COOL DOWN OF LOW TEMPERATURE LIQUEFIED GAS DELIVERY PIPING

摘要

PURPOSE:To prevent a damage of a piping by a method wherein cooling of the piping is controlled so as to keep a temperature difference between upper and lower portions of the piping within a specified allowable range to eliminate generation of a stress in the piping. CONSTITUTION:When low temperature fluid is flowed in a low temperature liquefied gas delivery piping 1a and the piping 1a is cooled to a temperature whereat the liquefied gas can be delivered, the cooling is effected under controlling a temperature difference DELTAT, detected by temperature sensors S1, S2 which are provided at upper and lower portions of the piping 1a, so as to be kept within a range specified in a following formula; DELTAT=(5sigmaa)/(3KalphaTE) (here, sigmaa: allowable stress of the piping, K: a constant determined by a temperature distribution in a section of the piping, alphaT: liner expansion coefficient of the piping, E: Young's modulus of the piping).