海上平台移动式制氮装置的设计

Design of the Mobile Nitrogen Generator for Offshore Platform

目前海洋平台上一般利用氮气瓶供气,施工效率低,流量较小,不满足现场要求,再者国内主要膜制氮设备基于可编程控制器PLC及现场仪表设计,这些设备提高了制氮装置的成本,延长了安装周期。为此,研制了移动式橇装制氮装置。该制氮装置的硬件由空气压缩单元、空气净化处理单元、入膜加热单元及膜分离制氮控制单元组成,装置结构简单,安装调试方便,采用喷油螺杆式空压机,过滤器采用3级过滤,降低了成本。其控制系统主要用于检测信号的输入和控制信号的输出。现场调试结果表明,移动式制氮装置启动20 min后就能得到体积分数高达97%的氮气,装置的稳定性较强。

At present offshore platforms generally use nitrogen cylinder for gas supply. The construction effi- ciency is low and the flowrate is small, which cannot satisfy the field requirement. Moreover, the design of domestic membrane separation nitrogen gas generating system is based on the programmable eontroller PLC and field instru- ments, and these equipments increase the cost of nitrogen generating system, lengthening the cycle of installation. Therefore, the mobile skid-mounted nitrogen generator was developed. The hardwares of the membrane separation nitrogen gas generating system consist of air compression unit, air purification treatment unit, input membrane heating unit and membrane separation nitrogen generating eontrol unit. The system structure is sim- ple. The installation and debugging are convenient. The system adopts oil-injected screw air compressor and the filter adopts three-stage filtration, thus deereasing the cost. The control system is mainly used to check signal input and control signal output. The field debugging shows that after 20 minutes of startup, the system can stably provide the nitrogen gas with a volume fraction as high as 97%.