To provide a monitoring system for boiling over which enables estimation of occurrence of boiling over with a simple configuration and which is easy to use, and to provide a monitoring method for boiling over.

Strip-shaped heat-sensitive material 17 are provided from an upper part 7 to a lower part 9 of the sidewall 5 of a floating roof tank 1 storing petroleum 21, such as crude oil or heavy oil. The heat-sensitive material 17 are provided in four areas of the side wall 5 of the tank at every 90° pitch, as viewed from above. Each heat-sensitive material 17 has such a width that a change in the color of the heat-sensitive material 17 is visible from the outside of the break-oil 19 of the tank 1. In the event of fire of the whole tank, a change in the color of each of the temperature indicating material 17 is monitored, and the position and moving speed of the high temperature layer 27 in the tank 1 are estimated, and thereby occurrence of boiling over is monitored and estimated.

COPYRIGHT: (C)2011,JPO&INPIT