XIII Международная студенческая научная конференция Студенческий научный форум - 2021

Analyzing the prospects for the development of engine building in Russia and abroad, we can say that one of the main directions in this area is to increase specific power indicators, fuel efficiency and durability. The total capacity of reciprocating internal combustion engines (PICE) used in the national economy is about 5 times more than the installed capacity of all stationary power plants, so their efficiency plays a crucial role in the fuel balance of our country, and the relevance of improvement increases, especially in the direction of reducing fuel consumption.

The increase in power, efficiency and environmental friendliness of the internal combustion engine is usually limited by the heat stress of the parts of the crank mechanism and the turbine wheel of the turbocharger. The improvement of combustion, gas exchange and fuel supply processes, as well as the use of modern materials and technologies for processing engine parts, leads to an increase in effective and mechanical efficiency and, at the same time, limits the limit of engine acceleration, both in terms of speed and load.

First of all, this limit depends on flow characteristics of air-gas paths of the gas exchange systems of PICE, which is influenced by the size and number of valves per cylinder, quality grading and inlet channels with valves, and intake and exhaust manifolds. Thus, gas exchange in 4-stroke PICE, both with and without supercharging, is carried out at the expense of the traditional valve timing mechanism (MGR), on which the flow characteristics, heat stress and the limits of forcing the engines as a whole largely depend.

Boosting engines by their liter capacity and speed mode leads to an increase in the amount of gas passing through the gas distribution organs, and a reduction in the time of gas exchange processes, and, as a rule, gas dynamic losses in the intake and exhaust processes of 4-stroke PICE become more important. All this leads to known negative consequences – an increase in gas-dynamic losses in the gas exchange organs of the PICE, deterioration in efficiency, reaching the limit limits for heat stress, smoke and toxicity.

Taking into account these circumstances, when working to reduce gas-dynamic losses in gas-air paths, it is possible to improve their consumption characteristics and technical and economic indicators of engines in general. Therefore, studies conducted both in our country and abroad give full grounds to assert that one of the promising directions for improving the effective performance of the PICE is to improve the flow characteristics of the main elements of the gas exchange system, in particular, channels with intake and exhaust valves of 4-stroke PICEs, since they are the main source of gas-dynamic losses when filling cylinders with fresh charge, purging and exhaust gases, because the existing reserves in this area have not yet been exhausted.

The latter is also confirmed by the practice of creating modern automobile engines, in which the recent decrease in power and efficiency due to the constantly tightening requirements for reducing exhaust gas toxicity was eliminated, in particular, by improving gas-air paths in the direction of increasing air consumption and reducing pump losses. To further enhance the limits of speeding up and reducing the heat stress of PICE is necessary to modernize the traditional (valve) engine timing (GDM) to increase the passage section of the gas path for the exhaust stroke and the organization of the purge cylinder on the intake stroke, i.e. to create non-traditional GDM with traditional valve and extra spool GDM.

An additional spool GDM is a window in the cylinder liner, made in the vicinity of the lower dead center of the piston, the opening and closing of which is made by the "spool", i.e. the piston. Exhaust gases are discharged into the common exhaust manifold at the exhaust stroke in non-traditional GDM both through the exhaust valve and through the window in the cylinder liner, and at the intake stroke the cylinder is purged through the intake valve and also the window in the sleeve, provided that the pressure in the intake manifold is higher than the pressure in the exhaust manifold. Such a technical solution exists and is protected by a patent, the author of which is L. M. Zhmudyak. The established working names of the proposed engine: "engine with double exhaust exhaust" or " engine with an additional window in the sleeve (engine with AWS)" or simply "engine with a window in the sleeve" abbreviated-AWS.

References:

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2. Andryushchenko A. I. Fundamentals of technical thermodynamics of real processes /A. I. Andryushchenko. - M: Higher School, 1975. - 264 p.

3. Vinokurov B. N. Improvement of economic indicators of VTZ diesel engines by improving exhaust channels /B. N. Vinokurov et al. //Improving the performance of engines and tractors. Perm, 1987, pp. 19-26.

4. Zhmudyak, JI. M. Method of operation of a four-stroke internal combustion engine / L. M. Zhmudyak Patent No. 2024773 M. cl. F02B 37/00 N4796343, application. 28.02.90; publ. 15.12.94, byul. No. 23.

5. Zhmudyak L. M. General approach to diesel optimization on its mathematical model//Engine building.-1981. - no. Z.-S. 3-10.