Abstract
In Hokkaido Eastern Iburi Earthquake in 2018, strong ground motion attacked a coal-fired thermal plant. A connecting part of a furnace and a cage of a boiler in the power plant and steam tubes in that part were damaged. Consequently the damage of the power plant induced a large impact to society. Suppressing relative displacement between the furnace and the cage might be effective to reduce this kind of the damage, because the furnace and the cage vibrate independently during earthquakes. Therefore this paper proposes application of dampers to the connecting part of the furnace and the cage of the boiler based on the results of the Part 9. The dampers are installed horizontally between the furnace and the cage and suppress relative displacement. The length and shape of the furnace are different from the cage, thus amount of the thermal expansion is also different. Therefore the damper has to allow the difference of the amount of the thermal expansion. In addition, the damper has to generate large damping force from the small vibration. Thus a viscous damper with high viscosity fluid is applied as a damper which satisfies above-mentioned requirements. A seismic response analysis using a frame model was conducted in order to verify the effect of the damper and to investigate the influence of the damping capacity of the damper. As a results, it was confirmed that the relative displacement between the furnace and the cage can be suppressed by applying the damper.
