The study of a tractor diesel engine operation on ethanol and rapeseed oil at various speed modes

Introduction (problem statement and relevance). The depletion of oil fuels reserves and the steady growth of their consumption will require new solutions in the development of technologies based on renewable energy sources. The study of the possible alternative fuels use in internal combustion engines is a complex scientific task, including the research of the alternative fuels effect on the power plants operation efficiency.The purpose of the study was to obtain the speed characteristics of a diesel engine operating on ethyl alcohol and rapeseed oil.Methodology and research methods. An air-cooled with volumetric mixture formation tractor diesel engine of dimension 2Ch 10.5/12.0 was selected as an object of research. The study was carried out by a comparative method. To measure the speed characteristic a fixed cyclic fuel supply was applied after the engine reaching the nominal operating mode at a crankshaft speed of 1800 min-1 and an average effective pressure in the cylinder of 0.588 MPa. This approach, with the all-mode regulator of the fuel pump turned off, made it possible to identify the main regularities of intra-cylinder processes at different speed modes of engine operation.Scientific novelty and results. The article presents the bench tests results of a diesel engine operating at various speed modes on ethanol and rapeseed oil, and analyzes in detail the main indicators of the combustion process and the effective engine performance in comparison to the use of traditional fuel. The practical significance lies in the possibility of using the obtained results to improve the diesel engines operation on alternative renewable fuels.

Results of calculations of soot formation in a tractor diesel engine running on biofuel

When burning fuel in a diesel internal combustion engine, soot is an undesirable product. To reduce the soot content in the exhaust gases, it is necessary to know the physical and chemical bases of the process of soot formation and soot burnout. Due to the determining role of acetylene in the formation of polycyclic aromatic hydrocarbons in rich mixtures in the low-temperature zone and the key role of acetylene in the surface growth of a particle in the high-temperature zone, it is concluded that the rate of surface growth of a particle is proportional to the concentration of acetylene in the reaction zone, which can be determined by the gas-kinetic method, numerically solving a system of differential equations for the components of the gas mixture under consideration.

Evaluation of the performance and gas emissions of a tractor diesel engine using blended fuel diesel and biodiesel to determine the best loading stages

Fossil fuels are the main energy sources responsible for harmful emissions and global warming. Using biodiesel made from waste deep-frying oil as an alternative fuel source in diesel engines has drawn great attention. This biodiesel is produced using the transesterification process and blends with mineral diesel at Faculty of Agriculture Saba Basha, Alexandria University, Egypt. The turbocharged diesel engine of a Kubota M-90 tractor was tested. The objectives of this work are to test tractor as a source of power in the farm using waste deep-frying oil biodiesel to utilize waste frying oils (WFO) in clean energy production on the farm and determine the best engine loading stages to maximize engine efficiencies for different fuel blends and reduce the environmental impact of gas emissions from tractor diesel engines in the farms. The experiment design was factorial, with two factors, where the first was the engine load (0%, 25%, 50%, 75%, and 100%) and the second was fuel blend (0%, 5%, 20%, and 100% biodiesel), and the effects of loading stages and biodiesel percentage on engine performance indicators of engine speed, power take off torque, power take off power, brake power, brake mean effective pressure, brake thermal efficiency, brake specific fuel consumption, and gas emissions were studied. The experimental results indicated that engine load percentage and fuel blend percentage significantly affected all studied characters, and the best engine loading stages were between 25 and 75% to maximize engine efficiency and minimize the specific fuel consumption and gas emissions. Increasing the biodiesel percentage at all loading stages resulted decreasing in Engine brake power (BP), brake thermal efficiency, Power take-off (PTO) torque, and brake mean effective pressure and increases in brake specific fuel consumption. Increasing the engine load resulted in decreases in O2 emissions and increases in CO2, CO, NO, and SO2 emissions. Increasing the biodiesel percentage in the blended fuel samples resulted in increases in O2 and NO emissions and decreases in CO2, CO, and SO2 emissions. The use of biodiesel with diesel fuel reduces the environmental impact of gas emissions and decreases engine efficiency.

THEORETICAL AND EXPERIMENTAL SUBSTANTIATION OF A METHOD FOR INCREASING THE EFFICIENCY OF REPAIR OF ELECTRIC HYDRAULIC NOZZLES OF AUTOMOTIVE DIESEL ENGINES

В работе рассмотрены вопросы ремонта электрогидравлических форсунок (ЭГФ), широко распространенных в автотракторных и комбайновых дизелях. Фактический ресурс ЭГФ в эксплуатации значительно ниже заявляемого и его восстановление путем проведения ремонтно – обслуживающих воздействий является целесообразным, как с технической, так и с экономической точек зрения. Проведенный анализ характерных неисправностей ЭГФ показывает, что одним из наиболее изнашиваемых элементов ЭГФ является контактная поверхность седла шарикового электромагнитного клапана. Рассмотрены типовые и альтернативные технологи ремонта седла клапана и предложен способ их улучшения вибронаклепом контактной поверхности. Сформулированы цель и задачи исследований. Проведены теоретическое обоснование процесса вибронаклепа седла шарикового клапана ЭГФ и его лабораторные и стендовые исследования, результаты которых подтвердили рабочую гипотезу о возможности формирования упрочненной вибронаклепом контактной поверхности клапана. Применение предлагаемого способа позволит увеличить ресурс отремонтированных форсунок, при небольших затратах на его реализацию. The article deals with the issues of repair of electro-hydraulic nozzles (EHN), which are widespread in automotive and tractor diesel engines. The actual resource of the EHN is significantly lower than the declared one and its restoration by carrying out repair and maintenance operations is expedient, both from a technical and economic point of view. The analysis of typical EHN malfunctions shows that one of the most wear-out elements of EHN is the contact surface of the seat of a ball electromagnetic valve. Typical and alternative technologies for repairing a valve seat are considered and a method for improving them with a vibration hardening of the contact surface is proposed. The goal and objectives of research are formulated. The theoretical substantiation of the process of vibration hardening of the EHN ball valve seat and its laboratory and bench studies, the results of which confirmed the working hypothesis about the possibility of forming a vibration rivet hardened contact surface of the valve, were carried out. The application of the proposed method will increase the resource of the repaired injectors at low costs for its implementation.