The article is devoted to one of the most important problems of modern power engineering is to improve the efficiency of fuel utilization, characterized by energy efficient motors. Traditional methods of improving energy efficiency are the use of secondary energy resources (heat) of the exhaust gas of engines and heat transfer for their cooling systems. The article presents the results of calculations of power efficiency of utilization of the turbine, working under direct Rankine cycle using different coolants. The basic reserve of increase of power efficiency of thermal engines is the rational use of secondary energy resources.To assess the prospects of using secondary energy resources heat transfer fluids (coolants) cooling systems the calculation of the heat pump, working on the reverse Rankine cycle. Based on the results of the calculations in the article the conclusion about the prospects of using these devices, including the replacement of Autonomous boilers in ship power plants. The article also contains proposals for use of alternative types of secondary energy resources, such as the mechanical energy of a fuel and its gladatorial. The article shows that the use of these energy resources seems to be promising when using gas fuel. This research is relevant in connection with active introduction of gas and gas-diesel engines in various sectors of energy and transport. The data obtained in the result of the research show that the use of secondary energy resources heat engines using the utilization of turbines and heat pumps of modern design is promising and allows to increase the rate of fuel consumption of piston and gas turbine engines. When using gaseous fuels have the additional possibility of using secondary energy resources.

The paper is devoted to the urgent problem of improving the automatic regulation of the thermal state of internal combustion engines and controlling the water-chemical cooling regimes during the transition to high-temperature cooling. Principal and functional diagrams of cooling systems with improved control are presented. The prospects of controlling the pressure in the internal circuit of high-temperature engine cooling systems and the automatic control of the physicochemical characteristics of the coolant have been proved.

The paper is devoted to the study of the regularities of changes in the quality of working fluids circulating through the systems of internal combustion piston engines. During the research, the parameters of fluids that characterize its operational properties, as well as external effects that can lead to changes in the properties of the fluid, were determined. It is shown that the deterioration of the quality of engine oil and coolant of piston engines during operation is caused by the destruction of additives that are part of the fluid and provide their required properties. A laboratory installation has been developed and created that allows simulating thermal and mechanical effects on working fluids similar to those acting during circulation through engine systems. The graphical dependencies obtained as a result of the experiment are presented. Mathematical processing of the experimental data allowed obtaining regression dependencies that correctly describe the processes of changes in time of the most important characteristics of working fluids under the action of cyclic thermal and mechanical effects. The described method can be used to study the influence of operational factors on the properties of various working fluids of internal combustion piston engines.

A prerequisite for the long-term and safe operation of marine diesel engines is the high quality of operational materials, which include engine oils and coolants. The required quality of operational materials is ensured by the introduction of additives into their composition, which are now increasingly used as nanoparticles. During operation, as a result of the destruction of additives, the operational properties of coolants and engine oils deteriorate. The conducted studies allowed us to evaluate the change in the lubricating ability of engine oils of two brands that are used in marine diesels during operation. As a characteristic of the lubricating ability of the oil, its kinematic viscosity was used. The experimental determination of the kinematic viscosity of engine oil samples having different periods of operation, and the subsequent mathematical processing of the experimental results made it possible to determine the dependencies characterizing the change in the kinematic viscosity of engine oil during its operation. The research results confirm the possibility of scientific justification for extending the use of marine diesel engine oils, which reduces operating costs and increases the environmental safety of marine diesel engines.

Forcing of ship internal combustion engines at the average effective pressure is accompanied by an increase in the maximum cycle pressure, an increase in the thermal stress of the cylinder-piston group parts and an intensification of their wear. Wear of parts of the cylinder group leads to an increase in the gap between the piston and the cylinder mirror. The consequence of increasing the gap is a decrease in heat transfer from the piston to the cylinder walls and an increase in the breakthrough of gases having a high temperature from the combustion chamber to the gap. A critical increase in the temperature of the piston can lead to its destruction and engine failure. The most typical types of piston failure are presented in the article. The aim of the research was to assess the influence of these two factors on the temperature condition of the piston. Calculation of heat transfer processes in the annular channel, performed using differential equations of energy and continuity, as well as the criterion equations of fluid flow in flat channels allowed to determine the temperature of the gases and the lateral surface of the piston at different values of the gap between the piston and the cylinder sleeve and different gas flow rates in the gap. The calculation was performed for the engine CHN 18/20, having a piston made of aluminum alloy. It was found that the increase in the number of gases entering the gap from the combustion chamber has a more significant effect on the temperature condition of the piston compared to the gap, increasing due to wear of the engine cylinder group parts. It is concluded that the number of gases with high temperature entering the gap leads to a significant increase in the temperature of the piston. The increase in the temperature of the piston due to wear of the parts of the cylinder group must be taken into account when determining its heat-stressed state. To ensure the permissible temperature level of the piston during operation, it is necessary to develop design and technological measures aimed at reducing the flow of gases through the gap between the piston and the cylinder mirror. Keywords: marine internal combustion engines, parts of cylinder and piston, wear, gas breakthrough, heat transfer in flat channels, the temperature condition of the piston, the reliability of marine diesel engines.

The article is devoted to the perspective direction of development of internal combustion piston enginesrealization of six-stroke working processes. The article presents an overview of possible options for the implementation of six-stroke cycles, known types of engines. The greatest interest is the six-stroke cycle with two working strokes of the piston, one of which is carried out under the pressure of the combustion products of fuel, and the second-under the pressure of steam formed as a result of water supply to the cylinder. This cycle is implemented in the Crower engine It is shown that the six-stroke cycle has a number of advantages over the four-stroke cycle: its implementation improves the economic and environmental performance of the engine, reduces the temperature level of parts, which has a positive effect on resource performance. On the basis of published indicator diagrams of six-stroke engines, diagrams of the total torques of four-cylinder engines operating on four-stroke and six-stroke cycles are constructed. It was found that the implementation of a six-stroke working cycle with additional injection of water into the cylinder leads to some deterioration of the uniformity of the alternation of the working strokes and the uniformity of the torque. The use of special schemes of crankshafts can contribute to some improvement in these indicators. Recommendations on the use of crankshafts with cross-shaped schemes in six-stroke engines are given The presented research technique can be used to select the preferred design of crankshafts for engines with different number of cylinders. Given the need for the preparation and storage of distilled water in the implementation of the six-stroke cycle, the conclusion is made about the possibility of using six-stroke engines as part of marine power plants. The necessity of further research of kinematics, dynamics and vibration activity of sixstroke engines is pointed out. Keywords: six-stroke engine, economic and environmental indicators, the order of working strokes, the uniformity of angular velocity and torque, the scheme of crankshafts.

No abstract

В статті проведено аналіз методів зниження токсичних компонентів відпрацьованих газів суднових дизелів та сформована узагальнююча таблиця. Визначено, що захист навколишнього середовища останнім часом є глобальною проблемою людства. Постійне збільшення споживання вуглеводних палив і викидів в атмосферу шкідливих речовин від їх використання викликає порушення природного процесу самоочищення біосфери і є загрозу життя людини. Для зупинки даного процесу, підписані міжнародні угоди, прийняті державні постанови і програми захисту навколишнього середовища від шкідливих викидів. Найбільш небезпечними компонентами відпрацьованих газів суднових дизельних двигунів фахівці більшості країн і співробітники Комітету з захисту морського середовища ІМО вважаються оксиди азоту NOx і оксиди сірки SOx. З огляду на специфіку суднових дизельних двигунів більшістю країн нормуються тільки викиди оксидів азоту, що знаходяться в складі відпрацьованих газів, а так само накладається обмеження на вміст сірки в суднових паливах, унаслідок чого відбувається зростання цін на паливо і збільшуються експлуатаційні витрати. Зроблено висновок, що розробка заходів із зменшення токсичності відпрацьованих газів може проводитися по таких напрямках: удосконалювання конструкції двигуна, урахування експлуатаційних факторів з корегуванням регулювальних параметрів дизельного двигуна, застосування альтернативних видів палива. Ідентифіковано, що найбільш перспективні рішення в області мінімізації викидів суднових дизельних двигунів можна відобразити наступними напрямками наукових досліджень і технологічних розробок: адаптація конструкції двигуна; оптимізація роботи паливної апаратури; використання каталізаторів виборчої нейтралізації; використання водопаливних емульсій. Доведено, що найбільш прийнятними методами є удосконалення робочого процесу дизеля (на його користь свідчать наступні показники: низькі початкові витрати, пов'язані в основній своїй масі з модернізацією окремих компонентів двигуна, практично незмінними експлуатаційними витратами і низький рівень технічного ризику) та використання водопаливних емульсій. Ключові слова: відпрацьовані гази, водний транспорт, водопаливна емульсія, екологічність, конструкція, судовий дизель.