Search results

Article is devoted to mathematical modeling of heat transfer to the cooling system of locomotive diesel engine . The article presents the features of calculation of heat to the cooling system of a diesel engine when idling.

The article deals with the cooling and heating of individual components and assemblies diesel engines at low ambient temperatures. The more attention is paid to the description of the characteristics of the intensity of the cooling water system of diesel locomotive engines. The article presents the results of investigation of the outdoor temperature , operating conditions of load and no-load on the cooling system of. The parameters of the cooling water and engine oil that characterize the thermal conditions of the diesel engine. We reviewed and analyzed various ways of warming systems, diesel engines using airborne and stationary devices. The work is aimed at improving the efficiency of diesel locomotive at warming by reducing the operating time of the diesel engine is idling.

In article the way increases in system effectiveness of cooling locomotives in operation - use relaunches of heat carriers between contours is considered.

Described the prospects for the use of highly efficient boilers as an autonomous source for generating heat for the priority tasks implementation of the strategy for the development of railway transport in the Russian Federation until 2030 approved by the Government of the Russian Federation. The features of operation and design of a vacuum boiler, advantages and disadvantages are considered. The necessity and method of heat exchange processes intensification in a vacuum boiler to increase its efficiency and reduce fuel consumption are substantiated. The main provisions of the mathematical model for thermal calculation of a vacuum boiler using the k-ε model ANSYS CFX to describe turbulent flows of a reacting gases mixture, taking into account heattransfer by radiation and convection, and the RPI ANSYS CFX model, describing the liquid boiling processes. The results of computational studies using the RPI ANSYS CFX model for boiling on smooth and finned cylindrical surfaces are presented. The computational studies results of the pressure effect in a rarefied volume on thermophysical characteristics and operating parameters of the boiler, such as wall temperature from the water side, heat losses with exhaust gases on a smooth and ribbed surface are shown. The influence of the ribbing coefficient on fuel economy is shown at various pressures. Reasonable recommendations for creating a design of energy-efficient vacuum boilers with improved weight and size characteristics are presented. The application of the design for an energy-efficient of vacuum boiler with transverse ribbing on the outer flame tube surface with rational geometric characteristics is substantiated; a rational coefficient of ribbing Ψ = 1,89 is presented.

Transportation in tank cars of viscous liquid cargo (fuel oil, paraffins, industrial oils, cracking residues, etc.) is difficult with their solidification, accompanied by a sharp increase in viscosity. In fact, this leads to the need to warm up or partially warm up the transported oil product before unloading, usually carried out as a gravity discharge, in order to restore the fluidity of the delivered oil cargo. The process of unloading in this case with heating leads to a significant increase in the cost of transporting petroleum products, including the downtime of tank cars, and in general, a decrease in the turnover of rolling stock. According to the analysis carried out to determine the costs of the technological process of heating frozen petroleum products transported by rail, about 600 thousand tons of conventional fuel are spent per year, and the idle time of tank cars under unloading and subsequent cleaning of boilers from high-viscosity residues of oil cargo exceeds 1 million car-hours. The urgency of the issue of reducing the cost of railway transportation of viscous cargo is due to the intensive development of the Northern and Eastern regions of the Russian Federation. Important factors for transportation in these conditions are not only the negative average daily air temperature, but also long distances. The issue of reducing the cost of transportation of viscous petroleum products at low air temperatures is considered. Viscous petroleum products, when thickened, turn into a rheological liquid, which does not have a clear interface between the liquid and solid phases. The methods of transfer to the stratified state of hot fuel oil during its slow cooling and partial solidification with the formation of a heat-insulating layer of solidified fuel oil are applied. The positive effect is achieved by reducing the time and cost of thermal energy for unloading the delivered oil product by reducing the rate of its cooling during transportation. This, in turn, is achieved by suppressing the natural convection of the hot oil product on the cold walls of the boiler of the tank car in the first few hours after filling the tank. From the comparison of the experimental data and the calculation results, the values of the empirical coefficients of the equation for the heat transfer coefficient of liquid petroleum products are selected. The standard deviation of the absolute temperature of the liquid petroleum product was 8 %.