DIAGNOSTICS OF DIESEL ENGINE REFRIGERATION ELEMENTS AND WAYS OF INCREASING TECHNICAL AND ECONOMIC INDICATORS

The reliability of automotive equipment is its ability to perform constructively laid down functions without additional labor and material costs to maintain an able-bodied condition for a long time. Due to the fact that the quality of automotive equipment is characterized by its reliability and performance, increasing the level of reliability is an urgent task at the present stage of development of the technical operation of agricultural equipment. In addition, increasing the reliability of automotive vehicles is a promising way to reduce production costs, since the operation of more reliable equipment requires less labor and material costs. In the restored FS, the stabilization of the initial parameters during operation depends on many technological factors. The main reasons are those that greatly affect the reliability and have a wide range of characteristics under repair conditions. Changes in the technical condition of diesel engines during operation have a great impact on the indicators of fuel efficiency and toxicity of exhaust gases, with the former accounting for half of the resource consumption in agriculture. In order to achieve the necessary environmental and economic performance indicators of an autotractor diesel engine, its characteristics and fuel supply parameters should be adjusted in accordance with the operation and operating mode of the engine. Such a solution will make it possible to change the required parameters and characteristics, thereby ensuring the required nature of the flow of such fuel supply processes as spraying, mixture formation and combustion in each mode of operation. For efficient fuel injection into a diesel cylinder, it is necessary to have a significant reserve of fuel pump performance. Accordingly, a decrease in productivity can lead to a decrease in the amount of cycle feed. Based on the determination of the fuel consumption in the low pressure line of the system, the following tasks can be solved: - assess the technical condition of the fuel system in operation; - to optimize the balance of fuel supply in the experimental FS of the accumulating type and thereby reduce the power consumption for the operation of the system.

Modernization of the Mechanical Fuel System of a Diesel Locomotive Engine through Physical and Numerical Modeling

Reducing harmful emissions from exhaust gases and increasing energy efficiency are urgent tasks when designing reciprocating internal combustion engines. In this experimental work, the fuel system of a diesel locomotive engine operating on the Miller cycle is improved. The purpose of the study is to improve the environmental and economic indicators of diesel engines at minimal financial cost. The article provides an overview of the main research on improving fuel supply, mixing and combustion. The features of engine operation are also briefly described. Numerical simulation of the diesel engine operating cycle was performed before the bench tests. The experiments were performed on a full-size diesel engine with a power of 1200 kW. The measuring equipment and experimental technique are described in the article. The technical solutions that made it possible to improve the fuel supply are described. A new design for the high-pressure fuel pump drive is proposed. The optimal fuel injection advance angles are determined. An original design for the fuel pump plunger was developed. The proposed technical solutions made it possible to reduce fuel consumption by up to 3% (from 217.8 to 211.4 g/kW·h) and NOx emissions two-fold (from 19.4 to 8.8 g/kW·h).

Stage 3a environmental compliance of the 6-cylinder tractor engine

The development strategy of the Minsk Motor Plant, implemented within the framework of plant and state scientific and technical programs, is aimed at producing competitive products that meet modern technical requirements of international standards and quality. The mandatory requirement for the successful promotion of diesel engines on the off-road vehicle market is to ensure the required environmental performance, with low fuel consumption and low engine cost. The well-known technical solutions aimed to achieve environmental indicators of the Stage 3A level significantly increase the cost of diesel engines, therefore, the achievement of the required environmental standards without a significant increase in the cost of engines can be considered an urgent task. Purpose. Stage3A Environmental Compliance for 6 Cylinder Tractor Diesel. Methodology. Experimental studies were carried out for diesel engines equipped with: a Common Rail BOSCH accumulator fuel supply system with an injection pressure of 140 MPa, injectors with 7 nozzle holes; a direct-action fuel supply system with a MOTORPAL fuel pump providing a maximum injection pressure of 100 MPa, MOTORPAL injectors and AZPI with five nozzle holes; combustion chambers of two types with bowl diameters of 55 and 67.5 mm; cylinder heads providing swirl ratios 3–4 and 3.5–4.5; high pressure exhaust gas recirculation system. The tests were carried out at characteristic points of the NRSC cycle at three crankshaft speeds: minimum idle speed 800 min-1, maximum torque 1600 min-1, and maximum power 2100 min-1. Results. It turned out that it is possible to achieve Stage3A emissions standards on 116 kW diesel engines using direct fuel equipment and a semi-open combustion chamber, on 156 kW diesel engines using a Low Cost Common Rail fuel supply system and an open combustion chamber. Originality. The results of the combustion chamber shape choice, the parameters of the fuel-injection equipment, the swirl ratio of the inlet channels, valve timings and parameters of the exhaust gas recirculation system made it possible to organize diesel engine workflow of the Stage 3A ecological level. Practical significance. Construction elements of the six-cylinder diesel engines have been developed and introduced at the Minsk Motor Plant.

A Study on the Application of Laser Cleaning on the Weld of the Gas Fuel Supply Pipe for DF Engine

While producing gas fuel supply pipes for duel fuel (DF) engines, a welding process is essential. Accordingly, specimen management before and after welding is crucial to obtain highly reliable weldments. In this study, we developed an environmentally friendly laser cleaning technology to address a toxic work environment and environmental pollution problems caused by chemical cleaning technology utilized in post-welding treatment of gas fuel supply for DF engines. An experiment was conducted by implementing surface laser cleaning of the butt and fillet weldment specimens according to process parameters. Conditions of process parameters were identified for facilitating laser cleaning and used in prototype production. The prototypes were processed through laser and chemical cleaning, and the quality of the end products was compared. The results indicated that the proposed method satisfactorily cleans the prototype surface without generating a toxic work environment and environmental pollution problems. Moreover, the roughness of approximately 5 μm was achieved on the laser cleaned surface. This is considered to be able to increase the adhesion of the paint compared to the smooth chemical cleaned surface during the painting for anticorrosion of the product.

Analysis of the Political Situation of the Protests: Cuba, between Disenchantment and Deprivation

This article seeks to provide a brief reflection on the causes of the recent social protests in Cuba that took place in July 2021, addressing in a special way the deprivation of services and rights as the main trigger for satiety and claims. As in 1994 protests were marked by the “special period”, in 2021 protests were set by the covid-19 pandemic and the unilateral coercive sanctions of the United States with an impact on three fundamental areas: tourism, remits and fuel supply.

TECHNOLOGICAL SOLUTION FOR MODIFICATION OF THE DESIGN OF HEATING DEVICES FOR FOOD PRODUCTION

Предложено технологическое решение для тепловых аппаратов пищевых производств, обеспечивающее снижение расхода энергоресурсов за счет автоматического регулирования температуры пламени, а также возможность функционирования на жидком и газообразном топливе без замены теплогенерирующего устройства. За счет конструктивных изменений устройства розжига и автоматизации подачи топлива в зависимости от его вида и требуемой температуры разогрева теплового блока возможна эксплуатация теплового аппарата в условиях низких температур окружающей среды. Модификация теплового блока обеспечивает возможность автоматического перехода работы теплового аппарата от топлива с низкой температурой воспламенения к топливу с более высокой. Предлагаемые изменения конструкции теплогенерирующего устройства позволяют расширить возможность управления температурой пламени с учетом температуры окружающей среды. Проведены теоретические и экспериментальные исследования работы тепловых аппаратов. Выявлено, что эффективность использования энергии от сгорания жидкого и газообразного топлива при разной концентрации углеводородного состава может быть обеспечена за счет использования термокапиллярного эффекта. Применение разработанного технического устройства автоматизации процессов подачи топлива и терморегулирования при работе теплогенерирующих элементов в конструкции тепловых блоков позволяет получить экономический эффект при сжигании жидкого топлива и повысить эффективность использования энергии от сгорания жидкого и газообразного топлива при разной концентрации углеводородного состава. A technological solution for heating devices of food production, which provides a reduction in energy consumption due to automatic control of the flame temperature, as well as the possibility of functioning on liquid and gaseous fuels without replacing the heat generating device, is proposed. Due to the design changes of the ignition device and automation of fuel supply, depending on its type and the required heating temperature of the thermal unit, the operation of the heating device in low ambient temperatures is possible. The modification of the heat block makes it possible to automatically switch the operation of the heat apparatus from fuel with a low ignition temperature to fuel with a higher one. The proposed changes in the design of the heat generating device make it possible to expand the possibility of controlling the flame temperature taking into account the ambient temperature. Theoretical and experimental studies of the operation of thermal devices have been carried out. It is revealed that the efficiency of using energy from the combustion of liquid and gaseous fuels at different concentrations of hydrocarbon composition can be ensured by using the thermocapillary effect. The application of the developed technical device for automating the processes of fuel supply and thermal regulation during the operation of heat-generating elements in the design of thermal blocks allows to obtain an economic effect when burning liquid fuel and increase the efficiency of using energy from the combustion of liquid and gaseous fuels at different concentrations of hydrocarbon composition.

Research On Fuel Compensation Control of High-pressure Common-Rail Diesel Engine Based On Crankshaft Segment Signals

This paper studies the high-pressure common-rail diesel engine fuel supply compensation based on crankshaft fragment signals in order to improve the uneven phenomenon of diesel engine fuel supply and realize high efficiency and low pollution combustion. The experiments were conducted on a diesel engine with the model of YN30CR. Based on the characteristics of crankshaft fragment signals, the proportional integral (PI) control algorithm was used to quantify the engine working nonuniformity and extract the missing degree of fuel injection. The quantization method of each cylinder working uniformity and algorithm of fuel compensation control (FOC) based on crankshaft fragment signal were established, and the control strategy of working uniformity at different operating conditions was put forward. According to the principle of FOC control, a FOC control software module for ECU was designed. The FOC software module was simulated on ASCET platform. The results show that: Compared with the traditional quantization method, the oil compensation information extracted from crankshaft fragment signal has stronger anti-interference and more accurate parameters. FOC algorithm can accurately reflect the engine's working nonuniformity, and the control of the nonuniformity is reasonable. The compensation fuel amount calculated by FOC is high consistency with the fuel supply state of each cylinder set by experiment, which meets the requirement of accurate fuel injection control of common-rail diesel engine.