Engine Combustion System Research Articles

Experimental study of the tribological characteristics of a honed cylinder liner during the running-in process

Abstract. The tribological properties of the cylinder liner are of great significance in reducing energy loss from an internal combustion engine's system. In order to improve the antiwear performance of the cylinder liner at top dead center (TDC), the friction and wear of the honed cylinder liner during the running-in process are investigated. Using a UMT TriboLab multifunction friction wear tester, the coefficients of friction (COFs) are analyzed under different lubrication conditions and loads, and the surface roughness and profile of the cylinder liner are obtained using a three-dimensional (3D) laser scanning confocal microscope (LSCM). The COF, roughness and surface profile are compared in order to investigate the variation in tribology parameters under different operating conditions. To monitor the COF in real time, it is predicted using the polynomial fitting method. It is shown that the COF decreases with an increase in the lubrication oil and load and that the surface profile more easily becomes smooth under dry (lubrication) conditions; this can effectively shorten the operation time during the running-in process. The polynomial fitting method can achieve an assessment of the COF with a very small standard error.

Reduction of lubricant life in lubrication systems for internal combustion engines due to high lubricant supply rates

The lubrication systems of internal combustion engines are not designed to avoid excessive oil consumption; therefore, the oil supply rate to the interior of the engine falls between two critical limits: ensuring the formation of a tribofilm that prevents engine wear and lowers high friction. However, it disregards the excessive depletion of the lubricating precursors that make up this protective tribofilm. In this work, the life of oil in lubrication systems for internal combustion engines is analyzed by means of simulations of the mass balances of the protective tribofilm formed inside the engine; results indicate that high lubricant supply rates cause early depletion of lubricant precursors, shortening the life of each batch of oil.

Genetic Optimization for Engine Combustion System Calibration: A Case Study of Optimization Performance Sensitivity to Algorithm Search Parameters

Abstract The use of genetic optimization algorithms (GOA) has been shown to significantly reduce the resource intensity of engine calibration, motivating investigation into the development of these methods. The objective of this work was to quantify the sensitivity of GOA performance to the algorithm search parameter values, in a case study of engine calibration. A GOA was used to calibrate four combustion system control parameters for a direct-injection gasoline engine at a single operating condition, with an optimization goal to minimize brake-specific fuel consumption (BSFC) for a specified engine-out NOx concentration limit. The calibration process was repeated for two NOx limit values and a wide range of values for five GOA search parameters, including the number of genes, mutation rate, and convergence criteria. Results indicated GOA performance is very sensitive to algorithm search parameter values, with converged calibrations yielding BSFC values from 1 to 14% higher than the global minimum value and the number of iterations required to converge ranging from 10 to 3000. Broadly, GOA performance sensitivity was found to increase as the NOx limit was decreased from 4500 to 1000 ppm. GOA performance was the most sensitive to the number of genes and the gene mutation rate, whereas sensitivity to convergence criteria values was minimal. Identification of one set of algorithm search parameter values which universally maximized GOA performance was not possible as ideal values depended strongly on engine behavior, NOx limit, and the maximum level of error acceptable to the user.

Rational Liquid Cooling Systems of Internal Combustion Engines

Rational Liquid Cooling Systems of Internal Combustion Engines

Improvement of a Heavy-Duty Natural Gas Engine's Combustion System: Cfd Modeling and Experimental Research

Improvement of a Heavy-Duty Natural Gas Engine's Combustion System: Cfd Modeling and Experimental Research

Combined heat and power production based on sewage sludge gasification: An energy-efficient solution for wastewater treatment plants

• Energy recovery from sewage sludge through gasification is analysed. • Different solutions for combined heat and power production are assessed. • The analysis is applied to the case study of a real wastewater treatment plant. • A feasibility analysis of the proposed system is carried out. • The system appears to be economically and environmentally feasible. The main operating costs of wastewater treatment plants are related to the energy consumption and the disposal of by-products. Energy recovery from sewage sludge may be a solution to face both these challenges, improving the sustainability of wastewater treatment plants and making them an example of a circular economy. In this work, the energy and economic analysis of an integrated combined heat and power system based on sewage sludge gasification is proposed. The whole process is simulated by using the commercial software Aspen Plus®. A restricted equilibrium model is used to simulate the gasification of sewage sludge in an atmospheric fluidized bed reactor using air as a gasification agent. Syngas produced from gasification is used as a fuel in an internal combustion engine for combined heat and power production. Different solutions are compared: the internal combustion engine is supposed to be fuelled with syngas or with syngas and methane. In line with the pertinent literature on integrated biomass gasification–internal combustion engine systems, the engine is modeled by combining a compressor, a combustor and a turbine to simulate the four thermodynamic steps of an internal combustion engine. Electric and thermal energy produced by the system is used to supply a fraction of the demand for wastewater and sludge treatment. The energy analysis is carried out for a real wastewater treatment plant that serves 1.2 million of population equivalent, located in Southern Italy. The obtained results are used to carry out an energy and economic analysis, which aims at assessing the feasibility and environmental benefits of the proposed system over conventional technologies.

Improving the Efficiency of HEV Electronic Applications Using CAN-BUS Communication

A new energy management technique with aid of Controller Area Network (CAN) bus for hybrid electric vehicle (HEV) is proposed in this research. HEV is a type of hybrid vehicle that combines with an electric propulsion system a conventional internal combustion engine system. The electric powertrain operation is intended to achieve greater fuel economy than a conventional vehicle. To accurately distribute power from one of the battery sources, the Energy Management System determines the reference speed for the electric motor drive and the internal combustion engine. The Proportional and Integral (PI) controller is used to maximize the gain of the primary and secondary controllers for maximum overshoot and resolution time. By optimizing the value, using the Naked Mole Rat optimization technique, the efficiency is improved. The CAN bus is a multi-master communication protocol characterized by the deterministic resolution, high efficiency and simple implementation. We introduce a secure technology that helps to automotive CAN protocol which is often used in HEV networks. The simulation results show that the proposed approach achieves an increased efficiency of 97%.

Conversion of Sewage Sludge to combined heat and power: Modeling and optimization

Combined Heat and Power (CHP) generation from Sewage Sludge (SS) offers two simultaneous advantages: greenhouse gas emission reduction and increase of renewable energy generation as promoted by the European Union Green Deal 2021. In this work, a numerical model has been developed via Aspen Plus for the evaluation of CHP generation potentiality from SS through gasification integrated with an internal combustion engine system. The model is applied to the case of Italy and eight other European countries for the first time. The gasification model has been developed based on the experimental data on syngas generation from SS in a bench-scale rotary kiln reactor under laboratory conditions available in the literature. Sensitivity analysis revealed optimal operating temperature and equivalence ratios for gasification were 900 °C and 0.2 respectively. The CHP generation potentiality of SS resulted to be 2.73 kWh per kg SS as dry solid.According to the statistical analysis used in the present study, SS generation will reach 680 kt per year as dry solid by 2030 based on the current sludge generation rate as well as improvement in the wastewater collection and treatment expected for the future in Italy. Within this time, the projected electrical and thermal energy generation rate per year can reach 714 GWh and 1142 GWh respectively. Electrical and thermal energy generation rates from sewage sludge have been estimated for eight EU countries in 2015 and compared with the Italian scenario, founding the highest one in Spain and the lowest in Luxembourg.

Применение прецизионных хронометрических технологий для мониторинга отклонений в работе двигателей внутреннего сгорания

The article considers the main methods of internal combustion engine diagnostics. A method based on measuring the time intervals between the phases of the working cycle of the mechanism is described. An algorithm for measuring the time intervals from the formulation of the problem to the proof of the efficiency of this method on an internal combustion engine has been determined. The installation of the angle sensor on the crankshaft of the experimental bench engine VAZ 21126 is shown. The basis for the construction of a mathematical model of the crankshaft is presented and the main factors influencing its movement are identified. A criterion has been established according to which the misfire is determined most accurately. The results obtained can be used for developing diagnostic systems for internal combustion engines, as well as engines operating in extreme conditions, for example, beyond the Arctic Circle, on ships, etc.

Investigations to characterize the interactions of light radiation, engine operating media and fluorescence tracers for the use of qualitative light-induced fluorescence in engine systems

The light-induced fluorescence (LIF) represents an important tool for the continuous improvement and further development of combustion engine systems regarding efficiency increase. In this work, the interactions between light-emitting diode (LED) and laser diode light radiation, engine oil/fuel and three fluorescence tracers are investigated on an application-related investigation system for the design of qualitative LIF experiments. Thereby two efficient light sources for engine combustion chamber lighting are presented. For different engine oil/fuel tracer combinations, the fluorescence is examined in its intensity and its spectrum depending on the temperature, concentration and temperature history. With oil temperature variations of up to 150 °C, changes in the fluorescence spectrum and fluorescence intensities that decrease by up to 80% are evident. For specific tracer oil/fuel mixtures, concentration-dependent maximum intensities and different temperature history behaviors can be revealed. The results shown support the design of spectral engine examination setups and give tracer dosage recommendations. Additionally, an engine LIF setup for in-cylinder tracking of engine operating media is presented.

Multi criteria decision-making for distributed energy system based on multi-source heterogeneous data

The distributed energy system (DES) has been regarded as a socio-technical innovation that can improve energy efficiency and reduce carbon emission. Based on the construction and planning of a DES project in Henan Province, this paper aims to develop a comprehensive decision-making framework for selecting the most appropriate DES composition schemes with multi-source heterogeneous data. Thus, a new multi-criteria decision-making method based on fuzzy preference relations and improved Choquet integral is generated. Firstly, an evaluation criteria system is established from economic, technical, environmental and social dimensions, and 10 secondary criteria are presented. Secondly, based on the interval fuzzy preference relations of criteria given by experts, the iteration of weights of criteria is continued until the group consistency degree reaches the threshold. Thirdly, the deviation degree is used to transform the initial data, which include crisp values, interval numbers and linguistic terms to isomorphism data. Thereafter, the fuzzy measures are calculated using Mobius transformation coefficients and the final scores of the alternatives are obtained by means of Choquet integral, which can eliminate the overlap information between criteria. Finally, a real case is given to illustrate the effectiveness of the proposed evaluation criteria and technique. The result shows the multi energy complementary system as the most appropriate alternative for the project, followed by the solar-air source heat pump system, fuel cell system, natural gas system, internal combustion engine system and traditional system. Conclusively, the discussion, comparative analysis and some policy implications to promote the development of distributed energy industry are given. This study not only can assist stakeholders to obtain greater benefits of the DES, but also can serve as a reference for the government towards the development of more robust regulations and policies.

Car exhaust waste heat recovery using hexagon shaped thermoelectric generator

Heat recovery technology using thermoelectric has attracted many research intentions mainly for its ability to generate power passively. The automotive engine usually produces waste heat ranging from 30-40% due to the thermodynamic limit. The use of thermoelectric generator (TEG) for waste heat recovery and power generation could increase the efficiency of the internal combustion engine system. This research developed and investigated a heat recovery system using a thermoelectric generator (TEG) for power generation. A thermoelectric generator (TEG) consisted of thermoelectric modules, hexagonal pipe connector and heat sinks was built and connected to an exhaust pipeline. A theoretical model was developed to access the thermal and electrical performance of the TEG system. The theoretical model consisted of the heat transfer mechanism including the thermal resistance networks from the flue gas to TEG and the heat sink. The electrical power output was determined using the Seebeck principle. The early stage of finding reveals that the system was able to produce an open circuit voltage of 0.13 V for a small temperature gradient of 3ᵒC between the cold and hot surface of the TEG. The further improvement of the system is currently under investigation for producing higher power. In the future, this system hopefully could replace the car battery for charging the alternator as well as increasing the overall efficiency of the engine system.

STAND FOR RESEARCH PARAMETERS OF ELEMENTS OF LUBRICATION SYSTEMS OF HIGH-SPEED INTERNAL COMBUSTION ENGINES

The issues of studying the operating parameters of the elements of lubrication systems for high-speed internal combustion engines preceded the creation of the stand. The engine lubrication system D-246.4 was chosen as a prototype. With the help of this stand it became possible to study the lubrication system for the following characteristics: change the performance of the engine oil pump D-246.4, change and control the engine oil temperature, control the pressure drop on the oil filter, control the engine oil flow, throttle oil at the inlet to the oil pump and on the conditional supply line to the friction units, measuring the vacuum of the system on the suction of the oil pump and recording the parameters of the pulsation of the oil pressure generated by the oil pump. To build mathematical models of the components in the lubrication systems of marine internal combustion engines there is a need to determine their operating parameters. In real operating conditions, such measurements cannot be obtained due to the lack of the necessary test equipment (TE) and the possibility of its installation. The authors describe in detail all the components of the stand for studying the parameters of the elements of lubrication systems of high-speed internal combustion engines, their technical characteristics, describes the diagnostic complex, which recorded the results of research, the results of measuring engine oil pressure pulsation. The stand is used to study the operating parameters of the oil pump and filter used for water. Signals are registered using the Autoscanner diagnostic system. The diagnostic complex is a 64-channel oscilloscope that is connected to a personal computer. This stand for studying the operating parameters of the elements of the lubrication system provides sufficient opportunities to simulate the operating conditions of the elements of the supply and purification of oil and register them both visually and with digital sensors and diagnostic system Autoscanner, digital oscilloscopes or other measuring instruments capable of recording and storing the received data.

Overview of modern control systems for internal combustion engines

The article provides an overview of modern microprocessor control systems for internal combustion engines, which allow improving the entire complex of design, technological, environmental and operational characteristics of engines due to the wide possibilities of regulating the working process in each cycle of each cylinder. The directions of research and development on the creation of adaptive engines are considered. It is indicated that the main distinguishing feature of engines with a variable workflow of any design scheme is that these adaptability properties are achieved by increasing the number of controlled elements in comparison with existing engines. The article provides an overview of the controlled elements implemented in internal combustion transport engines and discusses the technical solutions that are used by well-known global companies in the field of marine medium-and high-speed engines. The directions in the field of improving computers that control engines are described.

Towards Ecological Alternatives in Bearing Lubrication

Hydrogen is the cleanest fuel available because its combustion product is water. The internal combustion engine can, in principle and without significant modifications, run on hydrogen to produce mechanical energy. Regarding the technological solution leading to compact engines, a question to ask is the following: Can combustion engine systems be lubricated with hydrogen? In general, since many applications such as in turbomachines, is it possible to use the surrounding gas as a lubricant? In this paper, journal bearings global parameters are calculated and compared for steady state and dynamic conditions for different gas constituents such as air, pentafluoropropane, helium and hydrogen. Such a bearing may be promising as an ecological alternative to liquid lubrication.

Feasibility and impact of a Swedish fuel cell-powered rescue boat

With the increasing interest for zero-emission vehicles, electric boats represent a growing area. Weight is a limiting factor for battery-powered boats, therefore, the use of fuel cell/battery systems is investigated. The present study examines the power requirements, the energy-storage solutions and the sustainability assessment of a light and fast rescue boat operating in the Swedish lake Barken. A weight-optimized hybrid fuel cell/battery system is presented. The results show that if the hydrogen storage is wisely selected, the weight of the hybrid system is significantly less than that of a battery system and can compete with an internal combustion engine system. The sustainability assessment highlights and compares the impact in terms of cost and emissions of the different energy storage solutions. The quantification of the emissions for the different energy systems under several scenarios shows a clear advantage for the electric solutions.

Editorial: Design and Application of Novel Combustion Systems for Internal Combustion Engines

Editorial: Design and Application of Novel Combustion Systems for Internal Combustion Engines

Determining threshold values of operating motor oils to diagnose internal combustion engines

Technical fluids (engine oil, antifreeze) have to meet their requirements during the standard operating life to ensure the standard service life of combustion engine systems and mechanisms. The stability of the engine oil during engine operation depends on many factors. Motor oil touches all the processes in the internal combustion engine and can serve as a source of diagnostic information, which will make it possible to carry out maintenance and repair of engine parts as needed, to increase the reliability and durability of the internal combustion engine. The results of the oil sample analysis for each indicator allow us to draw distribution density curves for the serviceable and faulty engine condition. Following the results of the analysis, it is necessary to compare the value of the index with its threshold values, separating the zone of operation condition from the zone of the engine faulty condition. Since the number of serviceable engines under operating conditions is always greater than the number of faulty ones, at the first stage of oil quality control, it is possible to determine the threshold values of indicators separating the zone of normal wear (engine serviceable condition) from the zone of increased wear. The research has resulted in an algorithm for calculating and determining the threshold values of motor oils for tractor engines operated on farms in the Omsk region. The authors selected the values based on two oil indicators: kinematic viscosity at 1000 C and flashpoint. The distribution and probability integral of these indicators are better smoothed out by the normal Gauss law. The researchers obtained the maximum and minimum values of indicators corresponding to the 5% boundary of the probability integral.

Design and Analysis of Exhaust System for Ultra-fuel Efficient Vehicles

Exhaust systems for Internal Combustion (I.C) engines have been finding their significance in the performance of an engine from its inception. One of the detrimental factors for the performance of exhaust is the amount of backpressure building through the flow. This study focuses on reducing backpressure occurring in the exhaust and increasing the ease of manufacturability for a 50 cm3 single cylinder Spark Ignition (S.I.) engine used in an ultra-fuel efficient vehicle. The flow of the exhaust gases from the engine are analyzed with the help of ram induction theory. Computational Fluid Dynamics has been employed to facilitate the study of turbulent flow in the exhaust and obtain results close to a streamlined flow. Parameters such as dimensions, operating pressures and velocities are calculated to understand the flow characteristics. The results strengthen the bilateral scopes of study here being, smooth flow of exhaust gases and greater manufacturability. The bend and end cone angles are defined in such a way that the wastage of material is least and complexity of the geometry is moderate. The exhaust has been designed keeping the chassis and engine complacency constraints in concern. The results of this study can be useful in manufacturing and integration with light gasoline engines, but of the same orientation as the one discussed here, for prototyping purposes.

Assessment of the starter motor system use powered by capacitive power sources on internal combustion engine

The main power source of modern electric start systems for internal combustion engines is an acid-lead battery. Existence chemical reactions, which occur in between battery electrolyte and lead plates may be causes problems with it exploitation. For a many reasons, its operation requires a lot of labor, especially in cold conditions. In this regard, it was proposed to use a capacitor system electric supply taking in view its discharge characteristics. Electrolytic capacitors and supercapacitors are sources of temporary charge storage and have optimal properties for their use in the engine start system as a partial displacement of the acid-lead battery, against the background of its some negative qualities. The article deals with the evaluation and comparison of the electric motor start system from capacitors and supercapacitors, as well as the possibility of their implementation on a mobile machine equipped with ICE.