Diesel Engine System Research Articles

Thermoeconomic analysis of a new waste heat recovery system for large marine diesel engine and comparison with two other configurations

ABSTRACT The utilization of waste energy sources and their treatment are very important in marine science due to their numerous benefits such as energy saving and feasible fuel conservation. Hence, this paper proposes three different configurations of waste heat recovery systems for the successful recovery of waste heat sources in diesel engines to obtain the highest level of power generation from the ship engines. The results of this study indicate that the new organic Rankine cycle system with the utilization of jacket cooling water presents better thermodynamic efficiencies and lower unit power cost in comparison with two other systems. Among the evaluated refrigerants, the R600 shows better thermoeconomic characteristics among other refrigerants. Several analyses show that the utilization of water jacket cooling beside the exhaust gases of the engine resulted in the fuel conservation of 209486 gallons per year of operation, which is about 23.3% higher than the base system without jacket cooling exchanger. Furthermore, it is observed that increasing the engine loading improves the net power output and also the payback period of the systems. This method might provide researchers with information to assess the benefit and the cost of each configuration modification and determine the direction of further improvement.

Self-tuning Method of Electronic Governor Parameters for Marine Medium-speed Diesel Engine

Xu, C. and Xu, H., 2020. Self-tuning method of electronic governor parameters for marine medium-speed diesel engine. In: Yang, Y.; Mi, C.; Zhao, L., and Lam, S. (eds.), Global Topics and New Trends in Coastal Research: Port, Coastal and Ocean Engineering. Journal of Coastal Research, Special Issue No. 103, pp. 378–381. Coconut Creek (Florida), ISSN 0749-0208.In view of the importance of electronic governor in marine diesel engine and the poor stability and fault-tolerance of the research results on parameter self-tuning, a self-tuning method of electronic governor parameter for marine medium-speed diesel engine based on fuzzy PID is proposed. Based on the electronic governor control system of diesel engine, the self-tuning environment of electronic governor parameters is built by using real actuator and rapid control prototype hardware, and the self-tuning scheme of electronic governor parameters is studied. Considering the non-linearity and time-varying characteristics of diesel engine, the self-tuning of electronic governor parameters is realized by using adaptive fuzzy PID control technology and variable universe idea. The experimental results show that the proposed method can effectively enhance the fault-tolerance in the process of parameter self-tuning by means of fuzzy control. Its stability is superior to the reference results, and it has reliability.

Experimental study and optimization in the layouts and the structure of the high-pressure common-rail fuel injection system for a marine diesel engine

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

Locating Sensors in Large-Scale Engineering Systems for Fault Isolation Based on Fault Feature Reduction

Fault detection and diagnosis (FDD) modules in a modern control system are effective in detecting and identifying abnormal process behaviours in a timely manner, ensuring the high-performance of large-scale engineering systems. The detection and isolation of faults is essentially built on the characterisation of the observed behaviour of a system. However, due to the large number of technical indicators available for measurement, as well as the various constraints of sensor installation, monitoring all the operating parameters of a large-scale engineering system is not feasible. Therefore, locating sensors optimally in a large-scale system, to achieve a comprehensive description of an abnormality, becomes a key issue to successfully apply diagnostic technologies to real world situations. In this paper, a fault feature reduction (FFR) based sensor location approach is proposed for optimal sensor placement so as to achieve the desired performance of fault detection and isolation. The behaviour of faults is firstly analysed using a fault tree to obtain a comprehensive understanding of the multi-dimensional relationships between faults and symptoms. A Boolean matrix is then constructed to represent the corresponding relations around faults and potential sensors. All the alternative configurations of sensors, for a desired diagnosis of a system, are obtained by eliminating the redundant fault features. The trade-off without a certain sensor is also attained using the following proposed approach. Three large-scale systems, including, a diesel engine system and two chemical systems, are used to illustrate the proposed approach. Comparisons to existing competitive techniques indicate the enhanced abilities of the proposed approach to meet the varying requirements of a real-world monitoring network. The analysis of sensor placement can be performed at the design phase of a large-scale engineering system, to locate the preset measured hole, or, during the life-cycle, to perfect an incomplete or redundant monitoring system.

Study on thermodynamic matching optimization of variable flow cooling system of diesel engine at high altitudes

ABSTRACT It is significant to matching optimize of variable flow cooling system for diesel engine at high altitudes, which is helpful to enhance the power and economy, improve the thermal efficiency, and control the heat load of the diesel engine. The experimental design based on the Latin hypercube sampling method was carried out, the collaborative optimization method of variable flow cooling system control parameters based on Genetic Algorithm (GA) was established and the map of cooling fan speed and cooling water pump speed under the condition of variable altitudes (0 m ~ 5500 m) was obtained, which were based on the coupled model of diesel engine and cooling system. Results indicated that as the increase of altitudes, the convective heat transfer coefficient of the air side of the radiator and the cooling fan head decreased, the fan head decreased by 7.24% on average for every 1000 m rise. After optimizing the control parameters of the cooling system at different altitudes, the temperature field of the heated parts was ranked from high to low, which was piston, cylinder head and cylinder liner, and the heat load of the three parts was not over the limit value. Compared with the original engine, after the application of variable flow cooling system, the power and torque of the diesel engine increased, and the higher the altitude was, the more obvious the increase effect was. In the low- and medium-speed region (n ≤ 1500 r/min), the increase effect of the power and torque of the diesel engine increased by 5.27% on average for every 1000 m rise, and the recovery effect was better than that of the high-speed condition. Compared with the original engine, the fuel consumption rate of the diesel engine equipped with variable flow cooling system decreased by 15.88%, and the thermal efficiency increased by 10.99% (percent-to-percent) on average at the altitude of 5500 m.

A Fault Diagnosis Model of Marine Diesel Engine Fuel Oil Supply System Using PCA and Optimized SVM

The fuel oil supply system of the marine diesel engine contains many components, which fits plenty of sensors to monitor the condition of all components. A fault sample consists of data collected from all the sensors at certain time, which lead the dimension of the fault sample is very high. When the ship is sailing, there is a randomness in fault categories and fault duration, which leads the fault data unbalanced. This paper proposes an appropriate combinational approach to address the above problems. First, to reduce computational complexity, the high dimensional fault samples are converted into the low dimensional ones using the principal component analysis (PCA). Second, a sample size optimization (SSO) strategy is proposed to address the problem of the learning from the imbalanced datasets, which improve the classification performance of support vector machine (SVM). Third, a three-dimensional Arnold mapping is introduced into the particle swarm optimization (PSO) algorithm to improve its generalization capability. Finally, the SVM optimized by the improved PSO is trained as the classifier to identify the ten faults in the fuel oil supply system. Results demonstrate that the average correct diagnosis ratio can be as high as 93.9%.

Моделирование рабочих процессов саморегенерирующихся фильтров, функционирующих в смазочных системах судовых дизелей

The article highlights the urgency of the research of working processes of a self-cleaning filter designed to purify the engine oil in the internal combustion engines. There was carried out experimental modeling of countercurrent regeneration of self-cleaning filters used in fuel preparation and diesel lubrication systems on ships. The layout of the unit for modeling the working processes of self-regenerating filters includes a service tank, a hydraulic motor with a stirrer, a pump, a hydraulic cylinder, a receiver of compressed air, a waste tank, a filtering element, shut-off and pneumatic control equipment, a pollution gauge, a temperature sensor, and other elements. A planning matrix is formed, and the experiment results on evaluating the efficiency of the self-regenerating filters are illustrated. The main factors of the regeneration coefficient are considered. There are presented the dependencies of evaluating the process effectiveness and predicting the life of filters between dry cleanings. The methods of calculating the regeneration parameters of automated filters based on the SRF-60 and SRFD-120 modules have been presented, which allows choosing the hydrodynamic modes and backwash time of filter elements taking into account the operating conditions of oil filters. The influence of the filtering process regeneration efficiency identified by the specific intensity of the removal of the dispersed phase from the oil, hydrodynamics (Reynolds number) and the relative backwash time, the adhesive properties of sludge, the filter design, and dispersion of the pollution are analyzed. The evidence of the validation of the calculated experimental dependences obtained from the laboratory tests of the filter model and their compliance with the results of field tests of self-cleaning filters on ships are presented. The possibility of calculating and adjusting the off-line operation of the self-cleaning filter in the lubrication systems of marine diesel engines is presented subject to diesel forcing, fuel quality and lubricants used, oil aging, additives wear and contamination by coarse-grained mechanical impurities.

Influential factors on pressure characteristics of fuel system for a low-speed marine diesel engine

Maritime transport has made great contributions to the prosperity and development of the world economy. And the low-speed marine diesel engine has played an important role. However, with the aggravation of energy shortage and marine pollution, the development of diesel engines is facing unprecedented pressure. It is therefore urgent to improve the performance of fuel system of diesel engine. In this study, a simulation model of fuel system for a low-speed diesel engine was established. And the accuracy of the model was validated because of the good agreement between the experimental data and simulation results of system pressure characteristics. Based on the verified model, the influence of key parameters on system pressure characteristics was examined. The results show that the mass of pressure amplification piston and flow capacity of pressure amplification control valve have slightly influence on the pressure characteristics of the system. And the impact of diameter of big and small end of pressure amplification piston is more obvious than the first two, for they change the pressure amplification ratio. The diameter of high-pressure fuel tube is the most influential factor to system pressure characteristics. The reason is that the pressure accumulative effect is strengthened as it increases, which leads to a dramatical change happened to the movement of pressure amplification piston and the propagation of pressure waves.

Correlation analysis upon the influential factors related to the dynamic response characteristics of pressure amplification piston in the fuel system for a low-speed diesel engine

Response characteristics are the key index to measure the performance of diesel engine fuel system. In this study, a simulation model of double-valve controlled common rail fuel system for low-speed diesel engine was presented. The accuracy of the model was fully validated by comparing calculation results with experimental data. Since the motion of pressure amplification piston (PAP) is highly correlated to fuel injection performance, the dynamic response of PAP was investigated. To determine the key factors influencing PAP dynamic response characteristics, a correlation analysis upon the structural parameters influencing opening response time (ORT) and closing response time (CRT) of PAP was performed based on the validated model. The results show that the change of working condition has a great effect on the opening process of PAP, but has little on closing process. Among all the isolated factors, the diameters of fuel plunger, high-pressure fuel tube and nozzle hole are the crucial factors related to the ORT of PAP. The diameters of fuel plunger, hydraulic piston and high-pressure fuel tube influence the CRT of PAP significantly. Among all the quadratic factors, the effects of interactions between diameter of fuel plunger and diameter of high-pressure fuel tube and between diameter of fuel plunger and diameter of nozzle hole on the ORT of PAP could not be neglected. The interactions between diameter of fuel plunger and diameter of high-pressure fuel tube and the interaction between diameter of high-pressure fuel tube and diameter of nozzle hole make great contribution to the CRT of PAP.

Urea Injection and Uniformity of Ammonia Distribution in SCR System of Diesel Engine

Abstract The kinetic mechanism of chemical reaction was used to calculate the coupling of the fluid kinetics with the urea decomposition reaction and the SCR reaction kinetics. Combined with the engine test and simulation, the distribution uniformity of the urea injection and ammonia gas was studied. Through numerical simulation on urea spray and exhaust flow in Urea-SCR system, the flow field characteristics in whole after-treatment system are gotten. By using numerical calculation in different urea injection angle and orifice sizes, the urea-crystallization and ammonia distribution have been studied and the optimal urea spray angle and nozzle size are given.

Investigation of the impact of the configuration of exhaust after-treatment system for diesel engines

Exhaust After-Treatment (EAT) systems are necessary for automotive powertrains to meet stringent emission standards. Computational modelling has been applied to aid designing EAT systems. Models with global kinetic mechanisms are often used in practice, but they cannot accurately predict the behaviour of after-treatment devices under a wide range of conditions. In this study, a numerical EAT model with rigorous treatment of the catalytic chemistry is proposed to investigate the impact of the configuration of individual devices in the EAT system; one of the key design decisions. The performance of the proposed model is first critically assessed against experimental and simulation data from the literature before being applied to design a multi-device EAT system for a diesel engine. The target EAT system is composed of a diesel oxidation catalyst (DOC), an ammonia-based selective catalytic reduction (NH3-SCR) device and a diesel particulate filter (DPF). The steady state behaviour of various EAT designs under operating conditions across the engine map are examined. The DOC-DPF-SCR layout is found to be more beneficial than the alternative DOC-SCR-DPF for the specific engine studied. Furthermore, the DPF-front system is more robust with respect to changes in emission regulations. Flux analysis is applied to study the chemical interaction in the SCR and explain the disadvantage of the SCR-front system. In addition, it is demonstrated in the study that future catalyst investigations should consider more realistic feed compositions.

Weak links identification of diesel engine system under strong electromagnetic pulse

Weak links identification of diesel engine system under strong electromagnetic pulse

Experimental study and numerical simulation of impact factors on spray impingement of urea water solution

The impingement behavior is inevitable during the injection process of urea water solution in selective catalytic reduction aftertreatment system of diesel engine. The impingement contributes to the formation of liquid film on the pipe wall and mixer, and it will block the pipe and reduce the urea water solution decomposition efficiency. In this work, the morphological changes of the spray during the impingement process were captured by the CCD camera. The liquid film development under different injection flow rates, compressed air pressures, injection heights, injection angles and metal wall temperatures were simulated and analyzed by AVL_FIRE. A good agreement with the experiment results is achieved. The results indicate that the liquid film area increases with higher injection flow rate, compressed air pressure, injection height and lower injection angle. According to Kuhnke model, the behaviors of impingement droplets are dominated by the sub-velocity of droplets which is affected by the injection flow rate and injection angle. Higher metal wall temperature can promote the evaporation of the liquid film and droplets, which reduces the liquid film area. It is an effective way to prevent the liquid film formation through rising the metal wall temperature.

Pilot-Scale Combined Reduction of Accumulated Particulate Matter and NO x Using Nonthermal Plasma for Marine Diesel Engine

An effective NO x -reduction aftertreatment system for a marine diesel engine that employs combined nonthermal plasma (NTP) and adsorption is investigated. The system can also treat particulate matter (PM) that employs a diesel particulate filter (DPF) and its regeneration by NTP-induced ozone. The effect of the combined reduction of accumulated PM and NO x is studied. The marine diesel engine of interest provides an output power of 1 MW at 100% of the engine load. The NO x reduction is composed of repeated adsorption and desorption flow processes using NTP combined with NO x adsorbents. With a view toward practical use, experiments on a higher number of cycles are carried out. The amount of adsorbents is 105 kg, which is greater than that in the authors’ previous study. As a result, NO x reduction efficiency by NTP is higher than in the previous study and is greater at higher amounts of adsorbents owing to higher NO x desorption. Furthermore, DPF regeneration with plasma-induced O3 injection is achieved simultaneously. This aftertreatment system demonstrates an excellent energy efficiency of 114 g(NO2)/kWh. The present aftertreatment can generate a synergistic effect of PM and NO x reduction.

Composite control of fuel quantity actuator system for diesel engines via backstepping control technique and generalised proportional integral observer

In an electronically controlled VE distributive pump, the fuel quantity actuator (FQA) is a significant component. It is responsible for governing the quantity of fuel being injected into diesel-type engines. There exist non-linearities in the system, and usually, non-linearities are neglected in modelling and control design, which makes the performance of the closed-loop system degrade. Therefore, the authors take the non-linearities of the rotary electromagnet and offsetting spring into consideration and establish the more detailed mathematical model in this study. Besides, the FQA system always confronts disturbances caused by external torque and input voltage variation in the real working condition. Furthermore, to deal with the non-linearities and reject the disturbances, a generalised proportional integral observer (GPIO)-based backstepping control approach is presented. By using a GPIO, the state estimations and disturbances estimation can be obtained at the same time. In addition, a theoretical analysis of the closed-loop system is given, showing its asymptotic stability, even under acting lumped disturbance. The introduced control scheme exhibits satisfactory performance in terms of transient behaviour and disturbance rejection. Finally, a set of simulation and experimental tests are carried out to validate the feasibility as well as efficiency of the proposed control framework.

Simulation analysis on vaporizer/mixer performance of the high-pressure SCR system in a marine diesel

As an important part of high-pressure SCR system in a marine diesel, vaporizer/mixer is a vital place to improve the spray atomization of urea solution, the formation of reduction agent and the effective mixing of multiple components well. In this paper, vaporizer/mixer of high-pressure SCR (HP-SCR) system in a marine diesel engine was selected as the research subject, then I establish a three-dimensional model of the mixer by CFD and simulate the chemical reaction fluid dynamic by Fluent, and then its major design properties of pressure loss, flow velocity and species concentration uniformity, NH3/NOx deviation as well as sensitiveness of diesel load were studied. According to characteristics of vaporizer/mixer of high-pressure SCR system, working performances of vaporizer/mixer installed without and with flow-guiding plates were compared and analyzed, and mixing effects of five flow-guiding plates were also evaluated in the paper. It is found that both the vaporizer/mixers which are installed with the centralized curved plates and irregular trapezoidal plates can meet the needs of design requirements of HP-SCR system, and the vaporizer/mixer installed with the irregular trapezoidal plates is superior to other structural flow-guiding plates. In addition, compared with vaporizer/mixer without flow-guiding plate, the maximum pressure loss of the vaporizer/mixer installed with irregular trapezoidal plates is only increased by 126 Pa, but its NH3 concentration uniformity in the outlet is increased by 8.1 %, and the sensitiveness efficiency of diesel load is decreased to 0.1 %, which adapts to the various working conditions of high-pressure SCR system in the low-speed marine diesel.

МОДЕРНИЗАЦИЯ ВЫПУСКНЫХ КОЛЛЕКТОРОВ ТЕПЛОВОЗНОГО ДИЗЕЛЬ-ГЕНЕРАТОРА ДГ882Л

The paper considers a serial design of a collapsible exhaust manifold for pulse boosting system of 8DM-21EL2M diesel engine and it’s modernized variant made of cast iron. The authors present results of modeling of exhaust gas and coolant flows gas dynamics. They also show the temperature distribution over the manifold surface.

ДОСЛІДЖЕННЯ МОЖЛИВОСТЕЙ ПРИВОДНОГО НАГНІТАЧА ROTREX ДЛЯ ЗАСТОСУВАННЯ В СИСТЕМАХ НАДДУВУ

The purpose of the article is to describe the design and research of the new Rotrex superchargers of C15 series. In superchargers to ensure high boost pressure and efficiency centrifugal compressor wheel, shockless planetary gear of the original design, a special lubrication-cooling system were used. The article describes the design features of Rotrex centrifugal superchargers and the results of experimental researches of the C15 series supercharger on a motor less stand. The design feature of the C15 series superchargers is compactness and high speed - the compressor wheel speed reaches 200 000 rpm. In a planetary gear, cylindrical rollers on ball bearings are used instead of gear satellites. The gear ratio from the shaft of the stand motor to the shaft of the compressor wheel was 43. Tests of the C15-20 supercharger are performed in static modes. Characteristics of the consumer of boost air were modeled with special washers with minimum diameters of 10,1 ... 14,0 mm. The maximum overpressure of 1.1 ... 1.3 MPa was achieved at a flow rate of 460 ... 250 kg/h, respectively. The tests confirmed the efficiency of the stand for gas-dynamic research of centrifugal compressors, the electronic control system of the electric motor current frequency reliably worked. Characteristics of the C15-20 supercharger, test results confirmed its purpose for spark-ignition car engines. They can be used in combined boost systems of both gasoline engines and diesel engines. KEY WORDS: INTERNAL COMBUSTION ENGINE, BOOST, CENTRIFUGAL SUPERCHARGER, BOOST TESTS

Покращення показників автобусів комунального підприємства «Вінницька транспортна компанія» використанням суміші палив

The article analyzes and substantiates the feasibility of using biodiesel as fuel for the engines of buses of the utility company “Vinnytsia Transport Company”. The purpose of the conducted researches is to develop measures to reduce the amount of harmful emissions in the exhaust gases of the engines of buses of the utility enterprise Transport Company, while reducing the cost of their operation. As a subject of the study, a high-capacity bus Bogdan A 70110 was selected, equipped with a turbocharged and intercooled 6-cylinder DEUTZ TCD 2013 L6 4V diesel engine, meeting the requirements of EURO III exhaust emissions standards. The bus performed transport work in Vinnytsia on route No. 19 Vyshenka - Nemyrivske shose during the working shift. The analysis of physical and chemical properties of diesel and biodiesel were analyzed and the feasibility of using the mixture as fuel for the buses of the utility company Vinnytsia Transport Company. The economic effect of using a mixture of fuels as fuel for engines compared to the use of pure diesel fuel has been calculated. To perform the calculations, the following conditions were adopted: the bus diesel engine is warmed to operating temperature; since the urban traffic has a large irregularity in hours of the day, it is assumed that the bus is loaded at 70% of the maximum passenger capacity. The annual economic effect of using the B20 fuel mixture by all diesel buses of the Utility Enterprise Vinnitsa Transport Company was determined. To ensure reliable operation of the diesel system, the intervals of operations during maintenance of the fuel system of diesel engines running on a mixture of fuels were adjusted.

An appraisal of the application of open-cell foams in automotive SCR systems

This work aims to investigate the possibility to apply open-cell foams as catalytic substrates in SCR systems for Diesel engines, as a replacement of traditional honeycombs. In the literature, many studies compare the performance of foams and honeycombs as catalytic substrates, showing, in general, a better mass transfer behavior in foams, compensated on the other hand by a higher pressure drop. In this work, we consider the low-pressure injection of Ad-Blue and we evaluate the performance of the open-cell foam in enhancing the mixing and the evaporation of the spray. A Eulerian-Lagrangian CFD model has been adopted to simulate the spray evolution and its interaction with the microstructure of the open-cell foam. The model has been applied to evaluate the spray evaporation and the uniformity of the ammonia distribution in different sections of the substrate. Different operating conditions were tested comparing substrates with different geometrical properties. The results of this preliminary analysis can be regarded as promising, showing the capability of the foam to enhance the mixing of the spray and to achieve a uniform distribution of the ammonia over all the catalyst substrate.