基于功能安全的天然气低压机SCADA系统

SCADA System of Low-pressure Natural Gas Compressor Based on Functional Safety

天然气是易燃易爆气体,保障低压机系统及储备站的安全是低压机计算机控制系统设计时需要考虑的第一要素。为了增强传统SCADA(Supervisory Control And Data Acquisition,数据采集与监视控制系统)系统的安全性,通过引入功能安全分析和风险控制的理念,提出一种具有功能安全的天然气低压机SCADA系统。依据低压机的工艺要求和工艺分析需求,在设计了控制系统与安全相关系统相统一的SCADA系统架构基础上,重点描述了控制系统硬件设计、控制软件设计以及监控软件设计。SCADA系统采用Rockwell PLC作为控制站,实现对天然气储配站低压机的远程控制,完成对过程数据的采集,通过组态监控站实现对工艺参数和风险因素的实时显示和报警。基于功能安全的SCADA系统提高了储配站安全性、降低了设备风险,其在文星湾(重庆市北碚区)天然气储配站SCADA控制系统改造工程中的成功应用,证明了风险分析和功能安全对于提高储配站安全保障的可行性。

As the natural gas is flammable and explosive gas,how to protect the safety of the low-pressure natural gas compressor and the safety of the storage station is the first factor to be considered in the design of the control system. To improve the security of the traditional SCADA system,the paper proposed the SCADA system with functional safety by introducing the safety analysis and risk control.According to the low-pressure natural gas compressor＇ s technology process demand and functional safety requirements,the paper designed a unified architecture to coordinate the control system and safety related system,and mainly described the design of the control system＇s hardware,the realization of the control system＇ s software and the realization of supervisor software. The control station of the SCADA system uses the Rockwell PLC to undertake the remote automatic control and collect the local data and the data of equipment state. The supervisor station achieves the real-time display and alarm of technical parameters and risk factors. The SCADA system with functional safety improves the safety of the storage and station,reduces the risk of equipment. The successful application in the renovation project of the SCADA control system in Wenxingwan natural gas storage and distribution station,has proved the feasibility of risk analysis and functional safety to improving the security of storage and distribution station.