LNG气化站储罐最优配置模型

OPTIMAL CONFIGURATION MATHEMATICAL MODEL OF STORAGE TANKS IN LNG VAPORIZING STATION

液化天然气储罐是城镇液化天然气气化站的核心设备,投资大,对液化天然气供气技术的经济性影响很大。在建设液化天然气气化站时,设计者常凭经验选择储罐的型号和台数,而这些设备组合并非最优,影响了液化天然气供气技术的经济性。针对国内液化天然气气化站储罐配置不合理的情况,建立了在满足气化站正常运行的前提下,使气化站存储年费用最小化的数学规划模型;同时,针对模型求解的复杂性,对模型中的0-1变量和整数变量进行转化,将模型从整数非线性规划问题转化成易求解的普通非线性规划问题,并用罚函数法编制了求解程序。最后,以广东某液化天然气气化站储罐配置为例进行了实例计算,结果表明提出的模型合理有效,可准确地确定存储年费用最小的液化天然气储罐配置。

The economical efficiency of LNG supply technology is significantly affected by the storage of LNG, as storage tanks are very expensive and important in LNG vaporizing stations. During the construction of LNG vaporizing stations, designers often decide the number and the type of equipments by their experience. But these decisions are usually neither best nor most economical, and then the economical efficiency of LNG supply technology is badly affected. This paper studied the configuration optimization of LNG storage tanks, provided that the normal and safe operation of the vaporizing station is guaranteed. A storage tank configuration model was built based on non-linear integer programming theory. Annual cost was taken as the optimization target. The model with bounded variables was transformed into equivalent continuous non-linear programming model by transforming integer variables and 0 - 1 variables into some continuous variables. The program was also developed to solve the model based on the penalty function method. One LNG vaporizing station in Guangdong province was taken as an example to illustrate the application of the model. The computational result indicates that the model is rational and efficient. It can accurately determine the optimal storage scheme.