РАСЧЕТНОЕ ИССЛЕДОВАНИЕ ВОЗМОЖНОСТИ УЛУЧШЕНИЯ ТЕРМИЧЕСКОГО СОСТОЯНИЯ ЭЛЕМЕНТОВ ГАЗОТРУБНОГО КОТЛА-УТИЛИЗАТОРА

Abstract

The numerical experiment is described, made in the student version of the finite element analysis ELCUT software based on a mathematical model of one of the most thermally loaded units (gas chamber - building) of the gas-tube exhaust boiler, the results of the experiment are set out. The objectives of the modeling are to determine the fields of temperature and temperature gradients of the shell of the gas chamber options with and without thermal insulation inserts, as well as quantitative and qualitative evaluation of the thermal state of the exhaust boiler’s neck for both cases. The preparation of numerical experiment is described: the creation of a geometric model of the test site in the form of a set of blocks with an individual set of properties for each of them; assignment of the 3-rd class boundary conditions in the media of contact surfaces; due to the structural complexity of the model and the limitations imposed by the student version of the software ELCUT, the step of finite element grid was set manually. The numerical modeling results proved advisability of reducing the temperature gradient in the metal of the gas chamber along its axis, reducing the overall temperature in the experimental element by installing heat-insulating insertion, as well as sufficiently confirmed exactly a high level of stresses in the shell of the gas chamber, which has no insulation. As a result, the most dangerous section of the exhaust boiler’s neck case was determined and the information on the state of the temperature of the neck case elements for options with and without thermal insulation insert was provided, indicating the possibility of double reduction of temperature gradients along the generator of the gas chamber and, accordingly, the possibility of double reduction of thermal stresses in the most loaded zone.