COOL DOWN OF LOW TEMPERATURE LIQUEFIED GAS DELIVERY PIPING

摘要

PURPOSE:To enable to finish a cool down of a piping in a short time by a method wherein the cooling of the piping is controlled so that a generated stress in the piping upon the cool down is kept in a stress not exceeding an allowable stress of the piping multiplied by a safety factor. CONSTITUTION:A stress sigma generated in a piping 1 when a maximum bending moment M is generated in the piping 1 is controlled to be kept within a range smaller than a stress sigmaA in which an allowable stress sigmaa of the piping is added with an estimated safe stress sigmas. In order to restrain the stress sigma generated in the piping 1 within the range of sigma=sigmaA, a floating of the piping 1 at a point having a distance 1 from a central fixing point B is monitored and delivery of low temperature fluid is controlled when the floating of the piping 1 is caused. Accordingly, a cool down may be finished in a short time under a condition that the stress of the piping is not exceeding the stress the value thereof includes the stress safety.