High-speed Diesel Engine Research Articles

AUTOMATION OF MEASUREMENTS OF ENGINE HEAT CONSUMPTION IN THE LUBRICATION AND COOLING SYSTEMS

The paper presents the results of an intermediate stage of the study of heat transfer processes in high-speed diesel engines of the automotive tractor type at transient load discharge-load-injection modes, which are characteristic of this type of diesel engines. In such modes, as evidenced by the results of calculations of the thermal stress state of combustion chamber parts, in particular pistons, exhaust valves of the gas distribution mechanism, significant tensile and compressive stresses are observed compared to operation at steady-state conditions. This is the reason for the occurrence of defects in the form of cracks on the heat exchange surfaces of these parts, which limits the service life of automotive tractor engines. For a more detailed study of transient processes, as the main approach, it is proposed to use the well-known method of heat balance tests of a high-speed diesel engine, but with the involvement of automated processing of measurement results in digital form at steady-state and transient modes. It is proposed to focus on heat consumption, which is a component of the heat balance in the lubrication and cooling system. Without the use of automated information processing directly at the time of transient load shedding and load shedding, it is impossible to obtain such information on cooling and lubrication systems. Recording of transient heat transfer processes makes it possible to track the influence of engine operating parameters, the dynamics of the transient process depending on its duration, the initial and final steady-state modes between which the transition is being studied. In general, this way, it is possible to assess the adaptability of cooling and lubrication systems to heat dissipation during sudden changes in load, to avoid, or at least limit, the growth of thermal stresses. The publication presents a possible variant of the schematic solution of such a system for automated processing of the results of heat balance tests with the maximum use of equipment that is mass-produced and has already been used previously in heat balance tests.

Performance and Emission Characteristics of a High-Speed Diesel Engine Using a 20% Palm Oil Ester and Ethyl Alcohol Blend

Performance and Emission Characteristics of a High-Speed Diesel Engine Using a 20% Palm Oil Ester and Ethyl Alcohol Blend

Development of a semi-empirical physical model for transient NOx emissions prediction from a high-speed diesel engine.

With emissions regulations becoming increasingly restrictive and the advent of real driving emissions limits, control of engine-out NOx emissions remains an important research topic for diesel engines. Progress in experimental engine development and computational modelling has led to the generation of a large amount of high-fidelity emissions and in-cylinder data, making it attractive to use data-driven emissions prediction and control models. While pure data-driven methods have shown robustness in NOx prediction during steady-state engine operation, deficiencies are found under transient operation and at engine conditions far outside the training range. Therefore, physics-based, mean value models that capture cyclic-level changes in in-cylinder thermo-chemical properties appear as an attractive option for transient NOx emissions modelling. Previous experimental studies have highlighted the existence of a very strong correlation between peak cylinder pressure and cyclic NOx emissions. In this study, a cyclic peak pressure-based semi-empirical NOx prediction model is developed. The model is calibrated using high-speed NO and NO2 emissions measurements during transient engine operation and then tested under different transient operating conditions. The transient performance of the physical model is compared to that of a previously developed data-driven (artificial neural network) model, and is found to be superior, with a better dynamic response and low (<10%) errors. The results shown in this study are encouraging for the use of such models as virtual sensors for real-time emissions monitoring and as complimentary models for future physics-guided neural network development.

Experimental study on the effects of water addition in methanol on the performance of diesel-methanol diffusion combustion on a high-speed engine

Methanol is regarded as a low-carbon renewable fuel which is friendly to the environment. For purpose of investigating the impact of water introduction in methanol on diesel-methanol diffusion combustion, experimental tests were performed on a refitted dual-fuel high-speed diesel engine test bench. This research compared the differences between diesel-methanol diffusion combustion (DMDC) mode and diesel-hydrous methanol diffusion combustion (DHMDC) mode with a water mass content of 20%. The tests were performed by maintaining the engine speed of 3000 rpm and varying engine load as well as methanol injection timing (MIT). The results indicate that the heat release process in DHMDC mode begins later but is more rapid and concentrated compared to DMDC mode. The addition of 20% water in methanol does not significantly decreases the peak average in-cylinder temperature. However, it decreases the NOx emissions by up to approximately 40%. Water introduction leads to higher CO and THC emissions in DHMDC mode, but the retardation of MIT helps mitigate the increase in CO and THC emissions. The exhaust losses in DHMDC mode decrease by about 5%–8%, while the heat transfer losses increase by over 20%, resulting in a lower indicated thermal efficiency (ITE) in comparison with DMDC mode. The effects of the 20% water addition in methanol are sensitive to changes in engine load and MIT. Higher engine load and appropriately retarded MIT facilitate more efficient and cleaner combustion in DHMDC mode.

Dynamic stability analysis of a high-speed diesel engine turbocharger subjected to aerodynamic loads and engine-induced vibration

Dynamic stability analysis of a high-speed diesel engine turbocharger subjected to aerodynamic loads and engine-induced vibration

РЕШЕНИЕ ВТОРОЙ ЗАДАЧИ ПРОГНОЗИРОВАНИЯ ВОЗДЕЙСТВИЙ И ОСТАТОЧНОГО РЕСУРСА ТРАНСПОРТНЫХ СРЕДСТВ

A mechanism for solving the urgent problem of forecasting technical impacts and residual life depending on operating time is presented. It is proposed to use the theory of multiple regression analysis as a methodological basis, provided that the factors can be both independent, controlled, and dependent and uncontrollable, their combinations cannot be fully realized, and the objective function is measurable. The factors used are the values that determine the operating mode: the speed of the crankshaft, temperature, engine load. Such a task in the article is called the second forecasting task by the authors. The practical implementation of this mechanism is carried out using the example of constructing a multiple linear regression model of the dielectric constant of a high-speed diesel engine oil.

Experimental study of diesel engine running on petroleum diesel fuel and rapeseed oil

The article discusses the problem of replacing traditional diesel fuel with an alternative one. Rapeseed oil is considered as an alternative motor fuel. A deterioration in the quality of injection and atomization processes was noted when converting the engine to rapeseed oil. Experimental studies of the MD-6 diesel engine have shown that it can operate effectively on both petroleum diesel fuel and rapeseed oil. At the same time, the transfer of this engine from petroleum diesel fuel to rapeseed oil was accompanied by an increase in brake-specific fuel consumption, an increase in exhaust gas opacity, and an increase in emissions of nitrogen oxides and carbon monoxide. These negative phenomena are partly eliminated by adjusting the fuel injection advance angle. Improved engine performance is also achieved by optimizing the characteristics of the fuel supply system and two-phase fuel supply. The implementation of these measures makes it possible not only to achieve the performance of a diesel engine characteristic of running on diesel fuel, but also to meet the requirements for fuel efficiency and exhaust gas toxicity that are promising for small-sized high-speed diesel engines.

Dynamic stability analysis of a high-speed diesel engine turbocharger subjected to aerodynamic loads and engine-induced vibration

Dynamic stability analysis of a high-speed diesel engine turbocharger subjected to aerodynamic loads and engine-induced vibration

DESIGN IMPROVEMENT OF DIESEL ENGINES TAKING INTO ACCOUNT MODERN ENVIRONMENTAL REQUIREMENTS

Statement of the problem in a general form. Modernization of medium- and high-speed diesel engines at the current stage is reduced to increasing their energy efficiency with simultaneous strengthening of environmental requirements to combat global warming. This process involves not only a change in the structure and technical characteristics of vehicles, but also a transition to the use of alternative types of fuel. In our paper, we explore the key technical aspects of this transition, including fuel systems and their adaptation to the new requirements of today's medium- and highspeed diesel engines. The results of our research will reveal important information about the improvement of diesel fuel systems, contributing to the improvement of their operational efficiency and compliance with the new standards.

Контроль технического состояния цилиндропоршневой группы тепловозного дизеля в период предпусковой холодной прокрутки

High-speed diesel engines of small dimensions (with the cylinder diameter of up to 210 mm) are increasingly used as prime movers in the autonomous locomotives of various purposes. Characteristic design feature of many of them lies in the absence of indicator valves to connect devices measuring the intra-cylinder pressure (maximum meter or pressure sensor). It excludes the possibility of using diagnostic methods based on the indicator analysis to control technical state of the cylinder-piston group of such engines based on analyzing diagrams of the working process inside the cylinder. This circumstance determines relevance of searching for other approaches to solve this problem. One of such approaches is based on monitoring parameters of the signal of the crankshaft instantaneous angular velocity and the starter motor current in the engine cold cranking mode. Based on analyzing alteration in the crankshaft instantaneous angular speed and the starter motor current in the cold cranking mode during bench testing of the locomotive diesel, diagnostic parameters, indicators and criteria to monitor the diesel cylinders performance were proposed. Effectiveness of the proposed criteria was confirmed by analysis of the results of the diesel engine cold scrolling with the opened indicator cocks of individual cylinders. Using the proposed diagnostic criteria would improve operational reliability and reduce cost of the diesel locomotive maintenance through rational planning the scope of work within the scheduled repair operations.

Combined removal experiment of NOx, SO2 and PM from marine diesel exhaust gas with SCR-DryEGCS system

Pollutants such as nitrogen oxides (NOx), sulfur oxides (SO2), and particulate matter (PM) in ship exhaust have a great impact on human health, environment and climate conditions. Combined selective catalytic reduction technology and dry exhaust gas cleaning technology, a test rig (SCR-DryEGCS system) for WD10C195-15 marine four-stroke high speed diesel engine was established to analyse the removal effect of NOx, SO2, and PM from exhaust gas. The SCR-DryEGCS system removed 89.03%, 99%, and 96% of NOx, SO2, and PM respectively. And also compared with low sulfur oil combined SCR method to verify the feasibility of the SCR-DryEGCS method. It shows that the SCR-DryEGCS system has its own advantages and has a good effect on the removal of NOx, SOx, and PM at the same time.

Temperature control characteristics of intelligent cooling system for high-speed marine diesel engine

ABSTRACT To improve energy conservation and reduce emissions of an engine, this study applies intelligent thermal management to a cooling system. With a marine high-speed diesel engine as the research object, an intelligent cooling system based on controllable cooling components was developed. A variable-universe fuzzy control algorithm is designed to control an electronic thermostat, and a ‘T–S fuzzy control + BP-PID’ control algorithm is proposed to control standard electric drive pumps. The experimental results indicate that the intelligent cooling system considerably reduces the warm-up time, achieves accurate cooling, and effectively inhibits the hot immersion phenomenon. The intelligent control algorithm has control characteristics such as rapid response, strong adaptive ability, small overshoot, smooth transition, and high precision. The intelligent cooling system reduced the cooling-system power consumption by 5.52%–57.93%, fuel consumption rate by 1.43%–5.15%, smoke emission by 1.40%–4.69%, CO emission by 2.14%–6.03%, and HC emission by 7.41%–12.26%.

Modelling and optimisation of intermediate pyrolysis synthesis of bio-oil production from palm kernel shell

A Palm Kernel Shell (PKS) is an enclosed shell obtained as residue from processing palm kernel. Its regarded as lignocellulosic biomass that serves as an abundant renewable energy source. The thermal and physicochemical behaviour was investigated, and results showed a low Fixed Carbon (FC) (22.60 wt%), high Volatile Matter (VM) (74.60 wt%), and high Higher Heating Value (HHV) of 19.78 MJ/kg. The elemental results showed the presence of C (48.70 wt%), H (5.58 wt%), N (0.23 wt%), O (45.02 wt%), and S (0.04 wt%). The fixed-bed pyrolysis reactor was utilised for the decomposition of the PKS to produce an optimum bio-oil of 47.10 wt% at temperature (520 °C), reaction time (15 min), nitrogen (175 cm3/min), particle size (0.70 mm), and heating rate (22.5 °C/min). The efficient Response Surface Methodology (RSM) via Central Composite Design (CCD) was employed to model and optimise the operating parameters. P<0.05, a high F-value for bio-oil makes the established model predicted, suitable, responsive, and reliable. The actual and predicted value for the quantity of bio-oil produced showed clearly that the data is reasonably in consonance with the predicted value. Screening with FT-IR revealed that the peak of 3339.7, 1416 cm−1 attributed to O–H stretching vibrations depicted the presence of alcohol and carboxylic acids, respectively, the resent, while the peak at 1636.3, 1274.7 was due to C–H bend and C–O stretch indicating the presence of aromatic compounds and aromatic ester respectively. The most significant element in the bio-oil obtained via Gas Chromatography–Mass Spectrometry (GC–MS) analysis is phenol, 9, 17 – octadecadienoyl, oleic acids, 2-cyclo pentane-1-one, and pent ethylene glycol are the by-products in the sample. Hence, the bio-oil produced is suitable for high-speed diesel engines, vehicle locomotion, powering heavy machines, marine equipment, manufacturing industries, and mining types of machinery. This is a significant contribution in the field of bio-oil production and application.

Multi-sensor signals multi-scale fusion method for fault detection of high-speed and high-power diesel engine under variable operating conditions

Detecting faults in high-speed and high-power diesel engines under complex variable operating conditions is highly challenging. Online vibration monitoring systems have been used in such diesel engines in key fields, in which vibration sensors are installed on each cylinder to enable comprehensive monitoring. In this paper, a fault detection method for diesel engines under variable operating conditions is proposed based on multi-sensor signal multi-scale fusion. Firstly, a preprocessing framework is established for the raw vibration signals collected from each cylinder to eliminate random interference and system noise. Then, the resulting signals are phase-aligned based on the engine firing sequence and analyzed using a signal correlation algorithm to produce a multi-sensor multi-scale similarity matrix (MSMSSM). Finally, a multi-branch residual convolutional neural network (MBRCNN) model is constructed with the MSMSSM as the input to detect abnormal health states of the diesel engine. Fault simulation experiments are conducted on a 12-cylinder V-type high-speed and high-power diesel engine test rig. The comparative test results indicate that the proposed MSMSSM-MBRCNN method shows both the highest accuracy of 95.28% and the lowest standard deviation of 3.57% compared to other typical methods. The multi-sensor signals multi-scale fusion method proposed in this paper fully utilizes the key information that remains basically consistent in the synchronous acquisition signals of multiple sensors under different operating conditions. This can effectively reduce the interference of operating condition changes and improve the accuracy and robustness of fault detection.

Evaluation and extension of ignition delay correlations for dual-fuel operation with hydrogen or methanol in a medium speed single cylinder engine

Hydrogen (H2) and methanol (MeOH) are promising fuels for sustainable transport, owing to their ideal properties for use in internal combustion engines: CO2 neutral (when produced renewably), ultralow emissions, and high efficiencies. The dual-fuel (DF) technology where diesel is used as a pilot to ignite port fuel injected H2 or MeOH is of particular interest for retrofitting existing diesel engines (DE). Although some experimental work has been conducted on high-speed DE, there has been limited numerical investigation in this area. Therefore this work focuses on medium speed large bore engines and on the ignition delay (ID) timing of the diesel pilot, a crucial parameter to well predict numerically as it denotes the start of heat release. Experiments were carried out using H2 and MeOH in DF on the same single cylinder engine. The measured IDs are reported and visualize the difference of the effect of both fuels. Next, diesel ID correlations are evaluated on their predictive capabilities in DF. They fail however to predict the increasing ID from the inhibition effect of MeOH. Therefore, new ID correlations were developed for DF with H2 and MeOH, emphasizing the importance of additional terms such as the methanol equivalence ratio to describe this inhibition effect. Finally, the new correlations were compared with correlations for DF with natural gas to explore similarities and differences.

The Non-Uniformity Control Strategy of a Marine High-Speed Diesel Engine Based on Each Cylinder’s Exhaust Temperature

To improve the non-uniformity of a multi-cylinder marine diesel engine caused by manufacturing assembly errors and performance degradation of the fuel injection system, with the instantaneous speed applied as the control target, the feedback variable of each cylinder’s exhaust temperature was used to obtain the non-uniformity information and the injection quantity of each cylinder was applied as the control variable; the inhomogeneity control was accomplished by modifying the injection pulse spectrum. The model of AVL Cruise M was established and validated by bench test data. The non-uniformity control strategy based on the instantaneous speed and the exhaust temperature of each cylinder was developed in SIMULINK, and the control effect was compared with the closed-loop control of cylinder pressure by software in-loop simulation. The results showed that the non-uniformity control strategy based on exhaust temperature could significantly improve the uniformity of each cylinder; although the improvement effect was not as great as the non-uniformity control strategy based on cylinder pressure, the cost was significantly reduced, and the practicality and reliability were better. With the closed-loop control of exhaust temperature and instantaneous speed, the CV (Coefficient of Variation) of IMEP (indicated effective pressure) was close to the closed-loop control of cylinder pressure; the maximum occurred at 25% load when it was 0.199%. This co-simulation provided a theoretical basis for the subsequent hardware-in-the-loop simulation and actual engine tests.

Application of response surface methodology for the modelling and optimisation of bio-oil yield via intermediate pyrolysis process of sugarcane bagasse

ABSTRACT The search for renewable resources has grown globally as a result of the harmful effects of fossil fuel use on the environment, such as global warming and acid rain. Biomass fuels do not contribute to the accumulation of carbon dioxide in the atmosphere. This study utilised response surface methodology for the optimisation of pyrolysis process parameters (temperature, heating rate, reaction time, nitrogen flow rate, and particle size) at five levels of experimental runs to enhance bio-oil production from the intermediate pyrolysis of sugarcane bagasse. The bio-oil yield increased continuously with an increase in T (320–520°C) and H (7.5–12.5°C/min) due to complete pyrolysis, while a decrease in bio-oil was noticed at a T (520–720°C) and H (22.5–27.5°C/min) due to secondary cracking such as thermal cracking, repolymerisation and recondensation that might enhance the yield of NCG and biochar. The optimum bio-oil yield (46.7 wt%) was achieved at a temperature, reaction time, heating rate, nitrogen flow rate, and particle size of 493.7°C, 15.5 min, 24.5°C/min, 225 cm3/min, and 0.1 mm, respectively. Results showed that the predicted data closely correlated with the experimental data (p < 0.05, R2 = 0.9891). Hence, the model is suitable and can accurately predict the experimental data. The presence of alkene, alcohol, and ester makes the bio-oil applicable for energy generation to power heavy equipment, ships, compressor, and boilers. Likewise, the presence of by-products such as oleic acids, methyl ester, 9,17-octadecdienal, and 9,12-octadecadienoyl chloride makes it suitable as fuel for high-speed diesel engines, powering heavy machines, vehicle locomotion, marine equipment, mining types of machinery, and manufacturing industries.

Computational Investigation of Combustion, Performance, and Emissions of a Diesel-Hydrogen Dual-Fuel Engine

This paper aims to expose the effect of hydrogen on the combustion, performance, and emissions of a high-speed diesel engine. For this purpose, a three-dimensional dynamic simulation model was developed using a reasonable turbulence model, and a simplified reaction kinetic mechanism was chosen based on experimental data. The results show that in the hydrogen enrichment conditions, hydrogen causes complete combustion of diesel fuel and results in a 17.7% increase in work capacity. However, the increase in combustion temperature resulted in higher NOx emissions. In the hydrogen substitution condition, the combustion phases are significantly earlier with the increased hydrogen substitution ratio (HSR), which is not conducive to power output. However, when the HSR is 30%, the CO, soot, and THC reach near-zero emissions. The effect of the injection timing is also studied at an HSR of 90%. When delayed by 10°, IMEP improves by 3.4% compared with diesel mode and 2.4% compared with dual-fuel mode. The NOx is reduced by 53% compared with the original dual-fuel mode. This study provides theoretical guidance for the application of hydrogen in rail transportation.

Экспериментальная проверка способа выравнивания мощностей цилиндров многоцилиндрового дизеля

Purpose: The purpose of the present work is to test experimentally equalization method for the outputs of multi-cylinder diesel engine cylinders basing on energy minimization of amplitude spectrum low-frequency band for diesel crankshaft instantaneous angular speed signal. Methods: The work uses the methods of digital signal processing, spectral analysis, differential calculus, multidimensional undifferentiated function optimization, experimental results processing. Results: The fulfilled experimental studies at bench diesel generator device as a part of locomotive diesel D50 (6CHN31.8/33) and traction generator MPT 84/39 ensure the possibility to use proposed earlier method for power equalization for the cylinders of multi-cylinder diesel engine basing on energy control of amplitude spectrum low-frequency band of crankshaft instantaneous angular speed signal. Unrvenness index for cylinder power is proposed, its sensitivity to cyclic supply change and the advance angle of fuel supply to diesel engine individual cylinders is estimated. Practical significance: The possibility to apply being proposed equalization method for the powers of multi-cylinder diesel engine cylinders for to adjust fuel equipment after diesel engine repair as with the systems of electronic fuel supply control as well as with hydromechanical fuel equipment has been confirmed experimentally. The use of given method eliminates the need to measure the temperature of exhaust gases and flash pressure in cylinders for fuel equipment adjustment that’s especially important for high-speed diesel engines which cylinder cover construction doesn’t imply indicated valves.

Optimization of Miller Cycle, EGR, and VNT on Performance and NOx Emission of a Diesel Engine for Range Extender at High Altitude

Due to the increasing sales of extended-range hybrid vehicles and the increasingly stringent emission regulations for light vehicles in China, the performance and emission of diesel engines for range extenders in the plateau region have attracted increasing attention. In order to obtain the superior performance of diesel engines for range extenders operating at high altitudes, a multi-objective optimization of the optimal economic operating point of the diesel engine was performed at an altitude of 1960 m. A diesel engine system model with MC-EGR-VNT (MEV) technology was developed using GT-Power based on the data of the engine bench to analyze the effects of the Miller cycle (MC), exhaust gas recirculation (EGR), and variable nozzle turbine (VNT) technologies on the power, economy, and emission performance of high-speed diesel engines. The response surface method (RSM) design was carried out with the Miller cycle rate (MCR), EGR value opening, VNT nozzle opening as variable factors and torque, brake-specific fuel consumption (BFSC), nitrogen oxide (NOx) emission as optimization objectives based on Box Behnken Design (BBD). The optimization results showed that the torque and BFSC remained almost constant, and NOx emission decreased by 59.5% compared with the original machine. The proposed multi-objective optimization method could make the diesel engine with a MEV system achieve a good comprehensive performance.