The Influence On Channel Capacity Of LNG Ship Navigation

Under the background of energy conservation and emissions reduction around the world, natural gas received wide attention from all walks of life. With the increasing needs of natural gas, maritime transport of Liquefied Natural Gas (LNG) got unprecedented development. The reserve of natural gas is relatively insufficient in our country. The supply of LNG mainly relays on importing from other countries. In recent years, LNG receiving stations are set in coastal ports. As the quickly construction and expansion of berths and other infrastructure, especially large LNG terminal were completed and put into operation, channel has become the one of the main factors which affects port development and service level. In order to give full play to the operational capability of ports, and to ensure the safety of navigation and operation of ships, it is necessary to study the channel though capacity and the influence of LNG ship navigation on channel capacity. The results can provide theory basis to port construction and channel expansion.In order to calculate the channel through capacity accurately and response ship dynamic process of entering the port, berthing, loading and unloading cargos and leaving port factually, queuing theory model is proposed to calculate the channel maximum capacity. Each entity in the port service system is corresponded to the component of queuing theory. M/M/c and M/D/c queuing theory model are applied to calculate the ship number of entering and leaving channel respectively, and the sum of both is the channel capacity. Then, on the basis of exposing the characteristics of the LNG ship and the requirements of LNG ship navigation, the influence of LNG ship’s navigation on channel through capacity is analyzed. Sailing influence ratio model and channel occupancy ratio model are put forward to study the problem. Finally, above calculation model is applied to Ningbo-Zhoushan port’s main channel, Xiashimen channel, to calculate the channel through capacity and analyze the influence of LNG ship’s navigation. The measures of how to reduce the influence are proposed. The results can provide theoretical basis for the construction of Ningbo-Zhan port and Xiashimen channel.