分布式深冷分离能量系统的用能分析方法研究

Study on energy consumption analysis method of distributed cryogenic separation system

深冷分离方法是回收油田伴生气NGL(Natural Gas Liquid)的主要方法之一。油田双级膨胀式NGL深冷分离系统复杂,由多种物流、能流及多类设备组成,是典型的由供能、用能及余热回收三部分组成的分布式能量利用系统。根据在用的双级膨胀式深冷分离装置的工艺流程特点,采用"三箱"分析方法,将系统划分为六个子系统,建立了系统—单元—设备的火用分析模型,并给出了具体分析过程和评价指标。利用实测数据,对大庆油田实际运行的NGL装置进行了分析计算,据此提出了改进建议,并进行了工程实施,取得了较好的节能效果。

Cryogenic separation is one of the main method for recycling NGL（Natural Gas Liquid）.Oilfield two-stage expansion NGL cryogenic separation plant is a complex system composed of varieties of material flow,energy flow and equipments,which is a typical distributed energy consuming system composed of energy supply,energy use and waste heat recovery.In this paper,according to the process characteristics of two-stage expansion cryogenic separation plant,three-box analysis method was used,and the system was compartmentalized into six subsystems,the exergy analysis model of system—unit—equipment was established,the specific analysis process and the assessment rules for the NGL system were provided.Using the practical operational data,we conduct the exergy analysis on the operational working condition of NGL system in Daqing oilfield.Based on the calculation results,this paper gives some proposals to improve the operational efficiency,which is achieved a good energy saving effect in engineering practice.