Evaluation on reheater tube failure

The dynamic creep rupture of a secondary superheater tube in a 43MW coal-fired boiler by the decarburization and multilayer oxide scale buildup on both sides

“…There are various root causes resulting in the tube overheating, including a hotspot due to the localized uneven flue gas distribution [8,12], the tube scale buildup [1,4,8,9], and the steam flow reduction due to the scale exfoliation [10,21]. As the reference sample was cut from the same burst tube, the same steam flowed through from the reference location to the burst location.…”

“…Such as the steam-side oxide scales [1,9], the sodium aluminium silicate scale [4], the scale exfoliation [10,21], localized uneven flue gas distribution [8,12], and the clinker formation [8]. However, in all of previous studies, the continuing decarburization at high temperatures has not been taken account in boiler tube creep failure analyses.…”

“…In terms of the steam-side scales, the scale composition was believed to be magnetite (Fe 3 O 4 ) [2], which had been applied in simulation studies [8][9]. However, the research on the scale compositions reported diverse results.…”

“…The classic methodology applied the Larson-Miller Parameter (LMP) to analysis the tube life [5][6][7][8]. In recent studies, researches focused on the aspects of metallurgical and oxide scales [9][10][11][12][13][14][15][16][17][18][19][20][21].…”

The Effect of Temperature Distribution on Tube Rupture

“…They found that temperature was the main factor in the deformation due to tube restriction. Many researchers have reported failure analyses of boiler tubes (11)(12)(13). Purbolaksono et al emphasized overheating of the tube, concentrated flue gas flow, and coal having a low ash fusion temperature as the main causes of failure (13).…”