Internal Combustion Engine System Research Articles

Experimental Testing of Filter Materials for Two-Stage Inlet Air Systems of Internal Combustion Engines

Experimental Testing of Filter Materials for Two-Stage Inlet Air Systems of Internal Combustion Engines

Novel virtual sensors development based on machine learning combined with convolutional neural-network image processing-translation for feedback control systems of internal combustion engines

Physical sensors are commonly used to record performance data of internal combustion engines (ICEs) for online feedback control and calibration, but they are prone to diagnostic and increased development costs. Lookup tables are commonly used in conventional calibration and feedback control; however, the table parameters increase with the advancement of ICE technologies under transient operations. Consequently, the calibration and control systems are time-consuming. This work proposes novel virtual sensors to address these issues by predicting the combustion, performance, and emission of ICEs using neural networks and image processing/translation. The novel sensors are targeted for onboard feedback control systems under transient driving. Firstly, a virtual diesel engine (VDE) was developed and calibrated against experimental data taken from a production 2.2 L turbocharged diesel engine. The VDE was calibrated under WLTC, JC08, and NEDC transient operations and was used to generate teaching data. Next, the virtual sensors are developed using five machine learning (ML) regressors. The result shows that the coefficient of determination R2 from all ML regressors exceeded 0.94, and the XG-Boost outperforms other ML techniques with R2 > 0.977. XG-Boost parameter estimations were 8 times faster than that on a desktop simulation. Then, an image classification model using a deep convolutional neural network (D-CNN) is constructed, and the dependency of performance parameters and exhaust emissions with the rate of heat release (R.H.R) and in-cylinder pressure profile is confirmed. The performance parameters and emissions dependency was compared individually with R.H.R. and the in-cylinder pressure profile. As a result, a strong correlation between the performance and R.H.R. was observed. Finally, a generative adversarial network (GAN) model was constructed to translate the in-cylinder pressure profile to R.H.R. profile. A novel method to develop virtual sensors for advanced feedback control of any type of ICEs is proposed for the first time.

Structural and Material Analysis of an Electromagnetic Actuator for Pressure Control in an Internal Combustion Engine

The article describes the process of selecting the design parameters of the electromagnetic actuator, which was used to regulate the compression pressure in the cylinder of an internal combustion engine. The electromagnetic actuator was installed in the timing system of a single-cylinder internal combustion engine, which forced its basic design parameters in terms of force and frequency of operation. For the electromagnetic actuator in question, field calculations of the esign variants of the linear electromagnetic actuator for two types of materials were conducted. The finite element method was applied to the computer-aided design of electromagnetic actuators. The influence of the magnetic circuit and the dimensions of the windings on the distribution of the magnetic field were analyzed. The thickness and height of the magnetic field induces, and the dimensions of the stator poles have been changed while maintaining the same external dimensions of the actuator for design reasons. All this work was aimed at improving the performance of the internal combustion engine in terms of improving efficiency in terms of partial engine loads. In this area, the internal combustion engine is characterized by low efficiency, significantly deviating from the maximum, and at the same time, during normal operation of vehicles is the area most often exploited.

Die Design and Forging Analysis of Piston Connecting Rod of Aluminum Alloy

The piston connecting rod is an indispensable in the internal structure of the automobile. As one of the important components in the internal combustion engine system, the piston connecting rod needs to meet the requirements of high fatigue and impact load resistance. Forged piston connecting rod can obtain high strength and fatigue resistance. In this study, the parting line, draft angle, forging tolerance, die fillet radius, shrinkage and scrap are considered in the design of forging die. The process parameters and die dimensions of the forging process of aluminum alloy piston rod are simulated by finite element analysis. The aluminum alloy piston rod with high dimensional accuracy is then forged according to the finite element simulation results.

Development of thermoelectric exhaust energy recovery system of a hydrogen internal combustion engine in a city bus using a Three-Dimensional multiphysics model

In this study, individual thermoelectric generator (TEG) module was developed and validated through comprehensive analyses and experiments. A model of the TEG module was constructed and subsequently verified through a coherent alignment with experimental results, ensuring its viability and accuracy within the application of interest. A thermoelectric exhaust energy recovery (TEER) system designed with a robust rectangular structure was also developed for an urban mass transit bus, which operates using a hydrogen internal combustion engine. By accommodating 40 TEG modules, each complemented with cooling fins, and placing cooling channels at the top and bottom of the exhaust channel, it was demonstrated that a proportionality between the power output and load resistance of the TEER system through a dimensionless analysis. The system’s three-dimensional multiphysics model constructed concurrently with the actual system facilitated both optimization and validation, predicting an energy recovery of 1.0–1.1% from the hydrogen engine exhaust and an optimal load resistance of 3.2 Ω under various operating conditions.

Analysis of Noise Level with Convergent and Divergent Shape of Muffler and its Impact on Noise Pollution

Noise pollution is one of the key hazards that decreases people's quality of life globally. Due to the rapid development of technology, industrialization, urbanization, and transportation networks, noise pollution has reached serious levels in recent years. Sound transmission loss, the attenuation of sound as it passes through diverse objects and environments, is crucial in lowering noise pollution and preserving the acoustic integrity of ecosystems. Due to de-throttling tactics implemented to optimize cylinder fill, the intake system of internal combustion engines is the primary noise source while the vehicle is at low speeds and high loads. Therefore, achieving high acoustic performance of intake systems constitutes a critical issue in complying with the increasingly stringent European regulations for overall noise emission. The Transmission Loss computation is typically the most used technique for describing a system's acoustic performances. This work provided an overview of sound transmission loss and discussed its substantial environmental effects. It investigates the fundamentals of sound transmission, the factors that influence it, and the environmental impacts of sound attenuation. This paper proposed a comparison of three designs like straight duct (muffler), convergent and divergent design of muffler. The main aim is to observe sound transmission loss and compare the noise level with three muffler configurations with the same gas volume. High transmission loss indicates more noise reduction in muffler design, which will help reduce environmental noise pollution.

Analysis of the Sum Minimization Possibilities of Heat Exchanger Core Masses in Internal Combustion Engine Cooling Systems

Rational designs for cooling systems (CS) of internal combustion engines are formulated in the form of a series of circulation circuits. The engine is integrated into a circuit with the highest and unregulated flow of internal circuit coolant (ICC). All heat exchangers are placed in circulation circuits with relatively reduced and adjustable ICC flow rates. While the circuits are usually interconnected, they can also be designed to operate independently. This CS scheme enables the achievement of the minimum possible value of the sum of masses of exchanger cores, denoted as MΣ. The reduction in MΣ is achieved through the regulation of ICC flow in a closed circulation loop involving two heat exchangers. The variations in MΣ based on the circuit parameters have been thoroughly investigated. The reduction in MΣ can also be applicable to more intricate systems. A decrease in MΣ, under identical initial CS parameters, may occur in different magnitudes, depending on the specific features of the CS scheme and the operating conditions of the heat exchangers within it. Cooling systems, constructed with the same initial parameters and comprising multiple circulation circuits that meet all criteria for rational design, may exhibit diverse configurations. Examples of such systems are explored, and the minimum values of MΣ are calculated for each. It has been determined that the disparity in the minimum values of MΣ for such systems, while maintaining equal efficiency, can exceed 30%. The selection of the optimal CS scheme is contingent not only on achieving the minimum possible value of MΣ but also on various other factors.

Efficiency of limiting nitrogen oxides emissions by exhaust gas recirculation systems of marine internal combustion engines

The subject of this study is systems for ensuring environmental safety of marine internal combustion engines, in particular, technologies for limiting emissions of nitrogen oxides (NOx). The regulatory requirements for reducing emissions are presented in the paper. The main theoretical aspects of the problem of nitrogen oxides formation during combustion in a diesel engine are considered. On the basis of these theoretical aspects the effectiveness of using various methods to achieve the requirements for the permissible level of NOx concentration in the exhaust gases is assessed. Exhaust gas recirculation (EGR) systems and selective catalytic reduction (SCR) systems are considered as the main technologies; they allow achieving the highest indicators of nitrogen oxide emissions control in accordance with the requirements of the Tier 3 standard. Taking into account the peculiarities of the requirements for the design and layout of systems as part of a ship power plant, as well as operational and investment costs, the main attention in the work is paid to systems of indirect influence on the engine in-cylinder processes, which include exhaust gas recirculation systems. Based on the comparison of high and low pressure EGR, the advantages and disadvantages of the designs are determined. It is noted that high-pressure exhaust gas recirculation systems have a number of advantages, which primarily include the compactness and high speed of the system response to changes in operational conditions. On the example of the leading manufacturers developments, the potential capabilities of the high-pressure EGR system and the engine characteristics confirming the effectiveness of its use are demonstrated. Based on the results of the work, a conclusion about the high efficiency and expediency of using exhaust gas recirculation systems to meet the requirements of the current environmental safety standards of ship power plants is made.

A comprehensive assessment of the hybrid power generation system of PEMFC and internal combustion engine based on ammonia decomposition

This study presents a hybrid power generation system that combines a proton exchange membrane fuel cell (PEMFC) and an internal combustion engine (ICE), utilizing ammonia decomposition as the primary fuel source. The system comprises various components, including an ammonia decomposition subsystem, PEMFC, ICE, heat exchanger, solenoid valve, and power electronic converter. The research focuses on evaluating the system's performance by analyzing the impact of key thermodynamic parameters, such as decomposition temperature and separation ratio, as well as economic factors like ammonia and hydrogen prices, and service life. The findings reveal that the hybrid power generation system achieves a maximum output power of 16.23 kW and an efficiency of 50.28 %. Furthermore, it is observed that when the power ratio (α) between PEMFC and ICE is set to 1.2, the system achieves optimal electric power output. The levelized cost of energy (LCOE) for the system is calculated to be 0.0774 $ kWh−1 when the ammonia price is 0.35 $ kg−1. Additionally, the system exhibits a significant reduction in greenhouse gas (GHG) emissions, with an estimated decrease of 4.39 × 107 g. The hybrid power generation system has excellent thermodynamic, economic, and environmental performance, which lays a foundation for promoting the spread of high efficiency and zero pollution distributed hybrid power generation system.

Use of iron in oil concentration sensor for continuous monitoring of marine diesel engine technical condition

The article examines the features of the general problem of reliability, accuracy and durability of machines, mechanisms and devices, namely, the issue of friction, lubricating action, wear of the surfaces of parts and working bodies, which exist among themselves in very complex correlational dependencies. An approach to increasing the reliability of a ship's diesel engine is proposed, which requires the development of effective calculation methods and models for predicting the durability and wear resistance of materials of parts in friction nodes at the limit of lubrication in a wide range of changes in operating conditions and taking into account the variable modes of operation of a ship's diesel engine. The article considers the general approach and specific features of the construction of the components of the diagnostic system of the ship's internal combustion engine. Based on the selected volume of tasks solved by the diagnostic system, the sequence of functioning of its elements is determined. The implementation of this algorithm can have a significant effect in the complex use of diagnostic information together with statistical information stored individually for each mechanism, when managing its technical condition. On the basis of the proposed diagnostic model, it is possible to recognize the technical condition of marine diesel engines based on tribomonitoring data, detecting changes in friction conditions and an increase in the rate of wear of parts of the cylinder-piston group. This will enable the initiation of preventive corrective actions aimed at ensuring the reliable and safe operation of marine engines

Experimental Investigation on Gasoline—Water Mixture Fuel Impingement Preparation Method and Spray Characteristics with High Injection Temperatures and Pressures

Gasoline–water mixed injections are of great interest because of their advantages for reduced manufacturing costs and improved atomization, with the potential to alleviate engine detonation and reduce emissions. In this work, based on the principle of impinging flow, a real-time gasoline–water mixture preparation system for internal combustion engines was designed and the preparation system performance was compared with the standard swirl mixing technique. An image processing method was established to quantify the uniformity of the prepared mixture. Based on the flash-boiling spray flash-boiling spray experiment, the spray characteristics of different gasoline–water mixtures were analyzed under different injection temperatures (30–160 °C) and pressures (5–15 MPa). The experiments showed that the impinging pressure was the main factor affecting the emulsification performance of the real-time gasoline–water mixture, and that the proposed real-time mixing system could produce a stable gasoline–water emulsion. For temperatures in the 30–160 °C range, the flash-boiling spray flash-boiling spray experiments showed that the spray penetration distance first decreases and then increases with the injection temperature, while the spray angle shows an opposite trend. The turning point corresponded to the flash-boiling point of each gasoline–water mixture.

Fuel systems of high power stationary engine

The use of alternative fuels and, in the future, synthetic fuels has forced changes in the design of fuel supply systems in internal combustion engines. When operating a stationary engine at constant load, the possibility of using lean fuel mixtures appears. Selection of a precisely operating mixture ignition system requires changes in traditional fuel systems. The article presents the current designs of fuel supply systems and their properties. Attention was paid to operating parameters resulting in acceptable emissions of toxic exhaust gas components. Control systems that make the operation of the fuel system dependent on the properties of fuels are being developed.

Simulations of ammonia spray evaporation, cooling, mixture formation and combustion in a direct injection compression ignition engine

This study investigates the novel approach of direct liquid ammonia injection into the combustion chamber of a compression ignition engine. Unlike traditional gaseous ammonia port injection, this method shows promise in reducing ammonia slip and emissions. To simulate and analyze the behavior of the liquid ammonia spray, we employed numerical models based on existing literature on flashing and non-flashing spray simulations, as well as recent experimental studies on ammonia spray characteristics using a gasoline direct injection (GDI) injector. Our approach utilized a Lagrangian discrete phase modelling technique to perform a series of three-dimensional computational fluid dynamics (CFD) simulations. The primary objectives of this research were to evaluate the evaporation process of ammonia and its cooling effect, as well as to gain insights into mixture formation within the engine cylinder under different operating conditions. The simulations encompassed the entire engine cycle, considering a multi-hole GDI ammonia spray in conjunction with pilot n-heptane, a diesel surrogate, in equal proportions on an energy basis. Three distinct injection timings for ammonia were examined, leading to varying thermodynamic conditions within the combustion chamber during each spray formation. Consequently, different modelling parameters and initial conditions were necessary to accurately replicate the spray behavior. To address this, we proposed a systematic procedure for assigning pre-defined spray angles. The non-reacting, evaporating spray simulations yielded valuable insights into the mixture formation process, which guided our analysis. Finally, reacting conditions were considered to evaluate engine performance and resulting exhaust gas emissions. This study provides a comprehensive overview of critical aspects related to direct ammonia injection in internal combustion engine (ICE) systems. Moreover, it uncovers performance trends that can serve as a foundation for future investigations in this field.

Multiobjective optimization of a hybrid electricity generation system based on waste energy of internal combustion engine and solar system for sustainable environment

In recent years, the interest in generating power through hybrid power generation systems has increased. In this study, a hybrid power generation system including an internal combustion engine (ICE) and a solar system based on flat plate collectors to generate electricity is investigated. To benefit from the thermal energy absorbed by solar collectors, an organic Rankine cycle (ORC) is considered. In addition to the solar energy absorbed by the collectors, the heat source of the ORC is the wasted heat through exhaust gases and the cooling system of the ICE. A two-pressure configuration for ORC is proposed for optimal heat absorption from the three available heat sources. The proposed system is installed to produce power with a capacity of 10 kW. A bi-objective function optimization process is carried out to design this system. The objective of the optimization process is to minimize the total cost rate and maximize the exergy efficiency of the system. The design variables of the present problem include the ICE rated power, the number of solar flat plate collectors (SFPC), the pressure of the high-pressure (HP) and low-pressure (LP) stage of the ORC, the degree of superheating of the HP and LP stage of the ORC, and its condenser pressure. Finally, it is observed among the design variables the most impact on total cost and exergy efficiency is related to the ICE rated power and the number of SFPCs.

Modeling and Optimization of Natural Gas CCHP System in the Severe Cold Region

A natural gas combined cooling, heating, and power (CCHP) system is a typical integrated energy supply method that optimizes end−use energy. However, how to achieve economically feasible natural gas CCHP in severe cold regions with low−grade heat demand reaching 50% is still a pressing issue. This paper establishes a typical natural gas CCHP system model for severe cold regions and conducts the system. Based on the climate conditions of Harbin, the economic optimization of independent gas turbine systems, internal combustion engines, and gas turbine systems is still a pressing issue. Based on the climate conditions of Harbin, the economic optimization of independent gas turbine systems, internal combustion engine systems, and steam boiler systems under different cooling and heating load ratios was carried out. The combination of “internal combustion engine + steam boiler” has the most optimal cost of RMB 1.766 million (USD 0.255 million), saving 10.7%, 7.8%, and 18.3% compared to the three single equipment subsystems respectively. This provides good theoretical support for the construction of multi−energy heterogeneous energy systems.

Assessment of a methanol-fueled integrated hybrid power system of solid oxide fuel cell and low-speed two-stroke engine for maritime application

An integrated solid oxide fuel cell (SOFC)-internal combustion engine (ICE) system was proposed in this paper. Methanol was used as the fuel in the system, meaning that the SOFC exhaust gas could not enter the engine with methanol, due to the high-injection pressure of fuel in engine and difficulty of pressurizing SOFC exhaust gas. Therefore, this paper proposed SOFC exhaust gas was delivered with engine intake air to achieve waste gas reutilization, which could also reduce oxygen concentration and increase specific heat capacity of in-cylinder gas for low NOx emissions. Two modes were proposed, including delivering SOFC anode-off gas into engine for Tier II requirements and delivering SOFC cathode and anode off gas into engine for Tier III requirements. The effects of power ratio of SOFC and engine on proposed system were analyzed based on the electrochemical model of SOFC and filling and emptying model of engine. The results indicated that increasing the power ratio in both modes led to an increase in brake power but a decrease in indicated efficiency, mainly due to the increase in energy input and the decrease in exergy-to-power conversion efficiency. In addition, at Tier III mode, the Tier III requirements (weighted average NOx was 3.35 g/kWh) were met at power ratio of around 1:2, at which the energy and exergy efficiency of system reached 55.6% and 57.9%. Furthermore, an improvement for a tanker was proposed, substituting proposed system for combination of marine engine and diesel genset. Specifically, SOFC and ICE were used for auxiliary power unit and propulsion, respectively. The results showed that it could achieve better carbon-emission and techno-economic performances. The payment period of such improvement was 3.08 years taking carbon trading and government support into account.

Analysis of the combustion engine exhaust system structure in aspect of shaping acoustic energy

The flow of exhaust gases is the source of many physical processes, including thermal, acoustic, mechanical and chemical phenomena with high dynamics of changes. The study analyzes the impact of the entire structure of the exhaust system on the formation of acoustic energy, determining the transmission loss characteristics of its individual components and the entire system. On the example of a structure based on a proprietary solution of an adjustable reactive muffler, the possibilities of shaping the flow of acoustic waves in the process of designing and selecting exhaust systems for internal combustion engines were determined. The study was carried out with the use of the CFD method and a specialized package for advanced simulations AVL AST.

Experimental determination on cleaning the exhaust gas of an automobile muffler by an electric pulse

Nowadays, creating an environmentally reliable car by reducing the volume of harmful gases in it is a global problem of mankind. For this reason, one of the main areas of research is to improve the exhaust gas cleaning system of internal combustion engines. However, to date, there are no universal designs that would improve the performance of the purification system. In this regard, the development of new vehicle exhaust system designs based on an effective cleaning method is an urgent task. The article highlights the results of scientific and experimental research of the authors on the development of new designs of automobile exhaust muffler working on the basis of the method of electro-pulsed cleaning, designed to reduce the concentration of harmful exhaust gases. The developed experimental installation of the electric-pulse muffler performs gas purification by feeding an electric shock discharge to the electrodes installed in the muffler. The experimental data obtained show changes in the gas transparency depending on changes in the distance between the electrodes. Regression-correlation analysis established empirical dependences of gas transparency values on changes in the distance between the electrodes.

CFD Investigation of an Innovative Additive Manufactured POCS Substrate as Electrical Heated Solution for After-Treatment Systems

In the last decade, additive manufacturing (AM) techniques have been progressively applied to the manufacturing of many mechanical components. Compared to traditional techniques, this technology is characterized by disruptive potential in terms of the complexity of the objects that can be produced. This opens new frontiers in terms of design flexibility, making it possible to create new components with optimized performances in terms of mechanical properties and weight. In this work, the focus is on a specific field of application: the development of novel porous media structures which can be the basis of advanced after-treatment systems for internal combustion engines. In particular, the possibility to design periodic open cellular structures (POCSs) that can be applied as catalytic substrates opens new perspectives in terms of flexibility and integrated functionalities. The present study investigates an innovative solution where the catalytic substrates are located in the pipes of the exhaust manifolds of a high-performance engine. A preliminary characterization of the pressure drop induced by the POCS structure is carried out, with a particular focus on the impact of the backpressure on the engine performances. Moreover, each POCS integrates an electrical circuit which is used to promote the heating of the device, with beneficial effects on the light-off of the catalytic reactions. An advanced CFD model is applied to evaluate the potential of the solution, comparing the pollutant conversion with that of the baseline configuration equipped with a standard after-treatment system solution.

РАСЧЕТ БАРИЧЕСКИХ КОЭФФИЦИЕНТОВ ТЕПЛОПРОВОДНОСТИ СМЕШАННЫХ РАСТВОРОВ ЭЛЕКТРОЛИТОВ

In the paper presents the calculated optimal values of the baric thermal conductivity coefficients corresponding
 to the minimum of the quadratic functional in comparison with the baric dependences of aqueous solutions of
 ethylene glycol and electrolytes in the cooling systems of marine internal combustion engines. For the pressure
 dependences of electrolyte solutions, an equation was obtained that makes it possible to calculate the thermal
 conductivity of mixed solutions at any pressure with an average error of 1.2%. Scientific interest lies in the
 study of the nature of the dependence of the baric coefficients of thermal conductivity of mixed electrolyte
 solutions on temperature when using the latter along with ethylene glycol coolants