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Introduction. The tasks of increasing energy saving in heating systems for passenger cars of diesel trains are currently relevant. As an alternative source of energy for these systems, the possibility of using the waste heat of the diesel locomotive engine is analysed.Materials and methods. The article provides an analysis of the engine waste heat sources, cooling water and exhaust gases. A schematic diagram of exhaust gas heat exchanger for its use in the heating system of passenger cars has been deve loped. As a possible heat-exchange surface of the waste heat exchanger, plate-ribbed, coiled and tube surfaces with longitudinal boundary layer turbulators are proposed. The required area of this surface for the maximum power of the heating system for a passenger train is determined.Results. The article shows the possibility of using engine exhaust heat in the heating system of a 15-car passenger train without involving third-party energy sources.Discussion and conclusion. The obtained results demonstrate a sufficient potential for increasing the efficiency of using the diesel engine fuel energy when utilising its waste heat for the heating system of passenger cars. The selection of a waste heat exchanger is justified based on a performance of 50 % of the peak load on the heating system at the middle position of the controller.

Adoption by Russia of the Kigali Amendment to the Montreal Protocol on substances that deplete the ozone layer posed a very difficult task for consumers of artificial cold, including rail transport, to find an acceptable alternative to the R134a freon and mixtures based on it, which is being phased out. Considering that there are no equivalent alternatives to these substances on the market, it was proposed to consider the use of widely known and previously used working fluids in climate technology, based on the positive experience of the European Union (EU) countries. The article analyzes the reasons for the bans on the use of hydrofluorocarbons, presents the mechanism for the legal use of refrigerants that are safe for humans and nature in the EU and a version of the roadmap for converting the climatic units of the Russian Railways holding to R22 freon and other types of fluorocarbons within the framework of the Kigali Amendment.

Maintaining optimal parameters of the microclimate in the car along the route is the most important requirement for the passenger’s travel. In the 1st class passenger cars, maintaining optimal microclimate parameters is achieved through the operation of the air conditioning system, which provides individual regulation of the air temperature in each compartment. Individual air temperature control systems used in air conditioning systems are divided into two groups: active and passive.The article proposes for consideration a combined active-passive system with a separate air supply with a lower and higher temperature compared to the temperature maintained in the compartment and the installation of individual induction terminals, which makes it possible to increase the efficiency of individual regulation of air parameters in the compartment.To assess the uniformity of temperature distribution and air flow rate over the car volume with the proposed control scheme, a three-dimensional modeling of the distribution of these parameters in the compartment was carried out on the basis of Autodesk CFD software.The given simulation results indicate the uniformity of temperature and air flow rate distribution over the compartment volume, which makes it possible to characterize the proposed system as sufficiently energy efficient, easy to operate and reliable in operation.

Delivery of perishable freights in proper quality essentially depends on the correct choice of a special vehicle and the correct calculation of the delivery time. According to the requirements of the Rules for the transportation of perishable freights by rail, all special vehicles by January 1, 2022 must obtain certificates of compliance with the standards established by the Agreement on the International Transportation of Perishable Foodstuffs and on special vehicles intended for these transports. This requirement applies to special vehicles used both in international traffic and for transport of perishable freights within the country. The article presents a brief classification of special vehicles used for the transportation of perishable freights. Formulas are given that allow calculating duration of transportation of such freights and average temperature of the outside air along the entire route. Procedure for choosing a special vehicle for the already known duration of freight transportation has been developed. It is concluded that the procedure proposed by the authors allows choosing the optimal special vehicle for the transportation of perishable freights. Using this sequence of calculations makes it possible to take into account the maximum number of external factors that affect the duration of transportation.

Alternative energy sources, mostly related to “green” energy, are one of the promising trends in the development of energy generation, including for the global railway sector. This is due, firstly, to its desire to preserve its environmental advantages by reducing carbon dioxide emissions into the environment and increasing energy efficiency, and secondly, to a reduction in the use of such sources as oil and coal as fuel resources in the coming decades.In a world where 95 % of motorized vehicles use oil as fuel, the greenhouse gas emissions per passenger-kilometer for rail transport are five times less than for road transport and 20 times less than for air transport. Therefore, one of the key tasks in the development of railway transport is the creation of high-speed highways that will serve as an alternative to road and air communications over short distances.In addition to the well-known alternative energy technologies, the railway transport traditionally conducts scientific research to improve energy-saving technologies, which include the use of excess recuperation energy when rolling stock braking.Also, projects for the use of renewable energy sources — heat pump installations — have proved their effectiveness in railway transport: heating switches from the ground, use of heat from compressors of hill complexes to heat electrical centralization posts and heat transformers of traction substations for its own needs.The role of alternative energy sources in railway transport is constantly growing. The efficiency of using alternative energy sources at the Russian Railways is largely determined by a scientific approach that allows, based on own experience or experience in introducing innovations in related industries, to determine the place, time and degree of their implementation, taking into account technical and technological features of production processes inherent in a particular structural unit companies. Among the innovative technical solutions in railway transport, the most priority ones are solutions aimed at the development of high-speed lines, recuperation systems, as well as heat pump technologies.

Satisfying the needs of the population in the delivery of perishable freight of good quality largely depends on the stable operation of specialized vehicles and the accuracy of calculating the deadline for transporting freight to the consumer. The main value used to calculate the deadline for the transportation of perishable freight by rail is the heat transfer coefficient of the body of an insulated car or container. The accuracy of estimating this value is especially important when using isothermal cars or containers that are not equipped with cooling or heating systems as specialized vehicles. In this paper authors assess the influence of some external factors on the value of the heat transfer coefficient of the body of an isothermal vehicle. The change in the heat transfer coefficient due to the influence of the speed of the isothermal vehicle and insolation is taken into account. The heat transfer coefficients from the internal and external building envelopes to the ambient air for the standing car and during its movement are determined to assess the change in the heat transfer coefficient from the criterion dependencies. Taking into account real external factors, in particular outdoor temperature, humidity, train speed, significantly affects the heat transfer coefficient of the body of an isothermal vehicle, the value was determined in stationary conditions of the workshop and underlying the calculation of the maximum permissible terms for the transportation of perishable freights. This value is excellent from the actual value. As a result of the calculations, a discrepancy of the value of the deadline for the transportation of perishable freights in comparison with the current method is 3–10 %.Changes to the existing methodology will reduce the risk of delivery of perishable freight of inadequate quality due to incorrectly calculated deadlines for transportation.

Passenger rolling stock is operated in various climatic conditions, calculated outside temperature can vary from -40 to +40 °С. The microclimate parameters permissible for a long stay of people (the longest route is about 6 days) are achieved by installing ventilation, air conditioning and heating systems. Currently, more and more attention is being paid to the safety and comfort of passengers, and the urgent task is to create a climate system that ensures that the air environment in the premises of passenger rolling stock is up to date with all requirements. To ensure safe parameters of the car air environment, it is necessary to increase the influx of outdoor air to 20-35 m3/h per person, which allows achieving a CO2 content of 1000 ppm. It should be taken into account that an increase in the flow of external air and its conditioning leads to an increase in the cost of electricity (in order to fulfill the requirement for the content of CO2, an increase in the power of the heaters by 1.5-2 times is required), and therefore, the cost of transportation. Comparison of sources of additional energy, the use of which can increase the flow of external air into the car with minimal additional loads on the power supply system, showed the greatest efficiency of the installation with a heat pump that uses the heat of the exhaust air to heat the supply air in combination with maintaining air back-up for protection against dust. Proposed technical solution allows to increase the level of comfort in passenger cars with minimal energy costs for air processing and equipment dimensions. The problem of increased hydraulic resistance of the installation is solved by using a beam of transversely streamlined pipes with longitudinal turbulators of a hydraulic boundary layer as the heat exchange surface of the evaporator of the heat pump. This surface will allow to develop a heat exchanger with minimal resistance and thereby get away from the need for forced traction, limiting to a minimum back pressure of 15 Pa.

The main parameter determined in heat engineering tests of heat insulated cars superstructures or the locomotive operator’s cabs is the heat transfer coeffi cient К. The study introduces automated analysis technology for the heat transfer coeffi cient К of enclosure structures of the heat insulated transport means using a remote server. The underlying method provides coeffi cient K of the heat insulated transport means without additional work and time loss for complicated calculations. Personnel of test laboratories involved in heat engineering tests of vehicles possess tools for remotely calculating К, from any point in the world with internet access. To obtain К three controlled parameters measured during the heat engineering tests for 5.5 h including: the difference of the inside and outside temperature of the test object superstructure, total power of the electric heaters and geometric area of the heat transfer surface are sent to the server, after which the user promptly receives the calculated К. The economic effect of introducing the proposed technology for vehicle manufacture is the absence of required tests conducted at the test center; for an operating company — a signifi cant reduction of the idle time of the vehicle at the test center directly affects the loss of profi t. The proposed technology expands the area of operation of the test centers, while calculated К values are offi cially input into the data sheet of the vehicle.

When conducting thermal tests, the purpose of which is to determine the heat transfer coefficient of the body of an isothermal car K, the study of measurement errors affecting the accuracy of the obtained value plays an important role. The results of such experiments may contain various measurement errors that can introduce significant deviations into the resulting values of the desired coefficient. Obtaining accurate results when conducting this kind of experiments is impossible without a preliminary study of the causes that affect the final result. The article presents the types of measurement errors that affect the accuracy of determining the heat transfer coefficient of the body of an isothermal car when conducting thermal tests. It was noted that the magnitude of labor costs and energy losses during the further operation of this body significantly depends on the accuracy of the value of this coefficient. It was emphasized that one of the main types of random errors arising from measurements and compliance with the established procedure for conducting typical thermal tests is a voltage drop (“slump”) in the electrical network, leading to significant errors in the calculations of the heat transfer coefficient of the isothermal car body. The values of this coefficient are presented, which were obtained as a result of heat engineering tests performed using the equilibrium mode method and the express method. It is shown that the use of the express method to determine the heat transfer coefficient of the bodies of isothermal cars reduces the risk of random errors due to the minimum experiment duration (from 5.5 h), allows to obtain exact values of the desired coefficient (with an error not higher than 3 % of its value of long-term equilibrium method) and use this data for practical purposes.

The article shows the structure of the computer program “Express estimation system of the heat transfer coefficient for the vehicle”. The performance sequence of the automated calculation for determining the heat transfer coefficient ( K ) is described on the example of the refrigerator car body with the use of the data obtained during the accelerated thermal engineering tests. The advantages of the announced program are shown, consisting in a substantial reduction in the duration of testing, excluding the influence of the human factor when performing calculations and reducing the costs of organizing documentation flow. It was noted that for the operators of isothermal vehicles (ITV) the formation of an automated database with the calculated values results of K allows not only to monitor the dynamics of their changes during the ITV operations, but also with sufficient accuracy to predict the time of reaching the critical values of K , after which the regular energy installations will work with a significant expenditure of fuel and energy resources. The results of the expected economic efficiency in determining K by the accelerated method are presented; its value for the main types of ITV operating in the JSC “RZD” will be at least 14.0 billion rubles.

The article analyzes the heat exchange processes the thermal imaging method using a thermal imaging device. An occurring in the body of an isothermal vehicle when determining algorithm for determining the heat transfer coefficient is proposed, the heat transfer coefficient K by the internal heating method. which makes it possible to calculate its value with an accuracy not The differences are shown in the values of the heat transfer coef-exceeding 5 %, which is regulated by a number of international ficients obtained by the equilibrium internal heating method and normative documents, while reducing the duration of the experiment by at least 6 times. The study gives comparative experimental data and results of calculating the unknown values of K for bodies of isothermal vehicles obtained by the equilibrium method and an express method based on the algorithm described in the article. It is shown that the use of the algorithm for calculating the heat transfer coefficient of the body of an isothermal vehicle will not only increase the productivity of testing stations, but will also lead to the organization of an electronic passport for the thermotechnical state for each body of an isothermal vehicle, the control of which will enable timely diagnosing the thermo-technical condition of the bodies of isothermal vehicles, providing energy-optimal operating modes of energy equipment and, hence, increasing its resource.

At present, large-capacity refrigerated containers (LCRC) are widely used for the transport of perishable goods. Transportation of such containers by rail is carried out by couplings of 10-12 fitting platforms and a car with diesel-electric power station. Analysis of this method of transporting large-capacity refrigerated containers by rail showed that it has a number of shortcomings that complicate the transportation process and increase the costs of the carrier (or perishable freight owner).Reduction of costs for the transportation of LCRC can be achieved by equipping the fitting platforms with an autonomous power supply system with a generator-drive unit (GPU) from the axis of the wheel pair of the bogie. However, most of the fitting platforms are installed on three-piece freight bogies, and this creates certain difficulties when embedding the GPU into the undercarriage space.Based on the performed analysis of domestic and foreign designs of generator-driven units and the results of studies for 18-100 three-element freight bogies, it is recommended to use a two-stage drive from the wheel pair axis consisting of a single-stage gear reducer and a V-belt drive, allowing to achieve a total gear ratio of 5,3.According to the chosen scheme, design documentation was developed and two prototypes were made. Experimental samples of GPU with a two-stage drive passed preliminary and acceptance tests, according to the results of which it is recommended to make an installation batch. At present, two 60-foot fitting platforms equipped with an autonomous power supply system are being manufactured for the purpose of carrying out running tests.

In many areas of the economy the problem of bringing a complex control object at a predetermined state corresponding to a preassigned certain requirements arises. To solve it, the terminal management method is used. A typical example of tasks of terminal control is to manage synchronization of the tank emptying with the petroleum product with simultaneous synchronous writing off of its mass recorded in the database during supply of oil products. The article addresses the control method of supply of petroleum products to the consumer that allows in the terminal time to save the initial value of unbalance between the actual mass of oil product in a reservoir, and the mass of oil product indicated in the accounting documentation. In practice, the method can be implemented with control algorithm of terminal control, provided that the relative error of the incoming of the actual mass of oil product to the tank is within the range stated in regulations. The article offers mathematical apparatus, based on results of probability theory and statistical decision theory, showing that the use of control method allows keeping the original supplier relative error for oil product when it is delivered to the consumer, not increasing it by the error of measuring instruments by tank and / or accounting site.

To adapt container flats for transportation of high-capacity reefers (HCR) there was developed stand-alone power supply system (SAPSS) to be mounted on the flatcar three-piece freight bogie. Such a system ensures power supply to HCR all over the travel route by rail. One of the SAPSS key components proves to be generator drive unit comprising generator, V-belt transmission and single-reduction gear unit with dissectible driving gear mounted in the midpart of the wheelset axle. To confirm workability of the generator drive unit and obtain its pull and energy characteristics there were conducted rig tests of its prototype using for this purpose exerciser developed by the VNIIZhT design center. The exerciser was equipped with instrumentation systems capable to determine V-belt tension by the tension screw force value and assess slipping by rotating speeds of the driving and driven V-belt pulleys. Rig tests implied container flat running at various speeds. Three SAPSS loading modes were tested inclusive of open circuit operation. There was purposely developed testing procedure, allowing to assess slipping of the V-belt transmission within the accuracy of 0.01 %. Experimental data were collated with calculation results obtained by the authors beforehand. The SAPSS prototype tests outcomes evidence that generator drive unit is capable to support the system operation at power levels up to 16±1 kW within the container flat running speed range from 30 to 132 kph.