減圧弁を用いた低圧化樹枝状パイプラインにおける固有振動周期と圧力脈動の関係

抄録

   Low-pressure pipelines using pressure-reducing valves often have an arborescent system with multiple pressure-reducing valves installed at different locations, resulting in a complex system. In the case of low-pressure pipelines, pressure vibrations that do not decay continuously occur after the pipeline is put into service, and effective countermeasures are required. We examined the period and amplitude of pressure vibrations by spectral analysis based on the records of in-service arborescent pipelines. As a result, it was clarified that the occurrence of pressure vibration in a low-pressure arborescent pipeline using a pressure-reducing valve is determined by the combination of the natural frequency period of the upstream and downstream pipelines of the pressure-reducing valve. In the case of an arborescent pipeline with multiple pressure reducing valves, the natural frequency of the upstream pipeline is dominant when there is a branch pipeline whose natural frequency is synchronized with that of the upstream and downstream pipelines of the pressure reducing valve.