(ISSN: 2349-2082)

International Journal For Ignited Minds
 Published Article
Design Optimization of Thermal Sleeves for Desuperheating Applications
Jeevan Sunny , & G Satish Kumar
In the power plants, to improve the efficiency, it is a common practice to increase the steam temperature using superheaters. At the same time, when this steam is being sent to downstream components like condenser, it is essential to reduce the steam temperature due to the design conditions. This type of temperature reduction is called as desuperheating. In the current work, effect other two operating conditions (cold & warm starts) is neglected. Due to this reason, the allowable fatigue damage index is considered to 0.4 instead of 1.0. To understand the behavior of traditional design, a sequential thermomechanical analysis is performed. An axisymmetric model is taken which comprises of main stream pipe & liner geometries. A detailed nonlinear transient thermal analysis is performed for the hot start operating condition & thermal behavior of the component is analysed. Further, a full scale static structural analysis is performed and component’s deformation & stresses are studied. Fatigue life is estimated as per the method given in BS EN 12952-1:2010 Water tube boilers and Auxiliary installations Part-1. It is observed that current design is not qualifying. Thermal gradient in main steam pipe is creating inverted bow formation in the component & causing a high stress of 662MPa at the weld fillet. Fatigue damage index based on EN 12952-3 is calculated.
Fatigue Damage, Desuperheater, Thermomechanical, Axisymmetric, Nonlinear.
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