No abstract

The article proposes to evaluate the efficiency of an autonomous vehicle, taking into account not only the energy consumption for motion, but also the time of motion, i. e. both factors — efficiency and performance — should be taken into account. As a criterion for evaluating the efficiency of vehicles, authors propose the multiplication of efficiency on performance — the energy efficiency indicator (EEI). The best will be the vehicle with the highest EEI. The indicator should be calculated according to the specified technical characteristics of the vehicle laid down in the technical specifications. This criterion is suitable both for the evaluation of the vehicle during the design and during operation. At the same time, it is possible to evaluate and compare the EEI of technical vehicles not only of railway transport. The article presents the criterion values for water, rail and air transport. Proposed criterion makes it possible to evaluate the change in vehicle efficiency over time due to technical progress. Since 1953, the energy efficiency of a diesel locomotive has increased almost 3 times. To calculate the operational energy efficiency, it is necessary to obtain data on the actual performance of the vehicle. On railway transport, this is data on train work in t·km, speed and fuel consumption. The EEI assessment based on operating data will show how correctly the organization of vehicle operation is built, how non-stationary modes of the power plant and specific modes of traction influence the overall performance of the vehicle, how well the vehicle is selected for these operating conditions.

Due to the increase in the cost of diesel fuel, much attention is paid to the use of alternative types of fuel on diesel locomotives. Variants of using fuel obtained from coal, plants, gas fields and hydrogen are considered. Natural gas is the cheapest and most accessible today. The use of specially designed gas-piston engines on diesel locomotives, operating when the gas-air mixture is ignited from an external source, is the most attractive option. However, this approach has certain disadvantages:• it is necessary to create a new engine, since the modernization of existing engines requires serious structural changes;• gas piston engine operates essentially according to the Otto cycle and has lower efficiency and power indicators as compared to a diesel engine;• when modernizing existing diesel locomotives, switching to the Otto cycle excludes the possibility of using diesel fuel.Conversion of diesel locomotives to gas fuel must be carried out using the gas-diesel cycle. This approach is most acceptable for the modernization of diesel locomotives of the existing fleet, since it preserves the thermal performance of the engine and makes it possible to transfer diesel locomotives back to operation on diesel fuel. The main obstacle to the transfer of diesel locomotives to the gas-diesel cycle is the low degree of replacement of diesel fuel with gas. This circumstance is determined by the significant difficulties in ensuring the operation of the engine in the gas-diesel cycle at low loads and idling. It is necessary to ensure a stable supply of ignition fuel in these modes and guaranteed ignition of the gas-air mixture from it. The solution to this problem is ensured by maintaining a given stoichiometric ratio in the gas-air mixture and a temperature sufficient to ignite the ignition portion of the fuel.The main way to regulate the stoichiometric ratio is to reduce the amount of air entering the cylinders by throttling it at the engine inlet. This article discusses the methodology for calculating the performance of the engine when throttling the air inlet.

Подписку на научно-технический журнал «Вестник научно-исследовательского института железнодорожного транспорта» («Вестник ВНИИЖТ») можно оформить в любом почтовом отделении связи по Объединенному каталогу «Пресса России», том 1 или агентствах по распространению печатных изданий «Урал-Пресс», АРЗИ и др. Подписной индекс журнала-70116. Также можно оформить подписку (годовую и полугодовую) на договорных условиях в редакции.

To date, there is a large number of programs that simulate the train operation of the locomotive using the method of traction calculations. As input data in the program, information is entered about the track section, locomotive and train composition. The drawback of modeling the train motion using the traction calculation method is the obtaining of a local unimportant result for a particular section of the track. The article proposes a new approach to modeling the operation of freight mainline locomotive. The train operation of the mainline locomotive is represented by a limited number of generalized modes depending in turn on a limited set of initial conditions - the profile of the track section, the weight of the train, the speed of the locomotive, etc. In this case, the elements of the set of initial conditions are random variables. The advantage of the proposed approach is the ability to give a generalized assessment of the change in the performance of the locomotive train when introducing new elements and control algorithms into the diesel generator unit without linking to a particular section of the track. Comparison of the time of work on the positions of the driver's controller was obtained during the year by mathematical modeling and experienced runs with diesel locomotives of the 2TE116U series at Oktyabrskaya Railway, a branch of the Russian Railways. It showed that the maximum discrepancy between calculated and experimental data does not exceed 5 %. The proposed algorithm for simulating the train operation of the freight mainline locomotive allows reproducing the locomotive train performance parameters with an acceptable accuracy for practice. It can be used to obtain quantitative estimates of the impact of changes in the performance of the train operation of long-distance freight diesel locomotives when new elements and control algorithms are introduced into the diesel generator unit.