No 3 (2020)

Articles

Analysis of the effect of a closed crankcase ventilation system on the fuel efficiency of a compression ignition engine

Andriyanov S.M., Matveyev A.A., Nikishin V.N., Fardeyev L.I.

Abstract

This article provides relevant information regarding the analysis of the effect of crankcase gas bypass from the crankcase ventilation system into the intake manifold of a highly boosted compression-ignition engine with turbocharging. The information on the breakthrough of crankcase gases into the crankcase through a cylinder-piston group is provided. The data on the types of execution of crankcase ventilation systems, their features and environmental impact are presented. State standards and international standards for the development and requirements for closed and open crankcase ventilation systems are shown. The article reveals the need to evaluate the engine workflow when developing a closed crankcase ventilation system. The development and verification of a mathematical model of the engine workflow with a closed ventilation system was carried out. The reliability of the mathematical model is confirmed by a maximum deviation of up to 1 % from the results of full-scale engine tests, in terms of specific fuel consumption, maximum combustion pressure and crankcase gas consumption. A description of the methodology of the design study and the elements of the design of thermodynamic model of the engine with a closed and open crankcase ventilation system is described. An analysis of the design study and comparison of two versions of the engine ventilation system is made. The influence of an open and closed ventilation system on the effective engine performance in terms of specific fuel consumption and maximum combustion pressure is presented. There is evidence that confirms that the supply of crankcase gases to the intake manifold impairs the fuel economy of the engine, especially at low operating modes, and the difference can go up to 1 g/kWh.
Tractors and Agricultural Machinery. 2020;(3):3-9
pages 3-9 views

Advantages of locating the converter before the turbine of the boost unit

Kaminskiy V.N., Kaminskiy R.V., Filippov A.S., Titchenko A.Y.

Abstract

The article discusses the principles of operation of the catalytic neutralization system located in the exhaust path to the turbine of the diesel boost unit or gas engine. The important advantages of such a system are the high efficiency of reducing emissions of harmful substances in a wide range of loads and the possibility of using thermal energy of catalytic reactions in the operating cycle of a hybrid engine. Due to the increased neutralization efficiency, it is also possible to use catalytic reactors with a smaller core volume. The work on an experimental study of a new arrangement of the neutralization system was started in JSC “Scientific and Production Alliance “Turbotehnika”. The work is aimed at determining the possibility of regulating the power of the turbine using the heat flux of the neutralization system. To obtain the necessary thermal effect, it is proposed to use the supply of additional (secondary) fuel to the input of the catalytic converter. The oxidation of secondary fuel is provided by the presence of free oxygen in the exhaust gases of the engines during the combustion of lean mixtures. An additional regulation of the turbine power is designed to eliminate the known problems of a single-stage gas turbine pressurization, which is the lack of available exhaust energy in the low-speed region and the delay in the reaction to transient modes. The article presents the results of an experimental study of a prototype converter as part of an engine on a motor test bench. Confirmation of the possibility of additional control of the turbine was received. As a result of the research and testing, the features of the new design of the neutralization system, which provides for the combination of a converter with a turbocompressor in a single module, are identified. It is proposed to place a cellular toroidal catalytic unit in the cavity in front of the turbine coil.
Tractors and Agricultural Machinery. 2020;(3):10-18
pages 10-18 views

Estimation of fuel efficiency of automobile and tractor diesel engines, operating with the shutdown of part of the cylinders

Gots A.N., Guskov V.F., Fomin V.M.

Abstract

The analysis of previously performed studies to determine the fuel efficiency of automobile and tractor engines when a part of the cylinders is disconnected is carried out. This is done by stopping the fuel supply to them with simultaneous disconnection of the gas distribution mechanism for the same cylinders or without affecting the gas distribution organs in partial operating modes. It is shown that if the cylinder shut-off system for engines with forced ignition is used in serial engines, then additional research is required for diesels, since the results of experimental studies given in the literature are contradictory. The previously proposed methods are based on the use of experimental characteristics, empirical dependencies, and other experimental data that are valid only for specific diesels and their operating modes. In addition, the assessment of fuel efficiency is mainly performed by calculation without experimental confirmation. Therefore, the results of computational studies presented in some papers differ qualitatively from the results of experimental studies presented in other papers. A method based on generalized experimental data is proposed that allows the load characteristics of a full-size diesel engine to calculate its indicator and effective indicators when the fuel supply to some cylinders is stopped. The results of experimental and computational studies of changes in the fuel efficiency of a 4CH10,5/12 diesel engine in partial modes when a part of the cylinders is switched off are presented. At the same time, several options are considered - by stopping the fuel supply and closing the intake and exhaust valves, as well as without any impact on the organs of the gas distribution mechanism. It is shown that the improvement of the fuel economy of the 4CH10,5/12 diesel engine when a part of the cylinders is disconnected with the intake and exhaust valves closed is due to the absence of pump losses in the disconnected cylinders.
Tractors and Agricultural Machinery. 2020;(3):19-27
pages 19-27 views

Selection of the optimal system of differentiated fertilizer application and the laboratory research results in Northern Kazakhstan

Tokarev I.V., Kuvayev A.N., Derepaskin A.I., Bobkov S.I.

Abstract

The paper presents the analysis of systems for differentiated fertilization and the results of laboratory tests of subsurface fertilizer cultivator. The technology of the differentiated fertilizer application (DFA) is one of the priority areas in precision agriculture. The purpose of the research is to select the most effective DFA system for subsurface fertilizer cultivators applied in the northern regions of Kazakhstan and to test the design and technological scheme of pneumatic transport. The optimal system of differentiated application of fertilizers was chosen according to the generalized desirability function, the main difficulty was to create a sign that quantitatively determines the functioning of the object under study. To construct a multiple optimization parameter the idea of converting the natural values of specific object parameters into an unbounded scale was used. The obtained information on systems of differentiated fertilization was processed using standard methods of comparison, analysis, and synthesis. The results of laboratory tests were processed using methods of mathematical statistics. Based on the research results, according to the generalized desirability function the system «Agronavigator-Dozator» was chosen, which consists of a navigation system «Agronavigator Plus», GLONASS/GPS antenna, actuators, connecting cables and control panel for remote activation of the "Processing" mode. According to the laboratory tests, the functionality of the pneumatic transport system for mineral fertilizer granules and the dosing device was tested. The structural and technological scheme of pneumatic transport includes a fan driven by a hydraulic motor, airflow distributor, connecting pipelines and ejector funnels. It is established that in the range of fan revolutions from 2100 to 2700 rpm stable transportation of granules is provided without blockage of pipelines and ejector funnels, airflow speed in pipelines is provided in the range from 13 to 25 m/s. The deviation of the actual fertilizer dosage from the target was 2.1-5.0 %.
Tractors and Agricultural Machinery. 2020;(3):28-34
pages 28-34 views

Computational and experimental assessment of the influence of ultra-low pressure tires of mobile power equipment on soil

Godzhaev Z.A., Goncharenko S.V., Artemov A.V., Pryadkin V.I., Godzhaev T.Z.

Abstract

The article describes a method for determining the maximum pressures in contact of an ultra-low pressure tire with deformable soil: with low bearing capacity using the example of a thin-walled tire 1020x420-18 of the Bel-79 model. In the current practice of determining the effect of pneumatic tires on the soil, the method of determining the contact area of a tire on an undeformable flat bearing surface is used. By dividing the load on the tire by the obtained contact area, multiplied by correction factors, the maximum tire pressure on the soil is obtained. By comparing the maximum pressure obtained in the tire contact with the non-deformable bearing surface with the permissible pressure, the correspondence of tractor and agricultural tires to operating conditions on soils with a certain moisture and hardness is evaluated. But this method of assessment is unacceptable for tires of low and ultra-low pressure due to significant deformation of the tire and soil: in contact and, therefore, a larger contact area and lower values of maximum and average pressure on the soil. Therefore, the novelty of the work is an experimental assessment of the impact on the soil of tires of low and ultra-low pressure on deformable soil. The method includes the experimental determination of the dependence of tire and ground deformations on air pressure in a tire and load, as well as the dependence of the contact area sizes on deformable soil on tire and ground deformations. The contact areas and the coefficients of the uneven distribution of pressure in the contact according to the average values and shapes of the diagrams determine the maximum pressure in the contact of the tire with deformable soil. As a result, the curves of the dependences of maximum pressures in contact on air pressures and loads on deformable soil for low and ultra-low pressure tires were obtained for the first time. The dependences of maximum pressures in contact on air pressure at fixed loads can be a kind of passport for thin-walled tires, similar to the traction characteristics of tractor tires and the traction and speed characteristics of automobile tires. The results obtained make it possible to determine with high accuracy the operating conditions of high-traffic vehicles on low and ultra-low pressure tires.
Tractors and Agricultural Machinery. 2020;(3):35-47
pages 35-47 views

The increase of four-wheel tractor maneuverability

Akhmetov A.A., Kambarov B.A., Kambarova D.U.

Abstract

Along with the positive turning qualities, the shortcomings of three-wheeled tractors, associated with their instability, limited traction and coupling qualities and low total load capacity of tires, were noted. (Purpose of the study) The purpose of the study is increasing the maneuverability of a four-wheel universal row-crop tractor, ensuring minimal loss of productive areas in the headland zone at the edges of irrigated areas with cotton and other crops. (Materials and methods) The works on increasing the maneuverability of four-wheeled universal row-crop tractors are done at the Design and Technology Center for Agricultural Engineering. By increasing the angle of rotation of the steered wheels, the conditions to achieve a minimum radius of rotation of the tractor are created. (Results and discussion) There was developed a new design of the steering drive steering trapezoid of the universal row-crop tractor, where each half of the front cut symmetrical thrust from the side of the plain arm is shaded by a spring-loaded end disk, freely placed inside the hinged plain arm of the cage. In this case, the cavities of the cage, separating the end disk, are made in the form of communicating vessels, and the end disk itself is made in the form of a piston-valve, resting against the pressure of the spring on the saddle, cut at the bottom and connecting both cavities of the holder through two holes and ditches. (Conclusions) The new design of the steering trapezoid of the steering drive allows to increase the angle of rotation of the steered wheel during a turn, as a result when the tractor is turned, the axes of rotation of all three wheels in horizontal projection intersect at the intersection of the axes of symmetry of the fourth braked (right when turning «to the right» or left when «left turn») of the rear wheel. As a result, the intersection point of the axes of rotation of all the wheels is the center of the tractor’s turn, and it makes a turn around the braked rear wheel with a minimum radius and, thereby, eliminates the disadvantages of the well-known universal-row tractors.
Tractors and Agricultural Machinery. 2020;(3):48-53
pages 48-53 views

Regularities of contact interaction of small-sized supporting elements of walking machines with weakly bearing soils

Chernyshev V.V., Goncharov A.A., Kalinin Y.V., Arykantsev V.V., Al-Dumaini O.A.

Abstract

The results of finite-element modeling of the mechanics of contact interaction of small-sized support elements (feet) of walking machines with weakly bearing soils are discussed. A flat contact task is formulated for rigid feet of a rectangular shape interacting with an elastoplastic supporting surface. Nonlinear models of soil behavior under loading were used. A two-stage iterative algorithm for solving the non-linear problem in the computer system of finite element analysis ANSYS is implemented. The task was solved under conditions of large deformations of the supporting surface. The simulation results showed that a sufficiently large amount of soil is loaded during the interaction of a small foot with a supporting surface. Under normal loading, the greatest stresses and strains occur directly under the foot. Here may be the destruction of the soil. At a standardized depth of 0,5 m, the stress decreases. The top layer of soil remains lightly loaded. In addition to vertical deformations, there is a «squeezing» of soil to the right and left from under the foot. With a tangential load, the stress and strain fields lose their symmetrical nature. The zones of greatest equivalent stresses and strains are shifted towards the action of the tangential load. The greatest ground stresses occur under the foot and on the lateral surface of the foot. In the direction of the tangential load, the entire mass of the soil, including its upper layers, is substantially loaded. Near the foot, in the zone of greatest stresses, a characteristic area appears, where the soil is squeezed up. Here the reverse process of compaction of the soil takes place. It is shown that the use of feet with a small supporting surface leads to an undesirable increase in soil stresses in the contact zone. On the other hand, in small feet, there is a decrease in the soil compaction zone and its upper layer is less loaded. Also, for small feet, the supporting surface is used more efficiently - the stresses along its length are distributed more evenly, and the side surface acts as a grouser.
Tractors and Agricultural Machinery. 2020;(3):54-61
pages 54-61 views

Results of the study of the separator chopped heap of crops

Polyakov G.N., Shukhanov S.N.
Tractors and Agricultural Machinery. 2020;(3):62-67
pages 62-67 views

Development of indicators for a comprehensive assessment of the intellectualization of machine production of vegetable crops

Dorokhov A.S., Sibirev A.V., Aksenov A.G.

Abstract

Vegetable growing is an important branch of agricultural production. Among the many vegetable plants, more and more importance is given to crops whose products contain physiologically active substances. These crops include nightshade vegetables - tomatoes, bell peppers, eggplants and onions. For the production of vegetable crops, complexes of special and universal machines are used. Universal vehicles include general-purpose vehicles, energy vehicles of various traction classes, special vehicles - planting equipment, cultivators, irrigation machines, chemical protection. The intensity of agriculture in modern production conditions is impossible without a high level of saturation of machine-technological complexes with intellectualization. Obtaining high-quality competitive products is possible only with the use of modern high-performance machines that ensure the combination of technological operations, the design of which includes automated process control systems, soil fertility accounting, and ensuring ecological cleanliness of agricultural landscapes. The use of intelligent technologies is becoming a global trend in modern agricultural production, when during performing technological operations, large amounts of information is collected and processed. Technical means and machines for the implementation of such technologies should also have a certain degree of intelligence, should be equipped with devices for collecting, processing and transmitting information, making decisions on certain algorithms and implementing management decisions. The article presents the results of studies determining indicators of a comprehensive assessment of the intellectualization of machine production of vegetable crops.
Tractors and Agricultural Machinery. 2020;(3):68-74
pages 68-74 views

The relative position of the flax plant strip and stripping apparatus during separate cleaning

Zintsov A.N.

Abstract

Nowadays, with an acute shortage of high-quality raw materials for the textile industry and a significant increase in energy prices, the introduction of separate flax harvesting technology in production is becoming especially urgent. However, the use of such technology is constrained by its high dependence on weather conditions and the lack of reliable and inexpensive equipment. The greatest difficulty for mechanization is the second phase of separate cleaning, which is most dependent on weather conditions. The level of weather dependence entirely depends on the design features of the pick-up stripping apparatus, which main working body is the apparatus for separating the seed of the crop from the stems. It was established in the work that the quality of this apparatus depends on the width of the zone of arrangement of the boxes in the plant ribbon and on its ordinate relative to the clamping conveyor of the stripping apparatus. During the pickers operation, the indicated ordinate changes to a wider extent due to systematic errors in copying the flax tape in the horizontal plane by the selecting working body. In order to maximize the collection of products during separate flax harvesting, scientists of the Kostroma State Agricultural Academy investigated the process of separating the seed part of the crop from the stems with a stripping apparatus, taking into account the influence of the mentioned factors. The results of experimental studies have shown that the stated requirement is fulfilled with a minimum size of the box location zone (≤ 30 cm) and its distance from the front edge of the clamping conveyor by 53 cm. In this case, all seed boxes fall into the area of action of the ridges of the stripping apparatus, and the loss of stems does not exceed 3 %. It is possible to stabilize the optimal position of the plant ribbon using an orienting device and a system for automatically moving the stripping apparatus. The minimum size of the zone of location of seed boxes can be ensured only with high quality performance of all previous technological operations for the cultivation of flax.
Tractors and Agricultural Machinery. 2020;(3):75-80
pages 75-80 views

The development of fertilizer application technology and the structure of the fleet

Kokiyeva G.E., Voynash S.A.

Abstract

Intensive and industrial technologies are based on the effective use of chemicals. However, its capabilities are far from being fully utilized. The shortage of grain crops cultivated by intensive technologies was largely predetermined by the low level of organization of agrochemical work. A successful increase in the effectiveness of the use of all types of fertilizers and chemical plant protection products is possible only on the basis of an integrated quality management system for technological processes (IQMS TP), which includes interrelated organizational, technological and social activities. The technological process of using solid organic fertilizers is a set of technological operations for the preparation of fertilizers (composts), their loading, transportation and incorporation into the soil, i.e. complex system. The efficiency indicators for it are the uneven distribution of nutrients over the entire cultivated area and the dose of fertilizers. Given that the complete identification of the technological process is a complex task, in this paper authors restrict themselves to establishing functional relationships between indicators of the second, third, and fourth levels. The need to establish a connection between these levels is due, first of all, to the fact that the quality of the technological process of using fertilizers in a production environment is determined mainly by the operations of their preparation and application, which can be controlled and managed. To justify the technological tolerances for performing these operations, authors first established a functional relationship between indicators characterizing the quality of distribution of nutrients in the mass of fertilizers and the distribution of their physical mass throughout the field to be processed, and complex indicators of the quality of distribution of nutrients in the same field. According to the compost preparation operation, dependencies are established between such input indicators as the quality of the initial components (humidity, density, fractional composition), their ratio, and the output: humidity, density and fractional composition of the obtained fertilizer, quality of distribution of nutrients in the mass. As technological constants and parameters the dependence should also include the preparation time, energy consumption for preparation and other indicators. These data are necessary to optimize the preparation operation and the entire technological process.
Tractors and Agricultural Machinery. 2020;(3):81-88
pages 81-88 views

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