Consumption Of Internal Combustion Engines Research Articles

Study of the influence of thermodynamic processes on the parameters of the technical condition of power plants

The article substantiates the need to consider the dependence of the external characteristics of transport power plants on the parameters of thermodynamic processes in the combustion chambers of heat engines. The results of theoretical and experimental studies are presented. They prove the influence of the technical condition on the thermodynamic parameters of diesel internal combustion engines. Expressions are presented that describe the thermodynamic processes of power plants from the point of view of the relationship between the mechanical and thermodynamic components of torque. It is shown that the temperature of the working surfaces of a diesel engine is an important characteristic of its technical condition. The results of experimental studies of the influence of the temperature of the cylinder liner wall, which determines the rate of evaporation of the oil film between the piston and the cylinder liner, on the amount of engine oil consumption for waste under various technical conditions of the diesel engine are presented. It has been shown that reducing engine temperature can help reduce oil consumption in internal combustion engines.

Combustion of Lean Methane/Propane Mixtures with an Active Prechamber Engine in Terms of Various Fuel Distribution

The possibilities for reducing the fuel consumption of internal combustion engines focus mainly on developing combustion systems, as one such solution is a two-stage combustion system using jet ignition. The combustion of gaseous mixtures with a high excess air ratio leads to an increase in overall efficiency and a reduction in the emissions of selected exhaust components. In such a convention, gas combustion studies were conducted in the methane/propane configuration. Using an active prechamber where spark plugs were placed and direct injection through a check valve, the fuel dose was minimized into the prechamber. The tests were conducted for a constant center of combustion (CoC). The combustion process in both the prechamber and main chamber was analyzed using a test stand equipped with a 0.5 dm3 single-cylinder engine. The engine was controlled by varying the fuel supply to the prechamber and main chamber in excess air ratio λ = 1.3–1.8. The study analyzed thermodynamic indices such as the combustion pressure in both chambers, based on which the SoC in both chambers, the rate and amount of heat released, AI05, AI90 and, consequently, the indicated efficiency were determined. Based on the results, it was found that the use of CH4/C3H8 combination degraded the thermodynamic indicators of combustion more than using only the base gas (methane). In addition, the stability of the engine’s operation was decreased. The advantage of using propane for the prechamber is to obtain more beneficial ecological indicators. For the single-fuel system, a maximum indicated efficiency of more than 40% was obtained, while with the use of propane for the prechamber, a maximum of 39.3% was achieved.

A Novel Active Cooling System for Internal Combustion Engine Using Shape Memory Alloy Based Thermostat.

Pollutants in exhaust gases and the high fuel consumption of internal combustion engines remain key issues in the automotive industry despite the emergence of electric vehicles. Engine overheating is a major cause of these problems. Traditionally, engine overheating was solved using electric pumps and cooling fans with electrically operated thermostats. This method can be applied using active cooling systems that are currently available on the market. However, the performance of this method is undermined by its delayed response time to activate the main valve of the thermostat and the dependence of the coolant flow direction control on the engine. This study proposes a novel active engine cooling system incorporating a shape memory alloy-based thermostat. After discussing the operating principles, the governing equations of motion were formulated and analyzed using COMSOL Multiphysics and MATLAB. The results show that the proposed method improved the response time required to change the coolant flow direction and led to a coolant temperature difference of 4.90 °C at 90 °C cooling conditions. This result indicates that the proposed system can be applied to existing internal combustion engines to enhance their performance in terms of reduced pollution and fuel consumption.

JUSTIFICATION OF THE PARAMETERS OF THE PASSENGER CAR SERIES HYBRID POWER PLAN

The use of hybrid power plants in road transport can significantly improve driving dynamics and driving comfort, reduce its operating fuel consumption and emissions of harmful substances with exhaust gases. Due to the large number of used cars with internal combustion engines (ICE) in Ukraine, it is of interest to convert them into a hybrid power drive. However, the analysis of the literature revealed extremely limited information about the work in this direction. The paper proposes a method for selecting the parameters of elements of a series hybrid power drive based on a used Chevrolet Lacetti car. The technique is based on the use of mathematical models of the working process of the internal combustion engine, the dynamics of the acceleration of the car, the determination of the parameters of the series hybrid power plant in the modes of the European NEDC test cycle. Using the developed mathematical models, the rated power of the traction electric motor is 86 kW, the nominal and maximum rotational speed of its shaft, respectively, are 1860 and 7000 min-1. It is shown that the car will accelerate to 100 km/h in 11.4 seconds, which fully satisfies the conditions of comfortable driving in urban conditions. As part of a hybrid power plant, the internal combustion engine operates in one mode. The paper substantiates the choice of the operating mode of the internal combustion engine, where it has the best fuel efficiency. At the same time, its power is 34 kW, and the crankshaft speed is 2200 min-1. Accordingly, the power of the current generator will be 30 kW at a shaft speed of 2200 min-1. The paper analyzes the influence of the battery capacity, the presence of braking energy recuperation, the operating range of battery capacity change on the average operating fuel consumption of internal combustion engines. It is shown that an increase in the battery capacity, the presence of recuperation, and the expansion of the operating range of changes in the battery capacity lead to an improvement in the operational fuel efficiency of an internal combustion engine. Based on the results of computational studies, the maximum battery capacity of 1.3 kWh was selected; the operating range of capacity change was 0.8 kWh. The use of elements with such parameters will ensure the average operating fuel consumption of the internal combustion engine is 6.5 l/100 km, and with the recovery of braking energy - 6 l/100 km.

Research on Ultra-High Viscosity Index Engine Oil: Part 2 - Influence of Engine Oil Evaporation Characteristics on Oil Consumption of Internal Combustion Engines

<div class="section abstract"><div class="htmlview paragraph">The reduction of CO<sub>2</sub> emissions is one of the most important challenges for the automotive industry to contribute to address global warming. Reducing friction of internal combustion engines (ICEs) is one effective countermeasure to realize this objective. The improvement of engine oil can contribute to reduce fuel consumption by reducing friction between engine parts.</div><div class="htmlview paragraph">Electrification of ICE powertrains increases the overall efficiency of powertrains and reduces the average engine oil temperature during vehicle operation, due to intermittent engine operation. An effective way of reducing engine friction is to lower the viscosity of the engine oil in the low to medium temperature range. This can be accomplished while maintaining viscosity at high temperatures by reducing the base oil viscosity and increasing the viscosity modifier (VM) content to raise the viscosity index (so-called “flat viscosity” concept). However, reducing the base oil viscosity increases volatility loss and may cause an increase in oil consumption as a trade-off effect.</div><div class="htmlview paragraph">ASTM D5800 (NOACK test) has been utilized as an industry standard test since the 1930s to measure the evaporative loss of engine oils related to evaporative oil consumption. However, some reports indicate that standard NOACK does not correlate well with actual engine oil consumption. A new evaporative index with better correlation is necessary for further engine oil technology development.</div><div class="htmlview paragraph">This study investigated which physical properties of engine oil can express the evaporation rate related to evaporative engine oil consumption in actual engines. As a result, a modified NOACK test at 150°C, which is in the temperature range of the cylinder bore, showed good correlation with evaporative oil consumption in actual engine operation. This modified NOACK test has potential as a new evaporative index to realize new concept oils with flat viscosity properties.</div></div>

Numerical Assessment of Tribological Performance of Different Low Viscosity Engine Oils in a 4-Stroke CI Light-Duty ICE

<div class="section abstract"><div class="htmlview paragraph">Decreasing fuel consumption in Internal Combustion Engines (ICE) is a key target for engine developers in order to achieve the CO<sub>2</sub> emissions limits during a standard cycle. In this context, reduction of engine friction could help meet those targets. The use of Low Viscosity Engine Oils (LVEOs), which is currently one of the avenues to achieve such reductions, was studied in this manuscript through a validated numerical simulation model that predicts the friction of the engine’s piston-cylinder unit, journal bearings and camshaft. These frictional power losses were obtained for four different lubricant formulations which differ in their viscosity grades and design. Results showed a maximum friction variation of up to 6% depending on the engine operating condition, where the major reductions came from hydrodynamic-dominated components such as journal bearings, despite an increase in friction in boundary-dominated components such as the piston-ring assembly. Also, an evaluation of the potential fuel reduction that can be obtained by low viscosity oils during a WLTC approval cycle was performed. Overall, a fuel saving of 1% was obtained. In general terms, the majority of the engine map showed potential for mechanical loss reduction through LVEOs, that is, a better engine efficiency and consequently a decrease in the fuel consumption and CO<sub>2</sub> emitted to the atmosphere. The present work also exemplifies the trade-offs encountered when reducing the engine friction through LVEOs and highlights the need to co-engineer the hardware and lubricant in order to utilize the full friction reduction potential of LVEOs.</div></div>

Optimal engine mapping performances for dual spark-plug ignition internal combustion engine using neural network

Many variables affect the performance and fuel consumption of internal combustion engines. The most influential main variables include air, fuel, ignition, and compression. Spark plugs that play role in the ignition of fire have limitations in the propagation of fire due to their position because of the dual ignition technology. This study aimed to develop engine maps for dual ignition internal combustion engine using the Artificial Neural Network to predict the fuel consumption, generated torque, and find out the right combination of fire ignition on dual ignition systems to improve performance and reduce fuel consumption. The research was conducted with the initial step of retrieving the data engine map by using an engine scanner to find out the data on the current ECU. Then the data is modified to create a new engine map (modified engine mapping) that combines ignition timing 2 with a range of 0.5o - 2o. The test results show different torque and fuel consumption values in four modified engine maps. The optimum engine mapping is obtained on engine map 3 with an error value (Mean Square Error) of 0.002 and a regression value (R2) of 0.99. Modification map engine 3 with a combination of ignition timing 2 of 1.5o on ignition timing 1 shows the highest torque result with an increase in torque of 14.1% and a decrease in fuel consumption of 17.5%.

Engine Downsizing; Global Approach to Reduce Emissions: A World-Wide Review

Engine downsizing is a promising method to reduce emissions and fuel consumption of internal combustion engines. The main concept is reducing engine displacement volume keeping needed output characteristics unchanged. The issue became one of the most filed of interest in recent years after the International Energy Agency defined a target of 50 % reduction in global average emissions by the year 2030. In this review paper, different aspects of researchers’ efforts on engine downsizing are configured and due to overlaps, categorized into five main areas. Each category is discussed thoroughly and recent works are pointed. The global attention into these categories, countries involved and the trend changed in recent four years are presented in details. Doi: 10.28991/HIJ-2021-02-04-010 Full Text: PDF

Development of a model predictive controller for an active torsional vibration damper to suppress torsional vibrations in vehicle powertrains

The pressure of exhaust emission regulations on automotive manufacturers to reduce environmental pollution and fuel consumption of internal combustion engines (ICEs) have stimulated the works on the downsizing, downspeeding, and turbo supercharging concepts which result in boosted engine torsional vibrations. Despite significant momentum in the implementation of those concepts in modern ICEs in recent decades, similar progress has not taken place in parallel at torsional vibration isolation systems. To this end, this article centers on the development and implementation of a model predictive controller (MPC) on a novel active torsional vibration damper (ATVD) in which inertia, stiffness rate, and damping rate parameters can be varied to minimize torsional vibration transmission to the vehicle powertrain. Dynamic response of the ATVD is examined using an MPC inside a closed-loop control architecture with predicted variables. The MPC structure, state-space plant model, and physical constraint definitions are composed to be utilized in prediction models at various engine operating points. The MPC performance is evaluated in a co-simulation environment using Simcenter Amesim, NX Motion, and Matlab Simulink software, and are compared with that of the fuzzy logic controller (FLC). The simulation results clearly indicate that the MPC applied to the ATVD system has certain advantages over the FLC and is able to provide satisfactory isolation of the powertrain from engine-borne torsional vibrations while satisfying the physical constraints.

Practical Aspects of Cylinder Deactivation and Reactivation

Cylinder deactivation is an effective measure to reduce the fuel consumption of internal combustion engines. This paper deals with several practical aspects of switching from conventional operation to operation with deactivated cylinders, i.e., gas spring operation with closed intake and exhaust valves. The focus of this paper lies on one particular quantity-controlled stoichiometrically-operated engine where the load is controlled using the valve timing. Nevertheless, the main results are transferable to other engines and engine types, including quality-controlled engines. The first aspect of this paper is an analysis of the transition from fired to gas spring operation, and vice versa, as well as the gas spring operation itself. This is essential for mode changes, such as cylinder deactivation or skip-firing operation. Simulation results show that optimizing the valve timing in the last cycle before deactivating/first cycle after reactivating a cylinder, respectively, is advantageous. We further show that steady-state gas spring operation is reached after approximately 6 s regardless of the initial conditions and the engine speed. The second aspect of this paper experimentally verifies the advantage of optimized valve timings. Furthermore, we show measurements that demonstrate the occurrence of an unavoidable torque ripple, especially when the transition to and from the deactivated cylinder operation is performed too quickly. We also confirm with our experiments that a more gradual mode transition reduces the torque drop.

Influence of Engine Oil Evaporation Characteristics on Oil Consumption of Internal Combustion Engines.

Influence of Engine Oil Evaporation Characteristics on Oil Consumption of Internal Combustion Engines.

Lubricants used in internal combustion engines in times of downsizing

The operation of the internal combustion engine leads to the production of exhaust gases harmful to the natural environment. The introduced standards of the European exhaust emission standard aim, among other things, to reduce CO2 emissions. Such assumptions are related to the reduction of fuel consumption of internal combustion engines in vehicles. This means the need to make structural changes in the produced engines, and thus reduce the displacement while maintaining high power and torque. Engines constructed in this way require the use of individually selected oils and maintaining appropriate service intervals for their replacement.

Дизель-генераторная электростанция с вентильным генератором по схеме машины двойного питания

The article considers the problem of improving power efficiency of the diesel generator power plants as one of the priority objectives for development of low power generation in Russia. Improving energy efficiency for autonomous facilities is directly related to the optimization of hydrocarbon fuel consumption by marine diesel engines. It is possible to optimize the fuel consumption of internal combustion engines by creating variable-speed diesel generators (VSDG), which are diesel-generator units with semiconductor converters, i.e. systems with valved generators. Optimization of specific fuel consumption by VSDG is provided by the forced regulation of the rotational speed of the shaft of the internal combustion engine in accordance with its multi-parameter characteristic in the shared load conditions of the power plant. The synchronous electric machine is used as a generator as part of a ship power station. Its use in the classic constant-speed diesel generators is more preferable than an asynchronous electric machine. In the development of VSDG - valved power plant - the use of an electric machine with a phase rotor as a generator is technically justified, because the installed capacity of the frequency converter in the rotor circuit of an asynchronous generator with a phase rotor is determined by the sliding power and, with a limited range of speed control, SDGV significantly reduces the installed capacity of the electrical equipment. Such power topology of a ship’s power plant is called VSDG based on a dual-power machine. There has been proposed to consider a variant of a ship power plant based on VSDG with a dual-power machine. Its functional diagram and mathematical model are developed. A structural diagram is presented and dynamic modes of the amplitude and frequency of the generated voltage are modeled during electrical load switching.

A control strategy for cylinder deactivation

Cylinder deactivation is an effective measure to reduce the fuel consumption of internal combustion engines. This paper presents a control strategy for the cylinder deactivation (CDA) process and the cylinder reactivation (CRA) process, based on the inversion of a control-oriented discrete-event model. The focus of this paper lies on quantity-controlled stoichiometrically-operated engines with different layouts. Nevertheless, the main results are transferable to other engines, including quality-controlled engines. Two major aspects of CDA and CRA are considered in detail in this paper.The first aspect is the cycle-averaged torque during the CDA and CRA. Due to the reciprocating behaviour of the engine, an unavoidable discontinuity in the cycle-averaged torque is identified, irrespective of the type of engine. The amplitude of this torque ripple depends on the duration of the CDA or CRA and can be quantified a priori. A trade-off between the torque ripple amplitude and the CDA or CRA duration is identified.The second aspect is the amount of fuel consumed during the CDA and CRA. It is shown that to achieve a CDA or CRA with a limited torque ripple amplitude, some combustion cycles at unfavourable low-load conditions must occur. For example, ignition retardation might be used resulting in a significant portion of the fuel energy being lost. As a result an increase in the amount of fuel consumed during the CDA or CRA compared to that of continued operation in activated cylinder mode may arise. The conducted investigations show that this increase in fuel consumption is compensated after a few seconds of operation in the more fuel-efficient deactivated cylinder mode.

Transient plasto-elastohydrodynamic lubrication concerning surface features with application to split roller bearings

The use of roller bearings as crankshaft main bearings has shown potential in reducing the fuel consumption of internal combustion engines. An effective way to mount the roller bearing onto the crankshaft is to split the outer ring. However, this may lead to a severe out-of-roundness in the split region when the bearing is mounted, further implying increased noise, vibrations and contact stresses. In this work, a novel approach to study the plasto-elastohydrodynamic contact using commercial finite element software is developed. The modelling approach is based on the contact moving in space, allowing for the stress history based on the lubricant pressure to be studied in a straight-forward manner. The model is first utilised to study the influence of asperities on the lubricating conditions, indicating that stresses may exceed the yield strength of the material due to the transient effects taking place when the surface feature is over-rolled. Thereafter, the model is used to analyse the step in a mounted crankshaft roller bearing with the purpose of specifying a critical step height, which implies zero plasticity and thereby a reduced risk of accumulated damage in the vicinity of the step.

A Review of Commercial Electric Vehicle Charging Methods

Electric Vehicles (EVs) are rapidly becoming the forerunners of vehicle technology. First electric vehicles were overlooked because of not having adequate battery capacity and because of low efficiency of their electric motors. Developing semiconductor and battery technologies increased the interest in the EVs. Nevertheless, current batteries still have insufficient capacity. As a result of this, vehicles must be recharged at short distances (approximately 150 km). Due to scheduled departure and arrival times EVs appear to be more suitable for city buses rather than regular automobiles. Thanks to correct charging technology and the availability of renewable energy for electric buses, the cities have less noise and CO2 emissions. The energy consumption of internal combustion engines is higher than of the electric motors. In this paper, studies on the commercial electric vehicle charging methods will be reviewed and the plug-in charging processes will be described in detail. This study strives to answer the questions of how plug-in charging process communication has performed between the EV and Electric Vehicle Supply Equipment (EVSE).

Application of hydrogen and hydrogen-containing gases in internal combustion engines

The results of studies of the influence of hydrogen and hydrogen-containing gas additives on the parameters of various types of internal combustion engines are analyzed and summarized. It made possible to identify the features of the effect on the combustion of fuel during internal combustion engine operation at partial loads. The dependences of reducing the toxicity and fuel consumption of internal combustion engine on the amount of addition of hydrogen and a hydrogen-containing gas to the air-fuel mixture were obtained. It allowed to establish quantitative effects of free hydrogen, in particular, to quantify the region of small hydrogen additives and the conditions under which hydrogen exhibits the qualities of a chemically active component of the mixture.

Cordunum pistons increase diesel engine economy and reliability

Taking into account the oil resources depletion the requirements to fuel consumption of internal combustion engines are now increasing as well as to their reliability and durability. With the continual increase in the number of internal combustion engines in operation, along with the problem of parts of the cylinder piston group wearing out has caused exhaust from such engines to be one of the main source of harmful pollutant emissions in cities. Therefore, environmental requirements have in turn increased dramatically. The engine resource and its efficiency largely depend on the process of fuel combustion in the combustion chamber. Experimental studies aimed to improve the working process on diesel engines by piston insulation have shown an effective decrease in fuel consumption by reducing heat loss and more complete fuel combustion. When oxide ceramic coatings were used on the piston and cylinder head, the maximum power increased and the specific fuel consumption decreased. However ceramic coatings are not widely used due to their peeling. We have developed a technology for the galvanic plasma treatment of pistons, which made it possible to obtain on the pistons surface made of aluminum alloys a ceramic corundum layer with high adhesion to the base metal that does not peel and has electret properties. In 1993, pistons with a corundum surface layer were installed in a shunting diesel locomotive and life-time running tests were conducted. Such pistons increased wear resistance, reduced the wear of cylinder liners, increased the strength of the annular jumpers, and were not prone to burnouts and scuffing. They provided an increase in the resource of the cylinder-piston group of the diesel engine by more than 125 thousand engine hours. The paper provides an analysis of the effect of corundum pistons thermal insulation on significant increasing the, engine power and fuel consumption reduction. Basing on experimental bench studies of a gasoline engine, a tractor diesel engine and long-term operational life tests of diesel engines, an attempt had been made to explain the reasons for the improvement in the engines’ efficiency.

Intake charge temperature effect on performance characteristics of direct injection low-temperature combustion engines

The low-temperature combustion (LTC) concept presents solutions for simultaneous reduction in pollution and fuel consumption of internal combustion engines. However, the most important challenges of this concept are the lack of any direct combustion phasing control method and the limited operating range. Two LTC concepts, namely direct injection (DI) homogeneous charge compression ignition (HCCI) and partially premixed combustion, together with DI diesel can be combined to provide the desired performance for the whole load range. Although this combination provides the solution for the limited operating range, there still remains the problem with the method for combustion phasing control. Inlet temperature modulation may be used to regulate the combustion phasing. Therefore, this study investigates the effect of the intake charge temperature on the DI-HCCI combustion. The investigations are based on a novel two-stage combustion model. The combustion is predicted with the single-zone approach from the intake valve closing to the end of injection. Thereupon, it is predicted by the multi-zone approach. The results indicate that intake charge temperature has profound effects on in-cylinder charge pressure and temperature. It alters heat release rate magnitude and phasing, thus changing combustion timing. Moreover, this parameter affects indicated delivered power of the DI-HCCI combustion engine.

Influencia de productos de la hidrólisis en el desempeño de un vehículo que opera con gasolina y gas natural en la altura

Introducción: En la actualidad existe un gran interés en la reducción en el uso de combustibles fósiles por la variación de los precios y los fuertes controles normativos, por lo cual se buscan métodos para disminuir el consumo de combustible en los motores de combustión interna, tales como el suministro de productos de la hidrólisis del agua en la admisión del motor.
 Objetivo: El objetivo del este trabajo es presentar los resultados de una metodología experimental aplicada para estimar el desempeño mecánico y ambiental de un vehículo alimentado con gasolina y gas natural, específicamente cuando al motor se le suministran productos resultantes de la hidrólisis del agua.
 Metodología: Para el suministro de dichos productos al vehículo se le instalo un dispositivo hidrólisis externo, y el vehículo fue instrumentado con una quinta rueda, sensores de temperatura y velocidad de revoluciones del motor, para realizar pruebas de aceleración en una carretera plana y una carretera con pendiente longitudinal. Adicionalmente, se realizaron pruebas de torque y potencia con dinamómetro de chasis y pruebas de emisiones contaminantes y de consumo de combustible. Las pruebas fueron realizadas en las afueras de la ciudad de Bogotá DC - Colombia, ubicada a 2650 m sobre el nivel del mar.
 Resultados: Los resultados muestran que los productos de la hidrólisis no mejoran el desempeño mecánico del vehículo, ya que aumentan el tiempo para llegada a las velocidades definidas en las pruebas de aceleración hasta en un 18% en el motor con gasolina y 7% en el motor con gas natural, mientras que el torque y la potencia del motor se incrementa alrededor del 1%. Por otro lado, los resultados de las pruebas de emisiones contaminantes indican que el consumo de combustible se reduce aproximadamente en un 7%.
 Conclusiones: Los resultados indican que el desempeño del vehículo no mejora, aunque el consumo de combustible disminuye, el desempeño ambiental no disminuye.