Investigations on Strength of Piping for Non-Condensable Gas Combustion (Part 1: Fracture and Deformation of Carbon Steel Pipes Induced by Hydrogen-Oxygen Detonation)

概要

論文の詳細を見る
This study investigated the strength of piping in boiling water reactors (BWRs) subjected to detonation of flammable gas that accumulates in piping. Accumulated gases in the piping of BWRs are stoichiometric hydrogen-oxygen and steam. Stoichiometric hydrogen-oxygen gas and about 5% nitrogen gas were detonated in carbon steel pipes with an initial pressure from 2.5 to 4.0 MPa at room temperature in our experiment. Plastic strains were measured with strain gauges and the behaviours of pipe ruptures were recorded with a high speed camera. Pipe specimens were ruptured rapidly with large plastic circumferential strain of more than 8%. A dimple pattern was observed in the fracture surfaces. Therefore, the fracture mode of carbon steel pipes under detonation pressure is ductile fracture. Although the maximum pressure of detonation was about 20 times higher than the initial pressure, it did not have greatly influence the strength of piping, since the oscillation of detonation pressure was shorter than the period that plastic strain was increasing. The effect of piping elements was also investigated. The detonation experiment was conducted with an elbow specimen and the highest strain was observed in the downstream pipe from the elbow rather than in the elbow element. Strain of 0.5% was induced by a detonation wave at a matching pipe for a closed pipe specimen that simulated a closed valve. However, a reflected wave ruptured the matching pipe. Since the pressure of the reflected wave at the closed end is much higher than that of the detonation wave, the integrity of the piping system is governed by the strength of pipes attached to closed valves.

Investigations on Strength of Piping for Non-Condensable Gas Combustion (Part 1: Fracture and Deformation of Carbon Steel Pipes Induced by Hydrogen-Oxygen Detonation)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク