Авіаційно-космічна техніка та технологія (Aug 2023)
Features of the application of alternative fuels in heat engines
Abstract
The subject of the study is the use of alternative fuels and hydrogen in heat engines in different concentrations at different operating modes. The purpose of this study is to decarbonize various types of transport, especially aviation, to increase the energy efficiency and environmental performance of heat engines. Task: to investigate the use of such alternative fuels as biofuels, synthetic fuels, hydrogen and hydrogen mixtures. The use of aviation fuels shows that they must satisfy the relevant requirements, so the choice of alternative fuels must satisfy these requirements with the improvement of their characteristics, first in terms of energy efficiency and environmental indicators. To do this, starting with the ground test of a modern aircraft engine, Rolls-Royce conducted tests on an early conceptual demonstrator using green hydrogen. Green hydrogen was created by wind and tidal energy to prove that hydrogen could be the zero carbon aviation fuel of the future with zero carbon emissions. After analyzing the early ground test concept, the developers are planning a series of further bench tests leading to a full-scale ground test of a green hydrogen jet engine with the goal of achieving zero net carbon emissions from the engine Research Methods. According to the recommendations of the IPCC on the use of scarce fuel, the coefficients of harmful emissions (EI) are calculated for some types of aircraft for the Landing Take Off (LTO) cycle (landing / takeoff). Harmful emissions are calculated using the same method when alternative fuels are used in engines Since jet fuel emissions play an important role in the greenhouse effect, new technologies are being introduced to reduce emissions, among which one of the most effective and environmentally friendly is the use of biofuels, as biofuels are produced using modern biological processes. In this study, an experimental study of the influence of hydrogen addition on a traditional internal combustion diesel engine was conducted. The results. It was determined that the supply of small additions of gaseous hydrogen to the diesel manifold increases the efficiency of the engine at nominal and, largely, at partial modes of operation. The environmental parameters of the diesel engine are improved: the concentration of nitrogen oxides in the exhaust gases decreases, the soot content decreases by 30-40% and by 35%. A calculation method for the quantitative assessment of harmful emissions when using alternative fuels in aircraft engines is defined. Conclusions. The practical significance of the obtained results is that the obtained dependencies can be used when choosing the type of fuel for heat engines and determining the optimal concentration of an alternative fuel such as hydrogen to increase energy efficiency and improve the environmental performance of heat engines.
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