1.5MWth炉灰付着試験での熟流東低下挙動に基づく，石炭焚きボイラでのスートブロワ頻度に関する検討

摘要

近年，CO_2削減の観点から，国内外の石炭火力発電所を対象にバイオマス活用が薦められる一方，石炭はその豊富な埋蔵量から今後も主力なエネルギー源になると考えられている。石炭焚きボイラにおける共通，かつ，根本的な問題として伝熱面への灰付着が挙げられる。付着灰は伝熱面での収熟を減少させ，ボイラ効率を下げる他，火炉出口閉塞等により予期せぬユニット停止を招く。%To obtain practical knowledge in operating soot-blowers without ash related problems, a series of slagging tests have been conducted at 1.5 MWth pilot plant and the rates of decreasing heat fluxes through the test probe simulating the water-wall have been determined. In this study, initial heat flux, this heat flux decreasing rate, and the heat flux at which decreasing heat flux rate is reduced are employed to predict the soot blowing time. A simple equation is obtained for predicting the soot blowing timing. Discussion is made on the derivation of the equation, and it is expected that the derived equation holds for any furnace.