The main direction for the further development of internal combustion engines (ICEs) in the context of the global climate change problem relies on integrating power units, which will still have a carbon footprint for a certain period, into a circular carbon economy with zero carbon emissions throughout their full life cycle, coupled with intensive implementation of renewable energy sources. This publication analyzes existing global trends, challenges, and proposed promising ways for this transformation. Using examples from statistical data, analytical reports from research institutions, and information on investment projects, three key problems are examined, towards whose effective resolution efforts of researchers has to be directed. They constitute finding feasible means to achieve the desired effect from an entirety of coordinated measures within a circular carbon economy, addressing the challenges of using renewable energy sources whose electricity generation is characterized by daily and seasonal non-periodic cycles, and identifying scientifically sound directions for the further development of ICEs under the outlined conditions. It is shown that the use of ICEs in a circular economy should be considered carbon-neutral, regardless of the presence or absence of a carbon footprint. Removing ICEs from use complicates the achieving carbon neutrality. Carbon-based bio- and synthetic fuels, as well as carbon-free fuels for ICEs, can and should be viewed as methods for accumulating energy from renewable sources and converting it into other forms suitable for efficient storage, transportation and use. Five independent directions for the development of ICEs in a circular economy are considered: replacing traditional fuels in existing ICEs with carbon-neutral ones, improving designs to enhance their efficiency, applying additional onboard systems and devices, transitioning to the use of carbon-free fuels, and minimizing greenhouse gas emissions throughout the ICE life cycle. It is proven that the continuous improvement of ICEs directly contributes to meeting sustainable development requirements amidst the undeniable demands of transitioning to a climate-neutral economy.
The article considers the impact of the use of alternative fuels of plant origin on energy efficiency, environmental performance and combustion processes in a motor-tractor diesel engine. The relevance of the topic is due to the need to reduce the carbon footprint of diesel engines in the context of tightening requirements for greenhouse gas emissions, increasing energy independence and ensuring fuel autonomy of critical sectors of the economy. The main attention is paid to the evaluation of diesel engine performance when running on fuel mixtures containing fatty acid methyl esters (FAME) and hydrogenated vegetable oil (HVO) in comparison with traditional petroleum diesel fuel. A review of the physicochemical properties of these fuels, in particular: density, specific lower heating value, cetane number, viscosity, flash point, oxygen content, and carbon-to-hydrogen mass ratio, was carried out. Design and technological limitations on their use in modern diesel engines are discussed. The efficiency of internal oxygen in FAME in the combustion process is evaluated based on the analysis of the chemical structure, thermal stability of ester groups, and kinetic conditions in the combustion chamber. The mathematical modeling of the 4CHN10.7/12.4 diesel engine's operating process was carried out in the Blitz-PRO software package using the real properties of the mixtures and the calculated parameters of the fuel equipment. Changes in the indicator and effective efficiency, specific fuel consumption, maximum cycle pressure, cylinder pressure rise rate, ignition delay period, and specific CO2 emissions were analyzed. It was found that with an increase in the proportion of HVO in the mixture, a significant decrease in the rigidity of the working process (up to 30%) was observed due to the high cetane number. At the same time, a slight decrease in efficiency is mainly due to a decrease in the volumetric heat of combustion and a shift in the heat release law to the later phases of the cycle. CO2 emissions were analyzed for different blends: a reduction of up to 6% is possible when using pure HVO. The full life cycle from raw material cultivation to fuel production has the potential to reduce emissions by 15-55% compared to petroleum-based diesel, according to the UK government. The results confirm the feasibility of using fuels from renewable sources in diesel engines as a tool for reducing the carbon footprint without significant losses in energy efficiency.
The publication deals with the methodology for conducting motor experiments to study the effect of diesel intake system air filter fouling on the economic and environmental performance of the engine. The methodology also makes it possible to track the influence of changes in the air excess ratio on these indicators within the operating modes of the diesel engine. In modern internal combustion engines with electronic control units, air supply processes are controlled automatically. In this case, based on the program laid down in the control unit, the consumption of both fuel and air charge is adjusted, and the engine operating modes are considered for the development of such a program, which are determined, in turn, by the type of internal combustion engine, its purpose, boost level, and operating conditions. At the same time, the main goal is to select the optimal consumption of both fuel and air, depending on the operating mode. In particular, the air consumption, the excess air ratio can be adjusted both upward in forced modes to improve the processes of mixture formation, the completeness of fuel combustion, and downward in partial modes to reduce pumping costs and increase mechanical efficiency. Thus, modeling the processes of air filter fouling, limiting the air flow through the diesel engine can be considered in a broader sense by conducting certain experimental evaluations for both forced and partial load modes. The proposed experimental methodology is characterized by simplicity and can be used in the educational process to consolidate the relevant theoretical provisions, in particular, in the course “Operation and Repair of Internal Combustion Engines”.
This article presents the results of a comparative study on the operation of a small-displacement diesel engine 3ChN 8.8/8.2 within a hybrid powertrain system of a transport vehicle. The research was conducted by developing simulation models in the Simcenter Amesim environment for two basic hybrid drive architectures — parallel and series configurations. Currently, governments of many countries are implementing stringent emission standards for harmful substances (particularly NOx, CO, CO2, HC), which requires vehicle manufacturers to implement innovations in powertrain technology. The developers of the Euro 7 standard, which is set to come into force in 2025, clearly understand that tightening certain requirements, such as particulate matter emissions, has practically reached its limits, while establishing even stricter NOx emission limits for diesel vehicles remains possible, which also required attention. Therefore, within the scope of this research, the impact of each configuration on fuel economy, emission levels of harmful substances (CO, HC, NOx), and overall powertrain efficiency during typical urban and mixed driving modes (NEDC cycle) was analyzed. Special attention was given to the technical and functional feasibility of using a small-displacement diesel engine as an energy source in modern hybrid power systems, considering its design features, load characteristics, and adaptability to environmental constraints. The obtained results demonstrate comparable fuel efficiency of both configurations, significant advantage of the series architecture in reducing CO and NOx emissions, and lower HC levels in the parallel configuration. Meanwhile, the parallel configuration demonstrates higher dynamic flexibility and adaptability under variable driving conditions. The research has practical applications and is aimed at developing energy-efficient technologies in the field of specialized vehicles for military, expeditionary, or commercial purposes, where the combination of reliability, autonomy, and environmental compliance is particularly relevant. It was determined that the 3ChN 8.8/8.2 diesel engine demonstrated satisfactory technical and operational performance and adaptation potential to modern hybridization requirements. Its application is also feasible in the context of specialized transport, where economy, autonomy, and reliability are priorities.
Based on foreign sources, the article systematises and summarises the results of recent studies on the possibilities of using synthesised electronic fuels (e-fuels) in land transport for the gradual decarbonisation of the industry. The article focuses on liquid e-fuels for transport diesel engines. Diesel engines remain a relevant subject of research for Ukraine today, as they are used in vehicles not only for transporting goods, but also for the mobility of the defence sector and technological processes in food production. EU countries plan to reduce greenhouse gas emissions by 55 % by 2030 and achieve carbon neutrality by 2050. In this context, e-fuels have become a promising solution for reducing greenhouse gas emissions in transport. Classic e-fuels are synthesized from CO2 captured from the air and renewable hydrogen obtained by electrolysis of water. The energy for electrolysis comes from renewable sources of wind, solar, geothermal, tidal, or hydroelectric power. The main advantages of e-fuels are that they are produced from renewable energy sources and use existing fuel infrastructure with minimal changes. E-fuel production is not yet available on a large scale. Its use will gradually increase thanks to a phased increase in its concentration in blended fuels. At the same time, other similar carbon-neutral technologies will be introduced in transport. The first step towards carbon-neutral e-fuels is the introduction of paraffin fuels obtained from bio-raw materials using renewable energy sources. Such introduction in transport diesel engines ensures a reduction in CO2, soot and other harmful emissions. This is an intermediate stage until the mass production of purely synthetic paraffin e-fuels. The use of synthesised OMEx and DME e-esters in diesel engines as low-carbon fuels is possible in the short and medium term. This is the second step towards the spread of carbon-neutral e-fuels and technologies in transport. Before introducing such fuels, additional research is needed on their compatibility with diesel materials. Ukraine has an outdated fleet of vehicles that cannot be instantly replaced with new, more efficient ones. Research and development aimed at the phased introduction of carbon-neutral e-fuels in transport should minimise the harmful impact of existing motor vehicles on the environment.
