卸油管路校核计算理论的补充分析和修正

铁路轻油罐车的卸油管路系统，在夏天作业时常发生气阻气蚀现象，根据这一事实，调查了我国诸多油库，从大量的生产数据中发现，理论计算结果与实际生产状况存在着较大的差距，进而分析了恶劣工况下促使气阻的气蚀提前形成的各种原因，如烃类汽化特征、溶解气和夹带气泡、气泡窝存、罐内液体温度不均匀、管路漏失等加以考虑，并对过去的计算理论作了补充。为了增加管路系统的剩余压力，确保卸油安全，还提出了向罐车内输入压缩空气，

Supplement Analysis and Revision of the Checking Theory on Oil Unloading Calculation

Air-lock and caviation frequently occurs in the receiving and unloading tubing system of a rail tank truck of light oil during the operation in summer. Based on this phenomenon, investigation was carried out in many of the tank farms in China. From large quantity of operation information obtained, the calculated data are found to differ greatly from those got from practical operation. Reasons why airlock and caviation come ahead of time on poor working conditions are analyzed and listed as follows: vaporization characteristics of hydrocarbon; solution gas and entained air bubbles; bubble remaining, uneven temperture of the liquid inside the tank and tube leackage etc. Besides,the caculation theory is seen supplemented in the paper as well. In order to guarantee the system safety, and also with the consideration of the above mentioned factors, a new item called safety margin for vaporization is added to the calculation equation. In addition, to increase the remaining pressure inside the tube for safe unloading operation, a new method is put forward in the paper that compressed air is supposed to be injected into the tank, a submerged pump and jet pump etc can be allocated on the loading arm suction as the ancillary unloading measures so as to avoid airlock and caviation.