УЧЕТ ЛУЧИСТОГО ТЕПЛООБМЕНА В ТЕПЛОПРИТОКЕ К КРИОГЕННОМУ РЕЗЕРВУАРУ

Liquefied natural gas (LNG) is currently a dynamically developing energy source, providing flexibility in natural gas supplies and the ability to supply remote areas without access to main pipeline infrastructure. When operating LNG storage systems, one of the determining factors affecting energy efficiency is the heat flux from the environment to the cryogenic tank. The relevance of this study stems from the development of technologies for the production, transportation, and storage of liquefied natural gas, including small-scale LNG complexes, for which improving the accuracy of heat load assessment can be significant during the design and operation of the facility.The aim of this study is to develop a mathematical model for calculating the heat flux to LNG through the thermal insulation of a cryogenic tank, taking into account the influence of radiant heat exchange with the environment. A vertical semi-isothermal cryogenic tank with vacuum-powder insulation is considered as the object of study. The proposed mathematical model for calculating heat transfer allows us to determine the spatial distribution of heat fluxes across the tank surface depending on the orientation of individual sections relative to the sun. The model takes into account the main components of external thermal effects, determining the temperature state of the tanks outer surface and the magnitude of heat gain through the multilayer wall.This study simulated the distribution of the tanks outer surface temperature and the heat gain to the LNG along the circumference of the cylindrical section of the tank. The simulation revealed that the outer surface temperature and the heat gain to the LNG are distributed unevenly around the tanks circumference. Maximum heating is observed in sections directly oriented toward the sun, due to the varying intensity of solar radiation reaching individual surface areas. The obtained results confirm the need to consider the spatial nature of the thermal effect on the tank when performing thermal calculations. The proposed model can be used in the design of LNG storage systems, the selection of cryogenic tank design parameters, and expert assessments of their performance characteristics.