Thermomechanical finite element analysis of hot water boiler structure

Abstract

The paper presents an application of the Finite Elements Method for stress and strain analysis of the hot water boiler structure. The aim of the research was to investigate the influence of the boiler scale on the thermal stresses and strains of the structure of hot water boilers. Results show that maximum thermal stresses appear in the zone of the pipe carrying wall of the first reversing chamber. This indicates that the most critical part of the boiler are weld spots of the smoke pipes and pipe carrying plate, which in the case of significant scale deposits can lead to cracks in the welds and water leakage from the boiler. The nonlinear effects were taken into account by defining the bilinear isotropic hardening model for all boiler elements. Temperature dependency was defined for all relevant material properties, i. e. isotropic coefficient of thermal expansion, Young’s modulus, and isotropic thermal conductivity. The verification of the FEA model was performed by comparing the measured deformations of the hot water boiler with the simulation results. As a reference object, a Viessmann - Vitomax 200 HW boiler was used, with the installed power of 18.2 MW. CAD modeling was done within the Autodesk Inventor, and stress and strain analysis was performed in the ANSYS Software

Construction optimization of hot water fire-tube boiler using thermomechanical finite element analysis

“…Boiler breakdowns and destruction of their elements are caused by extreme values of contaminated stresses in the structure itself [18][19][20][21][22][23][24]. Other values are also important, because breakdowns in the structure do not always occur on locations where maximum stresses are located.…”

“…It should be emphasized again, that in this paper an absolutely clean boiler was analyzed, with clean boiler surfaces at nominal operation mode. The situation is certainly more critical with real operation conditions [18,24]. Accidents and failures that have so far occurred in hot water boilers with similar design mentioned in [18], occur in welded joints of pipe carrying wall and screened wall of the reversing chamber.…”

“…The analysis of the fire tube geometry and its influence on thermal loads in boiler construction is given in articles [14][15][16][17]. The influence of the scale deposits contaminated on heat exchange surfaces on thermal stress formation in hot water boiler structure was analyzed by authors in [18][19][20].…”

Numerical Simulation on Thermodynamics Performance in the Fireproof Sealing by Finite Element Analysis

“…Zhang [7] conducted a comprehensive modal analysis of Z-shaped beam electrothermal microactuators for the first time, and both longitudinal and lateral vibrations were taken into account to obtain the vibration equations of the unique geometric feature: a Z-shaped beam with a shuttle in the middle. Zivkovic et al [8] investigated the influence of the boiler scale on the thermal stresses and strains of the structure of hot water boilers with the finite elements method by ANSYS software, and maximum thermal stresses appeared in the zone of the pipe-carrying wall of the first reversing chamber. Tomecek [9] studied thermal response of steel columns with lost protection material and varying amounts of missing protection when exposed to the ASTME-119 furnace environment by a finite element analysis of heat transfer.…”

Thermo-plastic finite element analysis for metal honeycomb structure

“…A lot of researches had been made on metal honeycomb structure, but researches on its thermoplasticity is rare and preliminary, among which thermo-elastic analysis [1], impact damage [2,3] and elastoplastic analysis [4][5][6][7] of metal honeycomb structure have been studied extensively, and mathematical models for thermal systems are also available in open literature [8,9]. Figure 1 is a plate with considered composite material structure to withstand heat shock.…”