actual scientific and practical problem of substantiating at the design stage the potential for increasing the frequency of maintenance of an automobile diesel engine, which is distinguished by an improved design, improved indicators of reliability, efficiency, environmental friendliness and quality of the operating materials used. The general goal of scientific research is to reduce operating costs and increase the efficiency of using cars with high-tech engines by increasing the frequency of their maintenance. The solution of the problem within the framework of this article is to establish the factors that affect the potential for increasing the engine oil change interval, taking into account modern and future requirements for automotive diesel engines. The methodological apparatus for solving this problem consisted in an analytical study of many years of experience in designing, manufacturing, testing and operating engines of the KAMAZ V8 family, as well as engines from leading world manufacturers. It has been established that for modern high-tech automotive diesel engines, the potential for increasing the engine oil change interval is a combination of a set of factors, namely: the use of diesel fuel with a minimum sulfur content; reduction of heat stress of lubricated parts. The main results are that specific basic requirements have been formulated for engine oil, diesel fuel, design and manufacturing technologies for parts, assemblies, diesel engine systems to increase the frequency of maintenance and oil change intervals for engines of the new KAMAZ R6 family. The scientific novelty lies in the fact that a complex of factors has been identified, the combination of which affects the reduction in the rate of deterioration of the quality indicators of engine oil, taking into account which allows increasing the intervals for its replacement during the operation of a diesel engine. The theoretical value for the development of the branch of science “Operation of road transport” lies in the fact that the identified factors and relationships contribute to the study and improvement of the processes of organizing car maintenance, which helps to increase their operational reliability and operational efficiency. The direction of further research is the solution of the following complex task — bench and operational tests of the engine of the new KAMAZ R6 family to confirm the validity of the potential for increasing the frequency of maintenance.

APPLICATION OF FUZZY ANALYTIC HIERARCHY PROSES FOR ERROR DETECTION OF AUXILARY SYSTEMS OF SHIP MAIN DIESEL ENGINES

Ship engine room has a structure which has to meet a number of needs with regard to administrative conditions. Therefore, when the complicated structure of engine room are considered, even a simple mechanical failure, if no measures taken abruptly, grows into irreversible condition, causing losses that cannot be compensated. A well-qualified ship engine conductor along with an effective error detection system is needed to detect failure and act immediately against any engine impairments possible. This study aims to manage troubleshooting in main engine auxiliary systems which cover cooling, lubricating and cooling oil and fuel systems. The study is also thought to be a good reference for maintenance processes for marine engineering operators. Breakdown of main engine equipment are examined and troubles hooting program is developed for using Fuzzy Analytic Hierarchy Process (F-AHP) determine solution methods and causes of such breakdowns. In this paper, a fuzzy Multi Criteria Decision Making (MCDM) methodology was proposed to determine the most effected system of the ship main diesel engine. The results showed that fuel system was the most effected alternative, as being followed subsequently by cooling system, governor system, air supply system and oiling system. The results were based upon the opinions of three experts groups who ranked the ship main diesel engine systems alternatives according to twenty-nine criteria expert selected.

Analysis of Water-Cooled Intercooler Thermal Characteristics

With the incremental power of construction machinery diesel engines, the power performance of diesel engines and the pollutant emissions from the exhaust gas have imposed increasingly stringent requirements on the intake cooling system of diesel engines. This paper compared the j/f evaluation factors for fin unit bodies of water-cooled intercooler (including straight fins and rectangular misaligned fins) by means of CFD simulation, and found that the rectangular misaligned fins had an 8% advantage in comprehensive performance. With the rectangular staggered fin intercooler, it was found that under the same conditions, the cooling efficiency of the dual-pass water-cooled intercooler is higher than that of the single-pass water-cooled intercooler, and the uniformity factor of the temperature difference field of the dual-pass water-cooled intercooler is 1.5% higher than that of the latter. The accuracy of the overall simulation of the intercooler is verified by the field test. The dual-pass and single-pass water-cooled intercooler both can maintain heat balance under working conditions, and its average air inlet temperature is 10 °C lower than that of the original air-cooled intercooler, which provides support for further reducing the engine air inlet temperature. The results provide a theoretical basis for the performance improvement of water-cooled intercoolers.

Динамика судовых дизелей при использовании моторных масел с различными структурными характеристиками

Annotation – The influence of the structural characteristics of engine lube oil on the dynamics of a marine diesel engine is considered. It is indicated that micron layers of marine engine lube oils separating the contact surfaces of marine diesel engines acquire the properties of liquid crystals and are characterized by an ordered molecular structure. The qualitative indicator of this structure is the degree of ordering of the molecules, and the quantitative indicator is the thickness of the ordered (boundary) lubricating layer. It is proposed to determine the structural characteristics of marine engine lube oils (the degree of ordering of the molecules of the boundary layer and its thickness) using the optical method of absorption dichroism. A diagram of an experimental setup is presented that allows such studies to be carried out. It has been experimentally established that for Shell Rimula X15 and Castrol TPL 123 engine lube oils (used in the oil system of the Caterpillar CatC18 marine diesel engine), the thickness of the ordered (boundary) lubricating layer is 14.3 ... 14.7 microns and 16.4 ... 16.6 microns, respectively. The degree of ordering of molecules in the boundary layer for Shell Rimula X15 engine lube oil is in the range of 0.56 ... 0.58, for Castrol TPL 123 engine lube oil – in the range of 0.63 ... 0.64. The results of studies of the dynamics of the CatC18 marine diesel engine by Caterpillar, carried out in the starting mode, as well as at various increases and decreases in load, are presented. As indicators, which were used to assess the dynamics of the diesel engine, the overshoot of the rotational speed and the time to reach a new steady state mode were taken. Experiments have confirmed that Castrol TPL 123 engine lube oil, which has a higher molecular structure in the boundary layer compared to Shell Rimula X15 lube oil, ensures the transient processes of the Caterpillar CatC18 marine diesel engine with less overspeed and less time to reach a new state work. The proposed technology for determining the structural characteristics of engine lube oils can be used for any type and grade of oil (mineral or synthetic, high and low viscosity, used both in circulating and cylinder lubrication systems). The proposed method for assessing the dynamic characteristics of marine diesel engines (by overshoot of the speed and the time to reach a steady state of operation in the event of a change in load) can be used for any types of internal combustion engines (low-, medium- and high-speed; as well as performing the functions of both main and auxiliary engines).

Dependable Sensor Fault Reconstruction in Air-Path System of Heavy-Duty Diesel Engines.

This paper addresses the problem of robust sensor faults detection and isolation in the air-path system of heavy-duty diesel engines, which has not been completely considered in the literature. Calibration or the total failure of a sensor can cause sensor faults. In the worst-case scenario, the engines can be totally damaged by the sensor faults. For this purpose, a second-order sliding mode observer is proposed to reconstruct the sensor faults in the presence of unknown external disturbances. To this aim, the concept of the equivalent output error injection method and the linear matrix inequality (LMI) tool are utilized to minimize the effects of uncertainties and disturbances on the reconstructed fault signals. The simulation results verify the performance and robustness of the proposed method. By reconstructing the sensor faults, the whole system can be prevented from failing before the corrupted sensor measurements are used by the controller.

Starting System and Safety Protection of Explosion-proof Diesel Engine for Coal Mine Based on Compressed Air

The starting and safety protection system is an important part ofthe explosion-proof diesel engine, and there are malfunctions in the explosion-proof diesel engine, such as difficulty in starting and failure in protection. As a gas working medium, compressed air is safe, reliable, and advantageous in acquisition and storage. Therefore, analyzing the starting principle and safety protection requirements of explosion-proof diesel engines and studying the correlation between the two systems, a set of starting and safety protection systemsusing compressed air as the working medium is designed in this paper. Moreover, the performance requirements of the main components in the system are studied, analyzing and calculating the operating parameters in the system, so that the design plan can be optimized. The problems appearing instarting and safety protection of explosion-proof diesel engines are solved through this system.

Starved lubrication analysis for the top ring and cylinder liner of a two-stroke marine diesel engine considering the thermal effect of friction

The thermal effect of friction plays an important role in friction pairs working under heavy load and starved lubrication conditions, such as the piston ring and cylinder liner (PRCL) system of two-stroke marine diesel engines. Friction heat will degrade the lubrication and increase the scuffing risk. In this study, considering the thermal effect of friction, the tribological characteristics of the top ring and cylinder liner of a two-stroke marine diesel engine under starved lubrication are studied. It is found that the temperature rise due to friction is significant and has a strong influence on the tribological characteristics of the PRCL system. Moreover, based on the orthogonal test method, the effects of groove textures under different oil supplies are also explored. Only well-designed groove textures can reduce friction and wear at the same time.

АНАЛІЗ ЕКСПЛУАТАЦІЙНИХ ХАРАКТЕРИСТИК МОТОРНИХ МАСТИЛ СУДНОВИХ ДИЗЕЛІВ

The analysis of the performance characteristics of engine oils used in the lubrication systems of marine diesel engines is carried out. The requirements for oils for various purposes are given. Recommendations on the choice of engine oils for lubricating and circulating lubrication systems of marine low- and medium-speed diesel engines are proposed.

Establishment of a Real-Time Simulation of a Marine High-Pressure Common Rail System

In this paper, the high-pressure common rail system of the marine diesel engine is taken as case study to establish a real-time simulation model of the high-pressure common rail system that can be used as the controlled object of the control system. On the premise of ensuring accuracy, the real-time simulation should also respond quickly to instructions issued by the control system. The development of the real-time simulation is based on the modular modeling method, and the high-pressure common rail system is divided into submodels, including the high-pressure oil pump, common rail tube, injector, and mass conversion. The submodels are built using the “surrogate model” method, which is mainly composed of MAP data and empirical formulas. The data used to establish the real-time simulation are not only from the empirical research into the high-pressure common rail system, but also from simulations of the high-pressure common rail system undertaken in AEMSim. The data obtained from this real-time simulation were compared with the experimental data to verify the model. The error in fuel injection quality is less than 5%, under different pressures and injection durations. In order to carry out dynamic verification, the PID control strategy, the model-based control strategy, and the established real-time simulation are all closed-loop tested. The results show that the developed real-time simulation can simulate the rail pressure wave caused by cyclic injection according to the control signal, and can feedback the control effect of different control strategies. Through verification, it is clear that the real-time simulation of the high-pressure common rail system can depict the rail pressure fluctuation caused by each cycle of fuel injection, while ensuring the accuracy and responsiveness of the simulation, which provides the ideal conditions for the study of a rail pressure control strategy.

Efficient waste heat recovery system for diesel engines using nano-enhanced phase change materials

Cold start is one of the most difficult combustion phases of a diesel engine; and a large percentage of pollutants are produced during this period. Therefore, the present study focuses on proposing a numerical investigation of a novel design of an air preheating system to warm up the engine intake air at ambient air temperatures of 273 and 268 K. The preheating system consists of nano-enhanced phase change materials (NEPCM) housed in a plate heat exchanger. A comprehensive thermal model was developed and validated using experimental data from the literature. The model couples the transient turbulent fluid flow of the engine exhaust gases with the melting and solidification processes in the NEPCM domain. The effect of nanoparticle type, nanoparticle weight fraction, engine rotational speed, and ambient temperature were investigated. At 2000 rpm, the charging time was reduced by 34.88%, 30.23%, and 25.58% when using 5 w.t% of SiO2, Al2O3, and CuO nanoparticles, respectively. During the discharging process, in less than 1 min, the cold intake air can be heated from ambient temperatures of 273 and 268 K to 301.8 and 300.6 K, respectively.

Investigation of fuel injection rate identification algorithm based on rail pressure fluctuation characteristics induced by injection

As an important part of the common-rail (CR) fuel system for diesel engines, the injector circulation capacity and the fuel injection mass flow rate vary with carbon deposition and wear, affecting the engine output performance. This study proposes a method to identify the fuel injection rate online, based on the rail pressure fluctuation characteristics induced by fuel injection. The control algorithm uses the signal from the existing rail pressure sensor; the diesel engine does not require modification or additional sensors. A quasi-dimensional model of the CR fuel system was built to analyse the rail pressure wave fluctuation characteristics, and a parameter K was defined as the pressure drop rate. Based on K, a control algorithm was proposed. A high-pressure fuel pump test rig was built to test the fuel injection performance under different operating conditions, and the experimental data were processed by wavelet transform. From the test data, the K of the CR system was analysed using the feedback of the rail pressure sensor. The experimental results show that the value of K increases with an increase in the initial pressure and injection pulse, and is independent of the injection mode. The algorithm is feasible, and works more accurately with a longer injection pulse and a lower pump speed. This method uses the existing rail pressure sensor, does not incur extra cost and has great potential for improving the injection accuracy.

Study of super/turbocharger system for helicopter diesel engine

1. Lohinov VV, Ukrayinetsʹ YEA, Kravchenko IF, Elanskyy AV, Analiz lʹotno-tekhnichnykh kharakterystyk i ekonomichnykh pokaznykiv lehkoho rehionalʹnoho litaka z aviatsiynym dyzelʹnym i hazoturbinnym dvyhunamy. Aviatsiyno-kosmichna tekhnika i tekhnolohiya. – 2014; 10:35-48. Google Scholar

Multiobjective optimization of the cooling system of a marine diesel engine

AbstractAn intelligent cooling system directly influences the thermal load of high‐temperature components, heat distribution, and fuel economy of a diesel engine. An optimal coolant pump rotational speed map is a key factor in intelligent cooling control strategies. In this study, we designed an experimental variable coolant flow system for a maritime diesel engine. Experiment design and D‐optimal designs were used to optimize the parameters of the diesel engine cooling system. The diesel engine speed, load, and freshwater rotational pump speed were selected as variables. The temperature of the high‐thermal‐load zone of the combustion chamber components, fuel consumption rate, effective power, and peak cylinder pressure were selected as response variables, and the D‐optimal method was used to sample the experimental points. Polynomial response surface models were obtained using a stepwise algorithm. A multiobjective optimization problem was converted into a simple‐objective optimization problem using the ideal point method. A genetic algorithm was used to optimize the single‐objective function globally to obtain the optimal freshwater pump speed map for a diesel engine under all conditions. On average, the optimized cooling system decreased the fuel consumption by 1.901%. Six typical propulsive conditions were selected to confirm the validity of the optimization results. The experimental results indicate that the fuel consumption decreased by 2.35%, the effective power increased by 2.26%, and the power consumption of the water pump decreased by 17.83%. The combination of experiment design and D‐optimal designs offers the advantages of low cost, high efficiency, and high precision in solving multiobjective optimization problems involving strong coupling and nonlinear systems. The results of this research provide data support and a theoretical basis for intelligent cooling control strategies.

The assessment of the engine performance and emissions of a diesel engine fueled by biodiesel produced using different types of catalyst

In the present study, the biodiesel was produced from waste cooking oil using two types of catalyst (homogeneous (Hom. Cat.) and heterogeneous (Het. Cat.)). The produced biodiesels were characterized to obtain their physicochemical properties and fatty acid methyl esters (FAMEs) profile. Then, they were blended with net diesel fuel at volume ratios of 10:90 (B10), 25:75 (B25), and 40:60 (B40) for using in the injection system of a 6-cylinder diesel engine operated at a constant speed of 1500 rpm to compare changes in the combustion (engine performance) and exhaust emissions of engine. The results showed that the catalyst type had an insignificant effect on the physical properties of produced biodiesel such as density, viscosity, flash, cloud and pour point, higher heating value, etc., whereas the compositions of FAME contents slightly changed. On the other hand, the total production duration was lower for the biodiesel produced by heterogeneous catalyst (21 h against 26 h), while the higher amount of energy consumed (2165 against 1650 Wh/L). Blending net diesel fuel with biodiesels slightly improved the engine performance and combustion behavior. The exhaust gas emissions were also showed an appropriate decrease in carbon monoxide (5–40%), unreacted hydrocarbon (40–75%), and smoke opacity (8–25%) emissions using biodiesel produced heterogeneous catalyst. The statistical analysis of results showed that blending the net diesel fuel with 34 vol% of biodiesel and operating the diesel engine at 40% of fuel load can lead to an appropriate engine performance along with a considerably reduction in the exhaust gas emissions.