MULTI-OBJECT DECISION-MAKING ON PEAK SHAVING OF WEST-EAST GAS PIPELINE

This paper addresses the peak shaving of West-East Gas Pipeline. For a gas pipeline system, the decision-making on the peak shaving scenarios usually involves a delicate balance between low operation cost and high gas supply reliability. In order to select an acceptable peak shaving scenario from these two angles for West-East Gas Pipeline, the idea of multi-objective decision-making has been introduced. Based on design flow-rate, eight typical peak shaving scenarios have been evaluated, analyzed and optimized with the help of TGNET. During the simulation, in order to make the peak shaving process more approach to the actual operation of the pipeline system, 51 days of forecasted data are used to establish the system starting state for the study period. On the other hand, in order to reduce the effect of different peak shaving process to the subsequent operation, the study period is extended by 7 days to fully account for operating costs and conditions subsequent to the study period, which make different peak shaving scenarios comparable. According to multi-objective optimization criteria including operation cost, gas supply reliability and operation stability, different pareto peak shaving scenarios have been obtained. These scenarios show that from the object of minimizing operation cost, inlet pressure of Shanghai terminal should approach to contractual pressure, from the object of gas supply reliability and operation stability, inlet pressure of Shanghai terminal should maintain a higher value. Operators can adopt different peak shaving scenarios according to different optimization object. Furthermore, with mathematical statistics knowledge, control value of inlet pressure of Shanghai terminal is recommended. When the change of withdrawal flow-rate from underground gas storage is more frequent, the fluctuation of inlet flow-rate is smaller. When withdrawal flow-rate from underground natural gas storage increases, it will not only increase the inventory of whole pipeline and end segment, but also decrease the inlet flow-rate.