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).

SEARCH FOR WAYS TO IMPROVE THE TRACTION PROPERTIES OF LOCOMOTIVES AND TRACTION DRIVE DESIGN

The work objective is to increase the traction properties of locomotives without the use of traction drives with asynchronous traction motors and pulse width modulation. Research methods: methods of physical and field experiments, analytical methods for calculating the dynamics of the rolling stock. Conclusion: based on the conducted research, it is proposed to perform a promising diesel locomotive in the form of two sections on three two-axle bogies and a booster on two two-axle bogies, as well as to carry out experimental design work to develop an arc-type stator asynchronous motor and traction drives of a diesel locomotive using it.

Results of performance tests of an experimental class H insulation system for locomotive traction motors and its monitoring using the mobile diagnostics means

Objective: To perform traction electric motor performance tests with an experimental class H heat resistance insulation system. Methods: An experimental set of traction electric motors was manufactured at the Voronezh Diesel Locomotive Repair Plant to be compared with a motor of class F insulation. Results: The performance indicators of controlled locomotives have been summarized. Explanations and definition of additional insulation parameters and an example of their use in case of traction electric motor failure due to damage to controlled locomotives have been given. Practical importance: The proposed methodology for predictive diagnostics of traction electric motors performance can be used in service locomotive depots.

Thermal model of an asynchronous traction motor of a diesel locomotive

Objective: Evaluation of the temperature regime of the windings of an asynchronous traction electric motor with a squirrel-cage rotor (ATED) of the DAT-350 type of a 2TE25A diesel locomotive using the de- Современные технологии – транспорту 467 ISSN 1815-588Х. Известия ПГУПС 2021/4 veloped thermal model. Methods: The research was carried out by the fi nite element method in the application for calculating steady-state temperature fi elds SolidWorks. Resuls: To ensure the specifi ed service life of the ATED, the temperature rise of the windings must be limited to safe values, based on the insulation class. Therefore, it is crucial that designers and operators have access to accurate and computati onally effi cient, physics-based ATED thermal behavior modeling tools. Practical results: Using the proposed methods, it is possible to accurately and effectively evaluate the thermal characteristics of ATED of promising diesel locomotives. In addition, designers can easily and quickly adjust the parameters and performance characteristics of the ATED in such a way that they are conducive to improving the overall performance of the locomotive.

Simulation of thermal processes in asynchronous traction electric motor of a locomotive

This article analyzes the problem of increasing the reliability of AC traction electric machines installed on traction rolling stock. In the course of the study, a finite element model of thermal processes was built, and the thermal state of an asynchronous traction motor (ATED) of a diesel locomotive was studied in the Solid Works program. The basic method for studying thermal processes in ATED was the finite element method (FEM), as well as the basic equations of heat transfer and the theory of heating a multicomponent solid. The constructed finite element model of the ATED rotor of a diesel locomotive makes it possible to determine the dependence of the temperature values of the rotor elements on the current flowing through them. The obtained values of the temperature distribution of the ATED squirrel-cage rotor are recommended to be taken into account in the design, manufacture and testing of AC electric machines of diesel locomotives.

Study of heat transfer during steam condensation in the tubes of diesel radiator cores

The article contains an assumption about the practicability of using the processes of boiling and condensation of the coolant in the cooling system of a locomotive diesel in order to reduce the energy consumption of fans of the refrigerating chamber. The possibility of using of standard radiator cores of a diesel locomotive with flat tubes as steam condensers is considered. The results of the criterion equation of heat transfer from steam to a flat tube during condensation, obtained by the mathematical model of this process, are estimated. The assessment was carried out by comparison with experimental data. The influence of the initial steam velocity, the corresponding tube diameter, the working length of the tube, the physical properties of steam and condensate is considered. The comparison of the influence of these factors on heat transfer in round and flat tubes of a locomotive radiator core is carried out. The processed results of physical and numerical experiments for both circular and flat tubes are shown in the graphs and regression equations. The advantage of flat tubes over round ones in terms of heat transfer intensity during steam condensation, which can reach 24%, for a standard radiator core of a diesel locomotive was found.

SEARCH FOR RATIONAL EBGINEERING SOLUTIONS OF DIESEL LOCOMOTIVES FOR THE EASTERN RANGE

The purpose of the study is to search for rational engineering solutions for the main autonomous locomotive for the Eastern range of OAO Russian Railways. Research methods: methods of physical and field experiments, analytical methods for calculating the dynamics of the rolling stock. Research results and novelty: it is established that the use of a four-axle truck of a diesel locomotive TEM7 does not allow to create a locomotive that meets all the requirements of OAO Russian Railways, and the design of truck TEM7 is irrational for mainline locomotives; it is proved that the one-sided arrangement of brake blocks leads to deterioration in the locomotive braking properties. The bearing and axial towline, despite the use of an asynchronous engine, has an unsprung mass 1.5 times greater than that of the previously produced domestic analogue with a collector engine and almost the same mass of the wheel-motor unit; dynamic moments in the drive due to the lack of elastic elements during prolonged operation can reach 56% of the traction torque, which worsens the traction properties of the locomotive. Conclusion: it is advisable to carry out a design study of the drive variant with a support-frame asynchronous traction engine and an axial gearbox, as well as to conduct a technical and economic analysis and design study of a cheaper version of a diesel locomotive with sections on three two-axle bogies, maximally unified with electric locomotives, with a booster tanker module and AC-DC transmission with axial regulation of eight-pole collector motors with support-frame suspension.

Fracture failure analysis on drive shaft component of diesel locomotive

Failure analysis is a systematic method of investigation to find the cause of the failure mechanism of a component or equipment. This research describes the fracture analysis of driveshaft components in a diesel locomotive. The drive shaft which is a connecting component around the compressor in the locomotive engine has failed. The methods used in this study include literature studies, visual observations, data collection, material characteristics through chemical composition tests, hardness tests, tensile tests, microstructure observations, fractographic observation, data processing, and analysis of test results. Based on the results of chemical composition testing and mechanical testing shows that the drive shaft is classified as plain carbon steel, specifically AISI 1025 steel. Visual observations and microstructure observations show that the driveshaft failure occurred at the connection part, which is the connection around the welded region. From the fractography results show a visible pattern of deformation plastic that showing the fracture occurred since the connection cannot bear the load given.

Predictive analytics of the technical condition of diesel locomotive systems using neural network predictive models

Objective: Study of the possibility of carrying out predictive analysis of the technical condition of locomotive equipment using neural network predictive models enabling to plan the scope of equipment maintenance for routine types of maintenance and repair. Methods: A comparative assessment of the accuracy of forecasts made using a feedforward neural network and a recurrent network with an LSTM layer (Long Short-Term Memory) has been carried out. For training and test-ing of predictive models, we used the results of monitoring the parameters of the lubrication sys-tem of the 2TE116 (2ТЭ116) diesel locomotive by means of on-board diagnostics. Results: The aver-age interval for preventive inspections (TO-3) of locomotives in the existing locomotive mainte-nance system is 25–30 days, and therefore it is this interval that determines the minimum duration of the lead-in period, which the predictive model should provide. We have established that a mod-el based on a feedforward neural network provides sufficient accuracy only for short-term fore-casts with a lead period of no more than 1–3 days. With a further increase in the lead-in period, the error of the model res¬ponse increases to 10–15 %, which prevents it from being effectively used for solving practical problems associated with planning the operation of service locomotive depots. At the same time, the ave¬rage response error of the predictive model based on a recurrent net-work with an LSTM layer does not exceed 3,5–5 % over a 30-day lead-in period, so it can be used to plan the scope and timing of locomotive maintenance procedures. Practical importance: The possi-bility of using time-series analysis methods for predictive analytics of the technical condition of units and systems of a locomotive is shown. Predictive models based on recurrent neural networks with LSTM layers provide prediction accuracy and lead-in period sufficient for solving practical prob-lems that are associated with planning the scope and timing of locomotive maintenance.

ANALYSIS OF EFFECTIVENESS OF THE RISK MANAGEMENT SYSTEM FOR OCCURRENCE OF OCCUPATIONAL DISEASES FOR THE MOST DANGEROUS PROFESSIONS IN BELARUSIAN RAILWAY

The work examines the most dangerous, according to the results of certification of workplaces, professions of railway transport: driver (assistant) of an electric locomotive and a diesel locomotive, an attendant at a railway station, a track fitter, an electrician of a contact network. An analysis of the legislative acts in force in the Republic of Belarus, as well as local regulatory legal acts created on their basis, OSH management systems based on STB ISO 45001, the results of workplace certification showed the need to create a systematic approach to managing the risks of developing occupational diseases in the most dangerous professions on the railway. The work systematizes the factors that have the greatest influence on the risk of developing occupational diseases, based on the generalization and analysis of certification of workplaces, the leading production factors of the listed professions are highlighted.