As the production load of LNG vaporization facilities for peak-shaving station and the physical properties of LNG vary greatly with the season or time of day,the LNG could not be vaporized completely bysubmerged vaporizerunder extreme operating conditions, which affected safety of the vaporization facility.Taking avaporizationfacility for peak-shaving as an example, with the heat transfer theory, the total heat transfer coefficients of the submerged combustion vaporizer of the project under the design and extreme conditions of a certain winter were calculated respectively.The results showed that when the vaporizer was operating under extreme working conditions, the vaporizer could not provide sufficient heat to the LNG in the heat exchange tube.As a result, a small amount of LNG could not be vaporized, finally resulting in low-temperature embrittleness of the pipeline and an explosion.Tosolve the above issue, with properly increased heat exchange area of submerged vaporizer,apressure regulating valve was set up at the boundary of the peak-shaving facility to calculate the total heat transfer coefficient of the submerged combustion vaporizer under the design andactualconditions.Sufficient heat from thesubmerged vaporizercan be guaranteed to provide for the complete vaporization of LNGand the operating pressure is ensured to have a lower limit valueso as to improve the safety of vaporization facilities for peak shaving.This method can provide reference for the design of similar vaporization facilities.