CFD a MKP analýza kolektoru kotle

CFD and FEA Boiler Collector Analysis

conference paper

en

This article presents a troubleshooting analysis of a steam boiler which serves for steam overheating. Operating of this boiler is accompanied by unexpected difficulties – repetitive crack occurring on a boilers collector (Figure 1). Therefore, the substantial part of this paper is focused on identifying of the main reason of damaging. The first step in damage identification was static, respective quasi-static FEM (finite element method) analyses. These analyses did not confirm the cause of damaging. Therefore, it was approached to analytical calculations (thermal – hydraulic and vibration calculations) which were used for additional boundary conditions estimation. The vibration analytical analyses predicted vortex excitation. The occurrence of vortex excitation behind the tube (Figure 6) was subsequently confirmed by CFD (computational fluid dynamics) and FSI (fluid structure interaction) analyses. These analyses revealed the cause of tube bundle damaging, which was fluid induced vibration. Significant part of this article is devoted to discussion about used computational models, boundary conditions and results of analyses. The last part of this article is targeted at proposing corrective action.

Článek se zaměřuje na odstanění závad vzniklích při provozování parního kolektoru. Toto provozování je doprovázeno opakujícím se výskytem trhlin na kolektoru kotle. Podstatná část článku je zaměřena na identifikaci hlavního důvodu poškození. Prvním krokem je identifikace poškození statickým působení tlaku a teplot. Následně je přistupováno k tepelně hydraulickému kontrolnímu výpočtu a CFD analýze. CFD analýza odhalila vznik vírových excitací za jednotlivými trubkami trubkového svazku. Značná část článku je věnována diskuzi o použitých vpočtových modelech, okrajových podmínkách a výsledcích jednotlivých analýz. Poslední část článku je zaměřena na navrhování nápravných opatření.

This article presents a troubleshooting analysis of a steam boiler which serves for steam overheating. Operating of this boiler is accompanied by unexpected difficulties – repetitive crack occurring on a boilers collector (Figure 1). Therefore, the substantial part of this paper is focused on identifying of the main reason of damaging. The first step in damage identification was static, respective quasi-static FEM (finite element method) analyses. These analyses did not confirm the cause of damaging. Therefore, it was approached to analytical calculations (thermal – hydraulic and vibration calculations) which were used for additional boundary conditions estimation. The vibration analytical analyses predicted vortex excitation. The occurrence of vortex excitation behind the tube (Figure 6) was subsequently confirmed by CFD (computational fluid dynamics) and FSI (fluid structure interaction) analyses. These analyses revealed the cause of tube bundle damaging, which was fluid induced vibration. Significant part of this article is devoted to discussion about used computational models, boundary conditions and results of analyses. The last part of this article is targeted at proposing corrective action.

kotel, trubkový svazek, MKP, CFD, metoda vzájemné interakce, vibrace, vibrace vyvolané prouděním

boiler, tube bundle, FEA, CFD, FSI, vibration, vortex induced vibration

2014

23.08.2014

Aidic Servizi S.r.l.

Milan, Italy

978-88-95608-30-3

2283-9216

Proceedings of the 17th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction PRES 2014

39

847–852

6