Intensification of heat exchange in the vacuum boiler due to the application of external finishing of the heat pipe

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.