Diesel Internal Combustion Engine Research Articles

Dynamics of change in the polytropic exponent in the expansion stroke of diesel

In the article is considered the problem of achieving the optimal duration of the working stroke of a diesel engine piston during the expansion process and obtaining the maximum efficiency coefficient (EC). For this purpose, a hypothesis was put forward about the pumping action of the piston on the flow of expanding gases during the power stroke of an diesel internal combustion engine (ICE) as the piston moves from upper dead point (UDP) to bottom dead point (BDP).At a certain moment of expansion, the rate of the flow of expanding gases turns out to be equal to the rate with which the same flow is slowed down by the moving piston.The equality of these rates leads to the formation of a flow break line and has a significant impact on the nature of the change in the polytropic exponent; the value of the exponent becomes equal to one: n = 1. This indicates that the optimum duration of the engine’s working stroke has been achieved and corresponds to the maximum power that can be removed during the diesel engine’s operating cycle. An experimental relation was obtained between the initial p1 and final p2 pressures in the cylinder during gas expansion with the gas flow rate and the rate of deceleration of this flow due to the pumping action of the piston. An equation for the continuity of gas flow has been compiled for the process of gas expansion in the cylinder of an ICE with closed gas exchange organs. Based on this equation, the numericalvalue of the acceleration of gravity in the cylinder of ICE is obtained: gф ≈ 8,7 м/с2 < g, which confirms the pumping action of the piston. A theoretical (and graphical) dependence of the polytropic process exponent on the flow rate of expanding gases is obtained. The dependence allows to calculate the polytropic exponent and establish the gas relaxation period, indicating the achievement of the optimal duration of the piston stroke.

Organic Rankine Cycle System Design by Utilizing The Waste Heat of Internal Combustion Engine Based on Numerical Simulation

Abstract Most of the energy supply for today’s human activities still comes from fossil energy. Energy based on fossil fuels can cause an increase in greenhouse gas (GHG) emissions. Therefore, increasing the efficiency of energy conversion systems based on fossil fuels is necessary to mitigate pollutant emissions. The internal combustion engine (ICE) is one energy conversion machine that still consumes fossil energy to work in the transportation sector. Losses during internal combustion engine operation result in reduced engine thermal efficiency. Exhaust gas heat loss is one of the relatively significant losses. It leads to the waste of heat, which could be utilized and converted into valuable energy in the form of electrical energy that the engine can use, resulting in a considerable amount of primary fuel that could be saved. An organic Rankine cycle (ORC) system is considered in this analysis as a heat recovery unit from the Diesel ICE. The Aspen Plus simulation software was chosen to design the system consisting of an ORC unit integrated with a Diesel ICE unit. The working fluid for ORC used in this analysis is R-141B, R-123, and R-245fa. The simulation results show that the heat the ORC unit receives from the ICE via turbocharger is around 366 °C. Thus, the system has a thermal efficiency of 11.11% when using R-141B as the working fluid, 8.41% if R-123 as the working fluid, and 6.63% when using R-245fa as the working fluid. This study also obtained a condenser design as part of the ORC unit. The condenser can be considered a plate heat exchanger, with 53 plates needed to support the process.

The Indirect Carbon Cost of E-Mobility for Select Countries Based on Grid Energy Mix Using Real-World Data

Electric vehicles are considered by many as an emission-free or low-emission solution to meet the challenge of sustainable transportation. However, the operational input, electrical energy, has an associated cost, greenhouse gasses, which results in indirect emissions. Given this knowledge, we pose the following question: “Are zero-emission transportation targets achievable given our current energy mix?” The objective of this article is to assess the impact of a grid’s energy mix on the indirect emissions of an electric vehicle. The study considers real-world data, vehicle usage data from an electric vehicle, and carbon intensity data for India, the USA, France, the Netherlands, Brazil, Germany, and Poland. Linear programming-based optimization is used to compute the best charging scenario for each of the given grids and, consequently, the indirect emissions are compared to those of a high-efficiency 1.5 L diesel internal combustion engine for the vehicle: a 2019 Renault Clio dCi 85. The results indicate that for grids with low renewable energy penetration, such as those of Poland and India (Maharashtra), an electric vehicle, even when optimally charged, can be classified as neither a low- nor zero-emission alternative to normal thermal vehicles. Also, for grids with elevated levels of variation in their carbon intensity, there is significant potential to reduce the carbon footprint related to charging an electric vehicle. This article provides a real-world perspective of how an electric vehicle performs in the face of different energy mixes and serves as a precursor to the development of robust indicators for determining the carbon reductions related to the e-mobility transition.

Extraction and characterization of Cucumis melon seeds (Muskmelon seed oil) biodiesel and studying its blends impact on performance, combustion, and emission characteristics in an internal combustion engine

This study examines the performance, combustion, and emissions characteristics of a single-cylinder internal combustion diesel engine when fueled with a blend of diesel and biodiesel derived from muskmelon seeds. The kinematic viscosity of the extracted muskmelon seed oil was 6.1 cSt at 40 °C, which is higher than the kinematic viscosity of petroleum diesel of 2.6 cSt. Muskmelon biodiesel was further analyzed using thin-layer chromatography (TLC) and high-voltage separator tests. A comparison of the fuel properties of muskmelon biodiesel with conventional diesel fuel revealed that muskmelon biodiesel could be used alone or in a diesel–biodiesel blend to fuel compression diesel engines. In this study, muskmelon seed biodiesel was blended with diesel fuel at proportions of 10 %, 20 %, and 50 % (BD10, BD20, and BD50, respectively). At a relatively low rotational speed of 1200 rpm, the brake thermal efficiency (BTE) of the engine operated with BD10 and BD20 blends were 36.1 % and 36.0 %, respectively, while the brake-specific fuel consumption (BSFC) of the two blends were 0.260 kg/kWh, and 0.262 kg/kWh, respectively. These values closely resemble those typically observed in diesel fuel engines. Indeed, the average BTE of the BD20 blend was only 3.24 % less than the average BTE of diesel fuel. Diesel fuel generates less NOx and SO2 emissions compared to biodiesel blends: BD100 emitted the most NOx pollution of all fuels tested. In addition, BD10 released significantly more SO2 emissions compared to the other fuels tested. However, the BD20 blend outperformed all other blends in terms of CO, NOx, and SO2 emissions at high engine speeds. The only exception was H2S emissions, which were higher than BD50 and BD100. BD20 also exhibited significantly reduced CO emissions compared to diesel fuel, while BD10 emitted significantly more CO emissions than the other biodiesel blends. Our findings revealed that BD20 exhibited the best engine performance and lower emissions among all fuels tested. In other words, BD20 is the ideal fuel blend for use in diesel engines and does not require any alterations to the engine. Muskmelon waste seeds represent a non-edible waste stream that can be exploited in the production of biodiesel fuel, allowing for the upcycling of a potentially problematic thermochemical conversion feedstock. This potentially valuable use for waste muskmelon seeds in the energy sector could address the wastefulness associated with this particular waste stream.

Using the thermodynamic processes features to assess the diesel power plants technical condition

The results of studying the thermodynamic processes features and analyzing the prospects for using their characteristics to assess the technical condition of diesel power plants are contained in the paper. A structural diagram of a ship power plant, which is proposed to be considered consisting of separate components of mechanical part, thermodynamic part, fuel supply system and automatic speed control system equal in degree of influence on efficiency is proposed. The theoretical analysis results of the joint operation of the mechanical and thermodynamic components of the diesel power function have shown that the temperature of the working surfaces is an important characteristic of the power plant technical state. The concept of the thermodynamic component in this case refers to a combination of fuel combustion processes and combustion product expansion. To improve the design and efficiency of power plants operation, it is necessary to further study the in-cylinder fuel combustion processes and develop operational methods for monitoring the thermal state of diesel internal combustion engines. Control of changes in functional dependencies of working medium temperature on operating conditions and technical condition can in practice contribute to increase the efficiency of ship power plants operation. The experimental studies of the thermal imaging methods prospects to assess the diesel engines technical condition are carried out. It is found that the control reliability increases with an increase in the size of the diesel engine frame due to a decrease in the intensity of the dynamics of temperature equalization of individual cylinders. At the same time, the most expedient and informative is the control of the temperature of the diesel engine exhaust manifold, carried out during the heating of the cold engine or immediately after its completion.

Study on the Performance and Emissions of Triple Blends of Diesel/Waste Plastic Oil/Vegetable Oil in a Diesel Engine: Advancing Eco-Friendly Solutions

To provide technical and economical solutions regarding management of plastic waste, which is constantly increasing worldwide, this study addresses the possibility of using plastic oils (PO) obtained from these plastic wastes as biofuels. To this end, the replacement of the fossil diesel employed in internal combustion diesel engines with triple diesel/PO/vegetable oil mixtures has been investigated. Sunflower (SO) and castor oil (CO) mixed with PO in the most appropriate proportion are evaluated as pure vegetable oils (SVO). Thus, diesel/PO/SVO triple blends were prepared, characterized, and then tested on a diesel engine operating as electricity generator, evaluating power output, consumption, and exhaust emissions. The obtained results show that, with the incorporation of relatively small quantities of pure, non-edible vegetable oils, in double mixtures of PO/SO and PO/CO, an effective alternative fuel for transport is obtained, that allows for 100% of fossil diesel to be replaced. In fact, with these double PO/SVO biofuel mixtures, higher engine power values and lower consumption levels are obtained than those achieved with fossil diesel. Regarding exhaust emissions, these are produced with a slightly greater opacity than with fossil diesel, but there are lower values of carbon gases as a whole (CO + CO2) and in NOx gases.

Метод оценки факторов, влияющих на вибрацию судового дизеля, вызванную работой цилиндропоршневой группы

The efficiency of the use of the marine fleet is associated with a reduction in the cost of transportation, the need for which is steadily increasing. A significant share of the total transportation costs is occupied by the costs associated with the operation of ships, therefore, reducing these costs is a reserve for reducing the cost of maritime transportation. The problem of increasing the efficiency of the operation of marine vessels is closely related not only to reducing the cost of it, but also to reducing the time for maintenance and repair of ships. The existing system of scheduled preventive maintenance and repair provides for the maintenance and restoration of the normal technical condition of the vessel and its elements with a pre-planned frequency. The transfer of ships to work with extended repair periods is possible only when solving a whole range of engineering and technical measures and scientific research aimed at improving the quality of repairs, the level of technical operation, improving logistics, etc. An essential role in this is played by the use of modern methods and means to determine the technical condition of shipboard devices and mechanisms, primarily engines of shipboard power plants (SEUs), without disassembling them. High vibration loads of SEU parts lead to fatigue stresses, accelerate wear of the contacting surfaces, reducing the reliability and service life of marine diesel engines, therefore monitoring of their vibration activity is important, especially during operation. The safe operation of ships of the transport fleet largely depends on the reliability of marine diesel engines. Technical means of monitoring their operability in the process of work are currently insufficiently effective and need to be improved. It is relevant not only to develop new, more advanced and mobile hardware and software, but also to search for new scientific and methodological approaches to using the information contained in the spectrum of vibration parameters. Marine diesel internal combustion engines are complex systems that involve many variable parameters. The study of such engines requires the use of methods that can be used to systematically investigate the influence of various factors on their operation, in particular, random experimental schemes are used, since they provide systematic control over variable parameters and maximize the accuracy of estimates. The results of the application of the method of ranking the factors influencing the vibration of a marine diesel engine are presented in order to establish the most significant of them. A mathematical model is presented that allows calculating current values and predicting changes in the most significant indicators, among which the most important is the size of the gap between the piston and the cylinder sleeve.

Comparison of Effect of Conventional Fuel with Newly Developed Biofuel in Operation and Emission Conditions of Piston Combustion Engine

Abstract The present paper deals with the evaluation of the impact of newly developed biofuels together with a comparison with conventionally produced fuel, diesel, in terms of their impact on the technical and emission condition of a studied vehicle. The main energy and emission parameters of the internal combustion diesel engine were evaluated. For laboratory experiments, a discrete test method was used for comprehensive assessment, the procedure of which is described in the methodology of the paper together with a description of the measurement chain designed to achieve the determined results. The paper deals with the evaluation of the measured results of power, torque, consumption, and emissions such as CO2 and absorption coefficient. Among the technical parameters, the power and torque drop were observed for each biofuel. The decrease is attributed to lower values of calorific value, viscosity, and density. A positive effect was observed for the CO2 and absorption coefficient emission parameters, i.e., a decrease for each of the newly developed biofuels studied.

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.

РЕЗУЛЬТАТЫ ИССЛЕДОВАНИЙ ПО ОПРЕДЕЛЕНИЮ РАЦИОНАЛЬНОГО СПОСОБА УДАЛЕНИЯ ЗАГРЯЗНЕНИЙ ИЗ МОТОРНОГО МАСЛА БЕЗ ЕГО СЛИВА ИЗ СИСТЕМЫ СМАЗКИ

Contaminants are formed in diesel internal combustion engines of tractors during operation under the influence of high temperatures and loads on the parts of the cylinder-piston group, which then enter the engine oil, which affects the service life of the oil and the characteristics of the machine-tractor unit. An important measure that affects the contamination of parts and the service life of the oil is flushing the lubrication system during routine replacement of used oil. However, for a number of well-known objective and subjective reasons, this technological method is practically not carried out under real operating conditions. Resource-saving technology for flushing the lubrication system with motor oil running in the tractor engine was developed at TSTU. A number of technological methods for cleaning oil from contaminants and resins under the influence of chemical reagents added to the oil, followed by idling the engine, have been developed. The dependences of changes in contamination, base number, viscosity and color of the oil on the cleaning method, the concentration of the addition of urea, monoethanolamine, and isopropanol reagents were obtained. It has been determined that the addition of isopropanol can increase the flash point of the oil. The dependences of the change in base number and viscosity on the concentration of monoethanolamine with isopropanol in the oil have been established. The rational concentration for adding this additive is 2–3% of the oil volume. It was determined that the color of the oil changes from 9 to 4 points per unit. CNT. Research on the use of finely dispersed contaminants as a separating agent and coagulant has established that 3% vol. carbamide dissolved in ammonium hydroxide allows you to get the best result. Research in this area will be continued and requires confirmation in a wide range of oils and the technological state of tractor engines.

TRACTION ALTERNATOR FOR ELECTRIC DRIVE OF FRONT LOADER CHASSIS

For heavy construction equipment with a hybrid electric transmission, the power center of a group of traction electric drives can be formed by an electric generator and a renewable energy storage device (battery array) with the possibility of their joint operation to provide a surge of current in a group of traction electric drives. The battery array can be used to power a generator in a starter mode when starting a diesel internal combustion engine.
 
 The purpose of the study is to substantiate the choice of the magnetic system of the power generator for the electric transmission and the possibility of a starter mode for an internal combustion engine drive. The study was carried out within the framework of a subsidized project to create mass production of a family of front loaders with a hybrid electric drive in Chuvashia.
 
 Materials and research methods. The studies were carried out by the method of finite element analysis using the Russian software ELCUT (professional version and a set of reference books for domestic electrical and magnetic materials).
 
 Results. The stage of analytical calculation of the active parts of a transmission electric generator for the preliminary design stage is presented. It was carried out for the following conditions: the use of Russian electrical and magnetic materials, the use of common industrial bearings and antifreeze, compatibility with existing technological equipment in the production of traction electric motors, engine mode for performing the starter function. The substantiation of the choice of the magnetic system based on the ratios of magnetic fluxes of different sizes of stator teeth is given. The article is illustrated with diagrams of magnetic and thermal fields for given operational characteristics and properties of a transmission electric generator.
 
 Conclusions. For a given type of drive diesel engines installed on the front loaders, the highest efficiency indicators of the proposed generator magnetic system occur when using a multiplier. The power supply of the generator in the starter mode is provided by the installed array of traction batteries of the front loader without additional step-up converters.

Mathematical model of the hovercraft lift system

BACKGROUND: Currently, hovercrafts are used worldwide thanks to their amphibian capabilities and mobility at water and slightly prepared areas with low supporting properties. Whereas, in practice, hovercrafts have two main systems ensuring motion, lift and traction which can be combined (operating from a common source of mechanical energy) as well as separated.
 This paper considers a hovercraft with separated lift and traction systems. The lift system of this hovercraft consist of piston diesel internal combustion engine (ICE), hydrostatic transmission, axial fans, feeding channel and an air-cushion plenum. The considered variant is chosen because hydrostatic transmission has a number of sufficient advantages in comparison with mechanical transmission with universal shafts and pulley drives, widely used at present time. The paper considers the open plenum lift system.
 AIM: Development of the combined mathematical model of the hovercraft lift system consisting of piston diesel ICE, hydrostatic transmission and a fan supplying air into the air-cushion plenum.
 METHODS: Using the MATLAB/Simulink environment, the engine power adjustment at hovercraft motion on various ground surfaces is studied with regard to increasing the efficiency of the fan and the whole system. Analytical scheme of the system is given, acceptable transient characteristics are obtained. Efficiency and range of optimal operation of the Sauer-Danfoss pump and hydraulic motor are estimated. The process of hovercraft adjustment from the established mode to a new state when motion condition change is considered.
 RESULTS: According to the simulation results, there is influence of the income control signal (adjustment parameter of engine operation modes) and disturbance signal (pressure change coefficient that defines properties of ground surface) on parameters describing the hovercraft motion.
 CONCLUSION: The developed mathematical model helps to choose and evaluate adjustment parameters of engine operation modes at hovercraft motion on various ground surfaces, to analyze and to improve the system energy efficiency.

A solar-assisted liquefied biomethane production by anaerobic digestion: Dynamic simulations for harbors

This work presents a dynamic simulation model for the production of liquefied biomethane by anaerobic digestion. This layout includes anaerobic digesters supplied by the organic municipal solid wastes, biogas upgrading and biomethane liquefaction units, photovoltaic panels, evacuated solar collectors, electric and thermal storages. Solar collectors provide the heat to anaerobic digesters. Photovoltaic panels supply electricity to the electric devices of the plant. The dynamic model evaluates the electric consumption for the biogas upgrading and biomethane liquefaction units and the thermal load of the anaerobic digesters. The produced liquified biomethane is supplied as fuel to some ships traveling from the mainland to the islands of the Gulf of Naples. The simulation models of the anaerobic digester, biogas upgrading and biomethane liquefaction units are developed in MATLAB® environment and subsequently integrated in TRNSYS18, where the whole plant is modelled. The model of anaerobic digester takes into account both the biological and thermal processes and it considers the digester geometrical and structural features. The biogas upgrading unit consists of a three-stages selective membrane system, whereas the liquefaction system is modelled by the conventional Linde cycle. Significant energy savings and CO2 emissions reduction are obtained, that is a strategic outcome for harbours located in densely populated cities. When the proposed system is compared with the reference system consisting of an existing fleet, equipped with very old ferries using internal combustion diesel engines, the primary energy saving is about 50 %. Considering the present Italian funding policy for biomethane, such system exhibits a good economic profitability.

Performance, combustion, and emission characteristics of bio-oil produced by in situ catalytic pyrolysis of polypropylene using spent FCC.

Plastic waste is a rich source of hydrocarbons that can be converted into bio-oil through pyrolysis. In this study, bio-oil was produced by pyrolysis of waste-polypropylene using spent FCC catalyst. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that catalytically produced oil has the majority of compounds in the hydrocarbon range of C6-C18. The catalytic pyrolysis oil was blended with conventional fuel (diesel) to extensively investigate its suitability as a fuel substitute in a single-cylinder, four-stroke, 3.5kW, diesel internal combustion (IC) engine. Furthermore, four fuels, i.e., CF100PO00 (pure diesel), CF90PO10 (10% v/v pyrolysis oil blended with diesel), CF85PO15 (15% v/v pyrolysis oil blended with diesel), and CF80PO20 (20% v/v pyrolysis oil blended with diesel), were tested in IC diesel engine for performance, combustion, and exhaust emission analysis at 1500rpm. The tests were carried out at five loads, i.e., 1, 5, 10, 15, and 20 Nm. It was found that CF90PO10 produced 6.61% higher brake thermal efficiency (BTE), whereas CO2 exhaust emission decreased by 20% for CF80PO20 with respect to the pure diesel. Diesel blends with plastic pyrolysis oil can be a promising biofuel to improve engine performance and combustion characteristics without any significant engine modification.

Exergoeconomic Analysis of a Mechanical Compression Refrigeration Unit Run by an ORC.

To improve the efficiency of a diesel internal combustion engine (ICE), the waste heat carried out by the combustion gases can be recovered with an organic Rankine cycle (ORC) that further drives a vapor compression refrigeration cycle (VCRC). This work offers an exergoeconomic optimization methodology of the VCRC-ORC group. The exergetic analysis highlights the changes that can be made to the system structure to reduce the exergy destruction associated with internal irreversibilities. Thus, the preheating of the ORC fluid with the help of an internal heat exchanger leads to a decrease in the share of exergy destruction in the ORC boiler by 4.19% and, finally, to an increase in the global exergetic yield by 2.03% and, implicitly, in the COP of the ORC-VCRC installation. Exergoeconomic correlations are built for each individual piece of equipment. The mathematical model for calculating the monetary costs for each flow of substance and energy in the system is presented. Following the evolution of the exergoeconomic performance parameters, the optimization strategy is developed to reduce the exergy consumption in the system by choosing larger or higher-performance equipment. When reducing the temperature differences in the system heat exchangers (ORC boiler, condenser, and VCRC evaporator), the unitary cost of the refrigeration drops by 44%. The increase in the isentropic efficiency of the ORC expander and VCRC compressor further reduces the unitary cost of refrigeration by another 15%. Following the optimization procedure, the cost of the cooling unit drops by half. The cost of diesel fuel has a major influence on the unit cost of cooling. A doubling of the cost of diesel fuel leads to an 80% increase in the cost of the cold unit. The original merit of the work is to present a detailed and comprehensive model of optimization based on exergoeconomic principles that can serve as an example for any thermal system optimization.

The results of the influence of prepared diesel on the fuel and economic indicators of internal combustion engines

The article analyzes the existing methods and devices for reducing the fuel consumption of the internal combustion engine. The design of an additional device installed in the standard internal combustion engine power system, the cavitation principle of operation, is proposed. Comparative results of experimental tests of this device on a bench installation with a diesel internal combustion engine for fuel-economic and environmental properties of the internal combustion engine, as well as changes in the physicochemical properties of diesel fuel of various brands after its treatment by the device are presented. The most effective parameters of the cavitation device for processing diesel fuel and its place of installation in the standard internal combustion engine power system are determined. Keywords: fuel preparation device, cavitation device, reduction of fuel consumption, ways to reduce fuel consumption, fueleconomic properties of internal combustion engines, environmental properties of diesel internal combustion engines, properties of diesel fuel,

Innovative developments on the use of hydrogen in transport internal combustion engines and power plants

BACKGROUND: Innovative technologies and design solutions aimed at using hydrogen in internal combustion engines and hydrogen power plants are reviewed in the paper. The advantages of hydrogen fuel are shown and the main problems that Western automakers face and which determine the ways to solve problems in road transport are identified. In this regard, the method of using hydrogen energy in internal combustion engines and hydrogen power plants becomes a decisive factor.
 AIMS: Search for a reasonable and effective method of using hydrogen in transport.
 METHODS: The technologies of hydrogen production with the electrolysis method and on-board generation of hydrogen using hydrogen-containing components are considered. It is proposed to use ammonia as a hydrogen carrier reagent for operation in dual-fuel diesel internal combustion engines.
 RESULTS: It is noted that ammonia, with a high level of hydrogen content in the molecule, is relatively safe, has a low cost and a significant volume of production. It is easier to store and transport compared to hydrogen. For internal combustion engines operating on hydrocarbon fuel, the use of ammonia and hydrogen, its derivative product, is attractive due to the need to remove highly toxic nitrogen oxides containing in the exhaust gases of diesel internal combustion engines.
 One of the main problems of creating an environmentally friendly diesel engine associated with reducing the NOx content to an environmentally safe level is considered. A positive factor of using ammonia is the on-board production of hydrogen in the thermal reactor, as well as the possibility of organizing an effective process of neutralizing nitrogen oxides in a diesel engine.
 CONCLUSIONS: The use of ammonia to generate hydrogen allows the diesel engine to implement the process of selective reduction of nitrogen oxides when ammonia is injected into the combustion chamber at the exhaust stroke. This method will significantly increase the efficiency of NOx neutralization in a diesel internal combustion engine due to the possibility of temperature regulation of the NOx neutralization reaction directly in the cylinder and in the exhaust system of the internal combustion engine.

To the question of the description of the internal combustion engine in the mathematical model of the lifting system of the hovercraft (on the example of the ZMZ-51432.10 CRS engine)

Introduction. It is known that about one third of the total capacity of the power plant of the hovercraft (SVP) is spent on the creation of an air cushion that ensures the rise of the main hull of the vessel. At the same time, in SVP, the source of mechanical energy, as a rule, is a diesel internal combustion engine (ICE). This article discusses one of the issues related to the creation of a mathematical model of the lifting system of the SVP, using: ICE, hydraulic transmission, axial fans and an air cushion nozzle scheme. Since in the vast majority of cases, the internal combustion engine performs its work in partial load modes, it becomes necessary to effectively control the power of the internal combustion engine in order to achieve its high efficiency in partial load modes.
 AIMS. The purpose of this study is to develop a mathematical description of the operation of the internal combustion engine both in external and partial modes of operation, for use in a mathematical model of the operation of the lifting system of the SVP.
 Methods. In this study, a ZMZ-51432.10 CRS diesel engine is used for the lifting system of the hovercraft.
 Results. Using the data obtained using the DIESEL-RK program for this ICE, in the Microsoft Excel environment, the corresponding trend lines were obtained for them by approximating the points that identify the partial characteristics of the engine with fourth-order polynomials, as well as the dependence of the coefficients of these polynomials on the control parameter of the ICE operation mode .
 Conclusion. The developed mathematical description of engine operation can be integrated with various load models when simulating real systems using internal combustion engines as energy sources. This means that it can also be used in mathematical modeling of the SVP lifting system in the MATLAB Simulink package.The approach proposed in this article makes it possible to build mathematical models of various systems using internal combustion engines, simplifying the study and saving computational time. Also, the results obtained can be of reference value.

Evaluation of the influence of fuel pressure pulsation in the Common Rail system on the economic and environmental performance of a diesel engine

BACKGROUND: At present, all the worlds diesel engine manufacturers have directed their development strategy towards reducing harmful emissions, improving fuel efficiency and increasing power per liter. To achieve this, using only the Common Rail system is not sufficient. It is necessary to apply new additional devices, such as an exhaust gas converter, an exhaust gas recirculation system, the injection of additional fluids together with diesel fuel, as well as to improve existing ones. Increasing the accuracy of fuel delivery for an injector will make it possible to adjust the engine fuel system more precisely, leading to a positive effect on all areas of development of the diesel industry.
 In this article, the possibility of increasing fuel efficiency and reducing harmful emissions through exhaust gases of a diesel engine with a decrease in pressure pulsation in the accumulator of the Common Rail system is considered on the example of the D-442-59I-1 (4ChN 13/14) experimental four-cylinder diesel engine with a two-valve gas distribution system manufactured by Altai Motor Plant.
 AIMS: Study of the effect of fuel pressure pulsation in the Common Rail fuel system on the economic and environmental performance of a diesel engine.
 METHODS: On a non-motorized test rig, the dependence of the fuel delivery of the injector on the pressure in the accumulator was determined. To assess the effect of fuel pressure at the injector inlet on the performance of a diesel internal combustion engine, experimental designs of diesel engines were simulated using the specialized software. Theoretical studies have been carried out to assess the influence of fuel pressure in the fuel system.
 RESULTS: Data have been obtained on the effect of fuel pressure fluctuations in the high-pressure line on the injector cycling, harmful emissions and fuel efficiency.
 CONCLUSIONS: As a result of the study of the process of fuel supply and combustion in a 4CHN 13/14 diesel engine, it was found that with a pressure fluctuation range of 50 bar in the fuel accumulator, the concentration of wet NOx decreases by 11%. The concentration of solid particles increases to 13.4%, fuel efficiency deteriorates to 0.5% when the operating pressure of the fuel deviates 160 MPa in any direction from the set value.

Experimental investigation of liquid thermal diffusivity for fatty acid methyl/ethyl esters by dynamic light scattering method

Fatty acid methyl/ethyl esters have a potential application as fuel or fuel additives in internal combustion diesel engine. The present work focused on the determination of the liquid thermal diffusivity of six fatty acid methyl esters (FAMEs) and four fatty acid ethyl esters (FAEEs) over a wide temperature range from (303.15 to 473.15) K by dynamic light scattering (DLS) method. Results demonstrated that the liquid thermal diffusivity of FAMEs and FAEEs decreased as the increasing temperature but increased as the increasing carbon chain. Furthermore, the polynomial correlation of the liquid thermal diffusivity against the temperature was proposed. The maximum relative deviation (MRD) and absolute average relative deviation (AARD) between experimental data and the corresponding calculated values from the correlation were 2.00% and 1.00%, respectively. The obtained experimental data and proposed correlation in this study provide necessary data support for future industry applications of FAMEs and FAEEs as fuels or fuel additives in internal combustion engines.