加熱下降蒸気流管群の流動不安定現象に関する研究

抄録

Steam flow disturbance and the resultant tube metal temperature excursion have been experienced in heated downflow tubes in large capacity utility boilers during low load operation. In order to solve the problem, analysis has been made by studying the hydraulic characteristics of steady and unsteady conditions. The analysis results showed good agreement with the phenomena experienced at existing boilers. It is diagnosed that the stability of flow is improved by additional flow resistance to the tubes. The countermeasure to install thicker tubes has been applied to the boilers and it is demonstrated that the flow stability is acquired through the field operation and measurement.