实现操作费用最小化的LNG接收站卸船工艺优化

液化天然气(Liquefied Natural Gas,LNG)接收站卸船工艺操作是接收站运行过程中的重要环节,但在实际运行过程中,卸船工艺总是保持运行参数不变,不利于实现LNG接收站运行成本最小化。为此,基于卸船周期内接收站各设备的运行状况,划分卸船周期运行阶段,分析创建卸船工艺操作功耗的计算公式,建立卸船工艺流程动态仿真模型,构建以最小年总功耗为目标函数的卸船工艺优化运行模型,并采用优化模型实例与未优化实例进行效益对比分析。研究结果表明:(1)卸船工艺优化运行模型能够实现LNG接收站在面对不同的卸船工况时能够及时对操作变量进行调整,以最优方案运行,降低了功耗;(2)该研究成果应用于中石油江苏如东LNG接收站,优化运行方案比原方案降低了13.0%的功耗。结论认为,在工况复杂的实际生产过程中,卸船工艺优化运行模型可以通过实时调整运行参数来减小功耗,对于接收站的降本增效具有现实意义。

Optimization on the unloading process of LNG receiving terminals with the optimal operation cost

The unloading process at liquefied natural gas (LNG) receiving terminals is an important part in the whole process of its operation. In actual operation, however, the operating parameters of the unloading process always remain unchanged, being the disadvantage of minimizing the operation cost of an LNG receiving terminal. In this paper, the operation stage in an unloading cycle was divided based on the operation condition of each equipment at the LNG receiving terminal. Then, a formula for calculating the operation power consumption of unloading process was built, and a dynamic simulation model of unloading process was established. In addition, an optimal operation model of unloading process with minimizing annual total power assumption as the objective function was constructed. Finally, the benefit of the case optimized by the model was compared with that of the non-optimized case. And the following research results were obtained. First, the establishment of the optimal operation model of unloading process enables the LNG receiving terminal to adjust the operating variables in time in different unloading conditions, so as to realize the optimal operation and reduce the power consumption. Second, the research results are applied to the PetroChina's Rudong LNG receiving terminal in Jiangsu province. The optimized operation scheme can save 13.0% power consumption compared with the original scheme. In conclusion, in the actual production process with complex working conditions, the optimal operation model of unloading process can reduce the power consumption by adjusting the operating parameters in real time, which is of practical significance for cost reducing and efficiency increasing of LNG receiving terminals.